• 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 The amount of reverse polar developer is reduced before development. All. Summary of Solution of the Invention A power supply unit for supplying a polarity power source for charging the developer, and a charging blade for charging the developer attached to the developing roller by being placed on a developing roller between the photosensitive drum and the regulating blade by receiving the power supply of the power supply unit; It is characterized by. la. Important uses of the invention It is used in an image forming apparatus employing an electrophotographic developing method.
    公开号:KR19980057420A
    申请号:KR1019960076710
    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 in its deposition amount and layer. At this time, the regulating braid 18 is supplied with a positive polarity power supply with a conductive rubber braid to regulate the amount and layer of deposition of the developer, and at the same time, to charge the developer to positive polarity.
    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.
    As described above, the reverse polarity developer has a problem of forming a background image. In addition, in the image forming apparatus without the cleaning apparatus, the reverse polarity developer continues to increase every time the image is formed, and thus there is a problem that the image quality deteriorates rapidly.
    It is therefore an object of the present invention to provide a developer charging device for an image forming apparatus employing an electrophotographic developing method which reduces a reverse polarity developer among developers.
    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.
    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, and is applied to the developing roller is located on the developing roller between the photosensitive drum and the regulating blade is applied to the power supply unit A charging braid for charging a developer is provided.
    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 background image is generated as the reverse polarity developer is transferred onto the photosensitive drum of the non-exposed part, the developer charging device of the present invention adds the developer one more time, just before the developer is transferred to the photosensitive drum. To be charged.
    2 shows a configuration diagram of a developer charging device according to a preferred embodiment of the present invention for charging the developer once more immediately before development. The developer charging device shown in FIG. 2 is composed of a positive power supply (-V), a zener diode (ZD), and a charging braid (28).
    The positive power source (-V) is a power source provided to the charging braid 28 for charging the developer, and this power source (-V) may be replaced with the power source of the regulating braid. Zener diode (ZD) is connected to the power supply (-V) and the cathode, the anode is connected to the charging braid (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 charging braid 28 may be a flexible aluminum film or the like, and is provided with a power source (-V) controlled to a predetermined size by a zener diode (ZD). The charging braid 28 is located on the surface of the developing roller 16 between the regulating braid and the photosensitive drum 20 to charge the developer immediately before the developer is transferred to the photosensitive drum 20.
    Referring to FIG. 3, which shows an example in which the charging braid 28 is mounted on a developing device, the charging braid 28 is installed at an A portion between the regulating braid 18 and the photosensitive drum 20.
    As described above, the charging braid 28 installed in the A portion charges the developer passing through the regulation braid 18 in a positive polarity as the developing roller 16 rotates. In this way, since the charge is once again positively charged by the charging braid 28, the amount of the reverse polarity developer of the developer decreases. 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.
    In this case, in order to confirm that the reverse polarity of the developer decreases as the charge braid 28 is used as described above, the power supply (-V) is changed to the charge braid 28 per unit area of the developing roller 16. The mass of the toner (M / A = mg / cm 2 ) and the amount of charge per unit mass of the toner (M / Q = -μC / g) were measured. Table 1 shows experimental data obtained by measuring the mass of toner per unit area of the developing roller 16 and the amount of charge per unit mass of the toner.
    Power source (-V)-100V-200 V-300 V-500V M / AQ / MM / AQ / MM / AQ / MM / AQ / M If there is no charging braid0.3029.60.2733.00.2438.50.2731.9 When the charging braid is installed0.3122.40.2646.70.2448.00.2652.9
    The amount of charge per unit mass of the toner when the charging braid 28 is provided even when the charge braid 28 is provided, considering that the mass of the toner per unit area and the amount of charge per unit mass of the toner shown in Table 1 are very small and the measurement error is large. It can be seen that the increase is greater than without.
    In addition, it can be seen that the amount of charge per unit mass of the toner increases as the power source (-V) becomes positive.
    As described above, the present invention reduces the amount of reverse polarity developer by charging the developer once more immediately before 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. In addition, background image formation by the reverse polarity developer can be prevented in advance.
    In addition, 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 has the advantage of preventing the deterioration of the image by reducing the amount of the reverse polarity developer. In addition, there is an advantage that can prevent the background image formation by the reverse polarity developer in advance.
    权利要求:
    Claims (5)
    [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;
    An image forming apparatus employing an electrophotographic developing method comprising a charging braid for charging a developer attached to a developing roller by being placed on a developing roller between a photosensitive drum and a regulating blade by receiving power from the power supply unit. Developer charging device.
    [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 provided to the charging braid. 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 system characterized by having a potential between -100 and -500.
    [4" claim-type="Currently amended] The method of claim 1, wherein the charging braid,
    A developer charging device for an image forming apparatus employing an electrophotographic developing method, characterized in that it is a thin and light conductive material.
    [5" claim-type="Currently amended] The method of claim 1, wherein the charging braid,
    A developer charging device for an image forming apparatus employing an electrophotographic developing system, characterized in that an aluminum film.
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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 KR1019960076710A
    1998-09-25|Publication of KR19980057420A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019960076710A|KR19980057420A|1996-12-30|1996-12-30|Developer charging device for an image forming apparatus employing an electrophotographic developing method|
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