Phase difference detection device, imaging apparatus, phase difference detection method
AssigneeCanon Kabushiki Kaisha
InventorMakoto Oikawa
Life of this patent
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Abstract
The ratio between an image A and an image B is calculated as the comparison result of the images A and B obtained from a pair of optical images. The variance is then calculated in order to evaluate the statistical fluctuation of the ratio obtained for each pixel. The fluctuation due to the variance is evaluated for each phase difference while the phase between the image A and the image B is shifted. The phase difference detection is performed on the basis of the evaluation result of the fluctuation.
Claims14
A phase difference detection device comprising:
- a photoelectric conversion unit in which a plurality of pixels for photoelectrically converting received light are arrayed,
- the photoelectric conversion unit being configured to photoelectrically convert at least a pair of optical images received through a lens so as to generate a first image signal and a second image signal;
- and
- a phase difference detection unit comprising:
- unit for obtaining first and second image signals from each of at least two pixel positions in the photoelectric conversion unit,
- comparison unit for comparing the first image signal with the second image signal for each pixel position,
- fluctuation calculation unit for calculating a fluctuation of first and second image signals,
- unit for comparing the calculated fluctuation over a range of pixel positions to obtain a resultant first image signal and a resultant second image signal, and
- phase difference calculation unit for calculating a phase difference between the resultant first and second image signals in order to enable the determination of a focus state of the lens on the basis of the calculated fluctuation.
A phase difference detection method for a phase difference detection device comprising a photoelectric conversion unit in which a plurality of pixels for photoelectrically converting received light are arrayed, the method comprising:
- obtaining first and second image signals from each of at least two pixel positions;
- comparing the first image signal with the second image signal for each pixel position,
- calculating a fluctuation of first and second image signals,
- comparing the calculated fluctuation over a range of pixel positions to obtain a resultant first image signal and a resultant second image signal, and
- calculating a phase difference between the resultant first and second image signals in order to enable the determination of a focus state of the lens on the basis of the calculated fluctuation.
Dependencies are inferred from the claim text.