SOLID-STATE IMAGING DEVICE

• US 20130105666A1
• Filed: 12/20/2012
• Published: 05/02/2013
• Est. Priority Date: 07/01/2010
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: SAITOU, Shigeru, ONOZAWA, Kazutoshi
• Granted Patent: US 8,872,091 B2
• Time in Patent Office: Days
• US Class Current: 250/208.1
• CPC Class Codes: G02B 27/44 Grating systems; Zone plate systems G02B27/46 takes precedence
• CPC Class Codes: G02B 3/0043 Inhomogeneous or irregular arrays, e.g. varying shape, size, height
• CPC Class Codes: G02B 5/1819 Plural gratings positioned on the same surface, e.g. array of gratings plural diffractive elements positioned sequentially along the optical path G02B27/4272
• CPC Class Codes: G02B 5/188 Plurality of such optical elements formed in or on a supporting substrate
• CPC Class Codes: H01L 27/146 Imager structures
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14629 Reflectors
• CPC Class Codes: H04N 1/0306 using a plurality of optical elements arrayed in the main scan direction, e.g. an array of lenses

Abstract

The solid-state imaging device includes light collecting elements each of which includes a first light-transmissive film group and a second light transmissive film group adjacent to each other. The first light-transmissive film group and the second light transmissive film group have mutually different effective refractive index distributions for guiding at least two types of incident light rays to the light receiving element.

Claims

1. A solid-state imaging device which performs imaging using light incident on an imaging region formed on a flat surface, the solid-state imaging device comprising

a plurality of unit pixels arranged two-dimensionally in the imaging region, and each of the plurality of unit pixels including:

a light receiving element; and

a light collecting element for guiding incident light to the light receiving element,

wherein the light collecting element included in at least one of the plurality of unit pixels is a multi-structural light collecting element which includes a first light-transmissive film group and a second light-transmissive film group arranged adjacent to each other,

each of the first light-transmissive film group and the second light-transmissive film group includes a plurality of light-transmissive films each of which has a shape of an arc concentric about a center axis perpendicular to the imaging region,

the first light-transmissive film group and the second light-transmissive film group have mutually different effective refractive index distributions for guiding at least two types of incident light rays which make up the incident light to the light receiving element,

the first light-transmissive film group and the second light-transmissive film group share a boundary which is a straight line, and

the boundary is orthogonal to a line which connects a center point of the imaging region and a center point of the unit pixel including the multi-structural light collecting element.

2. The solid-state imaging device according to claim 1,

wherein the first light-transmissive film group is closer to the center point of the imaging region than the second light-transmissive film group, and

the second light-transmissive film group has a light refractive index higher than a light refractive index of the first light-transmissive film group.

3. The solid-state imaging device according to claim 2,

wherein the unit pixel including the multi-structural light collecting element is disposed, in the imaging region, at a part other than a center part of the imaging region.

4. The solid-state imaging device according to claim 3,

wherein a position of the boundary in the multi-structural light collecting element varies depending on a distance from the center point of the imaging region to the unit pixel including the multi-structural light collecting element, and

the position of the boundary in the multi-structural light collecting element is closer to the center point of the unit pixel including the multi-structural light collecting element when the position of the unit pixel including the multi-structural light collecting element is closer to a marginal part of the imaging region.

5. The solid-state imaging device according to claim 4,

wherein each of the light-transmissive films has the shape of the concentric arc having a width smaller than or equal to a wavelength of incident light.

6. The solid-state imaging device according to claim 5,

wherein a center axis of the first light-transmissive film group and a center axis of the second light-transmissive film group are different from each other.

7. The solid-state imaging device according to claim 6,

wherein, when the unit pixel including the multi-structural light collecting element is disposed in the marginal part of the imaging region, the boundary in the multi-structural light collecting element passes through the center point of the unit pixel including the multi-structural light collecting element.

8. The solid-state imaging device according to claim 7,

wherein the multi-structural light collecting element is a gradient index lens.

9. The solid-state imaging device according to claim 1,

wherein the unit pixel including the multi-structural light collecting element is disposed, in the imaging region, at a part other than a center part of the imaging region.

10. The solid-state imaging device according to claim 1,

wherein a position of the boundary in the multi-structural light collecting element varies depending on a distance from the center point of the imaging region to the unit pixel including the multi-structural light collecting element, and

the position of the boundary in the multi-structural light collecting element is closer to the center point of the unit pixel including the multi-structural light collecting element when the position of the unit pixel including the multi-structural light collecting element is closer to a marginal part of the imaging region.

11. The solid-state imaging device according to claim 1,

wherein each of the light-transmissive films has the shape of the concentric arc having a width smaller than or equal to a wavelength of incident light.

12. The solid-state imaging device according to claim 1,

wherein a center axis of the first light-transmissive film group and a center axis of the second light-transmissive film group are different from each other.

13. The solid-state imaging device according to claim 1,

wherein, when the unit pixel including the multi-structural light collecting element is disposed in the marginal part of the imaging region, the boundary in the multi-structural light collecting element passes through the center point of the unit pixel including the multi-structural light collecting element.

14. The solid-state imaging device according to claim 1,

wherein the multi-structural light collecting element is a gradient index lens.