Image forming apparatus
    2.
    发明授权
    Image forming apparatus 失效
    图像形成装置

    公开(公告)号:US4887102A

    公开(公告)日:1989-12-12

    申请号:US161029

    申请日:1988-02-26

    IPC分类号: G03G15/01

    CPC分类号: G03G15/0121

    摘要: An image forming apparatus includes a first developing device for forming a first toner image and a second developing device for forming a second toner image including a developer carrying member spaced apart from the image bearing member by a distance and a device for applying a developing bias voltage to form an electric field having a maximum voltage Vmax and a minimum voltage Vmin, such that when the first developer is positively charged,.vertline.Vmin-V.sub.T .vertline./d.ltoreq.2.25, or when the first developer is negatively charged,.vertline.Vmax-V.sub.T .vertline./d.ltoreq.2.25,where V.sub.T (V) is a potential of a first toner image immediately before formation of the second toner image after the first latent image is subjected to the charger, the potential of the first toner image being a surface potential of the first toner image under existence of the first latent image.

    摘要翻译: 图像形成装置包括用于形成第一调色剂图像的第一显影装置和用于形成第二调色剂图像的第二显影装置,所述第二显影装置包括与图像承载部件间隔一定距离的显影剂承载部件和用于施加显影偏压的装置 以形成具有最大电压Vmax和最小电压Vmin的电场,使得当第一显影剂为正电荷时,| Vmin-VT| / d <2.25,或当第一显影剂带负电时,| Vmax- VT / D

    Image forming apparatus with plural developing devices
    3.
    发明授权
    Image forming apparatus with plural developing devices 失效
    具有多个显影装置的图像形成装置

    公开(公告)号:US4774543A

    公开(公告)日:1988-09-27

    申请号:US90020

    申请日:1987-08-27

    IPC分类号: G03G15/01 G03G15/08 G03G15/09

    CPC分类号: G03G15/0126 G03G15/09

    摘要: An image forming apparatus includes a movable image bearing member; a device for forming a first latent image and a second latent image; a first developing device for developing the first latent image using a first developer containing magnetic particles and toner particles to form a first developed image; a second developing device, disposed downstream of the first developing means with respect to movement direction of the image bearing member, for developing the second latent image on the image bearing member bearing the first developed image and the second latent image, using a second developer which is different from the first developer, the second developing device including a developer containing portion and developer carrying sleeve for carrying from the developer containing portion the second developer to a developing zone where the developer carrying sleeve is opposed to the image bearing member; and a magnetic field generating pole, in the second developing device, for providing an attracting surface for attracting magnetic particles of the first developer carried on the developer carrying member of the second developing device, the magnetic field generating pole being opposed to a developer carrying surface of the developer carrying sleeve and being disposed downstream of the developing zone and upstream of the developer containing portion of the second developing device with respect to movement of the second developer carried on the developer carrying sleeve.

    摘要翻译: 图像形成装置包括可动图像承载部件; 用于形成第一潜像和第二潜像的装置; 用于使用包含磁性颗粒的第一显影剂和调色剂颗粒来显影第一潜像的第一显影装置,以形成第一显影图像; 第二显影装置,相对于图像承载部件的移动方向设置在第一显影装置的下游,用于使用第二显影剂将承载第一显影图像和第二潜像的图像承载部件上的第二潜像显影, 与第一显影剂不同,第二显影装置包括用于从显影剂容纳部分将第二显影剂携带到显影剂携带套筒与图像承载部件相对的显影区域的显影剂容纳部分和显影剂承载套筒; 和第二显影装置中的磁场产生极,用于提供吸引第二显影装置的显影剂承载构件上承载的第一显影剂的磁性颗粒的吸引表面,所述磁场产生极与显影剂承载表面相对 并且相对于承载在显影剂承载套筒上的第二显影剂的移动而设置在显影区的下游和第二显影装置的显影剂容纳部分的上游。