Patent ID: 7078753

Claim:
An image sensor comprising: a plurality of photoelectric conversion portions each of which photoelectrically converts an object image formed by a photographing lens; a high refractive index portion which is placed on each of said plurality of photoelectric conversion portions to cover at least part of said photoelectric conversion portion, and includes a first portion positioned near said photoelectric conversion portion and formed into a shape of a square pillar or column having a substantially uniform thickness, and a second portion formed contiguously with said first portion and having a taper shape whose aperture area increases from a side close to said photoelectric conversion portion to a side close to said photographing lens; and a low refractive index portion placed around said high refractive index portion, and having a refractive index lower than that of said high refractive index portion, wherein letting x 1 be an aperture width on a side at which the aperture area of said taper shape is large, x 2 be an aperture width on a side at which the aperture area of the taper shape is small, θ° be an inclination angle of the taper shape, n 1 be the refractive index of said high refractive index portion, n 2 be the refractive index of said low refractive index portion, F be an F number of said photographing lens, R be a distance from a center of an optical axis of said photographing lens to said photoelectric conversion portion, and f be a distance from a position of a pupil of said photographing lens to an imaging plane in which said plurality of photoelectric conversion portions are arranged, said high refractive index portion is formed into a shape which satisfies relations represented by 1 >x 2 /x 1≧(1−tan θ/tan θ′)/(1+tan θ/tan θ′) cos θ′≧ n 2 /n 1 where θ′=θ0′+2θ and sin θ0′=½n 1 F+R/n 1 f.