PURPOSE: To prevent stains on a developed image and fog on the background by allowing a developer carrying member to hold a mixed developer of magnetic insulating triboelectrifiable particles and conductive particles on the surface and bring it into contact with the surface of an image bearing member.
CONSTITUTION: A developer 10 composed of a mixture of conductive particles 10b and insulating magnetic particles 10a triboelectrifiable in the same polarity as that of an electrostatic charge density pattern formed on the image bearing face 1 of a photosensitive body or the like is attracted to and held on the surface of a sleeve 2 by the magnetic field of the magnet 4 located in the sleeve 2, and brought into contact with the image bearing face 1 to develop said pattern. At that time, while the developer 10 is stirred and conveyed on the sleeve 2, since in the conductive particles 10b, a charge opposite to the triboelectrified charge of the adjacent insulating particles 10a is induced, and the particles 10b are held with the particles 10a to alleviate scattering, and the particles 10b unnecessarily tending to attach to the image bearing face 1 are removed.
TOYONO TSUTOMU
FUKUSHIMA HISASHI
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