• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    end. The technical field to which the invention described in the claims belongs A developer charging device for an image forming apparatus employing an electrophotographic developing method. I. The technical problem that the invention is trying to solve Immediately before development, the charge amount of the developer adhered to the developing roller and the adhesion layer are recharged without disturbing the developer, thereby reducing the reverse polarity developer in the developer. All. Summary of Solution of the Invention It is attached to the developing roller by rotating it in conjunction with the rotation of the developing roller, and is located on the surface of the developing roller between the photosensitive drum and the regulating braid, which is supplied with a power supply for supplying polarity power for charging the developer. And a charging roller for charging the developer. la. Important uses of the invention It is used in an image forming apparatus employing an electrophotographic developing method.
    公开号:KR19980057459A
    申请号:KR1019960076749
    申请日:1996-12-30
    公开日:1998-09-25
    发明作者:유용백
    申请人:김광호；삼성전자 주식회사；
    IPC主号:
    专利说明:

    Developer charging device for an image forming apparatus employing an electrophotographic developing method
    BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus employing an electrophotographic developing system, and more particularly, to a charging device for a nonmagnetic one-component developer.
    Electrophotographic development is widely used in image forming apparatuses such as copiers, laser beam printers, LPH (LED Print Head) printers, and general paper fax machines. The process according to the electrophotographic development method is made of a charging ⇒ exposure ⇒ development ⇒ transfer ⇒ fixing process as known.
    The electrophotographic development method as described above can be divided into two-component development method, magnetic one-component development method, nonmagnetic one-component development method and the like according to the development method.
    In particular, the nonmagnetic one-component developing method is to form an image using a nonmagnetic one-component developer. Referring to FIG. 1, which is a conventional developing device of an image forming apparatus employing an electrophotographic developing method, the nonmagnetic one component is used. The component development method is explained in full detail.
    In Fig. 1, a non-magnetic one-component developer (hereinafter referred to as a "developer") is embedded in the toner hopper 10. The toner hopper 10 is provided with an edge taper 12. The edge taper 12 is rotated by an engine driving motor (not shown) which is a main motor to move the developer in the toner hopper 12. Stir. At this time, the developer is frictionally charged to the negative electrode (hereinafter referred to as 'positive') by the stirring of the edge data 12 and is discharged to the outside.
    As described above, the developer charged and discharged in the positive polarity is transferred to the supply roller 14. The supply roller 14 is a conductive rubber roller applied with a positive polarity power to charge the developer again to the positive polarity, and is rotated by an engine driving motor to supply the developer to the developing roller 16.
    The developing roller 16 is a conductive rubber roller and is supplied with a positive electric power and has a constant electric potential. Since the potential of the power applied to the developing roller 16 is greater than the potential of the power applied to the supply roller 14, the developer between the developing roller 16 and the supply roller 14 is transferred to the developing roller 16 and developed. It is attached to the surface of the roller 16.
    As described above, the developer adhered to the developing roller 16 is regulated by the regulating braid 18, and the adhesion amount and the adhesion layer are controlled. At this time, the regulating braid 18 is supplied with a positive polarity power supply with a conductive rubber braid to regulate the amount of deposition and the layer of the developer, and at the same time, to charge the developer to the positive again.
    On the other hand, the photosensitive drum 20 is charged by a charging roller 22 at a constant positive potential. As described above, the electrostatic latent image is formed by scanning light corresponding to the image to be formed by the exposure apparatus 24 on the photosensitive drum 20 that is positively charged. Here, the region of the photosensitive drum 20 to which light is scanned has an anode (hereinafter referred to as 'reverse polarity'), and the region where the light is not scanned has a positive polarity.
    As the photosensitive drum 20 and the developing roller 16 come into contact with each other, the positive developer attached to the developing roller 16 is transferred to the reverse polarity scanning area on the photosensitive drum 20. Accordingly, the electrostatic latent image becomes visible and this is called a phenomenon.
    In order to develop as described above, the developer must be positively charged. However, when looking at the actual charge distribution of the developer, it is not completely positive. That is, the developer contains a small amount of reverse polarity developer.
    The reverse polarity developer is transferred to the non-scanning area on the photosensitive drum 20 during development, and appears as a background image to deteriorate the image quality.
    The reverse polarity developer may be relatively generated during the triboelectric charging of the developer, or alternatively, the external additives separated from the developer may act as the reverse polarity developer due to the mechanical friction of the developer with a plurality of rollers or braids.
    In particular, when the developer passes between the photosensitive drum 20 and the developing roller 16, many of the above-mentioned reverse polarity developer was generated. Accordingly, in the related art, the image forming apparatus includes a cleaning device, and the waste developer, which has been completed once, is recovered and no longer used.
    However, in the case of the image forming apparatus without the cleaning apparatus, the waste developer is used again, and as this is repeated, the proportion of the reverse polarity developer in the developer increases.
    As described above, the increased reverse polarity developer not only produces the background image but also degrades the reproducibility of the dots, the fineness of the image, and the like, thereby dramatically degrading the overall image quality.
    Such a reverse polarity developer can be reduced by recharging the developer on the developing roller 16 just before the development.
    By the way, the developer adhering on the developing roller 16 is regulated by the regulating braid 18 in a fixed amount and an adhesion layer. The adhesion amount of the developer and the adhesion layer which are constantly regulated as described above are easily disturbed by friction with other appliances. Accordingly, when a charging mechanism is provided in the developing roller 16 to recharge the developer immediately before development, the deposition amount and the adhesion layer of the developer are disturbed. As described above, when the deposition amount of the developer and the adhesion layer are disturbed, the image quality is deteriorated, such as uneven development and staining of the formed image.
    As described above, the reverse polarity developer has a problem of forming a background image. Moreover, in the image forming apparatus without the cleaning apparatus, there has been a problem in that the reverse polarity developer is increased so that the image quality is rapidly decreased.
    Accordingly, if the charging mechanism is attached to the developing roller indiscriminately in order to recharge the above-mentioned reverse polarity developer immediately before development, there is a problem that the deposition amount and the adhesion layer of the developer are disturbed, thereby degrading the image quality.
    Accordingly, an object of the present invention is an image forming apparatus employing an electrophotographic development method that reduces the amount of reverse polarity in a developer during development by charging again without disturbing the deposition amount of the developer adhered to the developing roller and the adhesion layer. A developer charging device is provided.
    1 illustrates a developing device of an image forming apparatus employing a conventional electrophotographic developing method.
    2 illustrates a developer charging device of an image forming apparatus employing an electrophotographic developing method according to a preferred embodiment of the present invention.
    3 illustrates a developing device having a developer charging device of an image forming apparatus employing an electrophotographic developing method according to a preferred embodiment of the present invention.
    The present invention for achieving the above object is a power supply unit for providing a power supply of the polarity for charging the developer, the power supply unit is placed on the developing roller surface between the photosensitive drum and the regulating blade, the rotation of the development roller And a charging roller which charges the developer attached to the developing roller by rotating in conjunction with the roller.
    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the annexed drawings, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.
    Usually, since the reverse polarity developer generates a background image as it is transferred onto the photosensitive drum of the non-exposed portion, the developer charging device of the present invention charges the developer once more immediately before the developer is transferred to the photosensitive drum.
    In general, the developer is transferred to the photosensitive drum for development after the deposition amount and the adhesion layer of the developer adhered to the developing roller by the regulating blade are constantly regulated. Accordingly, the present invention charges the developer without disturbing the deposition amount and the adhesion layer of the developer regulated as described above.
    2 shows a configuration diagram of a developer charging device according to a preferred embodiment of the present invention in which the developer is charged once more immediately before development without disturbing the deposition amount of the developer and the adhesion layer. The developer charging device shown in FIG. 2 includes a positive power supply (-V), a zener diode (ZD), and a charging roller 28. As shown in FIG.
    The positive power source (-V) is a power source provided to the charging roller 28 to charge the developer, and this power source (-V) may be replaced by the power supply of the regulating braid. Zener diode (ZD) is the power supply (-V) and the cathode is connected, the anode is connected to the charging roller 28. Accordingly, the Zener voltage is provided to the charging braid 28 by the Zener diode ZD. That is, the zener diode ZD keeps the magnitude of the voltage supplied to the charging braid 28 constant at the zener voltage. The zener voltage may be -100V to -500V.
    The charging roller 28 may be a conductive rubber roller with low resistance, and is supplied with a power source (-V) controlled to a predetermined size by a zener diode (ZD). The charging roller 28 is located on the surface of the developing roller between the regulating blade and the photosensitive drum in order to charge the developer immediately before development.
    Referring to Fig. 3 showing an example in which the charging roller 28 is mounted on the developing machine, the charging roller 28 is installed on the A surface between the regulating blade 18 and the photosensitive drum 20.
    As described above, the charging roller 28 provided on the A surface is in contact with the developing roller 16 at a constant pressure. Accordingly, when the developing roller 16 rotates, the charging roller 28 rotates in association with the developing roller 16. In particular, the constant pressure is set to a pressure that will not affect the deposition amount of the developer and the adhesion layer.
    Therefore, the charging roller 28 charges the developer on the developing roller 16 passing through the regulating blade 18 with positive polarity as the developing roller 16 rotates. In addition, the reverse polarity developer may be attached to the charging roller 28 to reduce the reverse polarity developer transferred to the photosensitive drum 20.
    In this way, since the developer has been once more positively charged by the charging roller 28, the amount of the reverse polarity developer of the developer decreases. Since the developer is charged as the developer roller 16 and the charge roller 28 rotate in contact with each other, the deposition amount and the adhesion layer of the developer adhered to the development roller 16 are not disturbed.
    As described above, the developer having the reduced amount of the reverse polarity developer is transferred to the exposed portion of the photosensitive drum 20. And since the amount of the reverse polarity developer is reduced, the amount of the reverse polarity developer transferred to the non-exposed portion of the photosensitive drum 20 is reduced. This reduces the background image and improves the image quality.
    As described above, the present invention reduces the amount of the reverse polarity developer in the developer during development by recharging again without disturbing the layer of the developer attached to the developing roller immediately before the development. As described above, as the amount of the reverse polarity developer decreases, deterioration of image quality due to the reverse polarity developer can be prevented. It is also possible to reduce background image formation by the reverse polarity developer in advance.
    And even if the amount of the reverse polarity developer increases in the image forming apparatus without the cleaning device, the amount of the reverse polarity developer can be reduced by charging the developer once more before development.
    As described above, the present invention reduces the amount of the reverse polarity developer in the developer during development by recharging again without disturbing the layer of the developer attached to the developing roller immediately before the development. As described above, as the amount of the reverse polarity developer is reduced, there is an advantage of preventing deterioration of image quality due to the reverse polarity developer. In addition, there is an advantage that can reduce the background image formation by the reverse polarity developer in advance.
    权利要求:
    Claims (4)
    [1" claim-type="Currently amended] A developer charging device for an image forming apparatus employing an electrophotographic developing method,
    A power supply unit providing a power supply of polarity for charging the developer;
    And a charging roller which is located on the surface of the developing roller between the photosensitive drum and the regulating blade by receiving the power of the power supply unit and rotates in association with the rotation of the developing roller to charge the developer attached to the developing roller. A developer charging device for an image forming apparatus employing an electrophotographic developing method.
    [2" claim-type="Currently amended] The method of claim 1, wherein the power supply unit,
    Negative power supply,
    And a Zener diode connected to the power supply and the cathode and connected to the charging braid and the anode to control the size of the power supplied to the charging roller. Device.
    [3" claim-type="Currently amended] The method of claim 2, wherein the power source,
    A developer charging device for an image forming apparatus employing an electrophotographic development method characterized by a power supply between -100V and -500V.
    [4" claim-type="Currently amended] The method of claim 1, wherein the charging roller,
    A developer charging device for an image forming apparatus employing an electrophotographic development method characterized by a low resistance conductive rubber roller.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1996-12-30|Application filed by 김광호, 삼성전자 주식회사
    1996-12-30|Priority to KR1019960076749A
    1998-09-25|Publication of KR19980057459A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019960076749A|KR19980057459A|1996-12-30|1996-12-30|Developer charging device for an image forming apparatus employing an electrophotographic developing method|
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