Electrophotographic rotating member and electrophotographic image forming apparatus

An electrophotographic image forming apparatus, comprising:

• an image bearing member bearing a toner image;
• a movable intermediate transfer member onto which the toner image is transferred from the image bearing member;
• and
• an optical sensor which irradiates the intermediate transfer member with light and detects reflected light, wherein
• on an outer surface of the intermediate transfer member, there exist
• a plurality of grooves which extend in the movement direction of the intermediate transfer member and which are formed to be regularly aligned in a direction orthogonal to the movement direction of the intermediate transfer member, and
• a plurality of depressions irregularly arranged,
• average spacing of the plurality of grooves is 2.0 to 10.0 μm,
• the depressions exist so as to notch walls sandwiching the grooves so that a part of the walls form an arc shape when viewed from an outer surface side of the intermediate transfer member,
• when drawing circles based on the arc shape of the walls notched by the depressions,
• an average diameter of the circles is 0.5 to 4.5 μm,
• an average value of distances of closest approach between centers of the plurality of drawn circles is greater than the average diameter of the circles and is not more than 10.0 μm, and
• assuming there is no notch formed by the depressions, the walls extend in the movement direction of the intermediate transfer member so as to maintain a width of the grooves constant.