| CPC G03G 5/04 (2013.01) [G03G 15/75 (2013.01)] | 6 Claims |
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1. An electrophotographic photosensitive member comprising:
a support;
a photosensitive layer; and
an outer surface having wrinkles,
wherein
when, on the outer surface, 76 square observation regions each having a side of 300 μm and a center point, are placed so that each of the center point is respectively on each of 76 points which are intersection between 19 line segments that divide the electrophotographic photosensitive member into 20 equal parts in an axial direction and 4 line segments that divide the electrophotographic photosensitive member into 4 equal parts in a circumferential direction, and so that a direction of each of the 76 square observation regions is set to a direction in which one side of each of the 76 square observation regions is parallel to the circumferential direction of the electrophotographic photosensitive member, and, when, in each of the 76 square observation regions, a line that passes through the center point and is parallel to a circumferential direction of the electrophotographic photosensitive member is designated as a first reference line L1, and 1799 reference lines that are obtained by rotating the first reference line around the center point at intervals of 0.1° are designated as L2 to L1800, respectively,
a linear shape portion exists in a convex portion of the wrinkle,
the wrinkles have a convex portion in which a linear shape portion having a length of 50 μm or longer exists, the linear shape portion being parallel to any one of the reference lines L1 to L150 and the reference lines L1651 to L1800,
each of the reference lines L1 to L1800 intersects with the convex portion at a plurality of places, and at least two places selected from the plurality of places have intersection angles different from each other; and
when, in each of the observation regions, height information of the wrinkles is subjected to a frequency analysis, and a two-dimensional power spectrum F(r, θ) is obtained, wherein r represents a frequency component and θ represents an angle component,
a one-dimensional radial distribution function p(r) that is obtained by integrating the two-dimensional power spectrum F(r, θ) in a θ direction has at least one local maximum value, and
when an angular distribution q(θ) is calculated from the two-dimensional power spectrum F(r, θ) with respect to a frequency rp at which the one-dimensional radial distribution function p(r) takes the local maximum value,
a maximum value of power values in a range of θ=0° to 15° and a range of θ=165° to 180° is a power value that is 1.15 times or larger of an average value of power values in a range of θ=16° to 164°.
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