US Patent 9971258 Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

In an electrophotographic photosensitive member, a circumferential surface has concave portions that are independent one another; each of the concave portions has an opening, a contour of the opening has an apex having an angle α of more than 0° and 90° or less on at least an upstream side of a rotational direction of the electrophotographic photosensitive member, and has a largest width in an axial direction of the electrophotographic photosensitive member of 20 μm or more and 80 μm or less, a width of the contour in the axial direction of the electrophotographic photosensitive member decreasing from a portion having the largest width toward the apex, when viewing each of the concave portions in the axial direction, each of the concave portions has a depth that decreases from a deepest point of each of the concave portions toward the apex.