An average value of a hydrogen content ratio of a surface layer made of hydrogenated amorphous carbon is set to be 0.40 or less and a maximum value of an sp.sup.2 bonding ratio in an outermost surface region of the surface layer made of the hydrogenated amorphous carbon is set to be 0.50 or less.

The present invention provides an electrophotographic photosensitive member which has a substrate, a photoconductive layer and a surface layer formed from hydrogenated amorphous silicon carbide in this order. The average value of the carbon content (C/(C+Si)) of the surface layer formed from the hydrogenated amorphous silicon carbide is set at 0.90 or more and less than 1.00, and the average value of the hydrogen content (H/(H+C+Si)) is set at 0.40 or less; and when the average value of the ratios of the sum of a SiO bond and an OSiO bond in the outermost surface region that constitutes a range within a depth of 5 nm or less from the outermost surface of the surface layer is represented by a, and an average value of the silicon content (Si/(C+Si)) is represented by b, 0.015a*b0.090 holds.

In an example of a method for reducing contamination, a purified imaging oil is formed by filtering an imaging oil through an imaging oil filter, and then filtering the imaging oil through a polar absorbent filter. A surface of an amorphous silicon photoconductor of a liquid electrophotographic printing apparatus is maintained by periodically applying the purified imaging oil to the amorphous silicon photoconductor.

A surface layer of the electrophotographic photosensitive member has a change region in which a ratio of the number of carbon atoms with respect to the sum of the number of silicon atoms and the number of carbon atoms gradually increases toward a surface side of the electrophotographic photosensitive member from a photoconductive layer side, wherein the change region has an upper charge injection prohibiting portion containing a Group 13 atom, and a surface-side portion which is positioned closer to the surface side of the electrophotographic photosensitive member than the upper charge injection prohibiting portion and does not contain the Group 13 atom, and the distribution of the Group 13 atom in a boundary portion between the surface-side portion and the upper charge injection prohibiting portion is precipitous.

An image forming apparatus includes an image carrying member, a charging device, an exposure device, a development device, and a development voltage power supply. The image carrying member has an amorphous silicon photosensitive layer formed on its surface. The development device includes a developer carrying member carrying two-component developer containing toner and carrier. The development voltage power supply applies to the developer carrying member a development voltage having an alternating-current voltage superposed on a direct-current voltage. When the blank part potential on the image carrying member is V0 [V], the direct-current voltage is Vdc [V], the peak-to-peak value of the alternating-current voltage Vac is Vpp [kV], and the gap between the image carrying member and the developer carrying member is Ds [mm], 10V0Vdc90 and 1.2Vpp/Ds3.5 are fulfilled.

An electrophotographic apparatus including: an electrophotographic photosensitive member; a developing unit, which includes a toner, and which is configured to develop an electrostatic latent image with the toner to form a toner image on a surface of the electrophotographic photosensitive member; and a cleaning unit configured to remove a residual toner remaining on the surface of the electrophotographic photosensitive member after the toner image is transferred from the surface of the electrophotographic photosensitive member onto a transfer material, wherein the surface of the electrophotographic photosensitive member is formed of amorphous silicon carbide, wherein a Si atom density in a region in the vicinity of the surface of the electrophotographic photosensitive member from the surface to a depth of 100 nm is 1.010.sup.22 atoms/cm.sup.3 or less, and wherein the toner contains a toner particle that contains a polyester resin having a polyethylene terephthalate segment and an inorganic fine particle.

An electrophotographic photoreceptor includes a conductive substrate, a charge-generating layer provided on or above the conductive substrate, a charge transport layer provided on the charge-generating layer and containing inorganic oxide particles, the charge-generating layer and the charge transport layer forming a photosensitive layer, and an inorganic protective layer provided on the photosensitive layer, in which in a cross-sectional observation of the charge transport layer, the relationship between the percentage area A of inorganic oxide particles contained in a surface level and the percentage area B of inorganic oxide particles contained in an inner level satisfies the percentage area A>the percentage area B of the charge transport layer, with the boundary therebetween at the thickness of the charge transport layer.

An image forming apparatus includes an image carrying member, a charging device, an exposure device, a development device, and a development voltage power supply. The image carrying member has an amorphous silicon photosensitive layer formed on its surface. The development device includes a developer carrying member carrying two-component developer containing toner and carrier. The development voltage power supply applies to the developer carrying member a development voltage having an alternating-current voltage superposed on a direct-current voltage. When the blank part potential on the image carrying member is V0 [V], the direct-current voltage is Vdc [V], the peak-to-peak value of the alternating-current voltage Vac is Vpp [kV], and the gap between the image carrying member and the developer carrying member is Ds [mm], 10V0Vdc90 and 1.2Vpp/Ds3.5 are fulfilled.