阅读说明：本技术 检测设备、检测方法和摄像设备 (Detection apparatus, detection method, and image pickup apparatus ) 是由 福田浩一 稻垣优 于 2019-06-21 设计创作，主要内容包括：本发明提供一种检测设备、检测方法和摄像设备。该检测设备包括：生成单元,其被配置为通过使用由像素获取到的像素信号来生成与不同光瞳区域相对应的多个相应的焦点检测信号；以及检测单元,其被配置为基于多个焦点检测信号来计算图像偏差量并根据图像偏差量和转换系数来检测出散焦量。检测单元基于图像传感器的光瞳偏心量、图像传感器的入射光瞳距离和与成像光学系统中的多个框有关的开口信息来计算所述转换系数。(The invention provides a detection apparatus, a detection method, and an image pickup apparatus. The detection apparatus includes: a generation unit configured to generate a plurality of respective focus detection signals corresponding to different pupil areas by using pixel signals acquired by the pixels; and a detection unit configured to calculate an image deviation amount based on the plurality of focus detection signals and detect a defocus amount from the image deviation amount and the conversion coefficient. The detection unit calculates the conversion coefficient based on an amount of pupil decentering of the image sensor, an entrance pupil distance of the image sensor, and opening information about a plurality of frames in the imaging optical system.)

1. A detection apparatus, comprising:

a controller having a processor for executing instructions stored in a memory, the controller configured to function as:

a generation unit configured to generate a plurality of respective focus detection signals corresponding to different pupil areas of an imaging optical system by using an image sensor including an array of a plurality of pixels configured to receive light having passed through the different pupil areas and pixel signals acquired with the pixels; and

a detection unit configured to detect a defocus amount from an image deviation amount calculated from the plurality of focus detection signals and a conversion coefficient based on opening information on a plurality of frames forming the pupil area in the imaging optical system.

2. The detection apparatus according to claim 1, wherein the detection unit calculates the conversion coefficient based on an amount of pupil decentering of the image sensor, an entrance pupil distance of the image sensor, and opening information about the plurality of frames in the imaging optical system.

3. The detection apparatus according to claim 2, wherein the detection unit determines a pupil portion area based on the pupil decentering amount, an entrance pupil distance of the image sensor, and opening information about the plurality of frames in the imaging optical system, and calculates the conversion coefficient based on the pupil portion area.

4. The detection apparatus according to claim 2 or 3, wherein the pupil decentration comprises a deviation of the image sensor during production.

5. The detection apparatus according to claim 1, further comprising an acquisition unit configured to acquire the pixel signal from the array of the plurality of pixels in the image sensor under a predetermined acquisition condition,

wherein the detection unit calculates the conversion coefficient based on the acquisition condition.

6. The detection apparatus according to claim 1, wherein the opening information about the plurality of frames in the imaging optical system is determined based on centers and radii of the plurality of frames included in the imaging optical system.

7. The detection apparatus according to claim 6, wherein the opening information includes an aperture frame included in the imaging optical system.

8. The detection apparatus according to claim 6, wherein the opening information includes information on a plurality of frames having different radii or curvatures.

9. The detection apparatus according to claim 6, wherein the detection unit calculates the conversion coefficient based on a distance between centers of the plurality of frames.

10. The detection apparatus according to claim 1, further comprising a storage unit configured to store the conversion coefficient calculated based on an amount of pupil decentration of the image sensor, an entrance pupil distance of the image sensor, and opening information on the plurality of frames in the imaging optical system.

11. The detection apparatus according to claim 1, further comprising a storage unit configured to store coefficients in a case where the conversion coefficient is expressed as a function of opening information on the plurality of frames in the imaging optical system,

wherein the detection unit calculates the conversion coefficient by using the coefficient.

12. The detection apparatus according to claim 1, wherein the detection unit calculates the conversion coefficient from a rotation angle corresponding to an image height of the image sensor.

13. The detection apparatus according to claim 12, wherein a range of the rotation angle is limited based on symmetry of light reception sensitivity characteristics of the image sensor.

14. The detection apparatus according to claim 13, wherein the detection unit sets a virtual defocus amount under a plurality of conditions, generates a plurality of respective virtual focus detection signals corresponding to the different pupil areas, calculates a plurality of virtual image deviation amounts from correlation amounts of the plurality of virtual focus detection signals, and calculates the conversion coefficient based on the plurality of virtual image deviation amounts and the virtual defocus amount.

15. An image pickup apparatus includes:

the detection apparatus according to any one of claims 1 to 12; and

a control unit configured to control the imaging optical system,

wherein the control unit controls a focus position of the imaging optical system based on the detected defocus amount.

16. An image pickup apparatus includes:

the detection device of claim 1;

a mounting portion detachably mounted to the imaging optical system; and

a communication unit configured to communicate with the imaging optical system via the mount portion,

wherein the communication unit communicates at a timing of acquiring the image signal or at a predetermined period of time, and acquires opening information on the plurality of frames in the imaging optical system through the imaging optical system.

17. An image pickup apparatus including a lens unit configured to perform focus adjustment based on an amount of image deviation in a pixel signal from an image sensor included in a camera body, the image pickup apparatus further comprising:

a memory configured to store opening information on a plurality of frames for calculating a conversion coefficient for converting the image deviation amount into a defocus amount; and

a transmission unit configured to transmit opening information on the plurality of frames to calculate the defocus amount in the camera body.

18. An image pickup apparatus for calculating a defocus amount based on a pixel signal obtained by photoelectrically converting light having passed through different pupil areas in an imaging optical system, comprising:

a generation unit configured to generate a plurality of respective focus detection signals corresponding to the different pupil areas based on the pixel signals; and

a calculation unit configured to calculate the defocus amount from a detected image deviation amount based on the generated plurality of focus detection signals and a conversion coefficient,

wherein the calculation unit generates a plurality of respective virtual focus detection signals corresponding to the different pupil areas by setting a virtual defocus amount, calculates a virtual image deviation amount from a correlation amount of the virtual focus detection signals, and determines the conversion coefficient based on the virtual image deviation amount and the virtual defocus amount.

19. A detection method for performing focus detection using pixel signals obtained by photoelectrically converting light having passed through different pupil areas of an imaging optical system, the detection method comprising:

acquiring the pixel signal;

generating a plurality of respective focus detection signals corresponding to the different pupil areas by using the pixel signals; and

performing focus detection by calculating a detection image deviation amount based on the plurality of focus detection signals and detecting a detection defocus amount from the detection image deviation amount and a conversion coefficient,

wherein performing focus detection comprises:

generating a plurality of respective virtual focus detection signals corresponding to the different pupil areas by setting a virtual defocus amount;

calculating a virtual image offset amount according to the correlation amount of the virtual focus detection signal; and

calculating the conversion coefficient based on the virtual image deviation amount and the virtual defocus amount.

Technical Field

Background

Heretofore, there has been known an image pickup apparatus that performs focus detection of an image pickup lens by a phase difference detection method using a two-dimensional layout image sensor having a structure in which microlenses are formed in each pixel.

Japanese patent laid-open No. 2000-156823 discusses an image pickup apparatus having a structure in which a pair of focus detection pixels are partially arranged in a two-dimensional layout image sensor composed of a plurality of pixels. The pair of focus detection pixels receive light from different regions of an exit pupil of the imaging lens via a light shielding layer including an opening portion, and perform pupil division. Specifically, an image pickup signal is acquired by image pickup pixels arranged in most of the two-dimensional layout image sensor, and an image deviation amount is obtained based on a focus detection signal from focus detection pixels arranged in a part of the two-dimensional layout image sensor, thereby performing focus detection.

In addition, japanese patent laid-open No. 2015-11283 discusses an image pickup apparatus as follows: an effective aperture value corresponding to the image height is calculated from a reference aperture value at the central image height of the optical system, and a conversion coefficient for converting the image deviation amount into the defocus amount is calculated by using the calculated effective aperture value. Even if lens frame vignetting occurs due to a plurality of lens frames and aperture frames and the effective aperture value changes from lens to lens, the effective aperture value can be used to calculate the conversion coefficient.

Disclosure of Invention

According to an aspect of an embodiment, a detection apparatus includes: an image sensor including an array of a plurality of pixels configured to receive light that has passed through different pupil areas in an imaging optical system; a generation unit configured to generate a plurality of respective focus detection signals corresponding to different pupil areas by using pixel signals acquired by the pixels; and a detection unit configured to calculate an image deviation amount based on the plurality of focus detection signals and detect a defocus amount from the image deviation amount and the conversion coefficient. The detection unit calculates a conversion coefficient based on an amount of pupil decentering of the image sensor, an entrance pupil distance of the image sensor, and opening information about a plurality of frames in the imaging optical system.

According to an aspect of the embodiment, an image pickup apparatus includes: the detection device; and a control unit configured to control the imaging optical system, wherein the control unit controls a focal position of the imaging optical system based on the detected defocus amount.

According to an aspect of the embodiment, an image pickup apparatus includes: the detection device; a mounting portion detachably mounted to the imaging optical system; and a communication unit configured to communicate with the imaging optical system via the mount, wherein the communication unit communicates at a timing of acquiring an image signal or for a predetermined period of time, and acquires opening information about the plurality of frames in the imaging optical system through the imaging optical system.

According to an aspect of the embodiment, an image pickup apparatus includes a lens unit configured to perform focus adjustment based on an image deviation amount in a pixel signal from an image sensor included in a camera body, the image pickup apparatus further including: a memory configured to store opening information on a plurality of frames for calculating a conversion coefficient for converting the image deviation amount into a defocus amount; and a transmission unit configured to transmit opening information on the plurality of frames to calculate the defocus amount in the camera body.

According to an aspect of the embodiment, an image pickup apparatus for calculating a defocus amount based on a pixel signal obtained by photoelectrically converting light having passed through different pupil areas in an imaging optical system, includes: a generation unit configured to generate a plurality of respective focus detection signals corresponding to the different pupil areas based on the pixel signals; and a calculation unit configured to calculate the defocus amount from a detection image deviation amount based on the generated plurality of focus detection signals and a conversion coefficient, wherein the calculation unit generates a plurality of corresponding virtual focus detection signals corresponding to the different pupil regions by setting a virtual defocus amount, calculates a virtual image deviation amount from a correlation amount of the virtual focus detection signals, and determines the conversion coefficient based on the virtual image deviation amount and the virtual defocus amount.

According to an aspect of the embodiment, a detection method for performing focus detection using pixel signals obtained by photoelectrically converting light having passed through different pupil areas of an imaging optical system, includes: acquiring the pixel signal; generating a plurality of respective focus detection signals corresponding to the different pupil areas by using the pixel signals; and performing focus detection by calculating a detection image deviation amount based on the plurality of focus detection signals and detecting a detection defocus amount from the detection image deviation amount and a conversion coefficient, wherein performing focus detection includes: generating a plurality of respective virtual focus detection signals corresponding to the different pupil areas by setting a virtual defocus amount; calculating a virtual image offset amount according to the correlation amount of the virtual focus detection signal; and calculating the conversion coefficient based on the virtual image deviation amount and the virtual defocus amount.

Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Drawings

Fig. 1 is a block diagram illustrating the configuration of an image capturing apparatus including a focus detection apparatus according to a first exemplary embodiment.

Fig. 2 shows a pixel array according to a first exemplary embodiment.

Fig. 3A is a plan view of a pixel structure according to the first exemplary embodiment, and fig. 3B is a cross-sectional view of the pixel structure according to the first exemplary embodiment.

Fig. 4 illustrates a correspondence relationship between pixels and pupil intensity distributions of the image sensor according to the first exemplary embodiment.

Fig. 5 shows the correspondence between the image sensor and the pupil intensity distribution according to the first exemplary embodiment.

Fig. 6 illustrates pupil division in the imaging optical system and the image sensor according to the first exemplary embodiment.

Fig. 7A and 7B are sectional views each showing a light intensity distribution when light is incident on a microlens formed in each pixel according to the first exemplary embodiment.

Fig. 8 shows a pupil partial area according to the first exemplary embodiment.

Fig. 9 is a relational diagram showing a relationship between a defocus amount and an image deviation amount according to the first exemplary embodiment.

Fig. 10 illustrates a correspondence relationship between the image sensor and the pupil intensity distribution when pupil decentering or a change in the entrance pupil distance occurs according to the first exemplary embodiment.

Fig. 11 is a relationship diagram showing a relationship among a sensor entrance pupil, an amount of pupil decentering and an entrance pupil distance, lens frame vignetting in an imaging optical system, and a pupil partial area of an image sensor according to the first exemplary embodiment.

Fig. 12 is a relational diagram showing the relationship among the sensor entrance pupil, the pupil decentering amount and the entrance pupil distance, the lens frame vignetting in the imaging optical system, and the pupil partial area of the image sensor according to the first exemplary embodiment.

Fig. 13 is a flowchart illustrating a focus detection method according to the first exemplary embodiment.

Fig. 14 is a relational diagram showing lens frame vignetting in the imaging optical system according to the first exemplary embodiment.

Fig. 15 is a flowchart showing a conversion coefficient calculation method according to the first exemplary embodiment.

Fig. 16 illustrates a method for generating a virtual focus detection signal according to the first exemplary embodiment.

Fig. 17 shows a variation example of the virtual pupil intensity distribution according to the first exemplary embodiment.

Fig. 18 shows a pixel array according to a second exemplary embodiment.

Fig. 19A is a plan view of a pixel structure according to the second exemplary embodiment, and fig. 19B is a sectional view of the pixel structure according to the second exemplary embodiment.

Fig. 20A and 20B each schematically show a lens frame vignetting state according to the third exemplary embodiment.

Fig. 21A, 21B, 21C, and 21D each schematically show a lens frame vignetting state at each image height according to the third exemplary embodiment.

Fig. 22 is a flowchart showing conversion coefficient calculation according to the third exemplary embodiment.

Fig. 23 is a schematic relational diagram showing the center position and the size of each aperture information at the pupil distance of the image sensor according to each exemplary embodiment.

Fig. 24 is a flowchart showing conversion coefficient calculation according to the fourth exemplary embodiment.

Fig. 25 is a flowchart showing conversion coefficient calculation according to the fifth exemplary embodiment.

Aspects of the embodiments relate to a detection apparatus for detecting a distance.