Provided is a process cartridge removably mountable onto a main body of an electrophotographic apparatus, the process cartridge comprising an electrophotographic photosensitive member, a toner, and a developing member configured to supply the toner to the electrophotographic photosensitive member, wherein, in filter fitting analysis in STEM-EDS analysis, a hydrotalcite particle comprises fluorine, and wherein, when a number-average primary particle diameter of a particle A is represented by “m” [nm], a content ratio of the particle A with respect to the surface layer is represented by “p” [vol %], and a number-average primary particle diameter of the hydrotalcite particle is represented by “h” [nm], the “m”, the “p”, and the “h” satisfy the following expressions, respectively:

5≤m≤300  Expression (1);

5≤p≤40  Expression (2); and

60≤h≤1,000  Expression (3).

An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer disposed on the conductive substrate, and a lamination type photosensitive layer disposed on the undercoat layer and including a charge generation layer and a charge transport layer, in which the charge transport layer contains a charge transport material and a polyester resin, and in a case where an average thickness of the charge transport layer is defined as As (μm) and an average thickness of the undercoat layer is defined as Bs (μm), expressions 27≤As≤50, 10≤Bs≤40, and 0.70≤As/Bs≤4.80 are satisfied.

An electrophotographic photoreceptor includes an electrically conductive substrate, and a laminate-type photosensitive layer formed on the electrically conductive substrate. An allowable range of a charging voltage Vx to be applied to the electrophotographic photoreceptor by a charging device is V.sub.0−150≤V.sub.x≤V.sub.0+150, and an electrostatic capacitance per unit area of the electrophotographic photoreceptor is 90 pF/cm.sup.2 or more. VO is an initial charging voltage applied to the electrophotographic photoreceptor. Also, an image forming apparatus and an image forming cartridge can be provided with the electrophotographic photoreceptor.

Provided are an electrophotographic photoconductor that is less likely to cause transfer ghosting even when mounted in an electrophotographic apparatus with high transfer voltage set for high-speed or cleanerless processes, as well as a method of manufacturing the electrophotographic photoconductor, and an electrophotographic apparatus. The electrophotographic photoconductor includes a conductive substrate; an undercoat layer provided on the conductive substrate, and a photosensitive layer provided on the undercoat layer. In the electrophotographic photoconductor, the undercoat layer contains a resin binder and a first filler; and the first filler contains zinc oxide particles that are surface-treated with an N-acylated amino acid or an N-acylated amino acid salt.

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; an undercoat layer that is disposed on the conductive substrate and contains metal titanate compound particles, an electron transporting compound, and a binder resin; and a photosensitive layer on the undercoat layer.

Provided is an electrophotographic photosensitive member in which the generation of a positive ghost image is suppressed under a low-temperature and low-humidity environment, and the occurrence of cracking is suppressed under a high-temperature and high-humidity environment. Also provided are a process cartridge mounted with the electrophotographic photosensitive member, and an electrophotographic apparatus including the process cartridge. The electrophotographic photosensitive member of the present disclosure is characterized in that an undercoat layer contains aluminum oxide particles and titanium oxide particles at a specific mass ratio.

An electrophotographic photoreceptor includes a support, an undercoat layer placed on the support, a charge generation layer placed on the undercoat layer, and a charge transport layer placed on the charge generation layer. The undercoat layer contains titanium oxide particles surface-treated with an organosilicon compound that is at least one member selected from the group consisting of compounds represented by formulas (1) to (8) and a polyamide resin. The charge generation layer contains hydroxygallium phthalocyanine.

An electrophotographic photoreceptor includes: a conductive substrate; an undercoating layer that contains inorganic particles surface-treated with a surface treatment agent, and is provided in contact with an outer peripheral surface of the conductive substrate; and a photosensitive layer provided on the undercoating layer, wherein, with respect to the outer peripheral surface of the conductive substrate, a proportion of an area being in contact with the inorganic particles is from 82% to 91%.

An electrophotographic photosensitive member including a support, an intermediate layer, and a photosensitive layer in this order, wherein the intermediate layer comprises a tungsten oxide particle, and the tungsten oxide particle contains a tungsten atom, an oxygen atom, and a cesium atom.