EP0543630A2 - Appareil de développement - Google Patents

Appareil de développement Download PDF

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Publication number
EP0543630A2
EP0543630A2 EP92310508A EP92310508A EP0543630A2 EP 0543630 A2 EP0543630 A2 EP 0543630A2 EP 92310508 A EP92310508 A EP 92310508A EP 92310508 A EP92310508 A EP 92310508A EP 0543630 A2 EP0543630 A2 EP 0543630A2
Authority
EP
European Patent Office
Prior art keywords
developing agent
developing
sleeve
toner
brush
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.)
Withdrawn
Application number
EP92310508A
Other languages
German (de)
English (en)
Other versions
EP0543630A3 (en
Inventor
Takashi Ito
Takeshi 509 Nichimo-Hiyoshi Dai 5 Corporasu Hori
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.)
Kyocera Mita Industrial Co Ltd
Original Assignee
Mita Industrial Co Ltd
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 Mita Industrial Co Ltd filed Critical Mita Industrial Co Ltd
Publication of EP0543630A2 publication Critical patent/EP0543630A2/fr
Publication of EP0543630A3 publication Critical patent/EP0543630A3/en
Withdrawn legal-status Critical Current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
    • 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
    • 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
    • G03G15/0806—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller
    • G03G15/0808—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller characterised by the developer supplying means, e.g. structure of developer supply roller

Definitions

  • the present invention relates to a developing apparatus which uses a one-component type developing agent for electrophotography. More specifically, the invention relates to a developing apparatus equipped with a developing agent carrier sleeve of the type which holds and carried the developing agent to a developing zone by utilizing the electric attractive force.
  • an electrostatic latent image formed on the surface of a photosensitive material is developed by using a developing agent which is composed of an electroscopic toner in order to obtain a toner image which is visualized from said latent image.
  • the developing apparatus which effects such a developing is equipped with a developing agent carrier sleeve which is rotationally driven, and the toner that is electrically charged by the friction of the sleeve is carried to the developing zone to develop the image.
  • a known developing apparatus of this kind can be represented by the one of the type in which a bias voltage is applied to the sleeve, and the developing agent, i.e., the electrically charged toner is held and carried by utilizing the electric attractive force.
  • the apparatus of this type provision is made of a rotary fur brush in addition to the developing agent carrier sleeve, and the developing agent (toner) is aggitated by the fur brush to electrically charge it by friction.
  • the object of the present invention is to provide a developing apparatus equipped with a developing agent carrier sleeve of the type which holds and carriers an electrically charged toner to the developing zone by utilizing the electric attractive force, wherein the toner is electrically charged effectively by friction, and is effectively fed onto the sleeve.
  • a developing apparatus for one-component type developing agent comprising a developing agent carrier sleeve of the rotationally driven type which holds and carries a developing agent that is electrically charged to a predetermined polarity by utilizing the electric attractive force, and a rotary member having a flexible brush on the surface thereof which frictionally aggitates the developing agent and feeds the developing agent onto said sleeve, wherein said rotary member is provided without being contacted to said developing agent carrier sleeve, a charging plate that is electrically charged to the same polarity as the electrically charged polarity of said developing agent is provided at a position where it comes in contact with the brush on the surface of said rotary member, said brush comes in contact with the charging plate and is deflected accompanying the turn of said rotary member, and the developing agent is caused to fly by the restoring force thereof and is fed onto the developing agent carrier sleeve.
  • a developing apparatus for one-component type developing agent comprising a developing agent carrier sleeve of the rotationally driven type which holds and carries a developing agent that is electrically charged to a predetermined polarity by utilizing the electric attractive force, and a rotary member having a flexible brush on the surface thereof which frictionally aggitates the developing agent and feeds the developing agent onto said sleeve, wherein said rotary member is so provided that said brush on the surface of said rotary member comes in contact with the surface of said developing agent carrier sleeve, a charging plate that is electrically charged to the same polarity as the electrically charged polarity of said developing agent is provided at a position where it comes in contact with the brush, said brush comes in contact with the charging plate and is deflected accompanying the turn of said rotary member, and the developing agent is caused to fly by the restoring force thereof and is fed onto the developing agent carrier sleeve.
  • the charging plate having an electric charge of the same polarity as the electric charge possessed by the developing agent is provided in contact with the rotary member such as a fur brush in order to electrically charge the developing agent by bringing the charging plate into pressed contact therewith in addition to frictionally charging the developing agent by said rotary member.
  • the electrically charged toner can be effectively fed onto the sleeve by utilizing the repulsive force of the brush or the like on the rotary member that is in contact with the charging plate.
  • a developing agent carrier sleeve 2 of the rotationally driven type is provided in a developing vessel 1
  • a hopper 3 for replenishing the developing agent is provided at an upper portion of the developing vessel 1
  • an electroscopic toner 4 that is known per se is replenished from the hopper 3.
  • the toner 4 is frictionally charged into a predetermined polarity by being aggitated by a fur brush 15 that will be described later.
  • the developing agent carrier sleeve 2 is provided with an electret layer 30 having an electric charge of a polarity opposite to that of the electric charge possessed by the toner 4.
  • the electrically charged toner 4 is held and carried by utilizing the electrostatic attractive force.
  • a thickness-adjusting blade 6 is provided over the sleeve 2 maintaining a suitable gap, and is so adjusted that the electrically charged toner 4 carried by the sleeve 2 will have a predetermined thickness.
  • the developing agent carrier sleeve 2 is so provided as to be opposed to a photosensitive drum 11 which has a photosensitive layer 10, and an electrostatic latent image formed on the photosensitive layer 10 is developed by the electrically charged toner 4 that is carried by the sleeve 2.
  • the photosensitive drum 11 and the developing agent carrier sleeve 2 are rotated in the forward directions. They, however, may be rotated in the opposite directions.
  • the developing may be carried out in a so-called contacting manner or non-contacting manner.
  • the electret layer 30 can be formed by using any high molecular material provided it is capable of developing permanent electric polarization.
  • an olefin-type resin such as a polyethylene, a polypropylene, an ethylene-butene copolymer, an ionically crosslinked olefin copolymer or an ethylene-acrylic copolymer
  • a fluorine-containing resin such as a vinyl polyfluoride, a vinylidene polyfluoride, a vinyl fluoride/vinylidene fluoride copolymer, an ethylene tetrafluoride resin (PTFE), an ethylene tetrafluoride-perfluoroalkoxyethylene copolymer resin (PFA resin), or an ethylene tetrafluoride-propylene hexafluoride copolymer resin (FEP resin); a chlorine-containing resin such as a vinyl polychloride or a chlorinated polyolefin;
  • fluorine-containing resins such as PTFE resin, PFA resin, PFE resin and like resins, since they preserve electric charge well and exhibit durability.
  • the electret can be formed by any known method such as thermal electret-forming method, electric electret-forming method, radiant-ray electret-forming method or optical electret-forming method depending upon the kind of high molecular material that is used.
  • the thermal electret-forming method or the electric electret-forming method can be advantageously adopted for the high molecular materials and, particularly, for the fluorine-containing resin.
  • the density of electric charge on the surface of the electret layer 30 is set to such a degree that a sufficiently large electric attractive force acts upon the electrically charged toner 4.
  • the density of electric charge is so set that the surface potential (absolute value) of the electret layer 30 is smaller than the surface potential (absolute value) of the photosensitive layer 10.
  • the thickness of the electret layer 30 is usually set to be from 10 to 500 ⁇ m.
  • a rotary fur brush 15 is provided maintaining such a relation in position that it does not come into contact with the electret layer 30.
  • the rotary fur brush 15 frictionally charges the toner 4 by aggitation and feeds the electrically charged toner 4 onto the sleeve 2 (electret layer 30).
  • the fur brush 15 can be rotated in any direction. Generally, however, the fur brush 15 is better rotated in the same direction as the direction in which the sleeve 2 rotates.
  • a distinguished feature resides in that the charging plate 20 is so provided as to come in contact with the fur brush 15.
  • the charging plate 20 is electrically charged to the same polarity as that of the electrically charged toner 4.
  • the electrically charged toner 4 flies due to electric repulsive force from the charging plate 20 and the resilient restoring force of the brush 15, and is fed onto the developing sleeve 2 by which it is held, carried and is used for effecting the developing. Due to the press contact of the charging plate 20, furthermore, the toner 4 is more strongly charged by friction and whereby the occurrence of electrically non-charged toner is effectively suppressed.
  • the charging plate 20 is installed at such a position that causes the electrically charged toner 4 to effectively fly onto the developing sleeve 2.
  • the charging plate 20 will be made of an electrically conducting plate such as a metal plate and is impressed with a bias voltage from, for example, a bias power source 31, so that the metal plate is electrically charged to the same polarity as that of the toner 4.
  • the bias power source may be made up of a DC power source only or may be made up of a combination of a DC power source and an AC power source in order to apply an alternating voltage that is shifted to the same polarity as the toner 4. It is preferred that the bias voltage applied to the charging plate 20 is usually greater than 100 volts and, particularly, greater than 200 volts (in an absolute value). When the applied voltage is too small, it becomes difficult to electrically charge the toner to a sufficient degree.
  • the electrically charged toner is carried to the developing zone by forming the electret layer 30 on the developing sleeve 2. According to the present invention, however, the electrically charged toner can be carried even without using the electret layer 30. An embodiment of this case is shown in Fig. 2.
  • the fur brush 15 is provided in contact with the sleeve 2 in order to effect the electric charging by friction and to remove the unused toner remaining on the sleeve 2. That is, when the electret layer is provided, it is not desired to bring the fur brush into contact with the sleeve 2 since it damages the electret layer. It is therefore difficult to effectively remove the remaining toner. With the apparatus of Fig. 2, however, it is allowed to effectively remove the remaining tower. Even in this apparatus, the fur brush 15 may be provided without being contacted to the fur brush 15, as a matter of course.
  • the fur brush 15 is used as a member for feeding the toner onto the sleeve 2. It, however, is also allowable to use the one having resiliency which deflects when it comes in contact with the charging plate 20 but produces a repulsive force when it returns to the ordinary condition to fly the toner, such as the one which has a flexible plastic tape or the like in the form of a duster on the surface of a rotary member, in place of using the fur brush.
  • the toner used as a developing agent in the present invention is a non-magnetic toner which is basically obtained by blending a resin medium for fixing which is known per se such as a styrene-type resin, acrylic resin, or a styrene-acrylic resin with widely known blending agents for toner such as a coloring agent, an electric charge controlling agent and like agents. It is desired that the toner has a volume resistivity of from 1 x 108 to 3 x 109 ⁇ -cm, and particularly from 2 x 108 to 8 x 108 ⁇ -cm, and its dielectric constant should lie within a range of from 2.5 to 4.5, and particularly from 3.0 to 4.0.
  • the resins for fixing and the blending agents for toner should be so selected and used that the above-mentioned properties are obtained.
  • the toner particles should have a median size based on the volume of from 8 to 14 ⁇ m and, particularly, from 10 to 12 ⁇ m as measured by using the Coulter counter. Moreover, the toner particles may have either an amorphous shape as prepared by the melt kneading-pulverization method or a spherical shape as prepared by the dispersion or suspension polymerization method.
  • the toner was fed onto the electret sleeve under the following conditions while changing the bias voltage applied to the charging plate.
  • Electret material FEP Thickness of electret layer: 100 ⁇ m Surface potential: 200 V Sleeve diameter: 10 Number of revolutions: 57 rpm
  • Average amount of electric charge per a toner particle Potential of toner layer x 2 ⁇ 0 ⁇ x Volume of a toner particle Toner rate x (Thickness of toner layer)2 wherein:

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
EP19920310508 1991-11-22 1992-11-18 Developing apparatus Withdrawn EP0543630A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP30798691 1991-11-22
JP307986/91 1991-11-22

Publications (2)

Publication Number Publication Date
EP0543630A2 true EP0543630A2 (fr) 1993-05-26
EP0543630A3 EP0543630A3 (en) 1994-05-18

Family

ID=17975533

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19920310508 Withdrawn EP0543630A3 (en) 1991-11-22 1992-11-18 Developing apparatus

Country Status (1)

Country Link
EP (1) EP0543630A3 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56143468A (en) * 1980-04-10 1981-11-09 Toshiba Corp Developing device
JPS5792355A (en) * 1980-11-29 1982-06-08 Toshiba Corp Developing device
EP0087074A2 (fr) * 1982-02-19 1983-08-31 Hoechst Aktiengesellschaft Procédé et dispositif pour le développement d'un image électrostatique latente qui est préparée sur un support de copiage
JPS60136773A (ja) * 1983-12-26 1985-07-20 Ricoh Co Ltd 現像装置
JPS6152663A (ja) * 1984-08-22 1986-03-15 Matsushita Electric Ind Co Ltd 現像装置
EP0270104A2 (fr) * 1986-12-02 1988-06-08 Matsushita Electric Industrial Co., Ltd. Dispositif de développement

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56143468A (en) * 1980-04-10 1981-11-09 Toshiba Corp Developing device
JPS5792355A (en) * 1980-11-29 1982-06-08 Toshiba Corp Developing device
EP0087074A2 (fr) * 1982-02-19 1983-08-31 Hoechst Aktiengesellschaft Procédé et dispositif pour le développement d'un image électrostatique latente qui est préparée sur un support de copiage
JPS60136773A (ja) * 1983-12-26 1985-07-20 Ricoh Co Ltd 現像装置
JPS6152663A (ja) * 1984-08-22 1986-03-15 Matsushita Electric Ind Co Ltd 現像装置
EP0270104A2 (fr) * 1986-12-02 1988-06-08 Matsushita Electric Industrial Co., Ltd. Dispositif de développement

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 10, no. 212 (P-480)(2268) 24 July 1986 & JP-A-61 052 663 (MATSUSHITA ELECTRIC IND CO LTD) 15 March 1986 *
PATENT ABSTRACTS OF JAPAN vol. 6, no. 175 (P-141)(1053) 9 September 1982 & JP-A-57 092 355 (TOKYO SHIBAURA DENKI K.K.) 8 June 1982 *
PATENT ABSTRACTS OF JAPAN vol. 6, no. 22 (P-101)(900) 9 February 1982 & JP-A-56 143 468 (TOKYO SHIBAURA DENKI K.K.) 9 November 1981 *
PATENT ABSTRACTS OF JAPAN vol. 9, no. 304 (P-409)(2027) 30 November 1985 & JP-A-60 136 773 (RICOH K.K.) 20 July 1985 *

Also Published As

Publication number Publication date
EP0543630A3 (en) 1994-05-18

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