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US 2015/0146052 A1Published application
Imaging device and automatic focus adjustment method
AssigneeFUJIFILM Corporation
InventorsArito SAWADAISHI, Shu TAKAHASHI
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Abstract
The present invention utilizes color mixings with angle dependencies from adjacent R pixels, and in the case where a subject color is red, uses first and second B pixels as phase-difference pixels, allowing for an accurate phase-difference AF based on the output signals of the first and second B pixels. Here, it is unnecessary to provide phase-difference pixels dedicated to the case where the subject color is red, and the phase difference is detected using ordinary B pixels of an imaging element. Therefore, the resolution is not sacrificed.
Claims18
An imaging device comprising:
- an image-taking lens;
- an imaging element including at least red (R), green (G) and blue (B) pixels, and first and second phase-difference pixels on which subject images having passed through first and second regions are pupil-divided and are formed respectively, and having a first B pixel and a second B pixel, the first and second regions being different regions on the image-taking lens, the first B pixel being adjacent in a first direction to a first R pixel of the R pixels at a minimum pitch, the second B pixel being adjacent in a second direction to a second R pixel of the R pixels, the second direction being opposite to the first direction;
- a decision unit to decide whether a subject color in a focus detection region is a red color, based on an output signal of the focus detection region, the focus detection region being set in the imaging element;
- a phase-difference detection unit to detect a phase difference between respective output signals of the first and second phase-difference pixels in the focus detection region, based on the respective output signals, when the decision unit decides that the subject color in the focus detection region is not a red color, and to detect a phase difference between respective output signals of the first and second B pixels in the focus detection region, based on the respective output signals, when the decision unit decides that the subject color in the focus detection region is a red color;
- and
- a focus adjustment unit to adjust a focal position of the image-taking lens, based on the phase difference detected by the phase-difference detection unit.
3 more elements
An imaging device comprising:
- an image-taking lens;
- an imaging element including at least red (R), green (G) and blue (B) pixels, and first and second phase-difference pixels on which subject images having passed through first and second regions are pupil-divided and are formed respectively, and having a first B pixel and a second B pixel, the first and second regions being different regions on the image-taking lens, the first B pixel being adjacent in a first direction to a first R pixel of the R pixels at a minimum pitch, the second B pixel being adjacent in a second direction to a second R pixel of the R pixels, the second direction being opposite to the first direction, the imaging element arranging an R pixel such that the R pixel is adjacent in the first direction or the second direction to at least one phase-difference pixel of the first and second phase-difference pixels;
- a phase-difference detection unit to detect a phase difference between respective output signals of the first and second phase-difference pixels in a focus detection region, based on the respective output signals, the focus detection region being set in the imaging element;
- and
- a focus adjustment unit to adjust a focal position of the image-taking lens, based in the phase difference output by the phase-difference detection unit,
- wherein the phase-difference detection unit determines a rate of color mixing from a peripheral pixel to the at least one phase-difference pixel of the first and second phase-difference pixels, based on at least one output signal of an output signal of the first B pixel and an output signal of the second B pixel, and corrects the output signal of the at least one phase-difference pixel of the first and second phase-difference pixels, based on the determined rate of the color mixing and an output signal of the peripheral pixel.
3 more elements
An imaging device comprising:
- an image-taking lens;
- an imaging element including at least red (R), green (G) and blue (B) pixels, and first and second phase-difference pixels on which subject images having passed through first and second regions are pupil-divided and are formed respectively, and having a first B pixel and a second B pixel, the first and second regions being different regions on the image-taking lens, the first B pixel being adjacent in a first direction to a first R pixel of the R pixels at a minimum pitch, the second B pixel being adjacent in a second direction to a second R pixel of the R pixels, the second direction being opposite to the first direction, the imaging element arranging an R pixel such that the R pixel is adjacent in the first direction or the second direction to at least one phase-difference pixel of the first and second phase-difference pixels;
- a phase-difference detection unit to detect a phase difference between respective output signals of the first and second phase-difference pixels in a focus detection region, based on the respective output signals, the focus detection region being set in the imaging element;
- a defocus amount calculation unit to determine a defocus amount of the image-taking lens, based on the phase difference detected by the phase difference detection unit, and a rate of color mixing from a peripheral pixel to the at least one phase-difference pixel of the first and second phase-difference pixels;
- and
- a focus adjustment unit to move the image-taking lens to such a position that the defocus amount determined by the defocus amount calculation unit is zero,
- wherein the phase-difference detection unit determines the rate of the color mixing from the peripheral pixel, based on at least one output signal of the output signal of the first B pixel and the output signal of the second B pixel.
4 more elements
An automatic focus adjustment method comprising:
- a signal acquisition step of acquiring an output signal from an imaging element, the imaging element including at least red (R), green (G) and blue (B) pixels, and first and second phase-difference pixels on which subject images having passed through first and second regions are pupil-divided and are formed respectively, and having a first B pixel and a second B pixel, the first and second regions being different regions on an image-taking lens, the first B pixel being adjacent in a first direction to a first R pixel of the R pixels at a minimum pitch, the second B pixel being adjacent in a second direction to a second R pixel of the R pixels, the second direction being opposite to the first direction;
- a decision step of deciding whether a subject color in a focus detection region is a red color, based on an output signal of the focus detection region, the focus detection region being set in the imaging element, the output signal of the focus detection region being of the output signal acquired in the signal acquisition step;
- a phase-difference detection step of detecting a phase difference between respective output signals of the first and second phase-difference pixels in the focus detection region, based on the respective output signals, when a decision that the subject color in the focus detection region is not a red color is made in the decision step, and detecting a phase difference between respective output signals of the first and second B pixels in the focus detection region, based on the respective output signals, when a decision that the subject color in the focus detection region is a red color is made in the decision step;
- and
- a focus adjustment step of adjusting a focal position of the image-taking lens, based on the phase difference detected in the phase-difference detection step.
2 more elements
Dependencies are inferred from the claim text.