Imaging apparatus

• US 8,094,232 B2
• Filed: 11/10/2008
• Issued: 01/10/2012
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Kusaka, Yosuke
• Primary Examiner(s): Laballe, Clayton E
• Assistant Examiner(s): R., L. W.
• Application Number:
  US12/292,006
• Publication Number:
  US 20090128671A1
• Time in Patent Office: 1,156 Days
• Field of Search: 348/345, 348/349
• US Class Current: 348/349
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/672 based on the phase difference signals
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/704 Pixels specially adapted for focusing, e.g. phase difference pixel sets

Abstract

An imaging apparatus includes: an image sensor with imaging pixels and focus detection pixels arrayed on a plane, which captures an image via an optical system; and a correction unit that corrects image data output from an imaging pixel based upon output data from a focus detection pixel present near the imaging pixel.

Claims

1. An imaging apparatus, comprising:

an image sensor with imaging pixels and focus detection pixels arrayed on a plane, which captures an image via an optical system; and

a correction unit that corrects image data output from an imaging pixel based upon output data from a focus detection pixel near the imaging pixel.

2. An imaging apparatus according to claim 1, wherein:

the focus detection pixel is structurally different from the imaging pixel.

3. An imaging apparatus according to claim 2, wherein:

a photoelectric conversion element at the focus detection pixel has an areal size different from a photoelectric conversion element at the imaging pixel.

4. An imaging apparatus according to claim 2, wherein:

a photoelectric conversion element at the focus detection pixel has a shape different from a photoelectric conversion element at the imaging pixel.

5. An imaging apparatus according to claim 2, wherein:

a photoelectric conversion element at the focus detection pixel has a position different from a photoelectric conversion element at the imaging pixel.

6. An imaging apparatus according to claim 2, wherein:

the imaging pixel and the focus detection pixel each include a light condenser; and

the light condenser at the focus detection pixel is structurally different from the light condenser at the imaging pixel.

7. An imaging apparatus according to claim 1, wherein:

the focus detection pixel has spectral sensitivity characteristics different from spectral sensitivity characteristics of the imaging pixel.

8. An imaging apparatus according to claim 1, wherein:

the correction unit adjusts a correction amount based upon an areal size of a photoelectric conversion element at the focus detection pixel.

9. An imaging apparatus according to claim 1, wherein:

the correction unit adjusts a correction amount based upon an aperture opening F number of the optical system.

10. An imaging apparatus according to claim 1, wherein:

the correction unit adjusts a correction amount based upon a position of the imaging pixel on an imaging plane formed via the optical system.

11. An imaging apparatus according to claim 1, wherein:

the correction unit adjusts a correction amount based upon a distance between a photoelectric conversion element at the focus detection pixel and a photoelectric conversion element at the imaging pixel.

12. An imaging apparatus according to claim 1, wherein:

the imaging pixels include a plurality of types of imaging pixels with varying spectral sensitivity characteristics; and

the correction unit adjusts a correction amount based upon the spectral sensitivity characteristics of the imaging pixels.

13. An imaging apparatus according to claim 1, further comprising:

an interpolation unit that generates image data at a position occupied by the focus detection pixel through interpolation executed based upon image data at imaging pixels having been corrected by the correction unit.

14. An imaging apparatus according to claim 1, wherein:

the focus detection pixels include at least one photoelectric conversion element, the at least one photoelectric conversion element generates a pair of image signals corresponding to a pair of images formed with a pair of light fluxes passing through the optical system; and

the imaging apparatus further comprises a focus detection unit that detects a focusing condition of the optical system by determining a shift quantity, indicating an extent of relative offset between the pair of images, based upon the pair of image signals.

15. An imaging apparatus according to claim 14, wherein:

the focus detection pixel includes one micro lens and a pair of photoelectric conversion elements.

16. An imaging apparatus according to claim 14, wherein:

the focus detection pixels include first focus detection pixels each equipped with one micro lens and a photoelectric conversion element that receives one of the light fluxes making up the pair of light fluxes and second focus detection pixels each equipped with one micro lens and a photoelectric conversion element that receives another light flux making up the pair of light fluxes.

17. An imaging apparatus according to claim 1, wherein:

the correction unit corrects the image data output from the imaging pixel based upon the output data from the focus detection pixel near the imaging pixel and a difference of crosstalk effect between;

the imaging pixel when the imaging pixel is near another imaging pixel and

the imaging pixel when the imaging pixel is near a focus detection pixel.

18. An imaging apparatus according to claim 1, wherein:

the correction unit corrects crosstalk for image data output from an imaging pixel by assuming that all pixels are imaging pixels, and then corrects the corrected image data of an imaging pixel near a focus detection pixel, based upon data output from the focus detection pixel near the imaging pixel and a difference of crosstalk effect between;

the imaging pixel when the imaging pixel is near another imaging pixel and

the imaging pixel when the imaging pixel is near a focus detection pixel.

19. An imaging apparatus according to claim 17, wherein:

the correction unit determines a correction value by multiplying the output data from the focus detection pixel near the imaging pixel by a coefficient obtained based upon a difference of crosstalk effect between;

the imaging pixel when the imaging pixel is near another imaging pixel and

the imaging pixel when the imaging pixel is near a focus detection pixel and corrects the image data based upon the correction value.

20. An imaging apparatus, comprising:

an image sensor with imaging pixels and focus detection pixels arrayed on a plane, which captures an image via an optical system;

a correction unit that corrects image data output from an imaging pixel based upon output data from a pixel near the imaging pixel; and

an interpolation unit that generates image data at positions occupied by the focus detection pixels through interpolation executed based upon image data at the imaging pixels corrected by the correction unit.

21. A method of correcting image data, comprising:

acquiring data from an imaging pixel and output data from a focus detection pixel near the imaging pixel; and

correcting image data output from the imaging pixel based upon output data from the focus detection pixel near the imaging pixel, wherein

imaging pixels and focus detection pixels are included in an array on a plane of an image sensor that captures an image via an optical system.

22. A method of correcting image data according to claim 21, further comprising:

providing a first light condenser for the imaging pixel and a second light condenser for the focus detection pixel;

wherein the second light condenser at the focus detection pixel is structurally different from the first light condenser at the imaging pixel.

23. A method of correcting image data according to claim 21, wherein

the focus detection pixel has spectral sensitivity characteristics different from spectral sensitivity characteristics of the imaging pixel.

24. A method of correcting image data according to claim 21, wherein

the step of correcting image data comprises adjusting a correction amount based upon an areal size of a photoelectric conversion element at the focus detection pixel.

25. A method of correcting image data according to claim 21, wherein

the step of correcting image data comprises adjusting a correction amount based upon an aperture opening F number of the optical system.

26. A method of correcting image data according to claim 21, wherein

the step of correcting image data comprises adjusting a correction amount based upon a position of the imaging pixel on an imaging plane formed via the optical system.

27. A method of correcting image data according to claim 21, wherein

the step of correcting image data comprises adjusting a correction amount based upon a distance between a photoelectric conversion element at the focus detection pixel and a photoelectric conversion element at the imaging pixel.

28. A method of correcting image data according to claim 21, wherein

the imaging pixels include a plurality of types of imaging pixels with varying spectral sensitivity characteristics, and

the step of correcting image data comprises adjusting a correction amount based upon the spectral sensitivity characteristics of the imaging pixels.

29. A method of correcting image data according to claim 21, further comprising:

generating image data at a position occupied by the focus detection pixel through interpolation executed based upon image data at imaging pixels having been corrected by the step of correcting image data.

30. A method of correcting image data according to claim 21, wherein

the focus detection pixels include at least one photoelectric conversion element, the at least one photoelectric conversion element generates a pair of image signals corresponding to a pair of images formed with a pair of light fluxes passing through the optical system, and

the method further comprises detecting a focusing condition of the optical system by determining a shift quantity, indicating an extent of relative offset between the pair of images, based upon the pair of image signals.

31. A method of correcting image data according to claim 30, wherein

the focus detection pixels each include at least one micro lens and a pair of photoelectric conversion elements.

32. A method of correcting image data according to claim 30, wherein

the focus detection pixels include first focus detection pixels each including one micro lens and a photoelectric conversion element that receives one of the light fluxes making up the pair of light fluxes, and second focus detection pixels each including one micro lens and a photoelectric conversion element that receives another light flux making up the pair of light fluxes.

33. A method of correcting image data according to claim 21, wherein

the step of correcting image data corrects the image data based upon the output data output from the focus detection pixel and a difference of crosstalk effect between:

the imaging pixel when the imaging pixel is near another imaging pixel and

the imaging pixel when the imaging pixel is near a focus detection pixel.

34. A method of correcting image data according to claim 21, wherein the step of correcting image data further comprises:

correcting crosstalk for image data output from an imaging pixel by assuming that all pixels are imaging pixels; and

correcting the image data of an imaging pixel near a focus detection pixel, based upon the output data output from the focus detection pixel and a difference of crosstalk effect between;

the imaging pixel when the imaging pixel is near another imaging pixel, and

the imaging pixel when the imaging pixel is near a focus detection pixel.

35. A method of correcting image data according to claim 21, wherein the step of correcting image data comprises:

obtaining a coefficient based upon a difference of crosstalk effect between;

the imaging pixel when the imaging pixel is near another imaging pixel and

the imaging pixel when the imaging pixel is near a focus detection pixel;

determining a correction value by multiplying the output data from the focus detection pixel near the imaging pixel by a coefficient; and

correcting the image data based upon the correction value.

36. A method of correcting image data, comprising:

acquiring image data from an imaging pixel and output data from a focus detection pixel near the imaging pixel;

correcting image data output from the imaging pixel based upon output data from a pixel near the imaging pixel; and

generating image data at positions occupied by focus detection pixels through interpolation executed based upon image data at imaging pixels corrected by the step of correcting image data, wherein

imaging pixels and focus detection pixels are included in an array on a plane of an image sensor that captures an image via an optical system.