Fuji Xerox Co., Ltd.

Fujifilm Business Innovation Corp.

Yukimi Kawabata

Jiro Korenaga

Kenta Yamakoshi

Masahiro Iwasaki

Keisuke Kusano

Kazuyuki Tada

Yuko Yamano

Fuyuki Kano

Daisuke Haruyama

Hideya Katsuhara

Yoshifumi Shoji

Natsumi Kaneko

Yasuhiro Niida

Kenji Ikeda

Toshiyasu Yukawa

Kenta Shingu

Shinya Yamamoto

Yuki Tagawa

Mitsuhide Nakamura

Yoshiyuki Hayashi

A charging system includes a charging member that rotates while following a rotating image holding body and that charges the image holding body, a removing member that rotates while following the rotating charging member in a state of being arranged at a contact position in contact with the charging member and that removes an adhered deposit adhered to the charging member, a moving member that moves the removing member to a separation position separated from the charging member and the contact position, and at least one processor, in which the processor is configured to cause the removing member to remove the adhered deposit adhered to the charging member only for a removal time by controlling the moving member to move the removing member arranged at the separation position to the contact position at a time determined in advance.

Charging system and image forming system

A conductive member includes: a substrate; an elastic layer provided on the substrate; and a surface layer provided on the elastic layer, in which the surface layer contains a conductive agent and has a sea/island structure that includes a sea portion containing a first resin and an island portion containing a second resin, and an average length of connected island portions in observation of a cross-section of the surface layer is 2.0 μm or more and 4.5 μm or less.

Conductive member, charging device, process cartridge, and image forming apparatus

A conductive member includes: a substrate; an elastic layer provided on the substrate; and a surface layer provided on the elastic layer, in which the surface layer contains a conductive agent and has a sea/island structure that consists of a sea portion containing a first resin and an island portion containing a second resin, and a distance R between the island portions and a radius r of the island portion in a cross-section of the surface layer satisfy the following Expression (1-1),−0.20≤−2≤0.40  Expression (1-1).

Conductive member, charging device, process cartridge, and image forming apparatus having surface layer with sea/island structure

An electrophotographic photoconductor includes: a conductive substrate; and a single-layer-type photoconductive layer that is provided on the conductive substrate, contains a binder resin, a charge generating material, a hole transporting material, and an electron transporting material, and has an index A represented by the following equation (1) in a range of −7.98 or more and −7.28 or less, Equation (1): A=(0.057×M)−(0.002×F)−(0.252×μ), in which, in the equation (1), M represents a Martens hardness of the single-layer-type photoconductive layer, F represents a Young's modulus of the single-layer-type photoconductive layer, and μ represents an elastic deformation ratio of the single-layer-type photoconductive layer.

Electrophotographic photoconductor, process cartridge, and image forming apparatus

A conductive member includes a substrate, an elastic layer on the substrate, and a surface layer on the elastic layer. The surface layer contains a conductive agent and has a sea-island structure including a sea containing a first resin and islands containing a second resin. The area occupancy of the islands in a cross section of the surface layer is 10% or more and 50% or less.

An electrophotographic photoconductor includes: a conductive substrate; and a single-layer-type photoconductive layer that is provided on the conductive substrate and contains a binder resin, a charge generating material, a hole transporting material, and an electron transporting material, in which a volume resistivity of the photoconductive layer after wear is 5.0&#xd7;10&#x3a9;&#xb7;cm or more and 2.0&#xd7;10&#x3a9;&#xb7;cm or less when a ratio of a thickness of the photoconductive layer after wear to a thickness of the photoconductive layer before wear (the thickness of the photoconductive layer after wear/the thickness of the photoconductive layer before wear) is 0.8.

A charging member of a contact charging system that applies only a direct-current voltage to the charging member includes a conductive substrate, an elastic layer disposed on the conductive substrate, and a surface layer disposed on the elastic layer. When measured by an alternating-current impedance method within a range of 1 MHz to 1 mHz in an environment at a temperature of 28&#xb0; C. and a humidity of 85%, a resistance component R of an impedance within a range of 1 Hz to 100 Hz is 4.0&#xd7;10&#x3a9; or more and 1.0&#xd7;10&#x3a9; or less and an impedance Z within a range of 1 Hz to 100 Hz is over 3.6&#xd7;10&#x3a9; and 3.5&#xd7;10&#x3a9; or less.

Charging member, charging device, image forming apparatus, and process cartridge

An electrophotographic photoreceptor includes a conductive substrate and a single-layer-type photosensitive layer on the conductive substrate. The single-layer-type photosensitive layer contains a binder resin, a charge generating material, an electron transporting material, and a hole transporting material. The single-layer-type photosensitive layer has a concentration ratio (A/B) of 0.7 or more and 1.0 or less, where the concentration ratio (A/B) is a ratio of a concentration A of the electron transporting material relative to the binder resin measured from a surface of the photosensitive layer remote from the conductive substrate to a concentration B of the electron transporting material relative to the binder resin measured from a surface of the photosensitive layer close to the conductive substrate.

Electrophotographic photoreceptor, process cartridge, and image forming apparatus

An electrophotographic photosensitive member includes a conductive base and a single-layer-type photosensitive layer on the conductive base. The photosensitive layer contains a binder resin, a charge generation material, a hole transport material, a fluorine-atom-containing electron transport material, and fluorine-atom-containing resin particles. An amount of the charge generation material in the photosensitive layer is 0.5% by weight or more and less than 2.0% by weight. The charge generation material has a distribution that satisfies Formula (1): 30&#x2266;a/b in a thickness direction of the photosensitive layer where a and b are as defined in the specification, and b may be 0. The fluorine-atom-containing electron transport material has a distribution that satisfies Formula (2): 30&#x2266;c/d in the thickness direction of the photosensitive layer where c and d are as defined in the specification, and d may be 0.

Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photoreceptor includes a conductive substrate and a single-layer photosensitive layer which is provided on the conductive substrate and contains a binder resin, at least one charge generating material selected from a hydroxygallium phthalocyanine pigment and a chlorogallium phthalocyanine pigment, a first electron transporting material defined in the specification, a second electron transporting material defined in the specification, and a hole transporting material defined in the specification, wherein a total content of all electron transporting materials is greater than or equal to 4 parts by weight with respect to 100 parts by weight of a total solid content of the photosensitive layer, and an average loss elastic modulus E&#x2033; of the photosensitive layer, which is obtained by measuring dynamic viscoelasticity at a temperature of from 35&#xb0; C. to 50&#xb0; C. and a frequency of 0.5 Hz, is less than or equal to 1.000&#xd7;10.

An electrophotographic photoreceptor includes a conductive substrate, and a single-layer type photosensitive layer that contains a binder resin, a charge generating material, a hole transporting material, and an electron transporting material, wherein a content of the charge generating material in the photosensitive layer is 0.5% by weight or more and less than 2.0% by weight and the charge generating material satisfies expression (1): 30&#x2266;a/b, wherein a represents the number of the charge generating materials per unit cross-sectional area in a region ranging from the surface side of the film thickness of the photosensitive layer to a point corresponding to &#x2153;, and b represents the number of the charge generating materials per unit cross-sectional area in a region ranging from the conductive substrate side of the film thickness of the photosensitive layer to a position corresponding to &#x2154;, provided that a case where b is 0 is included.

Provided is an electron transport material represented by formula (1): wherein X represents an oxygen atom or &#x2550;C(CN); R, R, R, R, R, R, and Reach independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group, an alkoxy group, an aryl group, or an aralkyl group; R, R, and Reach independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group, an aralkyl group, an aryl group, &#x2014;R&#x2014;O&#x2014;R, or &#x2014;R&#x2014;CO&#x2014;O&#x2014;R; Rrepresents a linear or branched alkylene group; Rrepresents a linear or branched alkyl group; Rrepresents a single bond or a linear or branched alkylene group; and Rrepresents a linear or branched alkyl group, an aryl group, or an aralkyl group, provided that at least two or more groups of R, R, and Rrepresent a group other than a hydrogen atom.

Electron transport material, electrophotographic photoreceptor, process cartridge, and image forming apparatus

An electrophotographic photoreceptor includes a substrate and a photosensitive layer, wherein the electrophotographic photoreceptor has a surface layer containing fluorine resin particles, and the fluorine resin particles exposed on a surface satisfy the following Expression (1):0.5&#x2266;()/()&#x2266;10&#x2003;&#x2003;Expression (1)wherein, (A) represents a number of aggregated particles in which 5 to 20 fluorine resin particles are connected and aggregated, and (B) represents a total number of fluorine resin particles that are isolated without being aggregated and aggregated particles in which 2 to 4 fluorine resin particles are connected and aggregated.

Electrophotographic photoreceptor, image forming apparatus, and process cartridge

Provided is an additive for an electrophotographic photoreceptor which is represented by Formula (I): wherein, A represents an m-valent organic group derived from arylamine represented by Formula (II) or Formula (III); T represents a divalent hydrocarbon group having from 1 to 10 carbon atoms; Rf represents a branched hydrocarbon group having from 3 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; l represents 0 or 1; and m represents an integer of 1 to 4: wherein, Ar, Ar, and Areach independently represent a substituted or unsubstituted aryl group having from 6 to 20 carbon atoms; Ar, Ar, Ar, and Areach independently represent a substituted or unsubstituted aryl group having from 6 to 20 carbon atoms; and X represents a divalent organic group represented by Formula (IV), Formula (V), or Formula (VI): 

Additive for electrophotographic photoreceptor, electrophotographic photoreceptor, process cartridge, and image forming apparatus

An electrophotographic photoreceptor is provided, which includes: a substrate; a photosensitive layer; and a surface protective layer, in this order, in which the protective layer contains a crosslinked product of a curable charge transporting material in a content of from about 90 to 98% by weight, and fluorinated resin particles in a content of from about 2 to 10% by weight, and the protective layer satisfies Formula (1): 0.5&#x2266;b/a&#x2266;1, wherein, 'a' represents a ratio of fluorine atoms to the sum of carbon atoms, oxygen atoms, and fluorine atoms present in a region of the protective layer ranging from the photosensitive layer side surface thereof to a point corresponding to about &#x2154; of the thickness thereof, and 'b' represents the ratio in a region of the protective layer ranging from the outer surface thereof to a point corresponding to about &#x2153; of the thickness thereof.

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Kanagawa, Japan

Yukimi Kawabata