JP6492557B2 - Focus adjustment device and camera - Google Patents

Description

  The present invention relates to a focus adjustment device and a camera.

  Conventionally, a technique for performing focus adjustment by detecting a face of a subject from an imaging screen is known. For example, Patent Literature 1 describes a focus detection device that determines the size of an AF frame to be set in a body region according to the size of a detected face.

JP 2012-128287 A

  The focus detection apparatus described in Patent Document 1 has a problem that the human body is brought into focus regardless of the user's intention.

The focus adjustment apparatus according to claim 1, which captures an image of a subject formed by an optical system, outputs an imaging data, and detects a face from the captured image of the subject based on the imaging data. A face detection unit that detects a focus adjustment state of the optical system in a plurality of focus detection areas set in an imaging region for capturing an image of the subject, and a plurality of faces are detected by the face detection unit. Then, with respect to the position of at least one selected area selected from the plurality of focus detection areas, a face having a predetermined positional relationship based on the size of each of the plurality of faces is identified from among the plurality of faces. And a focus adjustment unit that performs focus adjustment of the optical system based on a focus adjustment state detected for a focus detection area corresponding to the specified face position of the plurality of focus detection areas .
The focus adjustment apparatus according to claim 3, which captures an image of a subject formed by an optical system and outputs imaging data, and detects a face from the captured image of the subject based on the imaging data A face detection unit, a focus detection unit for detecting a focus adjustment state of the optical system in a plurality of focus detection areas set in an imaging region for capturing an image of the subject, and the face detection unit detecting a face And determining a predetermined positional relationship based on the difference between the focus adjustment state detected last time and the focus adjustment state detected this time and the size of the detected face, and detecting the position of the face and the plurality of focus detections. When the position of at least one selected area selected from the areas satisfies the predetermined positional relationship, the focus adjustment state detected in the focus detection area corresponding to the position of the face among the plurality of focus detection areas Based on If the focus adjustment of the optical system is performed and the position of the face and the position of the selection area do not satisfy the predetermined positional relationship, the focus adjustment of the optical system is performed based on the focus adjustment state detected in the selection area. And a focus adjustment unit for performing.
A camera according to a sixth aspect includes the focus adjustment device according to any one of the first to fifth aspects.

It is sectional drawing which shows typically the structure of the imaging device which concerns on 1st Embodiment. It is a schematic diagram of an imaging screen and a focus detection area. It is a schematic diagram which shows the imaging screen containing only one face. It is a schematic diagram which shows the imaging screen containing only one face. It is a schematic diagram which shows the imaging screen 10 in which a vehicle exists in front of a person. It is a schematic diagram which shows the imaging screen containing two faces. It is a flowchart of a focus adjustment process. It is explanatory drawing which shows the modification of the check method of the positional relationship between a face and a selection area. It is explanatory drawing which shows the modification of the display form of a focus detection area.

(First embodiment)
FIG. 1 is a cross-sectional view schematically showing the configuration of the imaging apparatus 1 according to the first embodiment. The imaging device 1 is a so-called interchangeable lens digital camera. The imaging apparatus 1 includes a camera body 200 and an interchangeable lens 100 that can be attached to and detached from the camera body 200.

  The interchangeable lens 100 includes an imaging optical system 101 and a lens driving unit 102. The imaging optical system 101 includes a first lens 103, a focus lens 104, and a second lens 105. The lens driving unit 102 drives the focus lens 104 in the direction of the optical axis O using an actuator (not shown).

  The camera body 200 includes a control unit 201, a quick return mirror 202, a finder screen 203, a superimpose display unit 204, a pentaprism (pentagonal roof prism) 205, an eyepiece lens 206, a condenser lens 207, a photometric sensor 208, a sub mirror 209, A focus detection device 210 and an image sensor 211 are provided.

  The quick return mirror 202 is configured to be movable between a reflection position indicated by a solid line in FIG. 1 and a retracted position indicated by a broken line. The reflection position is on the optical path of the subject light. When the quick return mirror 202 is at the reflection position, the subject light does not enter the image sensor 211. During non-exposure (non-imaging), the control unit 201 moves the quick return mirror 202 to the reflection position. At this time, the subject light that has passed through the imaging optical system 101 is reflected upward of the camera body 200 by the quick return mirror 202. The reflected subject light passes through the finder screen 203 and the superimpose display unit 204 and enters the pentaprism 205. The pentaprism 205 reflects incident subject light toward the eyepiece lens 206. The user can visually recognize the subject image (imaging screen) through the eyepiece lens 206.

  A condensing lens 207 and a photometric sensor 208 are provided in the vicinity of the pentaprism 205 and the eyepiece lens 206. Part of the subject light incident on the pentaprism 205 passes through the condenser lens 207 and enters the photometric sensor 208. The photometric sensor 208 has photoelectric conversion elements arranged two-dimensionally. That is, the photometric sensor 208 is a small image sensor. The photometric sensor 208 measures the amount of subject light from the light reception output of the photoelectric conversion element. The light reception output of the photometric sensor 208 is further used for face detection described later.

  A sub mirror 209 is attached to the back surface of the quick return mirror 202. The quick return mirror 202 is a so-called half mirror. Accordingly, part of the subject light that has passed through the imaging optical system 101 passes through the quick return mirror 202 and enters the sub-mirror 209. The sub mirror 209 reflects the subject light toward the lower side of the camera body 200. The reflected subject light enters the focus detection device 210. The focus detection device 210 has a plurality of focus detection areas corresponding to each of a plurality of focus detection areas 11 provided on the imaging screen 10 described later. The focus detection device 210 detects the focus adjustment state of the imaging optical system 101 in a plurality of focus detection areas.

  When the image sensor 211 is exposed (during imaging), the control unit 201 moves the quick return mirror 202 to the retracted position. At this time, the subject light that has passed through the imaging optical system 101 enters the imaging surface of the imaging element 211. The image sensor 211 is a solid-state image sensor such as a CMOS or CCD. The image sensor 211 captures a subject image and outputs an image signal. The control unit 201 creates image data by performing various image processing on the imaging signal. The control unit 201 stores the created image data in a storage medium (not shown) (for example, a memory card).

  The control unit 201 includes a CPU (not shown) and its peripheral circuits. This CPU controls each unit of the imaging apparatus 1 by reading and executing a control program stored in advance in a storage medium (not shown).

  The control unit 201 functionally includes a face detection unit 221 and a focus adjustment unit 222. That is, the face detection unit 221 and the focus adjustment unit 222 are realized by software by the control program described above. Note that one or both of the face detection unit 221 and the focus adjustment unit 222 may be realized by an electronic circuit.

  The face detection unit 221 detects a face included in the imaging screen. The focus adjustment unit 222 adjusts the focus of the imaging optical system 101 based on the focus adjustment state detected by the focus detection device 210. The focus adjusting unit 222 adjusts the focus of the imaging optical system 101 by instructing the lens driving unit 102 about the driving direction and driving amount of the focus lens 104.

  FIG. 2 is a schematic diagram of the imaging screen 10 and the focus detection area 11. As schematically illustrated in FIG. 2, the imaging screen 10 is provided with 51 focus detection areas 11. That is, the focus detection device 210 is configured to be able to individually detect the focus adjustment state of the imaging optical system 101 for each of the 51 focus detection areas 11. The superimpose display unit 204 displays the positions of the 51 focus detection areas 11 superimposed on the imaging screen. For example, as schematically shown in FIG. 2, a rectangle representing the positions of 51 focus detection areas 11 is displayed. Note that the number and arrangement of the focus detection areas 11 may be different from those illustrated in FIG.

  The focus detection device 210 performs so-called phase difference type focus detection. That is, the focus detection apparatus 210 includes a plurality of pairs of photoelectric conversion units that respectively receive a pair of light beams that have passed through different regions of the imaging optical system 101. The focus detection device 210 performs a correlation operation between the light reception signal output from one of the pair of photoelectric conversion units and the light reception signal output from the other of the pair of photoelectric conversion units, thereby obtaining the pair of light reception signals. The phase difference is calculated. The focus detection device 210 detects the defocus amount of the imaging optical system 101 based on the calculated phase difference. That is, in the present embodiment, the focus adjustment state detected by the focus detection device 210 is a defocus amount.

  Note that focus detection using a different method may be performed. For example, a plurality of pairs of photoelectric conversion units that respectively receive a pair of light beams that have passed through different regions of the imaging optical system 101 are provided on the imaging surface of the imaging element 211, and light reception outputs of the plurality of sets of photoelectric conversion units Focus detection may be performed based on the so-called imaging surface phase difference focus detection. Alternatively, so-called contrast-type focus detection may be performed in which focus detection is performed based on the contrast of the imaging signal output from the imaging element 211.

  The imaging apparatus 1 has three types of focus detection modes: a selection area AF mode, an auto area AF mode, and a tracking AF mode. The user can select these three types of focus detection modes. The selection area AF mode is a mode in which automatic focus adjustment is performed for the focus detection area 11 specified by the user in advance, for example, the focus detection area 11a (FIG. 2). In the selection area AF mode, it is determined whether or not there is a face in the vicinity of the focus detection area 11a designated by the user. If it is determined that there is a face, automatic focus adjustment is performed by paying attention to the face. It can also be done. In the following description, the focus detection area 11a designated by the user is referred to as a selection area 11a. There may be a plurality of focus detection areas 11 that can be designated by the user. In the following description, a case where the user designates one focus detection area 11a will be described as an example.

  The auto area AF mode is a mode in which automatic focus adjustment is performed by paying attention to the face detected by the face detection unit 221. The focus adjustment unit 222 identifies the focus detection area 11 present at the face position detected by the face detection unit 221. Then, based on the defocus amount detected for the identified focus detection area 11, focus adjustment is performed so that the detected face is in focus.

  The tracking AF mode is a mode in which a subject specified by the user is tracked and automatic focus adjustment is repeatedly performed so that the subject is in focus. The control unit 201 detects the tracking target subject by performing, for example, a well-known color detection process or subject detection process on the light reception output of the photometric sensor 208. The focus adjusting unit 222 identifies the focus detection area 11 that exists at the detected position of the subject, for example, the focus detection area 11a. Then, based on the defocus amount detected for the identified focus detection area 11a, focus adjustment is performed so that the subject to be tracked is in focus. In the tracking AF mode, it is determined whether there is a face in the vicinity of the focus detection area 11a specified to be present at the position of the subject to be tracked, and when it is determined that there is a face, attention is paid to the face. Thus, automatic focusing can be performed. In the tracking AF mode, the subject to be tracked by the camera may be automatically recognized, and automatic focus adjustment may be repeatedly performed so that the subject is in focus. That is, in the tracking AF mode, the focus detection area 11a existing at the position of the subject to be tracked corresponds to the selection area 11a in the selection area AF mode.

  When the selection area AF mode is set, the superimpose display unit 204 displays the position of the selection area 11a superimposed on the imaging screen. For example, in FIG. 2, the superimpose display unit 204 displays the selection area 11 a with a thicker frame than the other focus detection areas 11. Thereby, the user can visually recognize the position of the current selection area 11a.

  When the auto area AF mode is set, the superimpose display unit 204 displays the position of the focus detection area 11 corresponding to the face subjected to focus adjustment, superimposed on the imaging screen.

  When the tracking AF mode is set, the superimpose display unit 204 displays the position of the focus detection area 11a existing at the position of the subject to be tracked superimposed on the imaging screen.

  The operation of the focus adjustment unit 222 in the selection area AF mode will be described in detail. FIG. 3 is a schematic diagram showing the imaging screen 10 including only one face. When the focus adjustment unit 222 performs focus adjustment, the face detection unit 221 detects a face from the imaging screen 10. The face detection unit 221 detects a face based on the light reception output of the photometric sensor 208. The face detection unit 221 detects a face using a known face detection technique. Since various techniques are known, description thereof will be omitted. For example, in FIG. 3, the face 20 is included in the imaging screen 10. The face detection unit 221 detects the face 20 and specifies the position and size of the face 20. Note that the face detection unit 221 may detect a face using a member different from the photometric sensor 208. For example, in a camera having a so-called live view display function, it is possible to detect a face from an image pickup signal from the image pickup device 211 that is the basis of the live view display and displayed image data (so-called through image). . Alternatively, a face can be detected using a thumbnail image or a reduced image.

  Next, the focus detection device 210 detects the defocus amount of the imaging optical system 101 for each focus detection area. Thereafter, the focus adjustment unit 222 sets the face estimation range 21 on the imaging screen 10. The face estimation range 21 is a range in which it is estimated that a face corresponding to the selection area 11a exists. The focus adjustment unit 222 sets the face estimation range 21 as a range including the area above the selection area 11a. For example, in FIG. 3, the face estimation range 21 is a rectangle, and the lower side of the face estimation range 21 matches the lower side of the selection area 11a. In addition, the center position of the face estimation range 21 in the left-right direction matches the center position of the selection area 11a in the left-right direction.

  The focus adjustment unit 222 determines the size of the face estimation range 21 based on the size of the detected face 20. For example, in FIG. 3, the length of the face 20 in the vertical direction is HF, and the length in the horizontal direction is WF. The focus adjustment unit 222 sets the vertical length of the face estimation range 21 to HF × 3 and the horizontal length to WF × 2. Note that the size of the face estimation range 21 may be determined by a different calculation. For example, the focus adjustment unit 222 reduces the size of the face estimation range 21 when the size of the face is small. The focus adjustment unit 222 increases the size of the face estimation range 21 when the face size is large.

  The focus adjustment unit 222 determines whether or not the face 20 detected by the face detection unit 221 exists in the face estimation range 21. When the face 20 does not exist in the face estimation range 21, the focus adjustment unit 222 performs focus adjustment so that the subject existing at the position of the selection area 11a is in focus. In other words, the focus adjustment unit 222 adjusts the focus of the imaging optical system 101 based on the defocus amount detected for the selection area 11a.

  When the face 20 exists in the face estimation range 21, the focus adjustment unit 222 performs focus adjustment so that the face 20 is in focus. In other words, the focus adjustment unit 222 adjusts the focus of the imaging optical system 101 based on the defocus amount detected for the focus detection area 11 a existing at the position of the face 20.

  The reason for this is to focus more accurately on the subject desired by the user. For example, consider a case where a person who is doing sports or the like is imaged. At this time, if face detection is performed and the detected face is focused as in the prior art, there is a possibility that the irrelevant person reflected in the background can be focused. On the other hand, it is particularly difficult for the user to actively match the selection area 11a with the face of the target person, as long as the person is making a violent movement. This is because the face part is a relatively small part when the whole body of the person is considered.

  Therefore, in the present embodiment, the user adjusts the focus in accordance with the selection area 11 a not on the face 20 but on the body 22. Since the body 22 is relatively large compared to the face 20, such an operation is relatively easy for the user. Even when the selection area 11 a is aligned with the body 22, the focus adjustment unit 222 performs focus adjustment based on the face 20 corresponding to the body 22, and thus the face 20 considered to be desired by the user. Automatic focus adjustment is made for.

  Note that there may be a plurality of focus detection areas 11 at the position of the face 20. In other words, the face 20 may include a plurality of focus detection areas 11. In such a case, the focus adjustment unit 222 selects one closest focus detection area 11 from the focus detection areas 11 and performs focus adjustment based on the selected focus detection area 11.

  When a plurality of focus detection areas 11 are present at the position of the face 20, it is possible to adjust the focus by a method different from this. For example, an average value of the defocus amounts detected in the plurality of focus detection areas 11 may be calculated, and focus adjustment may be performed based on the average value. Alternatively, a weighted average value of the defocus amount detected in one or more of the plurality of focus detection areas 11 and the defocus amount detected in the selection area 11a is calculated, and focus adjustment is performed based on the weighted average value. May be performed. In this case, it is desirable to set a smaller weight in the selection area 11a than in the focus detection area 11 at the face 20 position. That is, it is desirable to perform focus detection with a focus on the focus detection area 11 positioned on the face 20 rather than the selection area 11a.

  FIG. 4 is a schematic diagram illustrating the imaging screen 10 including only one face 20a that is smaller than FIG. Since the face 20a in FIG. 4 is smaller than the face 20 in FIG. 3, the face estimation range 21 is also smaller than that in FIG.

  FIG. 5 is a schematic diagram illustrating the imaging screen 10 when the vehicle 26 is present in front of the person 25. In FIG. 5, the selection area 11 a points to the car 26. And since the person 25 was present by chance behind the car 26, the face 20b is located above the selection area 11a.

  Here, when the selection area 11a points to the car 26, it is estimated that the user intends to focus on the car 26. Nevertheless, since the face 20b is included in the face estimation range 21, if focus adjustment is performed according to the procedure described in FIG. 3 or FIG. 4, the face 20b is focused against the user's intention. .

  Therefore, the focus adjustment unit 222 compares the defocus amount of the face 20b included in the face estimation range 21 with the defocus amount of the selection area 11a. When these two defocus amounts are different by a predetermined amount (for example, an amount equivalent to 1 m), the selection area 11a is emphasized even though the face 20b is included in the face estimation range 21. Adjust the focus. In other words, in the case of FIG. 5, the focus adjustment unit 222 focuses on the car 26 instead of the face 20b.

  FIG. 6 is a schematic diagram illustrating the imaging screen 10 including two faces 20c and 20d. The focus adjustment unit 222 determines a face estimation range 21c having a size based on the size of one face 20c included in the imaging screen 10. The focus adjustment unit 222 also determines the face estimation range 21d having a size based on the size of the other face 20d included in the imaging screen 10. That is, the focus adjustment unit 222 individually determines the face estimation ranges 21c and 21d for each of the faces 20c and 20d included in the imaging screen 10.

  In the example of FIG. 6, the face estimation range 21d corresponding to the face 20d does not include the face 20d. On the other hand, the face estimation range 21c corresponding to the face 20c includes the face 20c. Therefore, the focus adjustment unit 222 performs focus adjustment based on the face 20c. That is, the face 20c is focused.

  FIG. 7 is a flowchart of the focus adjustment process. The focus adjustment process illustrated in FIG. 7 is a process included in a control program executed by the control unit 201. The control unit 201 executes the focus adjustment process illustrated in FIG. 7 in response to the user performing a predetermined focus adjustment operation (for example, a half-press operation of a release switch (not illustrated)).

  First, in step S <b> 10, the face detection unit 221 detects a face included in the imaging screen 10. In step S <b> 20, the focus detection device 210 detects the defocus amount of the imaging optical system 101 for each of the plurality of focus detection areas 11 provided on the imaging screen 10.

  In step S <b> 30, the focus adjustment unit 222 selects one unprocessed (unselected) face 20 from the detected faces 20. In step S40, the focus adjustment unit 222 determines the face estimation range 21 having a size based on the size of the face 20 selected in step S30. In step S50, the focus adjustment unit 222 determines whether or not the face estimation range 21 set in step S40 includes the face 20 selected in step S30.

  When the face 20 is not included in the face estimation range 21, the focus adjustment unit 222 advances the process to step S60. In step S60, the focus adjustment unit 222 determines whether or not an unprocessed (unselected) face 20 remains. If an unprocessed (unselected) face 20 remains, the focus adjustment unit 222 advances the process to step S30. On the other hand, when all the faces 20 have been processed (selected), the focus adjusting unit 222 advances the process to step S70. In step S70, the focus adjustment unit 222 performs focus adjustment based on the selection area 11a. That is, the subject in the selection area 11a is focused.

  In step S50, when the selected face 20 is included in the face estimation range 21, the focus adjustment unit 222 advances the process to step S80. In step S80, the focus adjustment unit 222 determines whether the difference between the defocus amount detected in the focus detection area 11 existing at the position of the selected face 20 and the defocus amount detected in the selection area 11a is equal to or greater than a predetermined amount. Determine whether or not. If the defocus amount difference is equal to or greater than the predetermined amount, the focus adjusting unit 222 advances the process to step S30. On the other hand, when the difference in the defocus amount is less than the predetermined amount, the focus adjustment unit 222 advances the process to step S90. In step S90, the focus adjusting unit 222 focuses on the face 20 selected in step S30. That is, the focus adjustment unit 222 performs focus adjustment based on the focus detection area 11 present at the position of the face 20.

  The operation of the focus adjustment unit 222 in the tracking AF mode is the operation of the focus adjustment unit 222 in the selection area AF mode except that the focus detection area 11 existing at the position of the subject to be tracked is used instead of the selection area 11a. Since it is the same, description is abbreviate | omitted.

According to the imaging apparatus according to the first embodiment described above, the following operational effects can be obtained.
(1) The focus adjustment unit 222 detects the focus corresponding to the face position when the detected face position is above the position of one selection area 11a selected from the plurality of focus detection areas 11. The focus adjustment of the imaging optical system 101 is performed based on the defocus amount detected for the area 11. On the other hand, when the position of the face is not above the position of the selection area 11a, the focus adjustment of the imaging optical system 101 is performed based on the defocus amount detected for the selection area 11a. Since this is done, it is possible to accurately focus on the subject intended by the user. Further, it is possible to prevent the user's face from being unintentionally focused.

(2) When the face 20 exists within the face estimation range 21 including the upper part of the selection area 11a, the focus adjustment unit 222 sets the defocus amount detected for the focus detection area 11 corresponding to the position of the face 20 Based on this, the focus of the imaging optical system 101 is adjusted. Since this is done, it is possible to accurately focus on the subject intended by the user.

(3) The focus adjustment unit 222 determines the size of the face estimation range 21 based on the size of the face 20. Since it did in this way, focus adjustment to the face 20 can be performed reliably without being influenced by the perspective (large or small) of the face 20.

(4) When the face detection unit 221 detects a plurality of faces 20, the focus adjustment unit 222 determines a face estimation range 21 having a size corresponding to the size of the face 20 for each of the plurality of faces 20. . Since it did in this way, the focus adjustment to the face 20 can be reliably performed even when the perspective (large and small) of the face 20 is different.

(5) The focus adjustment unit 222 detects the defocus amount detected for the focus detection area 11 corresponding to the position of the face 20 and the selection area 11a even if the face 20 is positioned above the position of the selection area 11a. If the determined defocus amount differs by a predetermined amount or more, the focus adjustment of the imaging optical system 101 is performed based on the defocus amount detected for the selection area 11a. Since it did in this way, even if it is a case where the face 20 is accidentally located above the selection area 11a, it can prevent focusing on the face 20 contrary to a user's intention.

(6) The superimpose display unit 204 displays the position of the selection area 11a superimposed on the imaging screen 10. Since it did in this way, a user can grasp | ascertain correctly the subject used as the object of focus adjustment.

  The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.

(Modification 1)
The first embodiment described above may be provided with a posture detection unit that detects the posture of the imaging device 1. Such a posture detection unit can be realized by combining, for example, an acceleration sensor and a gyro sensor. When the posture detection unit is provided, the focus adjustment unit 222 can regard a direction based on the posture detected by the posture detection unit (for example, a direction opposite to the vertical direction) above the selection area 11a.

According to the modification 1, in addition to the operational effects (1) to (6) described in the first embodiment, the following operational effects are obtained.
(7) The focus adjustment unit 222 considers the direction based on the posture detected by the posture detection unit to be above the selection area 11a. By doing in this way, the face estimation range 21 can be set to a position where the face 20 is more likely to be detected, regardless of the posture in which the user holds the imaging device 1.

(Modification 2)
2. Description of the Related Art There is known a focus adjustment device that can repeatedly perform focus adjustment and maintain a state in which a moving object is in focus. In the first embodiment described above, when the focus adjustment is repeatedly performed as described above, the focus adjustment unit 222 changes the size of the face estimation range 21 according to the defocus amount at the previous focus adjustment. You may make it make it.

  For example, consider maintaining a state in which a person who is exercising is in focus. At this time, the user tries to hold the selection area 11a in the body part of the person. The focus adjustment unit 222 focuses on the person's face. Here, if the person moves greatly and the selection area 11a deviates from the body part, the face 20 also moves greatly, so the possibility that the face 20 deviates from the face estimation range 21 is high. As described above, when the defocus amount detected this time for the selection area 11a is different from the defocus amount previously detected for the selection area 11a by a predetermined amount (for example, an amount equivalent to 1 m), the focus adjustment unit 222 The size of the estimation range 21 is expanded.

According to the modified example 2, in addition to the operational effects (1) to (6) described in the first embodiment, the following operational effects are obtained.
(8) The focus adjustment unit 222 increases the size of the face estimation range 21 when the defocus amount detected this time for the selection area 11a differs from the defocus amount detected last time for the selection area 11a by a predetermined amount or more. To do. Since it did in this way, even if it is a case where a to-be-photographed object is imaged, it can continue to focus on the subject.

(Modification 3)
In the first embodiment described above, even when the focus detection area 11 corresponding to the position of the face 20 is actually focused, the superimpose display unit 204 displays only the selection area 11a on the imaging screen. 10 was displayed. The superimpose display unit 204 may superimpose and display the focus detection area 11 corresponding to the position of the face 20 on the imaging screen 10. This is schematically shown in FIG. In FIG. 9A, the focus detection area 11b existing at the position of the face 20 is displayed in the same form as the selection area 11a.

  As shown in FIG. 9A, both the focus detection area 11 corresponding to the position of the face 20 and the selection area 11a may be displayed, or the focus detection area 11b corresponding to the position of the face 20 may be displayed. Only the display may be performed and the selection area 11a may not be displayed. Further, the display of the focus detection area 11b corresponding to the position of the face 20 and the display of the selection area 11a may be performed in different forms. For example, the color of the frame line may be changed, or one of them may blink. FIG. 9B shows an example in which decoration is added to the frame line of the focus detection area 11 b corresponding to the position of the face 20.

According to the modified example 3, in addition to the operational effects (1) to (6) described in the first embodiment, the following operational effects are obtained.
(9) When the focus adjustment unit 222 performs focus adjustment of the imaging optical system 101 based on the defocus amount detected for the focus detection area 11 corresponding to the position of the face 20, The position of the focus detection area 11 is displayed superimposed on the imaging screen 10. Since it did in this way, the user can grasp | ascertain exactly the focus detection area 11 which is actually focused.

(Modification 4)
In the first embodiment described above, as shown in FIG. 2 and the like, for each face 20, the face estimation range 21 that matches the size is set above the selection area 11a. The positional relationship between the face 20 and the selection area 11a by the focus adjustment unit 222 can be checked by a different method.

  For example, as shown in FIG. 8A, a selected area estimation range 41e is set instead of the face estimation range 21 for the detected face 20e. The selection area estimation range 41e is a quadrangular region, and is arranged such that the center position in the left-right direction matches the center position of the face 20e, and the upper side matches the upper side of the face 20e. The focus detection unit 222 determines whether or not the selection area 11a is included in the corresponding selection area estimation range 41e for the face 20e. When the selection area 11a is included, focus adjustment is performed based on the focus detection area 11 existing at the position of the face 20e instead of the selection area 11a. Similarly, a selection area estimation range 41f is set for the detected face 20f, and it is determined whether or not the selection area 11a is included in the selection area estimation range 41f. In FIG. 8A, the selection area estimation range 41e does not include the selection area 11a, and the selection area estimation range 41f includes the selection area 11a. Therefore, the focus adjustment unit 222 performs focus adjustment based on the face 20f.

  That is, in the first embodiment described above, in order to determine whether or not the face 20 is positioned above the selection area 11a, the face estimation range 21 is arranged based on the selection area 11a. On the other hand, in the example shown in FIG. 8A, in order to determine whether or not the face 20 is positioned above the selection area 11a, the selection area estimation range 41 is arranged with the face 20 as a reference.

  A simpler example is shown in FIG. In FIG. 8B, the focus detection area 11 at least partially overlapping with the face 20 is displayed by shading. The focus adjustment unit 222 does not set the face estimation range 21 or the selection area estimation range 41 at all, and simply determines whether the shaded focus detection area 11 is included in the focus detection area 11 arranged above the selection area 11a. judge. When such a focus detection area 11 exists, focus adjustment is performed based on the focus detection area 11. That is, focus adjustment is performed by determining whether the face 20 exists above the selection area 11a.

  As described above, the positional relationship between the face 20 and the selection area 11a by the focus adjustment unit 222 can be checked by various methods. Regardless of which method is used, the effect (1) described in the first embodiment can be obtained.

(Modification 5)
The focus adjustment unit 222 may determine the face estimation range 21 at a different position according to the orientation of the face 20. For example, when the face 20 faces the lower right direction or the upper left direction of the imaging screen 10, the face estimation range 21 is determined so as to include the upper right side of the selection area 11a. Further, when the face 20 faces the upper right direction or the lower left direction of the imaging screen 10, the face estimation range 21 is determined so as to include the upper right of the selection area 11a. That is, the focus adjustment unit 222 checks whether the selection area 11a is located in the body direction estimated from the orientation of the face 20, and focuses on the face 20 when such a positional relationship is satisfied. Further, the face estimation range 21 may be determined from the orientation of the subject's head and the orientation of the face 20. For example, when the head is facing downward and the face 20 is facing the lower right direction or the upper left direction of the imaging screen 10, the face estimation range 21 is determined so as to include the lower left of the selection area 11a. When the head is facing downward and the face 20 is facing the upper right direction or the lower left direction of the imaging screen 10, the face estimation range 21 is determined so as to include the lower right side of the selection area 11a. That is, the focus adjustment unit 222 checks whether the selection area 11a is located in the body direction estimated from the orientation of the subject's head and the face 20, and if such a positional relationship is satisfied, the face 20 Focus on.

According to the modified example 5, in addition to the operational effects (1) to (6) described in the first embodiment, the following operational effects are obtained.
(10) The focus adjustment unit 222 sets the face estimation range 21 so as to include a range of directions according to the orientation of the face 20 when viewed from the selection area 11a. Since it did in this way, it can perform focusing reliably irrespective of what kind of pose the subject has taken.

(Modification 6)
As an example of a condition for performing focus adjustment based on the selection area 11a even though the face 20 is included in the face estimation range 21, in the first embodiment, the defocus amount of the selection area 11a and the face 20 The condition that the defocus amount of the focus detection area 11 is somewhat different is presented. Other conditions may be set.

  For example, when the reliability of the defocus amount of the focus detection area 11 located on the face 20 is smaller than a predetermined threshold, that is, when the probability of the defocus amount is less than a certain value, the selection area 11a Focus adjustment may be performed based on the defocus amount. Further, the same determination may be made regarding the reliability of face detection by the face detection unit 221.

According to the modified example 6, in addition to the operational effects (1) to (6) described in the first embodiment, the following operational effects are obtained.
(11) The focus adjustment unit 222 trusts the defocus amount detected for the focus detection area corresponding to the position of the face 20 even if the position of the face 20 and the position of the selection area 11a satisfy a predetermined positional relationship. When the degree is less than the predetermined threshold value, focus adjustment of the imaging optical system 101 is performed based on the defocus amount detected for the selection area 11a. Since it did in this way, it can focus on a desired subject reliably.

  As described above, the first embodiment and the modification thereof have been described based on the interchangeable lens digital camera, but an embodiment different from this can also be realized. For example, the above-described focus adjustment processing may be performed in a lens-integrated camera instead of the interchangeable lens camera, or the above-described focus adjustment processing may be performed in a film camera instead of a digital camera. Moreover, you may perform the focus adjustment process mentioned above in the camera of a smart phone or a tablet terminal.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... Imaging device, 100 ... Interchangeable lens, 101 ... Imaging optical system, 200 ... Camera body, 201 ... Control part, 204 ... Superimpose display part, 208 ... Photometric sensor, 210 ... Focus detection apparatus, 221 ... Face detection Part, 222 ... focus adjustment part

Claims (6)

An imaging unit that captures an image of a subject formed by the optical system and outputs imaging data;
A face detection unit that detects a face from the captured image of the subject based on the imaging data ;
A focus detection unit for detecting a focus adjustment state of the optical system in a plurality of focus detection areas set in an imaging region for capturing an image of the subject ;
When a plurality of faces are detected by the face detection unit, the size of each of the plurality of faces is selected from the plurality of faces with respect to the position of at least one selection area selected from the plurality of focus detection areas. Based on the specified position,
A focus adjustment unit that performs focus adjustment of the optical system based on a focus adjustment state detected for a focus detection area corresponding to the position of the identified face of the plurality of focus detection areas ;
A focus adjustment device. The focus adjustment apparatus according to claim 1,
The focus adjusting unit is configured as the predetermined positional relationship.
A first range of sizes including the selection area and based on a size of a first face of the plurality of faces;
A second range having a size based on a size of a second face of the plurality of faces including the selection area;
The focus detection area corresponding to the position of the first face of the plurality of focus detection areas when the first face is in the first range and the second face is not in the second range. A focus adjustment device that performs focus adjustment of the optical system based on the focus adjustment state detected in (1) .   An imaging unit that captures an image of a subject formed by the optical system and outputs imaging data;
  A face detection unit that detects a face from the captured image of the subject based on the imaging data;
  A focus detection unit for detecting a focus adjustment state of the optical system in a plurality of focus detection areas set in an imaging region for capturing an image of the subject;
  When a face is detected by the face detection unit, a predetermined positional relationship is determined based on the difference between the focus adjustment state detected last time and the focus adjustment state detected this time, and the size of the detected face, A focus corresponding to the position of the face in the plurality of focus detection areas when the position of the face and the position of at least one selection area selected from the plurality of focus detection areas satisfy the predetermined positional relationship. The focus adjustment of the optical system is performed based on the focus adjustment state detected in the detection area, and the focus detected in the selection area if the position of the face and the position of the selection area do not satisfy the predetermined positional relationship. A focus adjustment unit for adjusting the focus of the optical system based on an adjustment state;
A focus adjustment device.   In the focus adjustment apparatus according to any one of claims 1 to 3,
  The focus detection unit is a focus adjustment device that detects a defocus amount that is a shift amount between a position of an image of a subject formed by the optical system and an imaging surface of the imaging unit as a focus adjustment state of the optical system.   In the focus adjustment apparatus according to any one of claims 1 to 4,
  A focus adjustment apparatus comprising: a display that displays a position of the selected area; a display that indicates a position of a focus detection area that performs focus adjustment based on a focus state; and a display that displays an image of the subject. A camera provided with the focus adjustment apparatus as described in any one of Claim 1- Claim 5 .

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