Fuji Xerox Co., Ltd.

Fujifilm Business Innovation Corp.

Kosuke Narita

Hiroyuki Miura

Yasuhiko Kinuta

Akihiro Nonaka

Yoshiyuki Hayashi

Hirofumi Nakamura

Kazuhiro Koseki

Takuro Hoshio

Jiro Korenaga

Akihiro Kawasaki

Shigeto Hashiba

Kenta Ide

Hiroko Kobayashi

Satoya Sugiura

Taketoshi Hoshizaki

Fuyuki Kano

Shogo Tomari

Keiko Matsuki

Takahiro Suzuki

Masahiro Iwasaki

Tomoko Suzuki

Tomoya Sasaki

Keisuke Kusano

Yuki Tagawa

Yuto Okazaki

Ryosuke Fujii

Satoshi Mizoguchi

Yoshiteru Yamada

Yoichi Kigoshi

Michinori Fukuma

Yasuhiro Niida

Takuya Morishige

Toru Ogawa

Shuhei Yamazaki

An electrophotographic photoreceptor includes a conductive base body and a multilayered photosensitive layer disposed on the conductive base body and including a charge generation layer and a charge transport layer, wherein the charge transport layer is an uppermost surface layer and contains a charge transport material, a polyester resin, and a compound (T) represented by Formula (T) below, the polyester resin includes a polyester resin (1) including at least one selected from the group consisting of a diol unit (P1) represented by Formula (P1), a diol unit (P2) represented by Formula (P2), a diol unit (P3) represented by Formula (P3), a diol unit (P5) represented by Formula (P5), and a diol unit (P6) represented by Formula (P6), the polyester resin (1) further includes a unit including a biphenyl skeleton, and end groups of the polyester resin (1) do not include fluorine atoms.

Electrophotographic photoreceptor, process cartridge, and image forming apparatus

An electrophotographic photoconductor includes a conductive substrate, and a photoconductive layer, in which an outermost surface layer contains a binder resin, a charge transporting material, fluorine-containing resin particles, and an acidic compound, the number of carboxyl groups in the fluorine-containing resin particles is 0 or more and 30 or less per 10carbon atoms of the fluorine-containing resin particles, and in a case where charging and exposure of the electrophotographic photoconductor are repeated 10,000 times under conditions of a charging potential of −700 V and an exposure intensity of 5 mJ/m, an absolute value |RP−RP| of a difference between a residual potential RPafter charging and exposure once and a residual potential RPafter charging and exposure 10,000 times is 25 V or less.

Electrophotographic photoconductor, process cartridge, and image forming apparatus

A charging member includes a conductive substrate, an elastic layer disposed on the conductive substrate, and a surface layer disposed on the elastic layer. Regarding the surface of the surface layer, in the axial direction, the ratio of the mean spacing of profile irregularities Sm to the ten-point mean roughness Rz and the reduced peak height Spk respectively satisfy 15&#x2264;Sm/Rz&#x2264;35 and Spk&#x2264;5 &#x3bc;m.

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

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 charging device includes: a charging member that charges an image holding member according to a contact charging method, and includes a conductive substrate and a surface layer provided on the conductive substrate; and a clean member that cleans the charging member while contacting the charging member, and includes a shaft and a foamed elastic layer provided on the shaft, wherein a ratio of a distance between irregularities in an axial direction of the surface layer in the charging member (Sm) to a width of a nodal section of a foam cell wall surface protruding from a surface of the foamed elastic layer in the clean member (W) satisfies 2.4&#x2264;Sm/W&#x2264;5.9.

Charging device, process cartridge, and image forming apparatus

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.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer disposed on the conductive substrate, wherein when time that takes for a current value to reach the maximum after beginning of application of a square wave voltage to the electrophotographic photoreceptor is Tand time that takes for the current value to reach the maximum after the beginning of the application of the square wave voltage and then decrease to one fifth of the maximum is T, Tis approximately from 3.2 to 11.0 times as large as T.

A charging member includes a support, a conductive elastic layer disposed on the support, and a surface layer disposed on the conductive elastic layer. Domains with current values of 2.5 pA or more have an average size of about 300 nm or less in a binary image created using a current value of 2.5 pA as a threshold from current measured by contacting a conical probe having a tip diameter of 20 nm with an outer surface of the surface layer and applying a voltage of 3 V between the conical probe and the support while moving the conical probe.

Charging member, process cartridge, and image-forming apparatus for reducing small color lines

A charging member includes a support member, a conductive elastic layer disposed on the support member, and a front surface layer disposed on the conductive elastic layer. Irregularities with a cycle of shorter than 0.1 mm and irregularities with a cycle of 0.1 mm or longer are distributed on an entirety of an outer circumferential surface of the charging member, and satisfy the following conditions of (1) and (2): (1) the irregularities with the cycle of shorter than 0.1 mm have an average height of greater than 0 &#x3bc;m and 4 &#x3bc;m or less; and (2) the irregularities with the cycle of 0.1 mm or longer have an average height of from 5 &#x3bc;m to 30 &#x3bc;m. A half-value width of a maximum frequency value of height distribution on the outer circumferential surface is from 1 &#x3bc;m to 3 &#x3bc;m.

Charging member, process cartridge, and image forming apparatus

A charging member includes a support member, a conductive elastic layer disposed on the support member, and a front surface layer disposed on the conductive elastic layer. Irregularities with a cycle of shorter than 0.1 mm and irregularities with a cycle of 0.1 mm or longer are distributed on an entirety of an outer circumferential surface of the charging member, and satisfy the following conditions of (1) and (2): (1) the irregularities with the cycle of shorter than 0.1 mm have an average height of from 8 &#x3bc;m to 11 &#x3bc;m; and (2) the irregularities with the cycle of 0.1 mm or longer have an average height of from 2 &#x3bc;m to 5 &#x3bc;m. A half-value width of the maximum frequency value of height distribution on the outer circumferential surface is from 1 &#x3bc;m to 3 &#x3bc;m.

Charging member, process cartridge, and image forming apparatus for reducing production of micro-chromatic line and white spot

A charging member includes a support member, a conductive elastic layer disposed on the support member, and a front surface layer disposed on the conductive elastic layer. Irregularities with a cycle of shorter than 0.1 mm and irregularities with a cycle of 0.1 mm or longer are distributed on an entirety of an outer circumferential surface of the charging member, and satisfy the following conditions of (1) and (2): (1) The irregularities with the cycle of shorter than 0.1 mm have an average height of 5 &#x3bc;m to 8 &#x3bc;m; and (2) The irregularities with the cycle of 0.1 mm or longer have an average height of 6 &#x3bc;m to 30 &#x3bc;m. A half-value width of a maximum frequency value of a height distribution on the outer circumferential surface is 1 &#x3bc;m to 3 &#x3bc;m.

Charging member, process cartridge, and image forming apparatus for reducing production of micro-chromatic line

A charging member includes a conductive support and an outermost layer disposed on the conductive support. The outermost layer includes porous silica and an N-alkoxymethylated polyamide and has a gel fraction of 50% or more and a surface roughness Rz of 2 &#x3bc;m or more and 20 &#x3bc;m or less.

A charging member includes a conductive support and a surface layer provided on the conductive support, wherein electron emitting energy on a surface of the charging member is equal to or less than 10 cps/eV.

A charging member includes a conductive base material and a conductive outermost layer provided on the conductive base material, wherein the conductive outermost layer has a ten-point average surface roughness Rz of 2 &#x3bc;m to 20 &#x3bc;m and contains a resin and particles in which particles having a particle diameter of 5.0 &#x3bc;m or more and a circularity of 0.8 or less are 30% by number or less with respect to the total number of particles having a particle diameter of 5.0 &#x3bc;m or more and particles having a particle diameter of less than 5.0 &#x3bc;m and a circularity of 0.8 or less are from 20% by number to 80% by number with respect to the total number of particles having a particle diameter of less than 5.0 &#x3bc;m.

An electrophotographic photoreceptor includes a conductive support, an undercoat layer that is provided on the conductive support and that has a thickness of from 15 &#x3bc;m to 40 &#x3bc;m and has light transmittance of 20% or less with respect to light having a wavelength of 450 nm when the thickness is at least 15 &#x3bc;m, a charge generation layer that is provided on the undercoat layer, and a charge transport layer that is provided on the charge generation layer and that has a thickness of from 15 &#x3bc;m to 40 &#x3bc;m and has light transmittance of 30% or less with respect to light having a wavelength of 450 nm when the thickness is at least 15 &#x3bc;m.

Growing community of inventors

Kanagawa, Japan

Kosuke Narita