Canon Kabushiki Kaisha

Hiroshi Mayuzumi

Jun Murata

Yoshiaki Nishimura

Tomohito Taniguchi

Masataka Kodama

Akiya Kume

Noriaki Kuroda

Noriyuki Doi

Kenichi Yamauchi

Hiroki Masu

Noriko Suzumura

Kineo Takeno

Yukinori Nagata

Yusuke Yagisawa

Nobutoshi Hayashi

Hidekazu Matsuda

Satoshi Koide

Nozomu Takahata

A charging member which has high charging ability and prevents generation of abnormal discharge is provided. The charging member includes a support and a surface layer. The surface layer contains a polymetalloxane having a specific structure.

Charging member, process cartridge and electrophotographic apparatus

Provided is a charging member that suppresses the occurrence of abnormal discharge under low temperature and low humidity. The charging member includes a support and a surface layer on the support, and the surface layer contains a compound represented by the following formula (a), (b), (c), or (d). 

Charging member, process cartridge, and electrophotographic image forming apparatus

The present invention provides an electrophotographic member capable of more definitely suppressing occurrence of a C set image. The electrophotographic member has a surface layer including a modified polysiloxane having a structure represented by the following formula (1). In the formula (1), G represents a bivalent group having an ethylene oxide chain represented by (&#x2014;O&#x2014;CH&#x2014;) and L represents polysiloxane having at least a SiO(Q) unit or a SiO(T) unit. 

Electrophotographic member, process cartridge and electrophotographic apparatus

Provided is the following charging member of an electrophotographic apparatus. The charging member suppresses the occurrence of each of a streak-like image, a spot-like image, and a rough image that occur when image formation is performed over a long time period. Also provided are a process cartridge and an electrophotographic apparatus each having the charging member. A compound having a siloxane dendrimer structure at a vinyl group or a side chain of a vinyl polymer is incorporated into the surface layer of the charging member comprising a conductive substrate and the surface layer.

Charging member, process cartridge, and electrophotographic apparatus

A charging member is provided having a support, a conductive elastic layer formed on the support and a surface layer formed on the conductive elastic layer. The surface layer contains a polysiloxane having at least one of structures represented by the following formulas (1a1), (1a2), (1b1) and (1b2): Toners and external additives used in the toners clinging to the charging member surface can be minimized even through repeated use over a long period of time, thus the charging member can perform stable charging and image reproduction even when used in the DC contact charging method.

A charging member is provided which can inhibit defective images due to poor charging and adhering substances from occurring even after being repeatedly used for a long time, and can inhibit deformation and defective images due to the C set, caused by a change in rotational speed accompanying such deformation even after being left standing in a stopping state for a long time. The charging member includes a conductive support and a surface layer. The surface layer includes a binder and resin particles dispersed in the binder, each resin particle having a depressed portion on its surface. Protrusions resulting from the resin particles are formed on the surface of the surface layer. The protrusions each have a depressed portion resulting from the depressed portion of the resin particle, and the surface of the resin particle is covered with the binder.

Charging member including a conductive support and surface layer having protrusions formed on a surface thereof, a process cartridge including same for use in an image forming apparatus

A cellular conductive roller has closed cells and open cells with conductive powder filling the open cells of the cellular conductive roller. A method for making a cellular conductive roller includes filling the open cells in the cellular conductive roller with conductive powder, adhering a tacky sheet to the surface of said cellular conductive roller; then peeling said tacky sheet off the surface of said cellular conductive roller. Also disclosed is an electrophotographic device using the cellular conductive roller and a process cartridge into which the cellular conductive roller is integrated.

Cellular conductive roller with conductive powder filling open cells in

A charging member supplied with a voltage to charge a charge-receiving member such as an electrophotographic photosensitive member has an elastic layer of an ethylene-propylene copolymer containing a diene component. The ethylene-propylene copolymer has an iodine value of 23-32. The charging member is improved in resistance to permanent deformation while providing excellent images for a long period.

Charging member and electrophotographic apparatus using the same

A white electroconductive coating composition includes a white pigment having a whiteness of at least 60, a white conductive material having a whiteness of at least 50 and a volume resistivity of at most 1.times.10.sup.10 ohm.cm. The coating composition is suitable to provide a a coating film showing a whiteness of at least 60 and a surface resistivity of at most 1.times.10.sup.11 ohm/cm.sup.2. Such a white conductive layer may be formed on a back side of a surface insulating film of a transfer material carrying member of an electrophotographic image forming apparatus to provide a reference white pattern for detecting a density of a toner image formed on the carrying member, thereby allowing controlled image formation based on the detected density data.

White electroconductive coating composition and transfer

The present invention pertains to a charging member which is energized to charge a chargeable member by contact-electrification and which comprises a conductive elastic layer having a surface layer containing a polymer having a main chain containing a structural unit of the following formula:

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Yokohama, Japan

Hiroshi Mayuzumi