Fuji Xerox Co., Ltd.

Keiko Matsuki

Masahiro Iwasaki

Kosuke Narita

Mitsuhide Nakamura

Hirofumi Nakamura

Takayuki Yamashita

Fuyuki Kano

Daisuke Haruyama

Hiroshi Tamemasa

Jiro Korenaga

Yasuhiko Kinuta

Shogo Tomari

Akihiro Nonaka

Takanori Suga

Hirokazu Sakashita

Shingo Hirahara

A charging device includes a charging roller and a cleaning roller that includes a core and a foamed elastic layer disposed on an outer circumferential surface of the core and that rotates in contact with a surface of the charging roller. The number of ends of a cell skeleton that protrude from a surface of the foamed elastic layer is 25 ends/mmor more and 50 ends/mmor less. The cleaning roller is disposed in contact with the charging roller such that the compression ratio of the foamed elastic layer is 30% or less. The compression ratio is represented by Equation (1):compression ratio (%)=(1/2+2/2&#x2212;)/1&#xd7;100&#x2003;&#x2003;Equation (1):where r1 is the outer diameter (mm) of the cleaning roller, r2 is the outer diameter (mm) of the charging roller, d is the interaxial distance (mm) between the charging roller and the cleaning roller, and t1 is the thickness (mm) of the foamed elastic layer of the cleaning roller.

Charging device, process cartridge, image forming apparatus, and assembly

A height of convexities in a 0.7-mm-square area of a surface of the charging member is measured at five or more different positions in an axial direction and calculated. A height of a position where the charging member occupies 0.01 area % from a highest portion is defined as a reference height. An average proportion of areas occupied by the charging member at a position 1.7 &#x3bc;m lower than the reference height is 2 area % or less relative to 100 area % of the 0.7-mm-square area.

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

Provided is an electrophotographic photoreceptor including a conductive substrate and a photosensitive layer provided on the conductive substrate, wherein an uppermost surface layer thereof is constituted with a cured film of a composition that contains at least two kinds of reactive charge transporting materials selected from a first reactive charge transporting material having an &#x2014;OH group as a reactive functional group and a second reactive charge transporting material having an &#x2014;OCHgroup as a reactive functional group, fluororesin particles, and an alkyl fluoride group-containing copolymer having repeating units represented by the following Structural Formulae A and B, and a relative dielectric constant &#x2208;r of the uppermost surface layer satisfies the following Formula (1): 

Electrophotographic photoreceptor, process cartridge, and image forming apparatus

There is provided an electrophotographic photoreceptor including a conductive substrate; an intermediate layer; a photosensitive layer; and a surface layer, in this order, the surface layer including two or more charge transporting materials each including a reactive substituent and respectively having mutually different ionization potentials, in an amount of 90% by weight or more relative to the total solid content of the surface layer, and the content ratio X of each of the two or more charge transporting materials satisfying the following Formula (1). X(n) represents a content ratio (weight %) of a charge transporting material that has the nhighest ionization potential among the two or more charge transporting materials; X(n&#x2212;1) represents a content ratio (weight %) of a charge transporting material that has the (n&#x2212;1)highest ionization potential among the two or more charge transporting materials; and n is an integer of two or more and represents a variable equal to or lower than the number of charge transporting materials contained in the surface layer.(&#x2212;1)&#x2267;()&#x2003;&#x2003;Formula (1).

Electrophotographic photoreceptor, image forming apparatus and process cartridge

The endless belt is provided with: a metal layer that includes at least one layer, that is cylindrically formed, and that has not more than 10 degrees as a half width of a diffraction peak in X-ray diffraction; and a release layer that is stacked on the metal layer.

Endless belt including a metal layer having low residual strain, fixing device and image forming apparatus

Growing community of inventors

Kanagawa, Japan

Keiko Matsuki