WO2015198879A1 - Image pickup apparatus, focus control method, and program - Google Patents

Abstract

　The present technique pertains to an image pickup device, a focus control method, and a program, with which highly accurate focusing can be achieved at faster focusing speeds. An image pickup unit is provided with pixels for pickup of a picked up image, as well as with phase difference detection pixels for detecting phase difference. A phase difference detection processor performs phase difference detection on the basis of the output of the phase difference detection pixels, and computes a defocus level for the image pickup lens. In the event that phase difference detection is not possible, an aperture controller changes the aperture value of the image pickup lens to a larger value, and the phase difference detection processor again performs phase difference detection. In so doing, highly accurate focusing can be achieved at faster focusing speed. The present technology may be applied to a digital still camera.

Description

Imaging apparatus, focus control method, and program

The present technology relates to an imaging apparatus, a focusing control method, and a program, and more particularly, to an imaging apparatus, a focusing control method, and a program that are capable of focusing with higher accuracy at a faster focusing speed.

Conventionally, when performing autofocus control (automatic focus control), the amount of phase shift between two image signals obtained by pupil division is obtained, and focusing is performed by driving the focus lens based on the amount of shift. A phase difference type focusing control is known (see, for example, Patent Document 1 and Patent Document 2).

As a method for realizing such a phase difference method, for example, a method using a sensor dedicated to phase difference AF (Autofocus), and a method using an image sensor provided with a pixel for capturing a captured image and a phase difference detection pixel ( Hereinafter, it is referred to as an imaging surface phase difference method in particular.

JP 2013-37143 A JP2013-54120A

In the case of a so-called single-lens reflex camera that has a phase difference AF dedicated sensor and a mirror mechanism that is different from the image sensor for the captured image, the aperture of the imaging lens during focusing control is opened and only for phase difference AF The light beam incident on the sensor is limited to have a constant light beam thickness between the mirror mechanism and the phase difference AF dedicated sensor. For this reason, when focus control is performed using a phase difference AF dedicated sensor, the phase difference detection accuracy hardly changes depending on the F value (aperture value) of the imaging lens.

On the other hand, in the case of the imaging surface phase difference method, the F value (aperture value) differs for each imaging lens, so the phase difference detection accuracy varies greatly depending on the aperture state of the imaging lens.

For example, the smaller the F-number of the imaging lens, that is, the brighter the imaging lens, the longer the baseline length that is important in phase difference detection, so the phase difference detection accuracy on the imaging surface is improved. Conversely, the larger the F value of the imaging lens, that is, the darker the imaging lens, the shorter the baseline length, and therefore the phase difference detection accuracy on the imaging surface decreases. Thus, in the phase difference method, focusing accuracy is higher when phase difference detection is performed with a bright (small) F value.

However, if the F value is decreased, the depth of field becomes shallower, so that the image on the imaging surface becomes large and easily blurred, and the output waveform of the phase difference detection pixel collapses and phase difference detection cannot be performed in many cases. In this regard, in the method using the phase difference AF dedicated sensor, the thickness of the light beam is limited so that the light beam is thinned to some extent on the optical path in order to prevent such a large blurred state.

As described above, in the imaging surface phase difference method, phase difference detection may be disabled when the subject image is greatly blurred, such as when the F value of the imaging lens is small. In such a case, there is a technique in which focus control is performed by switching to another method different from the imaging surface phase difference method, but it takes time to focus.

The present technology has been made in view of such a situation, and makes it possible to focus with high accuracy at a faster focusing speed.

An imaging apparatus according to one aspect of the present technology includes a phase difference detection processing unit that performs phase difference detection based on an output from a phase difference detection pixel provided in the imaging unit, and the phase difference detection by the phase difference detection processing unit. When it is difficult, an aperture control unit that changes the aperture value to a larger value is provided.

The aperture control unit can change the aperture value to a predetermined value when the phase difference detection is difficult.

The aperture control unit can change the aperture value step by step whenever it is determined that the phase difference detection is difficult.

When the phase difference detection is difficult, the phase difference detection processing unit can change the detection characteristics in the phase difference detection.

When the phase difference detection is difficult, the aperture control unit can change the aperture value, and the phase difference detection processing unit can change the detection characteristics.

The phase difference detection processing unit can change the detection characteristics when it is determined that the phase difference detection is difficult in the phase difference detection performed by changing the aperture value.

The phase difference detection processing unit can change the filter processing applied to the output from the phase difference detection pixel as the detection characteristic.

The imaging apparatus may further include a focusing control unit that drives the imaging lens based on the result of the phase difference detection and performs focusing control.

When the aperture value is changed and the phase difference detection is performed again, the aperture control unit returns the aperture value to the value before the change after the focus control by the focus control unit. be able to.

When it is determined that the phase difference detection is difficult in the phase difference detection performed by changing the aperture value, the focus control unit performs the phase difference detection by the phase difference detection processing unit. Focus control can be performed by a method different from the method using the result.

A focus control method or program according to one aspect of the present technology performs phase difference detection based on an output from a phase difference detection pixel provided in an imaging unit, and if the phase difference detection is difficult, an aperture value is set. Including changing to a larger value.

When the phase difference detection is difficult, the aperture value can be changed to a predetermined value.

Each time the phase difference detection is determined to be difficult, the aperture value can be changed step by step.

When the phase difference detection is difficult, the detection characteristic in the phase difference detection can be changed.

When the phase difference detection is difficult, the aperture value can be changed and the detection characteristics can be changed.

In one aspect of the present technology, the phase difference detection is performed based on the output from the phase difference detection pixel provided in the imaging unit, and when the phase difference detection is difficult, the aperture value is changed to a larger value. Is done.

According to one aspect of the present technology, it is possible to focus with higher accuracy at a faster focusing speed.

Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a figure which shows the structural example of an imaging device. It is a figure which shows the pixel arrangement example in the imaging surface of an imaging part. It is a figure explaining the setting of the blur amount and F value of a detection limit. It is a flowchart explaining a focusing process. It is a flowchart explaining a focusing process. It is a flowchart explaining a focusing process. It is a flowchart explaining a focusing process. It is a flowchart explaining a focusing process. It is a flowchart explaining a focusing process. It is a figure which shows the structural example of an imaging device. It is a figure which shows the structural example of a computer.

Hereinafter, embodiments to which the present technology is applied will be described with reference to the drawings.

<First Embodiment>
<Configuration example of imaging device>
FIG. 1 is a diagram illustrating a configuration example of an embodiment of an imaging apparatus to which the present technology is applied.

The imaging device 11 is composed of an electronic device having a photographing function such as a digital still camera or a digital video camera.

The imaging device 11 includes an imaging lens 21, an imaging unit 22, a signal processing unit 23, a control unit 24, an input unit 25, a display unit 26, a recording unit 27, an aperture driving unit 28, and a lens driving unit 29.

The imaging lens 21 is composed of one or a plurality of lenses and the like, and collects the light incident from the subject and forms an image on the imaging surface of the imaging unit 22. The imaging lens 21 is provided with at least a focus lens 41 for focus control and a diaphragm 42 for adjusting the amount of light passing through the imaging lens 21.

The imaging lens 21 may be detachable from the imaging device 11 or may be fixed to the imaging device 11.

The imaging unit 22 is composed of an imaging element such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, for example. The imaging unit 22 receives light incident from a subject via the imaging lens 21 and photoelectrically converts the captured image to obtain a signal. This is supplied to the processing unit 23.

In addition, the imaging unit 22 includes a phase difference detection pixel used for phase difference detection, in addition to the pixel for capturing a captured image. The imaging unit 22 receives light from the subject. The phase difference detection signal obtained by photoelectric conversion is supplied to the signal processing unit 23.

The signal processing unit 23 performs predetermined signal processing on the image signal of the captured image and the phase difference detection signal supplied from the imaging unit 22 and supplies them to the control unit 24. For example, the signal processing unit 23 performs demosaic processing, gamma correction processing, and the like on the image signal of the captured image.

The control unit 24 controls the operation of the entire imaging apparatus 11. The control unit 24 includes a phase difference detection processing unit 51, a contrast detection processing unit 52, a focusing control unit 53, and an aperture control unit 54.

The phase difference detection processing unit 51 performs phase difference detection processing based on the phase difference detection signal supplied from the signal processing unit 23, and obtains the defocus amount of the focus lens 41. The defocus amount indicates the distance between the imaging position of the light from the subject to be focused by the imaging lens 21 and the imaging surface of the imaging unit 22, that is, the deviation amount of the imaging position with respect to the imaging surface.

The contrast detection processing unit 52 performs detection processing by a contrast method based on the captured image supplied from the signal processing unit 23, and calculates a contrast evaluation value.

The focusing control unit 53 uses the lens driving unit 29 based on the defocus amount obtained as a result of the detection processing by the phase difference detection processing unit 51 or the evaluation value obtained as a result of the detection processing by the contrast detection processing unit 52. By controlling this, focusing control of the focus lens 41 is performed. That is, the focus control unit 53 calculates the movement amount of the focus lens 41 based on the defocus amount or the evaluation value, and controls the lens driving unit 29 based on the movement amount to move the focus lens 41.

The aperture control unit 54 controls the aperture 42. That is, the aperture control unit 54 determines an appropriate F value (aperture value), and controls the aperture drive unit 28 based on the F value to adjust the aperture amount (opening degree) of the aperture 42.

The input unit 25 includes various buttons such as a shutter button and a power button, and supplies a signal corresponding to a user operation to the control unit 24. The display unit 26 includes a liquid crystal display panel, for example, and displays an image supplied from the control unit 24.

The recording unit 27 includes, for example, a recording medium that can be attached to and detached from the imaging device 11, and records images such as a captured image supplied from the control unit 24 and various types of information, and also records images that are recorded as required. Information is supplied to the control unit 24.

The aperture driving unit 28 drives the aperture 42 according to the control of the aperture control unit 54, and adjusts the aperture amount of the aperture 42, that is, the amount of light passing through the aperture 42 (imaging lens 21). The lens driving unit 29 moves the focus lens 41 so that the subject is focused according to the control of the focusing control unit 53.

<Pixel arrangement example of imaging unit>
In addition, on the imaging surface of the imaging unit 22 illustrated in FIG. 1, for example, as illustrated in FIG. 2, pixels for captured images (for imaging) and phase difference detection pixels are provided.

In FIG. 2, one square represents one pixel, and each pixel with R, G, and B characters in the square has R (red), G (green), and B (blue) colors. A pixel is shown. In this example, the pixel arrangement on the imaging surface is an arrangement in which pixels of each color of R, G, and B are arranged in a Bayer arrangement, and a part of the B pixels arranged in the Bayer arrangement is replaced with a phase difference detection pixel. Yes.

The opening of each phase difference detection pixel is provided with a biased opening on the left or right side in the figure. For example, the phase difference detection pixels GR11 to GR13 are provided with openings at positions shifted to the right in the drawing from the centers of the phase difference detection pixels. These phase difference detection pixels GR11 to GR13 receive light beams (light rays) that have passed through the left half of the exit pupil of the imaging lens 21.

Hereinafter, a phase difference detection pixel provided with an opening biased on the right side, such as the phase difference detection pixel GR11 to the phase difference detection pixel GR13, is also referred to as a right opening phase difference detection pixel. The phase difference detection signal output from is also referred to as a right aperture phase difference detection signal.

For example, the phase difference detection pixels GL11 to GL13 are provided with openings at positions shifted to the left in the figure from the centers of the phase difference detection pixels. These phase difference detection pixels GL11 to phase difference detection pixel GL13 receive light beams (light rays) that have passed through the right half of the exit pupil of the imaging lens 21.

Hereinafter, a phase difference detection pixel provided with an opening biased on the left side, such as the phase difference detection pixel GL11 to the phase difference detection pixel GL13, is also referred to as a left opening phase difference detection pixel, and the left opening phase difference detection pixel. The phase difference detection signal output from is also referred to as a left aperture phase difference detection signal.

The phase difference detection processing unit 51 compares the right opening phase difference detection signal and the left opening phase difference detection signal, and detects the phase difference (waveform deviation amount) of these phase difference detection signals, thereby the focus lens. A defocus amount of 41 is calculated. In other words, by detecting the amount of deviation between the subject position on the image captured by the right aperture phase difference detection pixel and the subject position on the image captured by the left aperture phase difference detection pixel, the focus lens 41 A defocus amount is calculated.

<About aperture control>
By the way, when the imaging device 11 performs focus control by the imaging surface phase difference method using the phase difference detection pixels provided in the imaging unit 22, when the phase difference detection is impossible, the F value of the diaphragm 42 is set. The phase difference is detected again with a larger value, and focusing control is performed.

At this time, what value should be used for the F value of the diaphragm 42 can be estimated in advance based on the amount of blur at the detection limit. Here, the blur amount at the detection limit is the blur amount on the imaging surface of the imaging unit 22 of the image of the subject to be focused, which is formed by the imaging lens 21, and the defocus amount is calculated by the phase difference method. The maximum amount of blur possible. The amount of blur at the detection limit is determined by detection characteristics of phase difference detection, for example, filter characteristics of filter processing for waveform shaping performed on the phase difference detection signal at the time of phase difference detection.

For example, a state where the F value of the diaphragm 42 is 1.4 (F1.4) as shown by an arrow A11 in FIG. 3 and a state where the F value of the diaphragm 42 is 5.6 (F5.6) as shown by an arrow A12. Compare. In FIG. 3, the focus lens 41 is located at a position where the blur amount of the subject image on the imaging surface IM11 becomes the blur limit of the detection limit in the state of F1.4 and the state of F5.6.

Further, the points P11 and P12 indicate the positions of the optical images formed by the focus lens 41 (imaging lens 21), respectively. In this example, the point P11 indicating the imaging position when the F value is smaller, F1.4, is lighter than the point P12 indicating the imaging position when the F value is larger, F5.6. It is located closer to the imaging surface IM11 in the axial direction.

Therefore, as the F value increases, the subject image blur amount does not reach the detection limit blur amount unless the focus lens 41 is moved greatly from the state where the subject image is formed on the imaging surface IM11. I understand. In other words, it can be seen that the larger the F value, the wider the range of the position of the focus lens 41 in which phase difference detection is possible, that is, the distance measurement possible range.

The amount of blur at the detection limit is constant regardless of the F value, and the range in which the focus lens 41 can move, that is, the drivable range is predetermined. Therefore, from the blur amount at the detection limit and the driveable range of the focus lens 41, when the focus control is performed by the imaging surface phase difference method, the F value useful for large defocusing, that is, even when the defocus amount is large, is ensured. It is possible to specify an F value capable of phase difference detection.

Specifically, from the relationship between the focal length of the focus lens 41 and the blurring amount of the detection limit, the range in which the focus lens 41 can measure the range where phase difference detection is possible is obtained for each F value.

For example, as indicated by an arrow A13, the range in which the focus lens 41 can be measured is obtained for each F value with respect to the range in which the focus lens 41 can be driven.

Here, the arrow Q11 indicates the driveable range of the focus lens 41, the arrow Q12 indicates the range in which the focus lens 41 can detect the phase difference in the case of F1.4, and the arrow Q13 indicates F5. The range in which the phase difference can be detected by the focus lens 41 in the case of .6 is shown.

For example, in the diagram of the drivable range indicated by the arrow Q11, the left end indicates the position of the focus lens 41 when the focus position of the imaging lens 21 is infinite, that is, the position of the infinite end. Further, in the diagram of the drivable range indicated by the arrow Q11, the right end is the position of the near end that is the position of the focus lens 41 when the focus position of the imaging lens 21 is closest to the front, that is, the imaging apparatus 11 side. Is shown.

In this example, the distance measurement possible range at F1.4 indicated by the arrow Q12 is a partial range of the drivable range indicated by the arrow Q11, whereas F5.6 indicated by the arrow Q13. The distance measurement possible range at that time is a range including the entire driveable range indicated by the arrow Q11.

Therefore, for example, when the F value is 1.4 or the like and phase difference detection is impossible at the time of focusing control by the imaging surface phase difference method, if the F value is changed to 5.6, phase difference detection should be possible.

Therefore, when it is determined that the phase difference detection is impossible, the imaging apparatus 11 can detect (range) reliably even when the defocus amount is large, so that the F value of the aperture 42 is set to a predetermined F value. Change (aperture value) and perform phase difference detection again. As a result, when focusing control is performed using the imaging plane phase difference method, the subject can be focused with high accuracy at a faster focusing speed.

When changing the F value at the time of phase difference detection, the focusable range is not limited to the F value including the entire driveable range of the focus lens 41, and the focus speed and focus accuracy are taken into consideration. What is necessary is just to change to the optimal F value.

In the following description, it is assumed that when it is determined that phase difference detection is impossible, the F value is changed and phase difference detection is performed again. However, phase difference detection is not completely impossible, and there is a possibility that phase difference detection can be performed, but if it is determined that phase difference detection is difficult, such as the possibility is not high, the F value is changed, The phase difference detection may be performed again. In the present embodiment, the fact that phase difference detection is difficult includes the case where phase difference detection is completely impossible.

<Description of focus processing>
Next, a specific operation of the imaging device 11 will be described.

For example, when the user operates the power button as the input unit 25 to turn on the power to capture a captured image, the imaging device 11 displays a live view image (through image) on the display unit 26.

That is, the imaging lens 21 forms an image of light incident from the subject on the imaging surface of the imaging unit 22, and the imaging unit 22, that is, a pixel for capturing a captured image receives the light incident from the imaging lens 21. The photoelectric conversion is performed, and an image obtained as a result is supplied to the control unit 24 via the signal processing unit 23. At this time, the signal processing unit 23 appropriately performs signal processing such as demosaic processing on the image.

The control unit 24 supplies the image supplied from the signal processing unit 23 to the display unit 26 and displays it as a live view image. The user performs a shooting operation while viewing the live view image displayed on the display unit 26 and confirming the angle of view and the like.

When the user tries to focus on a desired subject during shooting, when the shutter button as the input unit 25 is pressed halfway, the imaging device 11 performs a focusing operation in accordance with the user's operation, and focuses on the subject. Start processing. Hereinafter, the focusing process performed by the imaging apparatus 11 will be described with reference to the flowchart of FIG.

In step S11, the aperture controller 54 designates the F value (aperture value) for capturing a captured image as the F value of the aperture 42.

For example, when the program auto in which the imaging apparatus 11 automatically sets appropriate exposure, F value, shutter speed, and the like without depending on the user's operation is selected as the shooting mode, the control unit 24 sets the conditions of the shooting environment. Determine the exposure, F value, and shutter speed from the above. The aperture control unit 54 designates the F value determined by the control unit 24 as an F value for photographing the aperture 42.

Further, for example, when the aperture priority auto in which the user specifies the F value of the aperture 42 is selected as the shooting mode, the aperture control unit 54 sets the F value specified by the user operating the input unit 25 to the aperture value. Designated as an F-number for shooting 42.

In step S12, the diaphragm control unit 54 controls the driving of the diaphragm 42 so that the diaphragm amount of the diaphragm 42 becomes the diaphragm amount corresponding to the designated F value.

That is, the aperture control unit 54 controls the aperture drive unit 28 based on the designated F value, and the aperture drive unit 28 drives the aperture 42 according to the control of the aperture control unit 54 to change the aperture amount. For example, when the process proceeds from step S11 to step S12 and the diaphragm 42 is driven, the driving of the diaphragm 42 is controlled based on the F value designated in the process of step S11.

In step S13, the phase difference detection processing unit 51 performs phase difference detection.

Specifically, the phase difference detection pixel of the imaging unit 22 receives light incident from the subject via the imaging lens 21 and performs photoelectric conversion, and a phase difference detection signal obtained as a result is transmitted via the signal processing unit 23. To the control unit 24.

The phase difference detection processing unit 51 performs filter processing on the phase difference detection signal supplied from the signal processing unit 23 using a detection filter that shapes the waveform of the phase difference detection signal. Further, the phase difference detection processing unit 51 compares the phase difference detection signal subjected to the filter processing, more specifically, the right opening phase difference detection signal and the left opening phase difference detection signal, and those phase difference detection signals The defocus amount of the focus lens 41 is calculated by detecting the phase difference.

In step S14, the phase difference detection processing unit 51 determines whether or not phase difference detection is impossible.

For example, the phase difference detection processing unit 51 determines that phase difference detection is impossible when the phase difference cannot be detected by the phase difference detection in step S13 and the defocus amount cannot be obtained. More specifically, for example, when the phase difference is detected several times to detect the phase difference, but the phase difference cannot be detected for a certain period of time, the phase difference detection is difficult. That is, it is determined that phase difference detection is not possible.

Here, the fact that the phase difference could not be detected means, for example, the right opening phase difference detection signal at each deviation amount calculated when detecting the phase difference (waveform deviation amount) of the phase difference detection signal. For example, the degree of correlation with the left aperture phase difference detection signal, that is, the degree of similarity is lower than the threshold value, or the case where the minimum value of the degree of correlation of the phase difference detection signal obtained for each shift amount cannot be obtained.

If it is determined in step S14 that phase difference detection is not possible, in step S15, the aperture controller 54 sets the focusing F value as the F value of the aperture 42 based on the currently designated F value. specify.

For example, when phase difference detection is impossible (difficult), the current F value of the diaphragm 42 is small, so the subject image is greatly blurred on the imaging surface, and there is a high possibility that phase difference detection has failed. Therefore, the aperture control unit 54 designates an F value larger than the imaging F value designated in step S11 as the F value for focusing the aperture 42. Specifically, for example, as described with reference to FIG. 3, an F which is obtained in advance from the driveable range of the focus lens 41 and the blur amount at the detection limit and can be reliably detected even when the defocus amount is large. The value is designated as the F value for focusing.

In an imaging device called a so-called mirrorless single-lens camera, as a premise, it is important that the F value of the aperture 42 at the time of focusing control matches the F value when a captured image is captured (captured). This is for ensuring the expression of the depth of blur, or shortening the release time lag by shortening the drive time of the diaphragm 42.

Therefore, in the imaging apparatus 11, first, phase difference detection is performed with the F value for photographing, and when the phase difference detection is impossible (difficult) with the photographing F value, an F value predetermined for focusing is set. The F value is changed to, and phase difference detection is performed again. When the F value is changed, the blur amount of the subject image on the imaging surface of the imaging unit 22 is reduced, and phase difference detection is possible (easy).

This makes it possible to focus on the subject more quickly and with high accuracy while ensuring as much blur depth expression and a short release time lag as possible. In particular, since the imaging device 11 can estimate in advance the amount of narrowing necessary to enable phase difference detection from the amount of blur at the detection limit or the like, the defocus amount can be obtained quickly.

Thus, when a new F value is designated in step S15, the process returns to step S12, and the above-described process is repeated. That is, the aperture amount is adjusted based on the F value designated in the process of step S15, and phase difference detection is performed again.

If it is determined in step S14 that the phase difference detection is not impossible, that is, it is determined that the defocus amount is obtained by the phase difference detection, the focus control unit 53 moves the focus lens 41 based on the defocus amount in step S16. Calculate the amount. In other words, the focus control unit 53 converts the defocus amount obtained in the process of step S13 into a movement amount of the focus lens 41.

In step S17, the focus control unit 53 moves the focus lens 41 based on the movement amount calculated in the process of step S16. That is, the focus control unit 53 controls the lens driving unit 29 based on the movement amount of the focus lens 41, and the lens driving unit 29 moves the focus lens 41 in the optical axis direction according to the control of the focusing control unit 53. As a result, the subject is in focus.

In step S18, the aperture controller 54 determines whether or not the current F value of the aperture 42 is the F value for capturing a captured image, that is, the F value specified in step S11. In step S18, when the process of step S15 is performed even once, it is determined that the F value is different.

If it is determined in step S18 that the current F value is not the shooting F value, in step S19, the aperture control unit 54 determines that the aperture amount of the aperture 42 is designated in the process of step S11. The drive of the diaphragm 42 is controlled so that the diaphragm amount corresponds to.

That is, the aperture control unit 54 controls the aperture drive unit 28 based on the F value for photographing, and the aperture drive unit 28 drives the aperture 42 according to the control of the aperture control unit 54 to change the aperture amount. When the F value is returned from the F value for focusing to the F value for shooting in this way, that is, the F value changed for focusing control is changed from the F value after the change to the F value before the change. When the display is restored, the sense of blur (depth expression) of the live view image displayed on the display unit 26 is the same as when the captured image is captured.

When the diaphragm 42 is driven based on the F value for photographing, the process proceeds to step S20.

On the other hand, if it is determined in step S18 that the current F value is the F value for photographing, the diaphragm 42 does not need to be driven, and the process proceeds to step S20.

When it is determined in step S18 that the F-number is for photographing, or when the diaphragm 42 is driven in step S19, the control unit 24 controls the display unit 26 to perform in-focus display in step S20.

That is, the control unit 24 superimposes a rectangular frame indicating the focus on the subject on the in-focus area in the live view image, and supplies the live view image on which the rectangular frame is superimposed to the display unit 26 for display. When a rectangular frame indicating in-focus is displayed on the live view image, the in-focus processing ends.

When the in-focus display is performed as described above, the user appropriately presses the shutter button as the input unit 25 and instructs to capture a captured image. Then, the control unit 24 uses the image supplied from the imaging unit 22 via the signal processing unit 23 as a captured image, performs compression processing or the like as necessary, and then supplies the recording unit 27 for recording. A captured image is displayed on the display unit 26.

As described above, when the phase difference detection is impossible, the imaging device 11 changes the F value (aperture value) of the diaphragm 42 to a larger value and performs the phase difference detection again. As a result, the subject can be focused at a higher focusing speed and with higher accuracy. In particular, according to the imaging device 11, it is possible to realize high-speed focusing drive from a greatly blurred state, which is not good for the imaging surface phase difference method.

<Second Embodiment>
<Description of focus processing>
In the above description, it has been described that when the F value of the diaphragm 42 is changed to a larger value during the focus control, the F value is changed to a predetermined value. In this case, for example, if the difference between the F values before and after the change of the F value is large, the brightness of the live view image displayed on the display unit 26 will change drastically and drive quality will be reduced. .

Therefore, when the F value of the diaphragm 42 is changed during focus control, it is not changed to a specific F value regardless of the current F value, but from the current F value until phase difference detection is possible. You may make it change to a specific F value little by little in steps. By doing so, it is possible to realize rapid phase difference detection in a state where the defocus amount is large without impairing drive quality.

In such a case, the imaging device 11 performs the process shown in FIG. 5 as the focusing process. Hereinafter, the focusing process performed by the imaging apparatus 11 will be described with reference to the flowchart of FIG. In addition, since the process of step S51 thru | or step S54 is the same as the process of step S11 thru | or step S14 of FIG. 4, the description is abbreviate | omitted.

If it is determined in step S54 that phase difference detection is not possible, in step S55, the aperture control unit 54 sets a value obtained by reducing the currently specified F value by a predetermined number of steps to a new focus for the aperture 42. Specify as F value.

For example, in step S55, the F value for focusing is changed so that the F value (aperture value) is increased by 0.3 steps with respect to the F value for photographing.

When a new F value is designated, the process thereafter returns to step S52, and the above-described process is repeated.

If it is determined in step S54 that phase difference detection is not possible, then the processing from step S56 to step S60 is performed and the focusing processing ends, but these processing is performed from step S16 to step S20 in FIG. Since this is the same as the above process, the description thereof is omitted.

As described above, when the phase difference detection is impossible, the imaging apparatus 11 increases the F value (aperture value) of the diaphragm 42 in a stepwise manner and performs phase difference detection. As a result, the subject can be focused at a higher focusing speed and with higher accuracy. In addition, by increasing the F value stepwise until phase difference detection becomes possible, it is possible to prevent the brightness of the live view image from changing suddenly and to improve drive quality.

<Third Embodiment>
<Description of focus processing>
By the way, even if the diaphragm 42 is narrowed down to a certain extent at the time of phase difference detection, in some cases, phase difference detection may remain impossible (difficult). Therefore, for example, when phase difference detection is impossible (difficult) even when the diaphragm 42 is narrowed to some extent, the focus control may be switched to a method different from the imaging surface phase difference method.

In such a case, for example, the process shown in FIG. 6 is performed as the focusing process. Hereinafter, the focusing process performed by the imaging apparatus 11 will be described with reference to the flowchart of FIG. Note that the processing from step S91 to step S94 is the same as the processing from step S11 to step S14 in FIG.

If it is determined in step S94 that phase difference detection is not possible, in step S95, the aperture controller 54 determines whether or not the F value has been changed for phase difference detection.

For example, when the F value of the aperture 42 is changed from the F value for photographing to the F value for focusing and phase difference detection is performed, that is, when the processing of step S96 described later has already been performed, the F value Is determined to have been changed.

If it is determined in step S95 that the F value has not yet been changed, in step S96, the aperture control unit 54 sets the F value for focusing to the F value for the aperture 42 based on the currently designated F value. Specify as. That is, in step S96, processing similar to that in step S15 in FIG. 4 is performed.

When the F value for focusing is designated, the process returns to step S92 and the above-described process is performed.

On the other hand, when it is determined in step S95 that the F value has been changed, in step S97, the imaging device 11 performs a focusing operation using a contrast method.

That is, the contrast detection processing unit 52 calculates an evaluation value indicating the degree of contrast of each region of the image based on the image that is supplied from the signal processing unit 23 and is a live view image. That is, contrast detection is performed.

Further, the focusing control unit 53 calculates the moving amount of the focus lens 41 based on the evaluation value obtained by contrast detection, and further controls the lens driving unit 29 based on the moving amount. The lens driving unit 29 moves the focus lens 41 according to the control of the focusing control unit 53. Thus, by calculating the evaluation value and moving the focus lens 41 several times, the subject is in focus.

In addition, although the example in which the focus control is performed by the contrast method as the focusing method different from the imaging surface phase difference method has been described here, any focusing method may be used as long as the method is different from the imaging surface phase difference method. Also good. As a method different from the imaging surface phase difference method, for example, an active method in which infrared or ultrasonic waves are emitted to measure the distance to the subject, a phase difference method using a phase difference AF dedicated sensor, or the like can be used.

When the focusing operation is performed by the contrast method and the subject is brought into focus, the process proceeds to step S101.

If it is determined in step S94 that phase difference detection is not possible, the processes in steps S98 to S100 are thereafter performed, which are the same as the processes in steps S16 to S18 in FIG. Therefore, the description is omitted.

If it is determined in step S100 that the current F value is not the F value for photographing, or if it is determined in step S97 that the focusing operation has been performed, the processing in step S101 is performed.

That is, in step S101, the diaphragm control unit 54 controls the driving of the diaphragm 42 so that the diaphragm amount of the diaphragm 42 becomes the diaphragm amount corresponding to the F value for photographing specified in the process of step S91. When the focusing operation is performed by the contrast method, the contrast detection may be performed after the F value of the aperture 42 is returned to the F value for shooting, or after the focus display, the actual shooting is performed. The F value (aperture amount) may be returned before the image is taken.

If it is determined in step S101 that the aperture 42 has been driven or the current F value is the shooting F value in step S100, then in-focus display is performed in step S102 and the focusing process ends. . The process in step S102 is the same as the process in step S20 in FIG.

As described above, when the phase difference detection is impossible, the imaging apparatus 11 performs phase difference detection by increasing the F value of the diaphragm 42. When the phase difference detection is still impossible, the imaging surface 11 The focusing operation is performed by a focusing method different from the phase difference method. Thus, if phase difference detection is not possible even if the aperture 42 is reduced as necessary, the subject can be focused at a higher focus speed and with higher accuracy by performing a focusing operation with another focusing method. Can be in focus.

<Variation 1 of the third embodiment>
<Description of focus processing>
Furthermore, in the third embodiment, the example of switching to the contrast method when the phase difference detection is impossible even when the F value for focusing is changed is described. However, as described in the second embodiment, the F value may be changed step by step, and switching to the contrast method may be performed when phase difference detection is impossible even if the F value is changed a predetermined number of times. .

In such a case, for example, the process shown in FIG. 7 is performed as the focusing process. Hereinafter, the focusing process performed by the imaging apparatus 11 will be described with reference to the flowchart of FIG.

In addition, since the process of step S131 thru | or step S134 is the same as the process of step S11 thru | or step S14 of FIG. 4, the description is abbreviate | omitted.

If it is determined in step S134 that phase difference detection is not possible, in step S135, the aperture controller 54 determines whether the F value has been changed for phase difference detection a predetermined number of times.

For example, when the F value of the diaphragm 42 is changed by a predetermined number of steps, such as 0.3 steps from the F value for photographing, and phase difference detection is performed, that is, the process of step S136 described later is performed a predetermined number of times. In this case, it is determined that the F value has been changed a predetermined number of times.

Note that, here, an example will be described in which the F value is changed a predetermined number of times, and the phase difference detection cannot be performed even when the stop 42 is stopped, so that switching to the contrast method is performed. However, the F value may be changed step by step, and the phase shift detection may be switched to when the phase difference cannot be detected even if the F value is changed until the F value is reached.

If it is determined in step S135 that the F value has not been changed a predetermined number of times, then in step S136, the aperture control unit 54 sets a new value of the aperture 42 to a value obtained by reducing the currently specified F value by a predetermined number of steps. Specify as F value for focusing. That is, in step S136, the same process as step S55 of FIG. 5 is performed.

When the F value for focusing is designated, the process returns to step S132 and the above-described process is performed.

On the other hand, when it is determined in step S135 that the F value has been changed a predetermined number of times, in step S137, the imaging device 11 performs a focusing operation using a contrast method. In step S137, processing similar to that in step S97 in FIG. 6 is performed.

When the focusing operation is performed by the contrast method, the process thereafter proceeds to step S141, and after the diaphragm 42 is driven, in-focus display is performed in step S142, and the focusing process ends.

If it is determined in step S134 that phase difference detection is not possible, then the processing from step S138 to step S142 is performed, and the focusing process ends.

In addition, since the process of these step S138 thru | or step S142 is the same as the process of FIG.4 S16 thru | or step S20, the description is abbreviate | omitted.

As described above, when the phase difference detection is impossible, the imaging apparatus 11 performs phase difference detection by gradually increasing the F value of the aperture 42, and when the phase difference detection is still impossible. The focusing operation is performed by a focusing method different from the imaging surface phase difference method. As described above, when phase difference detection is impossible even if the diaphragm 42 is squeezed a predetermined number of times, by performing a focusing operation with another focusing method, it is possible to focus on a subject at a higher focusing speed and with higher accuracy. Can be focused.

<Fourth embodiment>
<Description of focus processing>
Incidentally, as described above, at the time of phase difference detection, it has been described that the phase difference of the phase difference detection signal is detected after the phase difference detection signal is filtered using the detection filter. The phase difference detection processing unit 51 can change the detection characteristics by changing the characteristics of such a detection filter.

For example, when a high-pass filter is used as a detection filter, the waveform of the phase difference detection signal becomes steep, that is, an edge is formed, so that it is easy to correlate the right opening phase difference detection signal and the left opening phase difference detection signal. Increases accuracy.

However, when a high-pass filter is used as the detection filter, the low-frequency component of the phase difference detection signal is removed, so that the phase difference detection signal is filtered when the subject image is blurred on the imaging surface. As a result, almost no signal component remains. Therefore, when a high-pass filter is used as a detection filter, it is effective when the defocus amount is small, but cannot be detected when the defocus amount is large.

On the other hand, if a low-pass filter is used as a detection filter, the accuracy of phase difference detection is lower than when a high-pass filter is used, but the right aperture phase difference detection signal and the left aperture position can be detected even when the defocus amount is large. It is possible to correlate the phase difference detection signal.

As an example of detection characteristics in this way, by changing the characteristics of the detection filter, etc., the amount of blur of the subject image on the imaging surface where phase difference detection is possible, that is, the range of the defocus amount, and the detection accuracy Can be controlled.

Therefore, when the phase difference detection is impossible, the detection characteristics may be changed so that the phase difference detection can be performed even when the defocus amount is large. In such a case, for example, the process shown in FIG. 8 is performed as the focusing process. Hereinafter, the focusing process by the imaging device 11 will be described with reference to the flowchart of FIG.

In addition, since the process of step S171 thru | or step S174 is the same as the process of step S11 thru | or step S14 of FIG. 4, the description is abbreviate | omitted. However, in step S173, it is assumed that, for example, a high-pass filter is used as a detection filter defined as an initial setting in the filter processing for the phase difference detection signal.

If it is determined in step S174 that phase difference detection is not possible, in step S175, the aperture controller 54 determines whether or not the F value has been changed for phase difference detection.

For example, when the F value of the diaphragm 42 is changed from the F value for photographing to the F value for focusing and phase difference detection is performed, that is, when the processing in step S176 described later has already been performed, the F value Is determined to have been changed.

If it is determined in step S175 that the F value has not been changed yet, in step S176, the aperture control unit 54 sets the F value for focusing to the F value of the aperture 42 based on the currently designated F value. Specify as. That is, in step S176, processing similar to that in step S15 in FIG. 4 is performed.

When the F value for focusing is designated, the process returns to step S172 and the above-described process is performed.

On the other hand, if it is determined in step S175 that the F value has been changed, that is, if the process of step S176 has already been performed, in step S177, the phase difference detection processing unit 51 determines the detection characteristics of the phase difference detection. change.

That is, the phase difference detection processing unit 51 detects the phase difference detection characteristics from the detection characteristics predetermined in the initial setting, so that the phase difference detection can be performed even when the defocus amount of the focus lens 41 is large. Change to In other words, the detection characteristic is changed to a detection characteristic suitable for a case where there are many low frequency components in the phase difference detection signal.

More specifically, for example, in order to change the detection characteristics, the detection filter is switched from a high-pass filter that is set as an initial setting to a low-pass filter that can perform phase difference detection even when the defocus amount is large. Therefore, in this case, in the next phase difference detection, that is, the processing in step S173, the low-pass filter is used as the detection filter, and the filter processing is performed.

Here, an example has been described in which the detection characteristic is changed when phase difference detection is impossible even if the F value of the diaphragm 42 is changed. However, the F value and the detection characteristic of the diaphragm 42 may be changed simultaneously. Good.

In addition, here, as an example of changing the detection characteristic, the case where the detection filter is changed from the high-pass filter to the low-pass filter has been described. However, how to change the detection characteristics, such as changing the detection filter from high-pass characteristics to low-pass characteristics by changing the filter coefficient of each tap constituting the detection filter and the number of taps. It may be.

When the detection characteristic is changed, the process returns to step S173 and the above-described process is performed.

If it is determined in step S174 that phase difference detection is not possible, the processing from step S178 to step S182 is performed thereafter, and the focusing processing ends. These processing is performed from step S16 to step S16 in FIG. Since it is the same as the process of S20, the description is abbreviate | omitted.

As described above, when the phase difference detection is impossible, the imaging apparatus 11 performs phase difference detection by increasing the F value of the diaphragm 42. When the phase difference detection is still impossible, the imaging device 11 performs phase difference detection. Change the detection characteristics of detection and perform phase difference detection again.

As described above, when phase difference detection is impossible even if the aperture 42 is reduced as necessary, the detection characteristics can be changed to focus on the subject with higher focusing speed and high accuracy. it can. In particular, by using both the change of the F value and the change of the detection characteristics, it is possible to make the phase difference detection possible by the imaging surface phase difference method with a small amount of narrowing down.

<Variation 1 of the fourth embodiment>
<Description of focus processing>
Note that the detection characteristics may be further changed when the F value is changed stepwise and phase difference detection is impossible even if the F value is changed a predetermined number of times.

In such a case, for example, the process shown in FIG. 9 is performed as the focusing process. Hereinafter, the focusing process performed by the imaging apparatus 11 will be described with reference to the flowchart of FIG.

In addition, since the process of step S211 thru | or step S214 is the same as the process of step S11 thru | or step S14 of FIG. 4, the description is abbreviate | omitted. However, in step S213, it is assumed that, for example, a high-pass filter is used as a detection filter defined as an initial setting in the filter processing for the phase difference detection signal.

If it is determined in step S214 that phase difference detection is not possible, in step S215, the aperture controller 54 determines whether or not the F value has been changed for phase difference detection a predetermined number of times.

For example, when the F value of the aperture 42 is changed by a predetermined number of steps, such as 0.3 steps from the F value for photographing, and phase difference detection is performed, that is, the process of step S216 described later is performed a predetermined number of times. In this case, it is determined that the F value has been changed a predetermined number of times.

If it is determined in step S215 that the F value has not been changed a predetermined number of times, then in step S216, the aperture control unit 54 sets a new value of the aperture 42 to a value obtained by reducing the currently specified F value by a predetermined number of steps. Specify as F value for focusing. That is, in step S216, the same process as step S55 of FIG. 5 is performed.

When the F value for focusing is designated, the process returns to step S212 and the above-described process is performed.

On the other hand, if it is determined in step S215 that the F value has been changed a predetermined number of times, the phase difference detection processing unit 51 changes the detection characteristics of the phase difference detection in step S217. For example, in step S217, processing similar to that in step S177 in FIG. 8 is performed, and the detection characteristic is changed from a high-pass filter in which a detection filter is set as an initial setting to a low-pass filter. In this example as well, the F value and the detection characteristic of the diaphragm 42 may be changed simultaneously.

When the detection characteristic is changed, the process returns to step S213, and the above-described process is performed.

If it is determined in step S214 that phase difference detection is not possible, then the processing from step S218 to step S222 is performed and the focusing processing ends, but these processing is performed from step S16 to step S16 in FIG. Since it is the same as the process of S20, the description is abbreviate | omitted.

As described above, when the phase difference detection is impossible, the imaging apparatus 11 performs phase difference detection by gradually increasing the F value of the aperture 42, and when the phase difference detection is still impossible. Then, the detection characteristics of phase difference detection are changed, and phase difference detection is performed again.

As described above, when phase difference detection is impossible even when the diaphragm 42 is stopped a predetermined number of times, the subject can be focused at a higher focusing speed and with higher accuracy by changing the detection characteristics. . In particular, by using both the change of the F value and the change of the detection characteristics, it is possible to make the phase difference detection possible by the imaging surface phase difference method with a small amount of narrowing down.

In the focusing process described with reference to FIGS. 8 and 9, if the phase difference detection is impossible even if the F value or the detection characteristic is changed, the focusing method is referred to as the imaging surface phase difference method. The focus control may be performed by changing to a different method.

<Fifth embodiment>
<Configuration example of imaging device>
Further, in the above description, the imaging apparatus 11 has been described with respect to an example in which focusing control by the contrast method can be performed in addition to the imaging surface phase difference method. Such a method may be adopted.

For example, in the imaging apparatus, when focus control is possible by the phase difference method using the phase difference AF dedicated sensor in addition to the imaging surface phase difference method, the imaging device is configured as shown in FIG. 10, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted as appropriate.

An imaging device 81 shown in FIG. 10 includes an imaging lens 21, a reflex mirror 91, a phase difference sensor 92, an imaging unit 22, a signal processing unit 23, a control unit 24, an input unit 25, a display unit 26, a recording unit 27, and a diaphragm drive. A unit 28 and a lens driving unit 29.

Further, the imaging lens 21 of the imaging device 81 is provided with a focus lens 41 and a diaphragm 42, and the control unit 24 is provided with a phase difference detection processing unit 51, a focusing control unit 53, and a diaphragm control unit 54. It has been.

The configuration of the imaging device 81 is different from the configuration of the imaging device 11 in that the reflex mirror 91 and the phase difference sensor 92 are provided, and the contrast detection processing unit 52 is not provided in the control unit 24. In other respects, imaging is performed. The configuration is the same as that of the device 11.

The reflex mirror 91 is provided between the imaging lens 21 and the imaging unit 22, and guides light incident from the subject via the imaging lens 21 to either the imaging unit 22 or the phase difference sensor 92.

That is, when the reflex mirror 91 is lowered, the light from the imaging lens 21 is reflected by the reflex mirror 91 and enters the phase difference sensor 92 and an optical finder (not shown). Further, in a state where the reflex mirror 91 is raised, the light from the imaging lens 21 does not enter the reflex mirror 91 but enters the imaging unit 22.

The phase difference sensor 92 is composed of an image sensor dedicated to focusing control by the phase difference method, in which a phase difference detection pixel is provided on the imaging surface. The phase difference sensor 92 receives light incident from the subject via the reflex mirror 91 and the imaging lens 21 and performs photoelectric conversion, and supplies a phase difference detection signal obtained as a result to the control unit 24. The phase difference detection processing unit 51 of the control unit 24 detects the phase difference of the phase difference detection signal supplied from the phase difference sensor 92 or the phase difference of the phase difference detection signal supplied from the signal processing unit 23, and the focus lens A defocus amount of 41 is obtained.

In more detail, a diaphragm is provided between the reflex mirror 91 and the phase difference sensor 92 to limit the thickness (beam diameter) of light incident on the phase difference sensor 92.

When a photographed image is photographed by such an imaging device 81, when the user performs photographing using an optical finder (not shown), the F value of the aperture 42 is set to an open value and the phase difference sensor 92 A defocus amount is calculated based on the output, and focusing control is performed.

In this case, the reflex mirror 91 is lowered when focusing control is performed, and the reflex mirror 91 is raised when a captured image is captured (captured).

On the other hand, when shooting is performed in a live view mode in which a shot image is shot while a live view image is displayed on the display unit 26, basically, shooting is performed with the reflex mirror 91 raised. Is done.

At this time, when the shutter button as the input unit 25 is half-pressed by the user, the imaging device 81 causes each of the operations described with reference to FIGS. 4 to 9 to be performed with the reflex mirror 91 raised. Processing similar to the focusing processing is performed. However, in the process corresponding to step S97 of the focusing process described with reference to FIG. 6 and the process corresponding to step S137 of the focusing process described with reference to FIG. 7, the F value of the aperture 42 is the open value. Thus, the reflex mirror 91 is lowered, the defocus amount is calculated based on the output from the phase difference sensor 92, and the focus lens 41 is moved.

By the way, the above-described series of processing can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose computer capable of executing various functions by installing a computer incorporated in dedicated hardware and various programs.

FIG. 11 is a block diagram showing an example of a hardware configuration of a computer that executes the above-described series of processing by a program.

In the computer, a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, and a RAM (Random Access Memory) 503 are connected to each other via a bus 504.

An input / output interface 505 is further connected to the bus 504. An input unit 506, an output unit 507, a recording unit 508, a communication unit 509, and a drive 510 are connected to the input / output interface 505.

The input unit 506 includes a keyboard, a mouse, a microphone, one or a plurality of image sensors. In this example, the image sensor constituting the input unit 506 corresponds to the image capturing unit 22 and the phase difference sensor 92. The output unit 507 includes a display, a speaker, and the like. The recording unit 508 includes a hard disk, a nonvolatile memory, and the like. The communication unit 509 includes a network interface or the like. The drive 510 drives a removable recording medium 511 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

In the computer configured as described above, the CPU 501 loads the program recorded in the recording unit 508 to the RAM 503 via the input / output interface 505 and the bus 504 and executes the program, for example. Is performed.

The program executed by the computer (CPU 501) can be provided by being recorded in a removable recording medium 511 as a package medium or the like, for example. The program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

In the computer, the program can be installed in the recording unit 508 via the input / output interface 505 by attaching the removable recording medium 511 to the drive 510. Further, the program can be received by the communication unit 509 via a wired or wireless transmission medium and installed in the recording unit 508. In addition, the program can be installed in advance in the ROM 502 or the recording unit 508.

The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

The embodiments of the present technology are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology.

For example, the present technology can take a cloud computing configuration in which one function is shared by a plurality of devices via a network and is jointly processed.

Further, each step described in the above flowchart can be executed by one device or can be shared by a plurality of devices.

Further, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.

Further, the effects described in the present specification are merely examples and are not limited, and other effects may be obtained.

Furthermore, the present technology can be configured as follows.

(1)
A phase difference detection processing unit that performs phase difference detection based on an output from a phase difference detection pixel provided in the imaging unit;
An aperture control unit that changes an aperture value to a larger value when the phase difference detection by the phase difference detection processing unit is difficult.
(2)
The aperture control unit changes the aperture value to a predetermined value when the phase difference detection is difficult. The imaging device according to (1).
(3)
The imaging device according to (1), wherein the aperture control unit changes the aperture value step by step whenever it is determined that the phase difference detection is difficult.
(4)
The imaging device according to any one of (1) to (3), wherein the phase difference detection processing unit changes detection characteristics in the phase difference detection when the phase difference detection is difficult.
(5)
The imaging device according to (4), wherein when the phase difference detection is difficult, the aperture control unit changes the aperture value, and the phase difference detection processing unit changes the detection characteristics.
(6)
The phase difference detection processing unit changes the detection characteristic when it is determined that the phase difference detection is difficult in the phase difference detection performed by changing the aperture value. (4) Imaging device.
(7)
The imaging device according to any one of (4) to (6), wherein the phase difference detection processing unit changes filter processing applied to an output from the phase difference detection pixel as the detection characteristic.
(8)
The imaging apparatus according to any one of (1) to (7), further including a focusing control unit that drives an imaging lens based on the result of the phase difference detection and performs focusing control.
(9)
When the aperture value is changed and the phase difference detection is performed again, the aperture control unit returns the aperture value to the value before the change after the focus control by the focus control unit. ).
(10)
The focus control unit, when it is determined that the phase difference detection is difficult in the phase difference detection performed by changing the aperture value, the result of the phase difference detection by the phase difference detection processing unit The imaging apparatus according to (8) or (9), in which focus control is performed by a method different from a method using.
(11)
Perform phase difference detection based on the output from the phase difference detection pixel provided in the imaging unit,
A focus control method including a step of changing the aperture value to a larger value when the phase difference detection is difficult.
(12)
The focusing control method according to (11), wherein when the phase difference detection is difficult, the aperture value is changed to a predetermined value.
(13)
The focus control method according to (11), wherein each time the phase difference detection is determined to be difficult, the aperture value is changed step by step.
(14)
The focusing control method according to any one of (11) to (13), wherein when the phase difference detection is difficult, a detection characteristic in the phase difference detection is changed.
(15)
The focus control method according to (14), wherein when the phase difference detection is difficult, the aperture value is changed and the detection characteristic is changed.
(16)
Perform phase difference detection based on the output from the phase difference detection pixel provided in the imaging unit,
A program for causing a computer to execute a process including a step of changing an aperture value to a larger value when the phase difference detection is difficult.
(17)
The program according to (16), wherein when the phase difference detection is difficult, the aperture value is changed to a predetermined value.
(18)
The program according to (16), wherein the aperture value is changed step by step whenever it is determined that the phase difference detection is difficult.
(19)
The program according to any one of (16) to (18), wherein when the phase difference detection is difficult, a detection characteristic in the phase difference detection is changed.
(20)
The program according to (19), wherein when the phase difference detection is difficult, the aperture value is changed and the detection characteristic is changed.

11 imaging device, 21 imaging lens, 22 imaging unit, 24 control unit, 28 aperture driving unit, 29 lens driving unit, 41 focus lens, 42 aperture, 51 phase difference detection processing unit, 52 contrast detection processing unit, 53 focusing control Part, 54 aperture control part, 92 phase difference sensor

Claims (20)

1. A phase difference detection processing unit that performs phase difference detection based on an output from a phase difference detection pixel provided in the imaging unit;
   An aperture control unit that changes an aperture value to a larger value when the phase difference detection by the phase difference detection processing unit is difficult.
2. The imaging device according to claim 1, wherein when the phase difference detection is difficult, the aperture control unit changes the aperture value to a predetermined value.
3. The imaging apparatus according to claim 1, wherein the aperture control unit changes the aperture value step by step whenever it is determined that the phase difference detection is difficult.
4. The imaging device according to claim 1, wherein the phase difference detection processing unit changes detection characteristics in the phase difference detection when the phase difference detection is difficult.
5. The imaging apparatus according to claim 4, wherein, when the phase difference detection is difficult, the aperture control unit changes the aperture value, and the phase difference detection processing unit changes the detection characteristics.
6. The phase difference detection processing unit changes the detection characteristic when it is determined that the phase difference detection is difficult in the phase difference detection performed by changing the aperture value. Imaging device.
7. The imaging apparatus according to claim 4, wherein the phase difference detection processing unit changes a filter process to be performed on an output from the phase difference detection pixel as the detection characteristic.
8. The imaging apparatus according to claim 1, further comprising a focusing control unit that drives an imaging lens based on the result of the phase difference detection to perform focusing control.
9. The aperture controller, when the aperture value is changed and the phase difference detection is performed again, returns the aperture value to the value before the change after the focus control by the focus controller. 8. The imaging device according to 8.
10. The focus control unit, when it is determined that the phase difference detection is difficult in the phase difference detection performed by changing the aperture value, the result of the phase difference detection by the phase difference detection processing unit The imaging apparatus according to claim 8, wherein the focus control is performed by a method different from a method using the image.
11. Perform phase difference detection based on the output from the phase difference detection pixel provided in the imaging unit,
    A focus control method including a step of changing the aperture value to a larger value when the phase difference detection is difficult.
12. The focus control method according to claim 11, wherein when the phase difference detection is difficult, the aperture value is changed to a predetermined value.
13. The focus control method according to claim 11, wherein the aperture value is changed stepwise whenever it is determined that the phase difference detection is difficult.
14. The focus control method according to claim 11, wherein when the phase difference detection is difficult, a detection characteristic in the phase difference detection is changed.
15. The focusing control method according to claim 14, wherein when the phase difference detection is difficult, the aperture value is changed and the detection characteristic is changed.
16. Perform phase difference detection based on the output from the phase difference detection pixel provided in the imaging unit,
    A program for causing a computer to execute a process including a step of changing an aperture value to a larger value when the phase difference detection is difficult.
17. The program according to claim 16, wherein when the phase difference detection is difficult, the aperture value is changed to a predetermined value.
18. The program according to claim 16, wherein each time the phase difference detection is determined to be difficult, the aperture value is changed step by step.
19. The program according to claim 16, wherein when the phase difference detection is difficult, a detection characteristic in the phase difference detection is changed.
20. The program according to claim 19, wherein when the phase difference detection is difficult, the aperture value is changed and the detection characteristic is changed.

Images