An electrophotographic photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, in which the charge transport layer contains a polyester resin having a structure represented by Formula (1) at a terminal and a charge transport material, and in a case where a weight-average molecular weight Mw of the polyester resin is defined as A (×10,000), a value of a ratio M1/M2 of a mass M1 of the charge transport material to a mass M2 of an entire charge transport layer is defined as Cs, and an average thickness of the charge transport layer is defined as Ds (μm), expressions of 7≤A≤40, 0.28≤Cs≤0.55, 27≤Ds≤50, and 5.0≤(A×Ds)/(Cs×100)≤70 are satisfied,

##STR00001## in Formula (1), nd represents an integer of 0 or greater and 4 or less, nd number of Rd's each independently represent a hydrocarbon group having 1 or more and 4 or less carbon atoms, L represents an ether bond or a —O—C(═O)— group, and * represent a bonding portion.

An image forming apparatus includes an image bearing member, a charger, a light exposure device, a development device, a transfer belt, a primary transfer device, a secondary transfer device, and a cleaning member. The cleaning member is pressed against a circumferential surface of the image bearing member and collects residual toner remaining on the circumferential surface of the image bearing member as a result of primary transfer of a toner. The transfer belt has a surface resistivity of at least 6 Log Ω and no greater than 11 Log Ω. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is at least 10 N/m and no greater than 40 N/m. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer. The image bearing member satisfies formula (1): $\begin{array}{cc}0.06\leqq \frac{V}{\left(Q/S\right)\times \left(d/{\epsilon }_r.Math.{\epsilon }_0\right)}.& \left(1\right)\end{array}$

An electrophotographic photosensitive member includes a conductive support and a photosensitive layer disposed on the conductive support. A top surface layer of the electrophotographic photosensitive member includes fluorine-containing resin particles, a fluorine-containing dispersant, and two or more charge transporting materials. When the charge transporting materials are listed in order of decreasing HOMO energy levels, a difference in HOMO energy level between each adjacent two of the charge The ratio A of the amount of each of the charge transporting materials to the total amount of the charge transporting materials satisfies the condition 1 below,
[(100/N)−(100/N×0.3)]≤A≤[(100/N)+(100/N×0.3)]  Condition 1 where N represents the number of types of the charge transporting materials included in the top surface layer.

An electrophotographic photoconductor includes: a conductive substrate; and a single-layer-type photoconductive layer that is provided on the conductive substrate and contains a binder resin, a charge generating material, a hole transporting material, and an electron transporting material, in which a volume resistivity of the photoconductive layer after wear is 5.0×10.sup.10 Ω.Math.cm or more and 2.0×10.sup.11 Ω.Math.cm or less when a ratio of a thickness of the photoconductive layer after wear to a thickness of the photoconductive layer before wear (the thickness of the photoconductive layer after wear/the thickness of the photoconductive layer before wear) is 0.8.

An object of the present invention is to provide an electrophotographic photoreceptor which can prevent an increase in potential even using a fluorine resin in a charge transport layer, and can achieve both electrical properties and abrasion resistance, and present invention relates to a lamination type electrophotographic photoreceptor, in which a charge transport layer of the lamination type electrophotographic photoreceptor contains a compound having an E_homo of −4.550 eV or more based on structure optimization calculation by density functional calculation B3LYP/6-31G (d, p) and fluorine resin particles, and a content of the fluorine resin particles is 3% by weight to 20% by weight based on a total mass of the charge transport layer.

The object of the present invention is to provide a positive charging electrophotographic photoreceptor having high sensitivity, low residual potential, and excellent chargeability, and relates to a positive charging electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a protective layer in this order, the photosensitive layer containing a charge generation substance, a positive hole transport substance, and an electron transport substance in the same layer, in which the positive hole transport substance includes at least one of the compounds represented by any one of the following formulas (1) to (5), and a binder resin of the protective layer is an alcohol-soluble thermoplastic resin, providing that the symbols in the formula are defined in the specification. ##STR00001##

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer, and contains a charge generating material, an electron transport material, a binder resin, and a hole transport material.

##STR00001##

The electron transport material includes a compound represented by general formula (1). The binder resin includes a polycarbonate resin having an end group and a main chain represented by general formula (10).

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer and contains a charge generating material, an electron transport material, a binder resin, and a hole transport material. The electron transport material includes a compound represented by general formula (1):

##STR00001##

In general formula (1), R.sup.1 and R.sup.2 each represent, independently of one another, a hydrogen atom, an alkyl group, a heterocyclic group, an alkoxy group, an aralkyl group, an allyl group, or an aryl group optionally substituted with at least 1 and no more than 5 substituents selected from the group consisting of a halogen atom, an alkyl group, and alkoxy group.

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.

The present invention relates to an electrophotographic photoreceptor having a plurality of layers containing at least one outermost layer, wherein at least one of the outermost layer contains a polymer having a first structure where at least one carbonyl group is bonded to an aromatic group and a second structure represented by Formula (A). In Formula (A), at least two of R.sup.11 to R.sup.13 are groups represented by Formula (2), and in Formula (2), R.sup.21 represents a hydrogen atom or a methyl group, and R.sup.22 and R.sup.23 each independently represent a hydrogen atom, a hydrocarbon group or an alkoxy group:

##STR00001##