An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The hole transport material includes a compound represented by chemical formula (1-1) or (1-2). The photosensitive layer further contains an n-type pigment. The n-type pigment is preferably an azo pigment or a perylene pigment. ##STR00001##

The process cartridge includes an electrophotographic photosensitive member having a first support and a photosensitive layer; and a charging member. In the photosensitive member when an electric current is measured which flows when a voltage is applied to a surface while being varied, a gradient a.sub.1 of a low electric field region and a gradient a.sub.2 of a high electric field region satisfy a.sub.2/a.sub.1≥1.50, in a graph. The charging member includes a second support having an electroconductive outer surface, and a second electroconductive layer including a matrix and a plurality of domains being dispersed in the matrix, at least a portion of the domain is exposed to an outer surface which includes at least the matrix and at least a portion of the domain, and a volume resistivity ρ.sub.M of the matrix is 1.00×10.sup.5 times or higher of a volume resistivity ρ.sub.D of the domain.

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 various thicknesses along 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. Various thicknesses and shapes of the charge generation layer are also disclosed.

An electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer arranged on the conductive substrate and containing, as a charge generating material, any one material selected from the group consisting of titanyl phthalocyanines, metal-free phthalocyanines, chlorogallium phthalocyanines and hydroxygallium phthalocyanines; and, as an electron transporting material, a naphthalene tetracarboxylic acid diimide compound represented by Formula (1) below, where R.sup.1 and R.sup.2 each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkylene group, an alkoxy group, an alkyl ester group, a phenyl group optionally having a substituent, a naphthyl group optionally having a substituent, or a halogen element; and R.sup.1 and R.sup.2 are optionally the same or different: ##STR00001##
The photoreceptor realizes a stable print density even in a low-temperature environment by suppressing a reduction in print density that is caused by potential fluctuation of the photoreceptor in the low-temperature environment.

The present disclosure provides an electrophotographic photosensitive member that reduces the accumulation of charge and the leakage which are caused by a repeated use in a long period of time. The electrophotographic photosensitive member has a support, an undercoat layer, a charge generation layer and a charge transport layer in this order, wherein the undercoat layer contains a polyamide resin, and a titanium oxide particle, wherein the titanium oxide particle has been surfacetreated with an organosilicon compound, wherein the undercoat layer satisfies 1070, where represents a degree [%] of hydrophobicity of the titanium oxide particle which has been surfacetreated with the organosilicon compound; and the undercoat layer satisfies 0.015()0.040, where represents an average primary particle size [m] of the titanium oxide particles, and represents a weight percentage [wt %] of an Si element of the organosilicon compound with respect to the titanium oxide particle.

Provided is an electrophotographic photosensitive member that can achieve both of abrasion resistance and the suppression of a ghost. The electrophotographic photosensitive member includes: a support; an undercoat layer; a charge-generating layer; and a charge-transporting layer, the undercoat layer, the charge-generating layer, and the charge-transporting layer being arranged in the stated order on the support, wherein the charge-transporting layer includes a charge-transporting substance, and a polymer containing a structure represented by the following general formula (1) and a structure represented by the following general formula (2), wherein the charge-generating layer includes a phthalocyanine crystal and a binder resin, and wherein the undercoat layer includes strontium titanate particles and a binder resin. ##STR00001##

An electrophotographic photoconductor includes: a conductive substrate; and a single-layer-type photoconductive layer that is provided on the conductive substrate, contains a binder resin, a charge generating material, a hole transporting material, and an electron transporting material, and has an index A represented by the following equation (1) in a range of 7.98 or more and 7.28 or less, Equation (1): A=(0.057M)(0.002F)(0.252), in which, in the equation (1), M represents a Martens hardness of the single-layer-type photoconductive layer, F represents a Young's modulus of the single-layer-type photoconductive layer, and represents an elastic deformation ratio of the single-layer-type photoconductive layer.

An image forming apparatus includes an image bearing member and a charging roller that charges a circumferential surface of the image bearing member to a positive polarity. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer, and satisfies formula (1) shown below. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin.

[00001]$\begin{array}{cc}0.60\frac{V}{\left(Q/S\right)\left(d/{\mathrm{.Math.}}_r.Math.{\mathrm{.Math.}}_0\right)}& \left(1\right)\end{array}$

In formula (1), Q represents a charge amount [C] of the circumferential surface of the image bearing member, S represents a charge area [m.sup.2] of the charged circumferential surface of the image bearing member, d represents a film thickness [m] of the photosensitive layer, co represents vacuum permittivity [F/m], and V represents a value calculated in accordance with formula V=V.sub.0V.sub.r.

In an image forming apparatus, a cleaning member is pressed against a circumferential surface of an image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. The toner has a number average roundness of 0.965 to 0.998. The toner has a D.sub.50 of 4.0 m to 7.0 m. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is 10 N/m to 40 N/m. The image bearing member includes a single-layer photosensitive layer containing a charge generating material and a hole transport material. Ionization potential Ip.sub.HTM of the hole transport material and ionization potential Ip.sub.CGM of the charge generating material satisfy mathematical formula (1) Ip.sub.HTM5.30 eV, mathematical formula (2) Ip.sub.CGM5.30 eV, and mathematical formula (3) 0.09 eV|Ip.sub.HTMIp.sub.CGM|0.30 eV.