Patent attributes
An electrophotographic photosensitive member superior in dot reproducibility and a process cartridge and an process cartridge having the electrophotographic photosensitive member are provided. Where in a light attenuation curve drawn in a way in which the surface of the electrophotographic photosensitive member is so charged that intensity of an electric field is 15 (V/μm) to establish the surface potential of the electrophotographic photosensitive member into a given value E(V) and then exposed to light under conditions that the electrophotographic photosensitive member has a surface potential of 0.8 E(V) at a time point T(ms) passes after exposure starts, the inclination of the light attenuation curve at a time point T(ms) passes after exposure starts is represented by m, and in a dark-time surface potential attenuation curve drawn in a way in which the surface of the electrophotographic photosensitive member is charged under conditions that the electrophotographic photosensitive member has a surface potential of 0.8 E(V) at a time point T(ms) passes after charging is finished and thereafter no exposure is performed, the inclination of the dark-time surface potential attenuation curve at a time point T(ms) passes after charging is finished is represented by m′, the m and m′ satisfy |m−m′|≦0.020, provided that T=[{d2/(μ×E)}×100]×10−5, where d is the layer thickness (μm) of the charge transport layer and μ is the drift mobility [cm2/(V·s)] of the charge transport layer.