Image sensor with improved light sensitivity

• US 20070177236A1
• Filed: 01/27/2006
• Published: 08/02/2007
• Est. Priority Date: 01/27/2006
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Eastman Kodak Company
• Inventors: Nakamura, Hideo, Hamilton, John, Kijima, Takayuki, Compton, John
• Granted Patent: US 7,688,368 B2
• Time in Patent Office: Days
• US Class Current: 358/514
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/133 including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements

Abstract

An image sensor for capturing a color image is disclosed having a two-dimensional array having first and second groups of pixels, arranged in rows and columns, wherein pixels from the first group of pixels have narrower spectral photoresponses than pixels from the second group of pixels; and the placement of the first and second groups of pixels defining a pattern that has a minimal repeating unit including at least six pixels, so that at least some rows or columns of the minimal repeating unit are composed only of pixels from the second group and some rows or columns of the minimal repeating unit are composed only of pixels from the first group, wherein the rows or columns that are composed only of pixels from the first group are composed of at most two colors of pixels from the first group.

Claims

1. An image sensor for capturing a color image, comprising:

a) a two-dimensional array having first and second groups of pixels, arranged in rows and columns, wherein pixels from the first group of pixels have narrower spectral photoresponses than pixels from the second group of pixels and wherein the first group of pixels has pixels that have spectral photoresponses that correspond to a set of at least two colors; and

b) the placement of the first and second groups of pixels defining a pattern that has a minimal repeating unit including at least six pixels, so that at least some rows or columns of the minimal repeating unit are composed only of pixels from the second group and some rows or columns of the minimal repeating unit are composed only of pixels from the first group, wherein the rows or columns that are composed only of pixels from the first group are composed of at most two colors of pixels from the first group

2. The image sensor of claim 1 having the following minimal repeating unit:

3. The image sensor of claim 1 wherein each row or column of a minimal repeating unit is composed only of pixels from either the first group or the second group of pixels.

4. The image sensor of claim 3 wherein the minimal repeating unit of the image sensor is

5. The image sensor of claim 3 wherein the minimal repeating unit of the image sensor is

6. The image sensor of claim 3 having the following minimal repeating unit:

7. The image sensor of claim 3 wherein the minimal repeating unit of the image sensor is

8. The image sensor of claim 3 having the following minimal repeating unit:

9. The image sensor of claim 3 wherein the minimal repeating unit of the image sensor is

10. An image sensor for capturing a color image, comprising:

a) a two-dimensional array having first and second groups of pixels, arranged in rows and columns, wherein pixels from the first group of pixels have narrower spectral photoresponses than pixels from the second group of pixels and wherein the first group of pixels has pixels that have spectral photoresponses that correspond to a set of at least two colors;

b) the placement of the first and second groups of pixels defining a pattern that has a minimal repeating unit including at least six pixels, so that at least some rows or columns of the minimal repeating unit are composed only of pixels from the second group, and

c) means for combining some pixels of like color from at least two adjacent minimal repeating units.

11. The image sensor of claim 10 wherein at least some rows or columns of a minimal repeating unit are composed only of pixels from the first group.

12. The image sensor of claim 11 wherein each row or column of a minimal repeating unit is composed only of pixels from either the first group or the second group of pixels.

13. The image sensor of claim 12 wherein each row or column of a minimal repeating unit containing pixels from the first group also include pixels of at least two different colors.

14. The image sensor of claim 13 having the following minimal repeating unit:

15. The image sensor of claim 13 wherein the minimal repeating unit of the image sensor is

16. The image sensor of claim 13 having the following minimal repeating unit:

17. The image sensor of claim 13 wherein the minimal repeating unit of the image sensor is

18. The image sensor of claim 13 having the following minimal repeating unit:

19. The image sensor of claim 13 having the following minimal repeating unit:

20. The image sensor of claim 13 wherein the minimal repeating unit of the image sensor is

21. The image sensor of claim 13 wherein the minimal repeating unit of the image sensor is

22. The image sensor of claim 10 further including means for combining some of the pixels of the second group.

23. The image sensor of claim 10 wherein the second group of pixels comprise no more than half of the pixels in a minimal repeating unit.

24. The image sensor of claim 10 wherein the second group of pixels comprise no less than half of the pixels in a minimal repeating unit.

25. An image sensor for capturing a color image, comprising:

a) a two-dimensional array having first and second groups of pixels wherein pixels from the first group of pixels have narrower spectral photoresponses than pixels from the second group of pixels and wherein the first group of pixels has individual pixels that have spectral photoresponses that correspond to a set of at least two colors;

b) the placement of the first and second groups of pixels defining a pattern that has a minimal repeating unit including at least twelve pixels, the minimal repeating unit having a plurality of cells wherein each cell has at least two pixels representing a specific color selected from the first group of pixels and a plurality of pixels selected from the second group of pixels arranged to permit the reproduction of a captured color image under different lighting conditions; and

c) means for combining some pixels of like color from at least two adjacent minimal repeating units.

26. The image sensor of claim 25 further including means for combining some pixels of the second group.