Imaging device and focus detection method
An imaging device of the present invention comprises a focus detection section using phase difference detection based on output of the focus detection pixels, a pixel adding section, for creating respective first addition outputs by adding outputs of a first number of focus detection pixels, and creating respective second addition outputs by dividing the first number of arrays into a plurality, and adding outputs of focus detection pixels of the divided array, and a determination section for determining whether or not to correct an angle error, wherein the focus detection section executes a focus detection operation on the basis of the first addition outputs, the determination section determines whether or not to correct angle error on the basis of the plurality of second addition outputs, and in the event that the determination section has determined to correct angle error, the focus detection section corrects angle error based on a result of a focus detection operation.
1. An imaging device, having an image sensor that is provided with a plurality of pixels having photoelectric conversion sections for converting an optical image that has been formed by an imaging optical system into electrical signals, including focus detection pixels, formed so as to restrict an incident direction of light flux that is incident on the pixels, and imaging pixels, formed so as not to restrict light flux incident on the pixels as much as the focus detection pixels, the plurality of pixels being arrayed two-dimensionally, comprising:
a focus detection section for detecting an out of focus amount and an out of focus direction by carrying out a focus detection operation using phase difference detection based on output of the focus detection pixels;
a pixel adding section, for creating respective first addition outputs by adding outputs of a first number of focus detection pixels that are arranged in a direction that is perpendicular to a detection direction for the phase difference detection, for a plurality of regions arranged in the detection direction for phase difference detection of an imaging region of the image sensor, and creating respective second addition outputs in a direction that is perpendicular to the phase difference detection direction by adding outputs of a second number of focus detection pixels that is smaller than the first number, arranged in a direction perpendicular to the phase difference detection direction, for a plurality of regions arranged in the detection direction for phase difference detection; and
a determination section for determining whether or not to correct an angle error arising as a result of inclination of an optical image with respect to the pixel array direction, wherein
the focus detection section executes a focus detection operation on the basis of the first addition outputs corresponding to the plurality of regions,
the determination section determines whether or not to correct angle error on the basis of the plurality of second addition outputs corresponding to the plurality of regions, and
in the event that the determination section has determined to correct angle error, the focus detection section corrects angle error based on a result of a focus detection operation.
2. The imaging device of claim 1 , wherein
the second number is ⅓ or less of the first number.
3. The imaging device of claim 1 , wherein
the focus detection section calculates a correction amount for the angle error and performs correction by calculating a degree of correlation between a plurality of second addition outputs for a direction perpendicular to the phase difference detection direction.
4. The imaging device of claim 3 , wherein:
the focus detection section calculates a plurality of degrees of correlation in accordance with a plurality of different combinations of the plurality of second addition outputs, and
the determination section determines to correct angle error if the plurality of degrees of correlation satisfy specified conditions.
5. An imaging device, having an image sensor that is provided with a plurality of pixels having photoelectric conversion sections for converting an optical image that has been formed by an imaging optical system into electrical signals, including focus detection pixels, formed so as to restrict an incident direction of light flux that is incident on the pixels, and imaging pixels, formed so as not to restrict light flux incident on the pixels as much as the focus detection pixels, the plurality of pixels being arrayed two-dimensionally, comprising:
a focus detection section for detecting an out of focus amount and an out of focus direction by carrying out a focus detection operation using phase difference detection based on output of the focus detection pixels;
a pixel adding section, for creating respective first addition outputs by adding outputs of a first number of focus detection pixels that are arranged in a direction that is perpendicular to a detection direction for the phase difference detection, for a plurality of regions arranged in the phase difference detection direction of an imaging region of the image sensor, and creating respective second addition outputs in a direction that is perpendicular to the phase difference detection direction by dividing the first number of arrays, that are arrayed in a direction perpendicular to the phase difference detection direction, into a plurality, and adding outputs of focus detection pixels of the divided array, for a plurality of regions arranged in the detection direction for phase difference detection; and
a determination section for determining whether or not to correct an angle error arising as a result of inclination of an optical image with respect to the pixel array direction, wherein
the focus detection section executes a focus detection operation on the basis of the first addition outputs corresponding to the plurality of regions,
the determination section determines whether or not to correct angle error on the basis of the plurality of second addition outputs corresponding to the plurality of regions, and
in the event that the determination section has determined to correct angle error, the focus detection section corrects angle error based on a result of a focus detection operation.
6. The imaging device of claim 5 , wherein:
the division of the pixel adding section is preferably three or more.
7. The imaging device of claim 5 , wherein:
the focus detection section calculates a correction amount for the angle error and performs correction by calculating a degree of correlation between a plurality of second addition outputs for a direction perpendicular to the phase difference detection direction.
8. The imaging device of claim 7 , wherein:
the focus detection section calculates a plurality of degrees of correlation in accordance with a plurality of different combinations of the plurality of second addition outputs, and
the determination section determines to correct angle error if the plurality of degrees of correlation satisfy specified conditions.
9. A focus detection method, for controlling a focus detection operation of an imaging device having an image sensor that is provided with a plurality of pixels having photoelectric conversion sections for converting an optical image that has been formed by an imaging optical system into electrical signals, including focus detection pixels, formed so as to restrict an incident direction of light flux that is incident on the pixels, and imaging pixels, formed so as not to restrict light flux incident on the pixels as much as the focus detection pixels, the plurality of pixels being arrayed two-dimensionally, comprising:
detecting an out of focus amount and an out of focus direction by carrying out a focus detection operation using phase difference detection based on output of the focus detection pixels;
creating respective first addition outputs by adding outputs of a first number of focus detection pixels that are arranged in a direction that is perpendicular to a detection direction for the phase difference detection, for a plurality of regions arranged in the detection phase difference detection direction of an imaging region of the image sensor;
creating respective second addition outputs in a direction that is perpendicular to the phase difference detection direction by adding outputs of a second number of focus detection pixels that is smaller than the first number, arranged in a direction perpendicular to the phase difference detection direction, for a plurality of regions arranged in the detection direction for phase difference detection;
executing a focus detection operation on the basis of the first addition outputs corresponding to the plurality of regions; and
determining whether or not to correct angle error, arising as a result of inclination of an optical image with respect to the pixel array direction, on the basis of the plurality of second addition outputs corresponding to the plurality of regions, and, in the event that it is determined to correct angle error, correcting angle error for a result of the focus detection operation.
10. The focus detection method of claim 9 , wherein:
the second number is ⅓ or less of the first number.
11. The focus detection method of claim 9 , wherein: a correction amount for the angle error is calculated, and angle error corrected, by calculating a degree of correlation between a plurality of second addition outputs for a direction perpendicular to the phase difference detection direction.
12. The focus detection method of claim 11 , wherein:
a plurality of degrees of correlation are calculated in accordance with a plurality of different combinations of the plurality of second addition outputs, and
if the plurality of degrees of correlation satisfy predetermined conditions, it is determined to correct angle error.
13. A focus detection method, for an imaging device having an image sensor that is provided with a plurality of pixels having photoelectric conversion sections for converting an optical image that has been formed by an imaging optical system into electrical signals, including focus detection pixels, formed so as to restrict an incident direction of light flux that is incident on the pixels, and imaging pixels, formed so as not to restrict light flux incident on the pixels as much as the focus detection pixels, the plurality of pixels being arrayed two-dimensionally, comprising:
detecting an out of focus amount and an out of focus direction by carrying out a focus detection operation using phase difference detection based on output of the focus detection pixels;
creating respective first addition outputs by adding outputs of a first number of focus detection pixels that are arranged in a direction that is perpendicular to the phase difference detection direction, for a plurality of regions arranged in the detection phase difference detection direction an imaging region of the image sensor;
creating respective second addition outputs in a direction that is perpendicular to the phase difference detection direction by dividing the first number of arrays, that are arrayed in a direction perpendicular to the phase difference detection direction, into a plurality, and adding outputs of focus detection pixels of the divided array for a plurality of regions arranged in the detection phase difference detection direction
executing a focus detection operation on the basis of the first addition outputs corresponding to the plurality of regions; and
determining whether or not to correct angle error, arising as a result of inclination of an optical image with respect to the pixel array direction, on the basis of the plurality of second addition outputs corresponding to the plurality of regions, and, in the event that it is determined to correct angle error, correcting angle error for a result of the focus detection operation.
14. The focus detection method of claim 13 , wherein:
the division of the pixel adding section is preferably three or more.
15. The focus detection method of claim 13 , wherein:
a correction amount for the angle error is calculated, and angle error corrected, by calculating a degree of correlation between a plurality of second addition outputs for a direction perpendicular to the phase difference detection direction.
16. The focus adjustment method of claim 15 , wherein
a plurality of degrees of correlation are calculated in accordance with a plurality of different combinations of the plurality of second addition outputs, and
if the plurality of degrees of correlation satisfy predetermined conditions, it is determined to correct angle error.