Abstract: 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 [?J/cm2] is represented by Vr [V], a maximum value of S [V·?J/cm2] represented by S=I·(V?Vr) in a range of I=0.000 to 0.030 [?J/cm2] is represented by Smax [V·?J/cm2], and a product of a light amount Ii [?J/cm2] on the horizontal axis and a potential Vi[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 [?J/cm2] and an approximate straight line in a range of I=0.490 to 0.500 [?J/cm2] is represented by Si=Ii·(Vi?Vr) [V·?J/cm2], a ratio of Si to Smax, which is represented by AR=Si/Smax, satisfies AR?0.10.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An electrophotographic photosensitive member that can not easily cause charging lines even where it is an electrophotographic photosensitive member employing as a conductive layer a layer containing metal oxide particles is disclosed. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member. The electrophotographic photosensitive member has a conductive layer which contains titanium oxide particles coated with tin oxide doped with phosphorus or tungsten.

Abstract: A conductive layer contains a binder material, a first particle, and a second particle. The first particle is composed of a core particle and aluminum-doped zinc oxide covering the core particle or is composed of a core particle and oxygen-deficient zinc oxide covering the core particle. The second particle is of the same material as that of the core particle of the first particle. The content of the first particle is 20% by volume or more and 50% by volume or less of the total volume of the conductive layer. The content of the second particle is 0.1% by volume or more and 15% by volume or less of the total volume of the conductive layer and is 0.5% by volume or more and 30% by volume or less of the volume of the first particle.

Abstract: A conductive layer of an electrophotographic photosensitive member includes a binder material, a first metal oxide particle, and a second metal oxide particle. The first metal oxide particle is a zinc oxide particle or tin oxide particle coated with tin oxide doped with phosphorus, tungsten, niobium, tantalum, or fluorine. The second metal oxide particle is an uncoated zinc oxide particle or tin oxide particle. The content of the first metal oxide particle is not less than 20% by volume and not more than 50% by volume based on the total volume of the conductive layer. The content of the second metal oxide particle is not less than 0.1% by volume and not more than 15% by volume based on the total volume of the conductive layer, and not less than 0.5% by volume and not more than 30% by volume based on the content of the first metal oxide particle.

Abstract: A conductive layer of an electrophotographic photosensitive member contains a first metal oxide particle, a second metal oxide particle, and a binder material. The first metal oxide particle is a zinc oxide particle or tin oxide particle coated with tin oxide doped with phosphorus, tungsten, fluorine, niobium, or tantalum, and the second metal oxide particle is a tin oxide particle doped with an element selected from the group consisting of phosphorus, tungsten, fluorine, niobium, and tantalum, the element being the same as the element with which the tin oxide of the first metal oxide particle is doped. The conductive layer satisfies formulae (1) and (2) 2?{(V2/VT)/(V1/VT)}×100?25??formulae (1): 15?{(V1/VT)+(V2/VT)}×100?45??formulae (2).

Abstract: Provided are an electrophotographic photosensitive member in which a residual potential hardly increases at the time of image formation, a pattern memory hardly occurs, and the crack of a conductive layer hardly occurs, and a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member. To this end, the conductive layer of the electrophotographic photosensitive member contains a titanium oxide particle coated with tin oxide doped with phosphorus, a tin oxide particle doped with phosphorus, and a binding material, and when a total volume of the conductive layer is represented by VT, a total volume of the titanium oxide particle coated with tin oxide doped with phosphorus in the conductive layer is represented by V1P, and a total volume of the tin oxide particle doped with phosphorus in the conductive layer is represented by V2P, the VT, the V1P, and the V2P satisfy the following expressions: 2?{(V2P/VT)/(V1P/VT)}×100?25 and 15?{(V1P/VT)+(V2P/VT)}×100?45.

Abstract: An electrophotographic photosensitive member in which a leak hardly occurs, and a process cartridge and electrophotographic apparatus having the same are provided. The conductive layer in the electrophotographic photosensitive member includes a binder material, a first metal oxide particle, and a second metal oxide particle. The first metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus, tungsten, niobium, tantalum, or fluorine, and the second metal oxide particle is an uncoated titanium oxide particle. The contents of the first and second metal oxide particles in the conductive layer is 20 to 50 vol. % and 1.0 to 15 vol. %, respectively based on the total volume of the conductive layer. The content of the second metal oxide particle in the conductive layer is 5.0 to 30% by volume based on the content of the first metal oxide particle in the conductive layer.

Abstract: A method for producing an electrophotographic photosensitive member in which leakage hardly occurs is provided. For this, in the method for producing an electrophotographic photosensitive member according to the present invention, a coating liquid for a conductive layer is prepared using a solvent, a binder material, and a metallic oxide particle having a water content of not less than 1.0% by mass and not more than 2.0% by mass; using the coating liquid for a conductive layer, a conductive layer having a volume resistivity of not less than 1.0×108 ?·cm and not more than 5.0×1012 ?·cm is formed; the mass ratio (P/B) of the metallic oxide particle (P) to the binder material (B) in the coating liquid for a conductive layer is not less than 1.5/1.0 and not more than 3.5/1.

Abstract: An electrophotographic photosensitive member that can not easily cause charging lines even where it is an electrophotographic photosensitive member employing as a conductive layer a layer containing metal oxide particles is disclosed. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member. The electrophotographic photosensitive member has a conductive layer which contains titanium oxide particles coated with tin oxide doped with phosphorus or tungsten.

Abstract: An inverted microscope that allows observation of a specimen from underneath includes an objective lens holding unit that holds an objective lens configured to collect at least observation light from the specimen, a tube lens configured to focus the observation light collected by the objective lens, a branching unit configured to branch an optical path of the observation light from the tube lens, and an observation image switching device that is removably provided in a microscope main body between the objective lens and the tube lens and is configured to switch between wavelengths of an observation image or between magnifications of the observation image.

Abstract: A conductive layer contains a binder material, a first particle, and a second particle. The first particle is composed of a core particle and aluminum-doped zinc oxide covering the core particle or is composed of a core particle and oxygen-deficient zinc oxide covering the core particle. The second particle is of the same material as that of the core particle of the first particle. The content of the first particle is 20% by volume or more and 50% by volume or less of the total volume of the conductive layer. The content of the second particle is 0.1% by volume or more and 15% by volume or less of the total volume of the conductive layer and is 0.5% by volume or more and 30% by volume or less of the volume of the first particle.

Abstract: A conductive layer of an electrophotographic photosensitive member includes a binder material, a first metal oxide particle, and a second metal oxide particle. The first metal oxide particle is a zinc oxide particle or tin oxide particle coated with tin oxide doped with phosphorus, tungsten, niobium, tantalum, or fluorine. The second metal oxide particle is an uncoated zinc oxide particle or tin oxide particle. The content of the first metal oxide particle is not less than 20% by volume and not more than 50% by volume based on the total volume of the conductive layer. The content of the second metal oxide particle is not less than 0.1% by volume and not more than 15% by volume based on the total volume of the conductive layer, and not less than 0.5% by volume and not more than 30% by volume based on the content of the first metal oxide particle.

Abstract: A conductive layer of an electrophotographic photosensitive member contains a first metal oxide particle, a second metal oxide particle, and a binder material. The first metal oxide particle is a zinc oxide particle or tin oxide particle coated with tin oxide doped with phosphorus, tungsten, fluorine, niobium, or tantalum, and the second metal oxide particle is a tin oxide particle doped with an element selected from the group consisting of phosphorus, tungsten, fluorine, niobium, and tantalum, the element being the same as the element with which the tin oxide of the first metal oxide particle is doped. The conductive layer satisfies formulae (1) and (2).

Abstract: An electrophotographic photosensitive member in which a leak hardly occurs, and a process cartridge and electrophotographic apparatus having the same are provided. The conductive layer in the electrophotographic photosensitive member includes a binder material, a first metal oxide particle, and a second metal oxide particle. The first metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus, tungsten, niobium, tantalum, or fluorine, and the second metal oxide particle is an uncoated titanium oxide particle. The contents of the first and second metal oxide particles in the conductive layer is 20 to 50 vol. % and 1.0 to 15 vol. %, respectively based on the total volume of the conductive layer. The content of the second metal oxide particle in the conductive layer is 5.0 to 30% by volume based on the content of the first metal oxide particle in the conductive layer.

Abstract: Provided are an electrophotographic photosensitive member in which a residual potential hardly increases at the time of image formation, a pattern memory hardly occurs, and the crack of a conductive layer hardly occurs, and a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member. To this end, the conductive layer of the electrophotographic photosensitive member contains a titanium oxide particle coated with tin oxide doped with phosphorus, a tin oxide particle doped with phosphorus, and a binding material, and when a total volume of the conductive layer is represented by VT, a total volume of the titanium oxide particle coated with tin oxide doped with phosphorus in the conductive layer is represented by V1P, and a total volume of the tin oxide particle doped with phosphorus in the conductive layer is represented by V2P, the VT, the V1P, and the V2P satisfy the following expressions: 2?{(V2P/VT)/(V1P/VT)}×100?25 and 15?{(V1P/VT)+(V2P/VT)}×100?45.