An electrophotographic photosensitive member, in which occurrences of image defects are suppressed, and a method for manufacturing the electrophotographic photosensitive member are provided. In addition, a process cartridge and an electrophotographic apparatus, which include the electrophotographic photosensitive member, are provided. The surface layer of the electrophotographic photosensitive member contains a cured material, and the cured material is a copolymer of a hole transport compound having a chain-polymerizable functional group and a vinyl ester compound containing a long-chain alkyl group.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a charge transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin is represented by general formula (1) shown below. In general formula (1), X represents a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4) shown below.

##STR00001##

The present invention relates to an electrophotographic photoreceptor which is a positive charging type electrophotographic photoreceptor comprising a conductive support and a photosensitive layer on the conductive support, wherein the photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin in the same layer, and a residual potential VL.sub.1 at a point at which an exposure amount for forming a latent image is 0.3 μJ/cm.sup.2 is equal to or lower than 130 V when an initial surface potential V0 is set to +700 V, exposure with monochromatic light of 780 nm is performed and measurement is performed by a dynamic method.

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 10.sup.6 carbon 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.sup.2, an absolute value |RP.sub.1−RP.sub.10000| of a difference between a residual potential RP.sub.1 after charging and exposure once and a residual potential RP.sub.10000 after charging and exposure 10,000 times is 25 V or less.

In an image forming apparatus in which an electrostatic image is formed on an electrophotographic photosensitive member using at least a process of a pseudo halftone formed by dots as a method of representing gradation, the electrophotographic photosensitive member is provided on a surface thereof with a plurality of recessed portions of 0.5 μm more and 5 μm or less in depth and 20 μm or more and 80 μm or less in longest diameter of an opening, when a square region of 500 μm×500 μm is arbitrarily extracted on the surface of the electrophotographic photosensitive member, in the square region, a total area of the recessed portions is 10000 μm.sup.2 or more and 90000 μm.sup.2 or less and a total area of a flat portion contained in a portion other than the recessed portion is 80000 μm.sup.2 or more and 240000 μm.sup.2 or less, and an arrangement (A) of the plurality of recessed portions is such an arrangement that an image quality lowering index (f) calculated by specific processing is 14% or less.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer, wherein an outermost layer contains a compound having a structure represented by general formula (I) below:

##STR00001## where R.sub.1 and R.sub.2 each independently represent a C.sub.1-12 alkyl group or a C.sub.5-12 cycloalkyl group; R.sub.3 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted C.sub.1-6 alkyl group, a substituted or unsubstituted C.sub.1-6 alkoxyl group, a C.sub.6-20 aryl group or a heterocycle group; X and Z each represent a single bond or a C.sub.1-6 alkylene group which may be substituted; and Y represents a OCO group or COO group. A method for manufacturing the photoreceptor and an electrophotographic device including the photoreceptor are additionally provided. The electrophotographic photoreceptor provides sufficient stain resistance and is less affected by temperature and humidity environments while maintaining various advantageous characteristics of photoreceptors.

The electrophotographic photosensitive member has: a cylindrical support; a charge generating layer formed on the cylindrical support; and a charge transport layer formed on the charge generating layer, the charge generating layer contains a hydroxygallium phthalocyanine crystal having a particular CuKα characteristic X-ray diffraction peak, a titanyl phthalocyanine crystal having a particular CuKα characteristic X-ray diffraction peak or a chlorogallium phthalocyanine crystal having a particular spectral absorption spectrum as a charge generating material, and in the charge generating layer, with respect to the film thickness of the charge generating layer, when a region from the central position of an image forming area to the end position of the image forming area is divided in the axial direction of the cylindrical support into five equal regions and the average film thickness of the charge generating layer in each region satisfies a specific condition.

Shaping a photoconductive drum includes preparing a dispersion having a charge generation composition and dipping an elongated support element into the dispersion. Withdrawing from the dispersion portions of the support element at different speeds results in different thicknesses of charge generation composition on the support element. Faster withdrawal results in thicker charge generation composition than does slower withdrawal. Portions with thicker composition provide denser optical densities compared to thinner composition allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. Coating the support element with a charge transport layer occurs next, then curing. Oxidation of the support element may occur prior to application of the charge generation composition. A protective overcoat may also exist over the charge transport layer.

A photoconductive drum includes an elongated support element with a shaped charge generation layer. The layer extends from the support element at a single thickness along about two-thirds of a length thereof. Thicker charge generation portions provides denser optical densities compared to thinner portions allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. A charge transport layer overcoats the charge generation layer. Optionally, an oxidation layer underlies the charge generation layer as does a protective overcoat overlying the charge transport layer.

A cylindrical electrophotographic photosensitive member having concave portions on a surface thereof includes a region A having concave portions at an end portion in an axial direction of the photosensitive member and a region B having concave portions different from those in the region A in a direction toward a center of the axial direction of the photosensitive member from the region A, wherein in the region A, an average value L1 is 20 to 200 μm, an average value W1 satisfies W1≤L1, an average value d1 is 1.7 to 4.0 μm, and an area ratio a1 is 5 to 65%; and in the region B, an average value L2 is 20 to 200 μm, an average value W2 satisfies W2≤L2, an average value d2 is 0.3 to 1.5 μm, and an area ratio a2 is 5 to 65%.