SOLID-STATE IMAGING DEVICE

Abstract

The present invention provides a solid-state imaging device which compensates a field curvature which occurs due to an aberration of the optical imaging system and surely receive light incident with a wide angle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings that illustrate a specific embodiment of the invention. In the Drawings:

FIG. 1 is a diagram showing a cross section structure of a solid-state imaging device according to a first embodiment;

FIG. 2 is a diagram showing a brief overview of a solid-state imaging device and an optical imaging system according to the first embodiment;

FIG. 3 is a diagram showing a brief overview of a light-transmitting film with the first effective refractive index distribution, a light-transmitting film with the second effective refractive index distribution, and light-collecting element on the solid-state imaging device configured of the light-transmitting films;

FIG. 4 is a diagram showing how a light-collecting element according to the first embodiment is arranged in two dimensions;

FIG. 5 is a top plan view of light-transmitting film with the first effective refractive index distribution according to the first embodiment;

FIG. 6 is a diagram showing a cross section structure of light-transmitting film with the first effective refractive index distribution according to the first embodiment;

FIGS. 7A to 7C are diagrams, each of which shows the first effective refractive index distribution according to the first embodiment;

FIG. 8 is a diagram showing an embodiment in which an inner layer lens made of refractive index material [SiN (n=1.95)] is used as the light-transmitting film with the second effective refractive index distribution according to the first embodiment;

FIG. 9 is a diagram showing an overview of a solid-state imaging device and an optical imaging system in the case where a inner layer lens is used as the light-transmitting film with the second effective refractive index distribution according to the first embodiment;

FIG. 10 is a diagram showing a top plan view of a light-transmitting film with the first effective refractive index distribution according to a second embodiment;

FIG. 11 is a diagram showing effective refractive index distribution of a light-transmitting film with the first effective refractive index distribution according to the second embodiment;

FIG. 12 is a diagram showing a bias incidence property in a solid-state imaging device according to the second embodiment;

FIG. 13 is a diagram showing a cross-section structure of a solid-state imaging device according to a third embodiment; and

FIG. 14 is a diagram showing a cross-section structure of a solid-state imaging apparatus according to a fourth embodiment.

Claims

1. A solid-state imaging device comprising a plurality of unit pixels, wherein each of said unit pixels includes a light-collecting unit operable to collect incident light from an optical imaging system, anda focal length or an angular magnification of said light-collecting unit varies from unit pixel to unit pixel so that an aberration of the optical imaging system is corrected.

2. The solid-state imaging device according to claim 1, wherein the further said unit pixel is located from the center of the solid-state imaging device, the longer a focal length of said light collecting unit becomes.

3. The solid-state imaging device according to claim 1, wherein the further said unit pixel is located from the center of the solid-state imaging device, the larger a angular magnification of said light collecting unit becomes.

4. The solid-state imaging device according to claim 1, wherein said light-collecting unit includes at least a light-transmitting film with a first refractive index distribution and a light-transmitting film with a second refractive index distribution.

5. The solid-state imaging device according to claim 4, wherein the light-transmitting film with the first refractive index distribution has an effective refractive index distribution which is determined by a light-transmitting film partially forming the light-transmitting film.

6. The solid-state imaging device according to claim 5, wherein the effective refractive index distribution is asymmetric to the center of said unit pixel.

7. The solid-state imaging device according to claim 4, wherein the focal point of the light-transmitting film with the second refractive index distribution is constant on a surface of the solid-state imaging device.

8. The solid-state imaging device according to claim 4, wherein said light-collecting unit further includes a light-transmitting film with a third refractive index distribution between the light-transmitting film with the first refractive index distribution and the light-transmitting film with the second refractive index distribution.

9. The solid-state imaging device according to claim 4, wherein said unit pixel further includes a wavelength selection filter which selects a light of predetermined wavelength, andsaid light-collecting unit has a refractive index distribution adapted to the light selected by said wavelength selection filter.

10. The solid-state imaging device according to claim 9, wherein said wavelength selection filter is placed between the light-transmitting film with the first refractive index distribution and the light-transmitting film with the second refractive index distribution.

11. A camera comprising a solid-state imaging device in which a plurality of unit pixels are placed, wherein each of said unit pixels includes a light-collecting unit operable to collect incident light from an optical imaging system, anda focal length or an angular magnification of said light-collecting unit varies from unit pixel to unit pixel so that an aberration of the optical imaging system is corrected.