Electrophotographic apparatus and electrophotographic photosensitive member

摘要

An electrophotographic apparatus and an electrophotographic photosensitive member for use in the electrophotographic apparatus are provided. The number of intermediate layers between a photoconductive layer and a surface layer is an odd number more than 2, and the refractive index monotonically decreases from the photoconductive layer toward the surface layer. The refractive index of an odd-numbered intermediate layer is in a predetermined range of the geometrical mean of the refractive indices of the two layers adjacent to the odd-numbered intermediate layer, and the product of the refractive index and the thickness is in a specific range of an odd multiple of λ/4n. The sum of the products of the refractive indices and the thicknesses of one or more intermediate layers disposed between at least two odd-numbered intermediate layers is in a range of −π/2<θ<π/2 in the terms of phases.

主权项

1. 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 n0 is a refractive index of the photoconductive layer, n1 is a refractive index of a first intermediate layer counting from the photoconductive layer side, ni 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, nN is a refractive index of an Nth intermediate layer counting from the photoconductive layer side, nN+1 is a refractive index of the surface layer, and di is a thickness [μm] of the ith intermediate layer, the refractive indices n0, n1, ni, nN, and nN+1 satisfy the following expression (1):
n0>n1> . . . >ni> . . . >nN>nN+1  (1) wherein, for each of odd-numbered intermediate layers counting from the photoconductive layer side, ni−1 being the refractive index n0 of the photoconductive layer when i is 1 and ni+1 being the refractive index nN+1 of the surface layer when i is N, the refractive index ni satisfies the following expression (2):ni-ni-1⁣·ni+1ni≤0.02(2) wherein, for each of the odd-numbered intermediate layers counting from the photoconductive layer side, there exists pi for enabling the refractive index ni and the thickness di [μm], pi being a positive integer, to satisfy the following expression (3):4⁢⁢π·ni·diλ-(2·pi-1)⁢π≤π16(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 (ni·di) of the refractive indices ni and the thicknesses di [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·∑ni·diλ-2⁢⁢π·q<π2.(4)