ELECTROPHOTOGRAPHIC ROLLER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS

The electrophotographic roller has a surface layer comprising an electro-conductive elastic layer on an electro-conductive substrate. The opening of a bowl-shaped resin particle is exposed on the surface of the electrophotographic roller. The number of contact portions of the convex portion with the glass plate in a square region where a length of a nip in a direction along the circumferential direction of the electrophotographic roller of a nip formed by pressing the roller on the glass plate with a specific load applied as the length of one side and is located at any position in the nip is 8 or more. The average value of the areas of the contact portions is 10 µm 2 to 111 µm 2 . The variation coefficient of the areas of the contact portions and the variation coefficient D of the areas of a plurality of Voronoi regions each including a contact portion satisfy specific relationships.