Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

A process cartridge, comprising:

• an electrophotographic photosensitive member;
• and
• at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit;
• the process cartridge integrally supporting the electrophotographic photosensitive member and the at least one unit, and being detachably attachable to a main body of an electrophotographic apparatus;
• the electrophotographic photosensitive member comprising a support, a photosensitive layer, and a surface layer in this order;
• an outer surface of the electrophotographic photosensitive member exhibiting a wrinkled shape by having a concavo-convex shape;
• the surface layer comprising a binder resin and an inorganic particle, and at least a part of the inorganic particle is exposed at a concave portion of the concavo-convex shape, wherein
• when a two-dimensional power spectrum F(r,θ) where r is a frequency component and θ is an angle component is obtained by performing frequency analysis of height information of the concavo-convex shape in the observation region, a one-dimensional radial direction distribution function p(r) obtained by integrating the two-dimensional power spectrum F(r,θ) in a θ direction has at least one maximum value, and
• when an angular distribution q(θ) is calculated from the two-dimensional power spectrum F(r,θ) at a frequency rp at which the one-dimensional radial direction distribution function p(r) has the maximum value, a variation in power values in the entire θ range is 15% or less, and
• when an observation region having square form with one side of 200 μm is provided at an arbitrary position on the outer surface, a line that passes through a central point of the observation region and is parallel to a circumferential direction of the electrophotographic photosensitive member is defined as a reference line L1, and 1,799 reference lines obtained by rotating the reference line L1 at every 0.1° around the central point are respectively defined as reference lines L2 to L1,800,
• (i) each of the reference lines L1 to L1,800 intersects with a ridgeline of a convex portion of the concavo-convex shape at a plurality of positions, and
• (ii) intersection angles between each of the reference lines L1 to L1,800 and the ridgelines at least two positions selected from the plurality of positions have different values from each other.

An electrophotographic apparatus, comprising:

• an electrophotographic photosensitive member;
• a charging unit;
• an exposing unit;
• a developing unit;
• and
• a transfer unit;
• the electrophotographic photosensitive member comprising a support, a photosensitive layer, and a surface layer in this order;
• an outer surface of the electrophotographic photosensitive member exhibiting a wrinkled shape by having a concavo-convex shape;
• the surface layer comprising a binder resin and an inorganic particle, and at least a part of the inorganic particle is exposed at a concave portion of the concavo-convex shape, wherein
• when a two-dimensional power spectrum F(r,θ) where r is a frequency component and θ is an angle component is obtained by performing frequency analysis of height information of the concavo-convex shape in the observation region, a one-dimensional radial direction distribution function p(r) obtained by integrating the two-dimensional power spectrum F(r,θ) in a θ direction has at least one maximum value, and
• when an angular distribution q(θ) is calculated from the two-dimensional power spectrum F(r,θ) at a frequency rp at which the one-dimensional radial direction distribution function p(r) has the maximum value, a variation in power values in the entire θ range is 15% or less, and
• when an observation region having square form with one side of 200 μm is provided at an arbitrary position on the outer surface, a line that passes through a central point of the observation region and is parallel to a circumferential direction of the electrophotographic photosensitive member is defined as a reference line L1, and 1,799 reference lines obtained by rotating the reference line L1 at every 0.1° around the central point are respectively defined as reference lines L2 to L1,800,
• (i) each of the reference lines L1 to L1,800 intersects with a ridgeline of a convex portion of the concavo-convex shape at a plurality of positions, and
• (ii) intersection angles between each of the reference lines L1 to L1,800 and the ridgelines at least two positions selected from the plurality of positions have different values from each other.