G03G5/056

IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

An image forming apparatus includes an image bearing member and a static elimination device. The static elimination device irradiates static elimination light onto a circumferential surface of the image bearing member. The image bearing member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The static elimination light has a wavelength of at least 600 nm and no greater than 800 nm. The photosensitive layer has an optical absorption coefficient of at least 600 cm.sup.1 and no greater than 1,500 cm.sup.1 with respect to light having a wavelength of 660 nm.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single-layer photosensitive layer and contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. A hole mobility .sub.h is at least 1.0010.sup.7 cm.sup.2/V/second and an electron mobility .sub.e is at least 4.0010.sup.8 cm.sup.2/V/second in the photosensitive layer as measured under conditions of a temperature of 23 C. and an electric field intensity of 1.5010.sup.5 V/cm. A ratio (.sub.h/.sub.e) of the hole mobility .sub.h to the electron mobility .sub.e is at least 1.0 and no greater than 50.0.

IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

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.

IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. 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 single-layer photosensitive layer. The single-layer photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The image bearing member satisfies formula (1)

[00001] 0.60 V ( Q / S ) ( d / .Math. r .Math. .Math. 0 ) . ( 1 )

IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. A linear pressure N of the cleaning member on the circumferential surface of the image bearing member is at least 14 N/m and no greater than 40 N/m. A rebound resilience R of the cleaning member at a temperature of 25 C. is at least 38%. The leaner pressure N and the rebound resilience R satisfy mathematical formula (1A). The image bearing member satisfies mathematical formula (1B)

[00001] R < 13.771 N 0.4043 ( 1 .Math. A ) 0.60 V ( Q / S ) ( d / .Math. r .Math. .Math. 0 ) ( 1 .Math. B )

Method of producing an electrophotographic photoreceptor

A method of producing an electrophotographic photoreceptor composed of a photosensitive layer provided on a conductive substrate, includes, in the formation of an outermost layer, controlling slope k of a straight line obtained by plotting the average film density of outermost layer and boiling point of solvent used for the formation of the outermost layer along the ordinate and the abscissa, respectively, to be 1.50E-4 (g/cm.sup.3.Math. C.) or greater, and adjusting the difference in film density of the outermost layer between the surface side and the side close to the conductive substrate to be 0.030 g/cm.sup.3 or less. The electrophotographic photoreceptor has reduced image defects even after long-term use and has excellent wear performance.

Process cartridge and electrophotographic apparatus

Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mm.sup.2 or more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mm.sup.2 or more and 20 N/mm.sup.2 or less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER AND IMAGE FORMING APPARATUS

An electrophotographic photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3) disposed directly or indirectly on the conductive substrate (2). The photosensitive layer (3) has a charge generating layer (3a) and a charge transport layer (3b) disposed in order from the conductive substrate (2). The charge generating layer (3a) contains a charge generating material. The charge transport layer (3b) contains a charge transport material, a binder resin, and a pigment that absorbs light having an irradiation wavelength. The binder resin includes a polyarylate resin including a repeating unit represented by general formula (1):

##STR00001##

In general formula (1), X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1). (1-2), (1-3), or (1-4):

##STR00002##

The pigment is a naphthalocyanine compound represented by general formula (2) or (3):

##STR00003##

IMAGE FORMING METHOD, IMAGE FORMING APPARATUS, AND PROCESS CARTRIDGE

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.

ELECTROPHOTOGRAPHIC PHOTORECEPTOR, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

An electrophotographic photoreceptor includes a conductive substrate, and a lamination type photosensitive layer including a charge generation layer and a charge transport layer or a single layer type photosensitive layer that is a photosensitive layer disposed on the conductive substrate, in which the charge transport layer or the single layer type photosensitive layer is an outermost layer and contains a charge transport material, a polyester resin having a dicarboxylic acid unit (A) represented by Formula (A), and a compound that has a molecular weight of 255 or greater, has a phenol skeleton in which a primary carbon atom or a secondary carbon atom is bonded to one ortho position and a tertiary carbon atom or a quaternary carbon atom is bonded to the other ortho position, and has no linear alkylene structure having 4 or more carbon atoms.

##STR00001##

In Formula (A), Ar.sup.A1 and Ar.sup.A2 each independently represent an aromatic ring that may have a substituent, L.sup.A represents a single bond or a divalent linking group, and n.sup.A1 represents 0, 1, or 2.