Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

A process cartridge integrally supporting an electrophotographic photosensitive member and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, and a cleaning unit, the process cartridge being detachably attachable with respect to a main body of an electrophotographic apparatus,

• wherein the electrophotographic photosensitive member includes a cylindrical support, a charge generating layer formed on the cylindrical support, and a charge transport layer formed on the charge generating layer,
• in the charge generating layer, when a region from a central position of an image forming region to an end position of the image forming region in an axis direction of the cylindrical support is divided equally into five regions, and average values of film thicknesses [μm] of the charge generating layers in each of the regions obtained by being divided equally are respectively defined as d11, d12, d13, d14, and d15 in order from the central position of the image forming region toward the end position of the image forming region, the film thickness of the charge generating layer satisfies a relationship of d11<d12<d13<d14<d15, and
• in the charge transport layer, when a region from the central position of the image forming region to the end position of the image forming region in the axis direction of the cylindrical support is divided equally into five regions, and average values of film thicknesses [μm] of the charge transport layers in each of the regions obtained by being divided equally are respectively defined as d21, d22, d23, d24, and d25 in order from the central position of the image forming region toward the end position of the image forming region, the film thickness of the charge transport layer satisfies a relationship of d21>d22>d23>d24>d25.

An electrophotographic apparatus, comprising:

• an electrophotographic photosensitive member;
• a charging unit;
• an exposing unit;
• a developing unit;
• and
• a transfer unit,
• wherein the electrophotographic photosensitive member includes a cylindrical support, a charge generating layer formed on the cylindrical support, and a charge transport layer formed on the charge generating layer,
• in the charge generating layer, when a region from a central position of an image forming region to an end position of the image forming region in an axis direction of the cylindrical support is divided equally into five regions, and average values of film thicknesses [μm] of the charge generating layers in each of the regions obtained by being divided equally are respectively defined as d11, d12, d13, d14, and d15 in order from the central position of the image forming region toward the end position of the image forming region, the film thickness of the charge generating layer satisfies a relationship of d11<d12<d13<d14<d15, and
• in the charge transport layer, when a region from the central position of the image forming region to the end position of the image forming region in the axis direction of the cylindrical support is divided equally into five regions, and average values of film thicknesses [μm] of the charge transport layers in each of the regions obtained by being divided equally are respectively defined as d21, d22, d23, d24, and d25 in order from the central position of the image forming region toward the end position of the image forming region, the film thickness of the charge transport layer satisfies a relationship of d21>d22>d23>d24>d25.