Provided is an electrophotographic photosensitive member that can achieve both of the suppression of a fluctuation in potential of the photosensitive member at the time of its repeated use, and the prevention of the occurrence of a black spot-like image defect at high levels. The electrophotographic photosensitive member includes in this order: a support; an intermediate layer; and a photosensitive layer, the intermediate layer containing particles each containing titanium oxide, and the particles having a mass increase ratio of 0.005% or more when heated under a nitrogen atmosphere from 300 C. to 900 C.

An image forming method includes forming an image with a toner using a photoconductor in which an intermediate layer and a photosensitive layer including a charge generating layer and a charge transport layer are formed overlying an electroconductive substrate, wherein the ionization potential of the surface of the photoconductor and the ionization potential of the surface of the toner satisfy the following relations 1 and 2,

|Ip (the surface of the photoconductor)Ip (the surface of the toner)|5.53 (eV) Relation 1

5.45 (eV)Ip (the surface of the photoconductor)5.53 (eV) Relation 2

where Ip (the surface of the photoconductor) represents the ionization potential of the surface of the photoconductor and Ip (the surface of the toner) represents the ionization potential of the surface of the toner.

An image forming method includes forming an image with a toner using a photoconductor in which an intermediate layer and a photosensitive layer including a charge generating layer and a charge transport layer are formed overlying an electroconductive substrate, wherein the ionization potential of the surface of the photoconductor and the ionization potential of the surface of the toner satisfy the following relations 1 and 2,
|Ip (the surface of the photoconductor)Ip (the surface of the toner)|0.18 (eV) Relation 1
5.45 (eV)Ip (the surface of the photoconductor)5.53 (eV) Relation 2 where Ip (the surface of the photoconductor) represents the ionization potential of the surface of the photoconductor and Ip (the surface of the toner) represents the ionization potential of the surface of the toner.

An image forming apparatus includes a rotatable image bearing member and a rotatable developer bearing member. The image bearing member, configured to carry a toner image, includes first recess portions provided at intervals substantially equal to a first pitch Pdr (mm) in a rotation direction of the image bearing member. The developer bearing member, configured to carry developer comprising toner and carrier and to form the toner image on the image bearing member, includes second recess portions provided at intervals substantially equal to a second pitch Ps (mm) in a rotation direction of the developer bearing member. The following relationship is satisfied
Vs/Vdr<Ws/Pdr where Vdr represents a movement speed (mm/sec) of the first recess portions, Vs represents a movement speed (mm/sec) of the second recess portions, and Ws represents a length (mm) of each of the second recess portions in the rotation direction of the developer bearing member.

Disclosed herein is an electrophotographic photosensitive member in which leakage hardly occurs even in the case of using a layer containing metal oxide particles as an electrically conductive layer in the electrophotographic photosensitive member, and which is compatible with definition in output images, the electrophotographic photosensitive member sequentially including: a support, an electrically conductive layer, and a photosensitive layer, the electrically conductive layer containing a binder material and particles represented by General Formula (1).
Nb.sub.2.00O.sub.5.00-XN.sub.Y(1)
(In Formula (1), Nb is a niobium atom, O is an oxygen atom, N is a nitrogen atom, and 0.00<Y<X4.00).

An image forming apparatus includes a rotatable image bearing member and a rotatable developer bearing member. The image bearing member, configured to carry a toner image, includes first recess portions provided at intervals substantially equal to a first pitch Pdr (mm) in a rotation direction of the image bearing member. The developer bearing member, configured to carry developer comprising toner and carrier and to form the toner image on the image bearing member, includes second recess portions provided at intervals substantially equal to a second pitch Ps (mm) in a rotation direction of the developer bearing member. The following relationship is satisfied

Vs/Vdr<Ws/Pdr where Vdr represents a movement speed (mm/sec) of the first recess portions, Vs represents a movement speed (mm/sec) of the second recess portions, and Ws represents a length (mm) of each of the second recess portions in the rotation direction of the developer bearing member.

The disclosure provides an electrophotographic photoconductor comprises a photosensitive layer and a protective layer in sequence on a conductive support, wherein the protective layer contains a polymer having a structure represented by the following formula (1) or (2):

##STR00001##

A process cartridge includes an electrophotographic photoreceptor that includes a photosensitive layer and a protective layer on a conductive substrate in this order, and a charging member that includes an elastic layer and a surface layer on a conductive base material in this order and comes into contact with the electrophotographic photoreceptor to charge a surface of the electrophotographic photoreceptor, in which the protective layer in the electrophotographic photoreceptor is a cured film formed to contain a crosslinked material of a composition containing at least one compound X selected from the group consisting of a compound having a guanamine structure and a compound having a melamine structure and a charge transport material Y containing at least one group selected from the group consisting of OH, OCH.sub.3, NH.sub.2, SH, and COOH, a water contact angle ?1 of the surface of the electrophotographic photoreceptor is 65? or greater and less than 80?, and a water contact angle ?2 of a surface of the charging member satisfies a relationship of ?1<?2.

An electrophotographic roller comprising a substrate comprising a conductive outer surface and a resin layer on the outer surface of the substrate, wherein the resin layer comprises a polyurethane having a polycarbonate structure, an impedance at a frequency of 1.0?10.sup.0 to 1.0?10.sup.1 Hz is 1.00?10.sup.6? or more when a specific AC voltage is applied to the outer surface of the electrophotographic roller while a frequency is changed between specific range, and when a corona discharger having a grid part is moved along an axial direction of the electrophotographic roller at a speed of 400 mm/sec, a maximum value of an electric potential of the outer surface is less than 20.0 V when measured at 0.06 seconds after a passage of the grid part.

An electrophotographic photosensitive member includes at least one photosensitive layer on which a first photosensitive layer disposed on an outermost side thereof. The first photosensitive layer contains a charge generating material, a binder resin including a polyarylate resin with repeating units (1), (2), (3), and (4), an electron transport material, and a hole transport material.

##STR00001##

The electron transport material includes a compound represented by formula (10), (11), or (12). The hole transport material includes compounds represented by formulas (21) and (22):

##STR00002##

A percentage content of a number of repeats of the repeating unit (3) to the total number of repeats of the repeating units (1) and (3) is greater than 0% and less than 50%. A percentage content of a number of repeats of the repeating unit (4) to the total number of repeats of the repeating units (2) and (4) is at least 35% and less than 70%.