IMAGE CAPTURING APPARATUS AND FOCUS DETECTION METHOD
First Claim
1. An image capturing apparatus comprising:
- an image sensor including a plurality of two-dimensionally arranged pixels including pixels each having a pair of photoelectric conversion units arranged to output a pair of image signals obtained by independently receiving a pair of light beams that have passed through different exit pupil regions of an imaging optical system;
a first filter formed from a summation filter;
a second filter formed from the summation filter and a differential filter;
an acquisition unit arranged to acquire an f-number of the imaging optical system;
a filtering unit arranged to perform filtering of the pair of image signals by selecting the first filter when the f-number is less than a predetermined threshold and selecting the second filter when the f-number is not less than the threshold; and
a focus detection unit arranged to perform focus detection by a phase difference method based on the pair of image signals that have undergone the filtering by the filtering unit.
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Accused Products
Abstract
An image capturing apparatus performs focus detection based on a pair of image signals obtained from an image sensor including pixels each having a pair of photoelectric conversion units capable of outputting the pair of image signals obtained by independently receiving a pair of light beams that have passed through different exit pupil regions of an imaging optical system. In the focus detection, an f-number of the imaging optical system is acquired, the pair of image signals undergo filtering using a first filter formed from an summation filter when the f-number is less than a predetermined threshold, or using a second filter formed from the summation filter and a differential filter when the f-number is not less than the threshold, and focus detection is performed by a phase difference method based on the pair of filtered image signals.
33 Citations
8 Claims
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1. An image capturing apparatus comprising:
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an image sensor including a plurality of two-dimensionally arranged pixels including pixels each having a pair of photoelectric conversion units arranged to output a pair of image signals obtained by independently receiving a pair of light beams that have passed through different exit pupil regions of an imaging optical system; a first filter formed from a summation filter; a second filter formed from the summation filter and a differential filter; an acquisition unit arranged to acquire an f-number of the imaging optical system; a filtering unit arranged to perform filtering of the pair of image signals by selecting the first filter when the f-number is less than a predetermined threshold and selecting the second filter when the f-number is not less than the threshold; and a focus detection unit arranged to perform focus detection by a phase difference method based on the pair of image signals that have undergone the filtering by the filtering unit. - View Dependent Claims (2, 3)
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4. An image capturing apparatus comprising:
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an image sensor including a plurality of two-dimensionally arranged pixels including pixels each having a pair of photoelectric conversion units arranged to output a pair of image signals obtained by independently receiving a pair of light beams that have passed through different exit pupil regions of an imaging optical system; a first filter formed from a summation filter; a second filter formed from the summation filter and a differential filter; an acquisition unit arranged to acquire an f-number of the imaging optical system and a pupil distance of the imaging optical system; a filtering unit arranged to evaluate an effect of vignetting based on the f-number and the pupil distance, and to perform filtering of the pair of image signals by selecting the first filter when the effect of vignetting is more than a predetermined threshold and selecting the second filter when the effect of vignetting is not more than the threshold; and a focus detection unit arranged to perform focus detection by a phase difference method based on the pair of image signals that have undergone filtering by the filtering unit. - View Dependent Claims (5, 6)
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7. A focus detection method of performing focus detection based on a pair of image signals obtained from an image sensor including a plurality of two-dimensionally arranged pixels including pixels each having a pair of photoelectric conversion units capable of outputting the pair of image signals obtained by independently receiving a pair of light beams that have passed through different exit pupil regions of an imaging optical system, the method comprising:
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an acquisition step of acquiring an f-number of the imaging optical system; a filtering step of performing filtering of the pair of image signals using a first filter formed from a summation filter when the f-number is less than a predetermined threshold, and performing filtering of the pair of image signals using a second filter formed from the summation filter and a differential filter when the f-number is not less than the threshold; and a focus detection step of performing focus detection by a phase difference method based on the pair of image signals that have undergone the filtering in the filtering step.
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8. A focus detection method of performing focus detection based on a pair of image signals obtained from an image sensor including a plurality of two-dimensionally arranged pixels including pixels each having a pair of photoelectric conversion units capable of outputting the pair of image signals obtained by independently receiving a pair of light beams that have passed through different exit pupil regions of an imaging optical system, the method comprising:
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an acquisition step of acquiring an f-number and a pupil distance of the imaging optical system; an evaluation step of evaluating an effect of vignetting based on the f-number and the pupil distance; a filtering step of performing filtering of the pair of image signals using a first filter formed from a summation filter when the effect of vignetting is more than a predetermined threshold, and performing filtering of the pair of image signals using a second filter formed from the summation filter and a differential filter when the effect of vignetting is not more than the threshold; and a focus detection step of performing focus detection by a phase difference method based on the pair of image signals that have undergone the filtering in the filtering step.
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Specification