Patent ID: 8771908

Claim:
An electrophotographic apparatus comprising: an electrophotographic photosensitive member including a photoconductive layer, a surface layer, and N intermediate layers disposed between the photoconductive layer and the surface layer, N being an odd number more than 2; and an image exposure apparatus for irradiating a surface of the electrophotographic photosensitive member with an image exposure beam having a central wavelength of λ [μm] and forming a latent image on the surface, wherein, where n 0 is a refractive index of the photoconductive layer, n 1 is a refractive index of a first intermediate layer counting from the photoconductive layer side, n i is a refractive index of an ith intermediate layer counting from the photoconductive layer side, i being an integer equal to or more than 1 and equal to or less than N, n N is a refractive index of an Nth intermediate layer counting from the photoconductive layer side, n N+1 is a refractive index of the surface layer, and d i is a thickness [μm] of the ith intermediate layer, the refractive indices n 0 , n 1 , n i , n N , and n N+1 satisfy the following expression (1): n 0 >n 1 > . . . >n i > . . . >n N >n N+1 (1) wherein, for each of odd-numbered intermediate layers counting from the photoconductive layer side, n i−1 being the refractive index n 0 of the photoconductive layer when i is 1 and n i+1 being the refractive index n N+1 of the surface layer when i is N, the refractive index n i satisfies the following expression (2):  n i - n i - 1 ⁣ · n i + 1 n i  ≤ 0.02 ( 2 ) wherein, for each of the odd-numbered intermediate layers counting from the photoconductive layer side, there exists p i for enabling the refractive index n i and the thickness d i [μm], p i being a positive integer, to satisfy the following expression (3):  4 ⁢ ⁢ π · n i · d i λ - ( 2 · p i - 1 ) ⁢ π  ≤ π 16 ( 3 ) wherein, among combinations in which two intermediate layers are selected from the odd-numbered layers counting from the photoconductive layer side, there exists at least one combination at which q for enabling the sum of the products (n i ·d i ) of the refractive indices n i and the thicknesses d i [μm] of one or more intermediate layers disposed between selected two intermediate layers, q being an integer equal to or more than 0, to satisfy the following expression (4):  4 ⁢ ⁢ π · ∑ n i · d i λ - 2 ⁢ ⁢ π · q  < π 2 . ( 4 )