Canon Kabushiki Kaisha

Kenichi Kaku

Yuka Ishiduka

Hideharu Shimozawa

Michiyo Sekiya

Koji Takahashi

Masato Tanaka

Atsushi Okuda

Nobuhiro Nakamura

Tsutomu Nishida

Kaname Watariguchi

Takashi Anezaki

Hiroyuki Watanabe

Atsushi Fujii

Wataru Kitamura

Akihiro Maruyama

Jumpei Kuno

Mai Murakami

Taichi Sato

Kohei Makisumi

Harunobu Ogaki

Kunihiko Sekido

Hiroyuki Tomono

Yota Ito

Haruyuki Tsuji

Tatsuya Yamaai

Takeshi Murakami

Akira Yoshida

Koichi Nakata

Kazuhiro Yamauchi

Takakazu Tanaka

Kazunori Noguchi

Masaki Nonaka

Haruki Mori

Ryoichi Tokimitsu

Shuhei Iwasaki

Yuichi Kikuchi

Hideaki Nagasaka

Satoshi Nishida

Shuntaro Watanabe

Daisuke Miura

Takanori Mitani

Itaru Takaya

Yasuhiro Kawai

Kazuhisa Shida

Tomohito Ishida

Naoki Fukushima

Kazuko Araki

Takehiko Endo

Provided is an electrophotographic photosensitive member including a support, an undercoat layer, a charge-generating layer, and a charge-transporting layer in the stated order, wherein with regard to an S, an S, an S, an S, and an Sdetermined by a specific procedure (A), a ratio S/Sis 0.34 or less, and one of the S, the S, or the Sis a positive value, and the other two thereof are negative values, or two thereof are positive values, and the other one thereof is a negative value.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

The present disclosure provides a photoelectric conversion element including a first electrode, a second electrode, a photoelectric conversion layerbetween the first electrodeand the second electrode, and a reflection layerbetween one of the first electrodeand the second electrodeand the photoelectric conversion layer. The wavelength at which the reflectance of the reflection layeris maximum in the visible region is within the range of wavelengths in which the optical absorption coefficient of the photoelectric conversion layeris ⅕ or more of the maximum optical absorption coefficient in the visible region.

Photoelectric conversion element and photoelectric conversion device including the photoelectric conversion element

Provided is an electrophotographic photosensitive member having a feature in that, in a graph that is obtained by a method of measuring an EV curve, and that has a horizontal axis representing I and a vertical axis representing V, when V at I=0.500 [μJ/cm] is represented by V[V], a maximum value of S [V·μJ/cm] represented by S=I·(V−V) in a range of I=0.000 to 0.030 [μJ/cm] is represented by S[V·μJ/cm], and a product of a light amount I[μJ/cm] on the horizontal axis and a potential V[V] on the vertical axis at a point of intersection between an approximate straight line in a range of I=0.000 to 0.010 [μJ/cm] and an approximate straight line in a range of I=0.490 to 0.500 [μJ/cm] is represented by S=I·(V−V) [V·μJ/cm], a ratio of Sto S, which is represented by AR=S/S, satisfies AR≤0.10.

Provided is an electrophotographic photosensitive member that includes a support, a charge generation layer on the support, and a charge transfer layer on the charge generation layer and that satisfies specifications on an EV curve based on a measurement method of NESA-EV curve. The electrophotographic photosensitive member can exhibit high character quality and a digital gradation characteristic in a low-line-number halftone while maintaining an analog gradation characteristic in a high-speed process.

The electrophotographic apparatus includes: an electrophotographic photosensitive member; a charging unit; an image-exposing unit; a charge transfer amount-sensing unit for sensing the amount of charge transferred to the electrophotographic photosensitive member; and an exposed portion potential-controlling unit for controlling the potential of each of the exposed portions of the electrophotographic photosensitive member based on a sensing result, which is obtained by charging the electrophotographic photosensitive member with the charging unit, performing image exposure with the image-exposing unit in at least one light amount weaker than a light amount in which the normalized radius of curvature R of the electrophotographic photosensitive member represented by the following equation (E1), the normalized radius of curvature being obtained by a method of measuring an EV curve, shows a minimum, and in at least two light amounts stronger than the light amount in which the normalized radius of curvature shows the minimum.

Electrophotographic apparatus

An electrophotographic photosensitive member includes: a support; an undercoat layer; a charge generation layer; and a charge transport layer, wherein the undercoat layer contains a polyamide resin and a titanium oxide fine particle, and on the surface of the undercoat layer, an arithmetic mean roughness Ra and an average length Rsm of a roughness curve element both according to JIS B0601:2001 satisfy Ra≤50 nm and 0.1≤Ra/Rsm≤0.5; and the charge generation layer contains a hydroxygallium phthalocyanine pigment, wherein the hydroxygallium phthalocyanine pigment includes crystal particles having a crystal form exhibiting peaks at 7.4°±0.3° and 28.2°±0.3° at Bragg angles 2θ in a spectrum of X-ray diffraction using a CuKα, ray; and in a size distribution of the crystal particles, which is measured using small-angle X-ray scattering, a peak exists in a range of 20 to 50 nm, and the peak has a half-value width of 50 nm or smaller.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

Provided is an electrophotographic apparatus including: an electrophotographic photosensitive member; a voltage application unit configured to cause discharge from an electroconductive member to the electrophotographic photosensitive member; a charge transfer amount detection unit configured to detect a charge transfer amount per unit time resulting from the discharge from the electroconductive member to the electrophotographic photosensitive member; and a charging potential control unit, wherein Vand Vdefined by specific procedures for the electrophotographic photosensitive member satisfy a relationship represented by the following expression (E-4): 100V<V−V(E-4), and wherein the charging potential control unit is configured to control the charging potential of the electrophotographic photosensitive member at the time of image formation.

An electrophotographic photosensitive member, which is suppressed in occurrence of fogging and is excellent in abrasion resistance. In the electrophotographic photosensitive member, an outermost surface layer of the electrophotographic photosensitive member comprises a polymerized product of a composition comprising at least a polyrotaxane and a monomer having a polymerizable reactive group, and a chain molecule of the polyrotaxane has two blocking groups at both terminals thereof, and a (meth)acryloyloxy group of a cyclic molecule of the polyrotaxane forms a bond.

Electrophotographic photosensitive member, process cartridge, and electrophotographic image forming apparatus

An electrophotographic photosensitive member having a support and a photosensitive layer on the support, wherein the electrophotographic photosensitive member comprises a surface layer comprising a polymerization product of a composition containing polyrotaxane and a charge transporting substance, and the polymerization product including a bond between the polyrotaxane and the charge transporting substance.

Electrophotographic photosensitive member, process cartridge and electrophotographic image forming apparatus

A process cartridge which allows any spot and stripe as image defects to be suppressed is provided. A process cartridge, in which an electroconductive layer of a charging member has a matrix including a first rubber, and domains dispersed in the matrix, the domains include a second rubber and an electron electroconductive agent, at least some of the domains are exposed on a surface of the charging member, when a volume resistivity of the matrix is 10times or more a volume resistivity of the domains, a protective layer of an electrophotographic photosensitive member includes a metal oxide particle, and when a number average primary particle size of the metal oxide particle is defined as Sm and an average value of equivalent circle diameters of the domains is defined as Sd, the Sd/Sm satisfies the following expression (1): 0.5&#x3c;Sd/Sm&#x3c;100 . . . expression (1).

Process cartridge and electrophotographic apparatus

There is provided a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including an electrophotographic photosensitive member and a charging member, wherein an outer surface of the charging member is composed of at least a matrix and at least a part of domains, a volume resistivity of the matrix is 1.0&#xd7;10times or more of a volume resistivity of the domain, an average value Sd of circle equivalent diameters of the domains observed on the outer surface of the charging member is in a predetermined range, the electrophotographic photosensitive member contains a support, a photosensitive layer, and a protective layer in this order and when a surface roughness of the protective layer is measured, each of a protruding valley portion Rvk, a load length ratio Mr2, and Sd/Rvk is in a predetermined range.

Process cartridge and electrophotographic apparatus using the same

The present disclosure provides an electrophotographic photosensitive member that suppresses electric potential fluctuations in repeated use. The electrophotographic photosensitive member includes a support, a photosensitive layer and a protective layer, in this order, wherein the photosensitive layer includes a compound having a structure represented by formula (1), and the protective layer includes a resin having a structure represented by formula (2) and a structure represented by formula (3).

A method for producing an electrophotographic photosensitive member having a photosensitive layer and a protective layer above a support in this order includes: forming a coating film for a protective layer by coating a coating liquid for the protective layer for forming the protective layer on the photosensitive layer and curing the coating film for the protective layer, in which the coating liquid for the protective layer contains a solvent, a compound represented by a general formula (1), a compound represented by a general formula (2), and a compound represented by a general formula (3) at a specific ratio. In addition, in an electrophotographic photosensitive member having a photosensitive layer and a protective layer above a support in this order, the protective layer is obtained by curing a coating liquid for the protective layer.

Electrophotographic photosensitive member and method for producing electrophotographic photosensitive member

An electrophotographic photosensitive member suppressing potential variation due to repeated use is provided. The electrophotographic photosensitive member is an electrophotographic photosensitive member including a support, a photosensitive layer and a protective layer in this order, wherein the protective layer contains: a resin including a structure represented by a general formula (1) and a structure represented by a general formula (2); and a compound represented by a general formula (3), the molar ratio of the proportion of the structure represented by the general formula (2) to the proportion of the structure represented by the general formula (1) in the resin is 0.0002 to 0.1000 in a molar ratio, and the molar ratio of the content of the compound represented by the general formula (3) to the content of the structure represented by the general formula (1) in the resin in the protective layer is 0.0002 to 0.1000 in a molar ratio.

An electrophotographic photosensitive member includes a support and a surface layer, in which the surface layer contains a copolymer of a composition which contains at least a compound represented by the following general formula (1) and a compound represented by the following general formula (2), a content of the compound represented by the general formula (1) in the composition is 25 mass % or more and 70 mass % or less with respect to a total content of the compound represented by the general formula (1) and the compound represented by the general formula (2), and the total content of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 55 mass % or more with respect to a total mass of the composition.

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Suntou-gun, Japan

Kenichi Kaku