Electrophotographic apparatus
An electrophotographic apparatus includes an electrophotographic photosensitive member, a charging roller disposed so as to come into contact with the electrophotographic photosensitive member, and a charging device operable to apply only a DC voltage to charge the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a support member, an undercoat layer over the support member, and a photosensitive layer over the undercoat layer and having a plurality of discrete recesses in the surface thereof. The undercoat layer contains zinc oxide particles and a binder resin. The undercoat layer has cavities therein, and the cavities account for 5.00% or less of the volume of the undercoat layer.
1. An electrophotographic apparatus comprising:
an electrophotographic photosensitive member having discrete recesses in the surface thereof;
a charging roller disposed so as to come into contact with the electrophotographic photosensitive member; and
a charging device operable to apply only a DC voltage to the charging roller so as to electrically charge the electrophotographic photosensitive member,
wherein the electrophotographic photosensitive member includes:
a support member,
an undercoat layer over the support member, and
a photosensitive layer over the undercoat layer,
wherein the undercoat layer contains zinc oxide particles and a binder resin, and the undercoat layer has cavities therein, the cavities accounting for 5.00% or less of the volume of the undercoat layer, and
wherein the undercoat layer has thickness of 25.0 μm or more, and wherein a volume average particle size of the zinc oxide particles is 30 nm or more and 50 nm or less.
2. The electrophotographic apparatus according to claim 1 , wherein the cavities in the undercoat layer account for 0.05% or more of the volume of the undercoat layer.
3. The electrophotographic apparatus according to claim 1 , wherein the cavities in the undercoat layer account for 0.46% to 1.99% of the volume of the undercoat layer.
4. The electrophotographic apparatus according to claim 1 , wherein the recesses have a depth of 3.0 μm or less.
5. The electrophotographic apparatus according to claim 1 , wherein the photosensitive layer includes a charge generating layer and a charge transport layer, and wherein the total thickness of the charge transport layer and layers overlying the charge transport layer is 15.0 μm or more.