JP2016126299A - Imaging apparatus, method for controlling the same, imaging system, program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of performing an accurate automatic focus adjustment operation, even when the position of a focus lens cannot be acquired at a proper timing.SOLUTION: The imaging apparatus includes a focus adjustment part which calculates a focus evaluation value indicating the contrast of a focus detection area on the basis of image data formed by a photographic lens, while moving a focus lens in an optical axis direction and adjusts the position of the focus lens so as to make the focus evaluation value maximum, a first acquisition part which acquires the focus evaluation value from an image captured at a first timing, a second acquisition part which acquires the position of the focus lens by communication with the photographic lens at a second timing, a storage part which stores the focus evaluation value and the position of the focus lens in the acquisition order, and a control part which associates the position of the focus lens with the focus evaluation value, when being in such a state that both of the position of the focus lens and the focus evaluation value are stored in the storage part at the first timing or the second timing.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an automatic focus detection technique in an imaging apparatus such as a digital camera or a video camera.

  Conventionally, in a digital camera or the like, as a method of moving a focus lens to focus on a subject, a contrast detection type autofocus (AF) that automatically performs a focusing operation using an image signal obtained from an image sensor such as a CCD is used. ) Is used. In this AF method, the lens position is periodically acquired and stored while moving the focus lens, and at the timing when a high frequency component (hereinafter referred to as a focus evaluation value) of the luminance signal obtained from the image sensor is generated. Correlate with saved lens position. Then, the focus lens is moved to the lens position where the focus evaluation value is maximized to focus.

  Here, in the interchangeable lens single-lens reflex camera system, the position of the focus lens is acquired from the interchangeable lens by communication between the camera body and the interchangeable lens. At this time, there are cases where the acquisition timing of the lens position is delayed or the lens position cannot be acquired due to obstruction by other communication processing. In such a case, the above-described association between the focus evaluation value and the lens position may not be accurate, and the focus detection accuracy may decrease.

  In relation to this, in Patent Document 1, in the autofocus of the contrast detection method, the camera body periodically generates a timing, and periodically obtains and associates the focus evaluation value and the lens position according to the timing. However, a method for performing focusing control has been proposed. Further, Patent Document 2 acquires lens position information at a predetermined interval, stores the lens position information together with time information, and lens position information corresponding to the focus evaluation value when the calculation of the focus evaluation value is completed. A method of selecting is proposed.

JP 2008-242442 A JP 2009-199047 A

  However, in the technique described in Patent Document 1, as described above, when the lens position cannot be acquired because communication between the camera body and the interchangeable lens is obstructed by other processing, the lens position that is not at the exposure timing. And the focus evaluation value may be associated with each other. Therefore, there is a problem that the focus detection accuracy is lowered.

  Further, in the technique described in Patent Document 2, when the acquisition of the lens position is delayed by other processing, there is no lens position associated with the focus evaluation value when the focus evaluation value is acquired. There is a problem that the association itself is not possible.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an imaging apparatus that enables an accurate automatic focus adjustment operation even when the position of the focus lens cannot be acquired at an appropriate timing. is there.

  An imaging apparatus according to the present invention is an imaging apparatus in which a photographic lens is replaceably mounted, and an object image formed by the photographic lens while moving a focus lens provided in the photographic lens in an optical axis direction. A focus adjustment unit that calculates a focus evaluation value indicating the contrast of the focus detection region based on the image data obtained by capturing the image and adjusts the position of the focus lens so that the focus evaluation value is maximized; and a first timing. A first acquisition unit that acquires the focus evaluation value from the image captured in step 2; a second acquisition unit that acquires a position of the focus lens through communication with the photographing lens at a second timing; and the first acquisition unit. Storage means for storing the focus evaluation value and the position of the focus lens in the order of acquisition in each of the first acquisition means and the second acquisition means; Control means for associating the position of the focus lens with the focus evaluation value when the position of the focus lens and the focus evaluation value are stored in the storage means at the time of the imming or the second timing. And.

  According to the present invention, it is possible to provide an imaging apparatus that enables an accurate automatic focus adjustment operation even when the position of the focus lens cannot be acquired at an appropriate timing.

1 is a block diagram showing a configuration of a camera system that is an embodiment of an imaging apparatus of the present invention. 6 is a flowchart for explaining the operation of the imaging apparatus according to the embodiment. 6 is a flowchart for explaining an AF operation of the imaging apparatus according to the embodiment. 4 is a flowchart for explaining a read operation in FIG. 3. FIG. 4 is a flowchart for explaining a focus evaluation value generation operation in FIG. 3. FIG. 4 is a flowchart for explaining a lens communication operation in FIG. 3. 7 is a flowchart for explaining calculation of an exposure center lens position in FIGS. The figure explaining calculation of the exposure center lens position in FIG. The figure which showed the specific operation example which matches the focus evaluation value and exposure center lens position which were demonstrated in FIG. 5 and FIG.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a configuration of a camera system (imaging system) which is an embodiment of an imaging apparatus of the present invention. As shown in FIG. 1, the interchangeable lens 100 is detachably mounted on the digital camera body 200 via a lens mount 106 having an electrical contact unit 106a.

  101 is a photographing lens for forming a subject image including a zoom mechanism, 102 is an aperture and shutter for controlling the amount of light, 103 is a focus lens for focusing on an image sensor to be described later, and 104 drives the focus lens. It is a motor. A lens controller 105 controls the entire interchangeable lens 200. Reference numeral 201 denotes an image sensor that converts reflected light from an object into an electrical signal. Reference numeral 202 denotes a CDS circuit that removes output noise of the image sensor 201 and a non-linear amplifier circuit that is performed before A / D conversion, and an A / D converter that outputs image data. 203 is an image processor. . Reference numeral 205 denotes a high-speed built-in memory (for example, a random access memory or the like, hereinafter referred to as DRAM), 206 denotes an image recording unit including a recording medium such as a memory card and its interface, and 207 denotes a timing generator. Reference numeral 208 denotes a system control unit (hereinafter referred to as a CPU) that controls the photographing sequence and controls the entire camera system. Reference numeral 209 denotes a lens communication unit that performs communication between the camera body 200 and the interchangeable lens 100, 210 denotes an AF processing unit that performs automatic focus adjustment processing, and 211 denotes an AE processing unit that performs exposure control processing. Reference numeral 212 denotes an image display memory (hereinafter referred to as VRAM). An image display unit 213 displays an image after shooting, a display for assisting operation, a display of a camera state, a shooting screen at the time of shooting, a focus detection area, and the like. Reference numeral 214 denotes an operation unit for operating the camera from the outside. Reference numeral 215 denotes a shooting mode switch for selecting a shooting mode such as a macro mode or a sports mode. Reference numeral 216 denotes a main switch for turning on the system. A switch 217 is turned on when the release button is half-pressed, and a switch for performing a shooting standby operation such as AF processing or AE processing (hereinafter referred to as SW1). 218 is turned on when the release button is fully pressed. A shooting switch (hereinafter referred to as SW2). The DRAM 205 is used as a high-speed buffer for temporary image storage or as a working memory for image compression / decompression. The operation unit 214 includes, for example, a menu switch for performing various settings such as a shooting function setting of the imaging apparatus and a setting at the time of image reproduction, an operation mode switching switch between a shooting mode and a playback mode, and the like.

  Hereinafter, the operation of the camera system of the present embodiment will be described. FIG. 2 is a flowchart showing the overall operation of the camera system.

  First, in S201, the AE processing unit 211 performs AE processing for determining the shutter speed, sensitivity, aperture value, and the like according to the brightness of the subject from the output of the image processing unit 203, and proceeds to S202. In S202, the state of the switch SW1 (217) is checked. If it is ON, the process proceeds to S203, and if not, the process returns to S201. In S203, an automatic focus adjustment operation (AF operation) described later is performed, and the process proceeds to S204. Here, the exposure conditions (shutter speed, aperture, sensitivity) during the AF operation are determined by the AE process in S201 immediately before. In S204, the state of the switch SW1 (217) is checked. If it is ON, the process proceeds to S205, and if not, the process returns to S201. In S205, the state of the switch SW2 (218) is checked, and if it is ON, the process proceeds to S206, and if not, the process returns to S204. In S206, after performing a photographing operation, the process returns to S201.

  FIG. 3 is a flowchart for explaining the AF operation in S203 of FIG. First, in S301, a focus detection area is set as a predetermined area in the screen, and the process proceeds to S302. In S302, charge accumulation and charge readout operations for acquiring an image necessary for generating a focus evaluation value indicating the contrast of the image while moving the focus lens 103 in the optical axis direction are started, and then the process proceeds to S303. . The charge reading operation will be described later.

  In S303, the focus evaluation value generation operation is started, and the process proceeds to S304. The focus evaluation value generation operation will be described later. It should be noted that the focus evaluation value generation operation is repeated at a constant cycle after starting in S303. In S304, the lens position acquisition operation by the lens communication operation is started, and the process proceeds to S305. The lens communication operation will be described later. It should be noted that the lens communication operation starts at S304 and is repeated at a constant cycle unless another process is entered. Further, the focus evaluation value generation operation in S303 and the lens position acquisition operation by the lens communication operation in S304 are performed alternately in time.

  By performing a series of operations in S302 to S304, each of charge accumulation and charge readout operations for acquiring an image necessary for generating a focus evaluation value, focus evaluation value generation operation, and lens communication operation is performed periodically. Is called.

  In S305, it is checked whether LinkFlg, which will be described later, is TRUE. If TRUE, the process proceeds to S306, and if not, the process proceeds to S308. Note that LinkFlg indicates that the focus evaluation value and the lens position at the exposure center corresponding to the focus evaluation value are aligned. In S306, the focus evaluation value peak determination is performed using the focus evaluation value and the exposure center lens position described later, and the process proceeds to S307. Here, the focus evaluation value peak determination determines whether or not the subject is to be focused based on the shape of the peak, and if the subject is to be focused, calculates the lens position where the focus evaluation value is the maximum and calculates the focus position. And Since the method of determining the peak shape is not the main point of the present embodiment, detailed description thereof is omitted.

  In S308, it is checked whether ExpStartFlg, which will be described later, is TRUE. If TRUE, the process proceeds to S309, and if not, the process proceeds to S310. In S309, the moving speed of the focus lens 103 is determined based on the focus evaluation value to perform lens drive control, and then the process proceeds to S310. In S310, ExpStartFlg is set to FALSE, and the process proceeds to S311. In S311, whether or not to end the AF operation is checked based on the result determined in S306. If the AF operation is to be ended, the process proceeds to S312; otherwise, the process returns to S305. In S312, the focus lens 103 is moved to the in-focus position calculated in S306, and then the process proceeds to S313. In S313, after stopping the above-described charge accumulation and charge reading operations, the process proceeds to S314. In S314, the focus evaluation value generation operation described above is stopped, and the process proceeds to S315. In S315, the lens communication operation described above is stopped and the AF operation is terminated.

  FIG. 4 is a flowchart for explaining the read operation started in S302 in FIG. First, in S401, it is checked whether or not the current time is the read start timing. If it is the read timing, the process proceeds to S402. In S402, FrmID which is the ID of the frame from which reading is started is incremented, and the process proceeds to S403. With this FrmID, it is possible to confirm the correlation between EvaFrmID, which is an ID of a frame that generates a focus evaluation value, which will be described later, and LensFrmID, which is an ID of a frame, which acquires a lens position, which will be described later. In S403, it is checked whether or not the difference between FrmID and EvaFrmID is larger than a predetermined value. If the difference is larger than the predetermined value, the process proceeds to S406, and if not, the process proceeds to S404. In S404, it is checked whether or not the difference between FrmID and LensFrmID is larger than a predetermined value. If the difference is larger than the predetermined value, the process proceeds to S406, and if not, the process proceeds to S405. In S405, ExpStartFlg is set to TRUE and this flow ends. In S406, after performing error processing such as determining whether the focus evaluation value is generated or the lens communication is not performed for a predetermined time or more based on the determination in S403 or S404, the AF operation is terminated. End the flow.

  FIG. 5 is a flowchart for explaining the focus evaluation value generation operation started in S303 in FIG. First, in S501, it is checked whether or not a focus evaluation value has been generated. If it has been generated, the process proceeds to S502, and if not, the process waits as it is. In S502, EvaFrmID, which is the ID of the frame that generated the focus evaluation value, is incremented, and the process proceeds to S503. In S503, the focus evaluation values are stored in the buffer in the order of generation, and the process proceeds to S504. In S504, it is checked whether or not the lens position is stored in the buffer by a lens communication operation to be described later. If it is stored, the process proceeds to S505, and if not, this flow ends. In S505, the oldest lens position stored in the buffer is taken out, and the oldest lens position is deleted from the buffer, and the process proceeds to S506. The deleted lens position is stored as BefPos in a storage unit different from the buffer in S711 of FIG. 7 described later. In S506, the lens position (StdPos) extracted in S505 and the lens position previously stored in a storage unit different from the buffer (the lens position stored as BefPos in S711 in FIG. 7 as described above) are used. After calculating the exposure center lens position (the position of the focus lens 103 at the center of the exposure period) which will be described later, the process proceeds to S507. In S507, the LinkFlg indicating that both the focus evaluation value and the exposure center lens position corresponding to the focus evaluation value are set to TRUE is set, and this flow is finished. As will be described later with reference to FIG. 6, when the focus evaluation value is not stored in the buffer despite the lens position information being distributed, a plurality of lens positions are stored in the buffer (in S606). In the case of No). In this case, the focus evaluation value is not obtained because it cannot be acquired even if the timing at which the focus evaluation value is generated is delayed. Therefore, by extracting the oldest lens position stored in the buffer in S505, the focus evaluation value and the lens position can be properly associated.

  FIG. 6 is a flowchart for explaining the lens communication operation started in S304 in FIG. First, in S601, it is checked whether or not lens position information has been distributed. If distributed, the process proceeds to S602, and if not, the process waits as it is. In S602, LensFrmID which is the ID of the frame to which the lens position is distributed is incremented, and the process proceeds to S603. In S603, SkipCnt is added to LensFrmID, and the process proceeds to S604. This SkipCnt indicates the number of frames for which lens position information was not delivered because the lens communication operation was hindered by other processing, and adding the SkipCnt prevents the above-mentioned correlation between FrmID and EvaFrmID from becoming an error. Can be. In S604, focus evaluation values are deleted from the old ones by the number of SkipCnts, and the process proceeds to S605. By deleting the focus evaluation values by the number of SkipCnts, the correspondence between the focus evaluation values and the lens positions can be prevented from being erroneous. In S605, the lens position distributed in the buffer is stored, and the process proceeds to S606. In S606, it is checked whether or not the focus evaluation value is stored in the buffer. If it is stored, the process proceeds to S607, and if not, this flow ends. In S607, the oldest focus evaluation value stored in the buffer is extracted, and the oldest one is deleted from the buffer, and the process proceeds to S608. In S608, an exposure center lens position to be described later is calculated, and the process proceeds to S609. In S609, LinkFlg indicating that the focus evaluation value and the exposure center lens position corresponding to the focus evaluation value are set to TRUE is set to TRUE, and this flow ends.

  FIG. 7 is a flowchart for explaining the calculation of the exposure center lens position in FIGS. FIG. 8 is a diagram for explaining the calculation of the exposure center lens position of FIG. A method for calculating the exposure center lens position will be described with reference to FIGS.

  First, in S701, the center line Vaf of the focus detection area shown in FIG. 8 is calculated, and the process proceeds to S702. In S702, it is checked whether or not the exposure center lens position calculation is the first time. If it is the first time, the process proceeds to S710, and if not, the process proceeds to S703. In S703, it is determined whether or not the lens is currently stopped. If it is stopped, the process proceeds to S710, and if not, the process proceeds to S704.

  In S704, as shown in FIG. 8, PosDiff, which is the difference between the lens position BefPos distributed in the previous lens communication and the lens position StdPos distributed in the current lens communication, is calculated, and the process proceeds to S705. In S705, it is checked whether SkipCnt is 1 or more. If 1 or more, the process proceeds to S706, and if not, the process proceeds to S707. In S706, a value obtained by dividing PosDiff by SkipCnt is newly set as PosDiff, and the process proceeds to S707. Thereby, even if there is a timing at which the lens communication operation is inhibited by other processing and the lens position cannot be distributed, the exposure center lens position can be calculated using the lens position distributed at the previous timing. .

  In S707, the exposure completion lens position FirstLineCompPos (see FIG. 8) of the uppermost line of the focus detection area set in S301 is calculated as follows, and the process proceeds to S708.

FirstLineCompPos = StdPos + (PosDiff x DifTime-DelayTime) / FrameTime)
If the lens communication operation operates normally without being obstructed by other processing, the lens moves by PosDiff during one frame time FrameTime. Based on the lens movement amount PosDiff, the lens movement amount is calculated from the lens communication operation to DifTime, which is the difference in exposure completion time, thereby calculating the exposure completion lens position. Further, when the lens communication operation is hindered by other processing and delayed by DelayTime, it can be corrected by the lens movement amount at that time.

  In S708, as in S707, PosDiff is used as a reference, and the exposure center lens position FirstLineCenterPos of the uppermost line is calculated as follows using the exposure time ExpTime, and the process proceeds to S709.

FirstLineCenterPos = FirstLineCompPos-PosDiff x ExpTime / (FrameRate x 2)
In S709, as in S707 and S708, using PosDiff as a reference, the exposure center lens of the central line of the focus detection area is obtained using the time ImageReadoutTime for reading the entire focus detection area, the number of vertical lines Vall of the entire focus detection area, and the Vaf described above. The position ExpCenterPos is calculated as follows, and the process proceeds to S711.

ExpCenterPos
= FirstLineCenterPos + PosDiff x (ImageReadoutTime / FrameRate) x (Vaf / Vall)
In S710, the lens position StdPos distributed by the current lens communication is assigned to ExpCenterPos, and the process proceeds to S711. In S711, StdPos is substituted for BefPos, which is the lens position distributed in the previous lens communication, and this flow ends.

  Next, FIG. 9 is a diagram showing a specific operation example in which the focus evaluation value and the exposure center lens position described in FIGS. 5 and 6 are associated with each other. In FIG. 9A, the focus evaluation value is obtained at the timing when the digital camera body 200 can acquire the lens position of the focus lens 103 by adding other processing to the communication between the interchangeable lens 100 and the digital camera body 200. An example in the case of being delayed from the timing is shown. FIG. 9B shows an example in which the digital camera body 200 cannot acquire the lens position due to other processing added to the communication between the interchangeable lens 100 and the digital camera body 200.

  First, in FIG. 9A, the flow of the lens communication operation of FIG. 6 starts at the beginning of the autofocus operation. At time t1, the digital camera body 200 can acquire the lens position Pos3 of the focus lens 103 by the lens communication. To do. In this case, since the lens position Pos3 is the lens position that can be acquired first, the lens position Pos3 is stored in the buffer in S605, and the focus evaluation value has not yet been acquired in S605, so No in S606. The flow in FIG. 6 ends.

  Further, it is assumed that the flow of the focus evaluation value generation operation of FIG. 5 is executed in parallel with the processing of FIG. 6, and the first focus evaluation value Eva3 is generated at time t2. In this case, the focus evaluation value Eva3 is stored in the buffer in S503. In S504, since the lens position Pos3 is stored in the buffer, the result in S504 is Yes, and the flow proceeds to S505. In S505, the oldest lens position, that is, Pos3 is extracted. In S506, the lens position (StdPos = Pos3) extracted in S505 and the lens position (BefPos = Pos2: see S711 in FIG. 7) previously stored in a storage unit different from the buffer are used. The position is calculated. As a result, the corresponding focus evaluation value Eva3 and the exposure center lens position calculated from Pos3 and Pos2 are aligned, and are associated with each other.

  Next, in the process of FIG. 5 again, it is assumed that the focus evaluation value Eva4 is generated at time t3. In this case, the focus evaluation value Eva4 is stored in the buffer in S503. Further, since the lens position is not stored in S504, No is obtained in S504, and the flow of FIG.

  Next, in the process of FIG. 6 again, it is assumed that the lens position Pos4 can be acquired at time t4. In this case, since the lens position cannot be acquired and there is no skipped frame, SkipCnt is 0 in S603, and LensFrmID = LensFrmID + 0. In step S604, the focus evaluation value is not deleted. In step S605, the lens position Pos4 is stored in the buffer. And it becomes Yes in S606 and a flow progresses to S607. In S607, the oldest focus evaluation value Eva4 of the stored focus evaluation values is taken out. In S608, the exposure center lens using the lens position (StdPos = Pos4) stored this time and the lens position (BefPos = Pos3: see S711 in FIG. 7) previously stored in a storage unit different from the buffer. The position is calculated. As a result, the corresponding focus evaluation value Eva4 and the exposure center lens position calculated from Pos4 and Pos3 are aligned, and are associated with each other.

  Thereafter, the above is repeated, and the focus evaluation value and the exposure center lens position corresponding to the focus evaluation value are successively associated.

  As described above, in the present embodiment, even when the communication timing of the focus lens position from the interchangeable lens 100 to the digital camera body 200 is shifted, the correspondence is made when the lens position and the focus evaluation value are aligned. Incorrect distance measurement due to matching can be prevented.

  Next, as shown in FIG. 9B, a case where the digital camera body 200 cannot acquire the lens position due to other processing added to the communication between the interchangeable lens 100 and the digital camera body 200 will be described.

  As indicated by a broken line in FIG. 9B, it is assumed that at time t3, other processing is added to the lens communication, the communication is delayed, and the digital camera body 200 cannot acquire the lens position Pos4. In this case, the focus evaluation value Eva4 is generated and stored in the buffer at time t4 (S501 to S503 in FIG. 5), but since the lens position is not stored, No in S504 and the flow in FIG. 5 ends. To do.

  Next, it is assumed that the lens position Pos5 can be acquired at the time t5 by the processing of FIG. In this case, the user is notified at this next timing that the lens position Pos4 could not be acquired at the previous time t3. In this case, since the lens position cannot be acquired and the skipped frame is one frame, SkipCnt is 1 in S603, and one focus evaluation value is deleted in S604. Here, the focus evaluation value Eva4 is deleted. In S605, the lens position Pos5 is stored in the buffer. In S605, the focus evaluation value Eva4 is deleted in the previous S604, and therefore it is determined that the focus evaluation value has not yet been acquired. Therefore, it becomes No in S606, and the flow of FIG.

  Next, it is assumed that the focus evaluation value Eva5 is generated again at time t6 in the process of FIG. In this case, the focus evaluation value Eva5 is stored in the buffer (S501 to S503 in FIG. 5). In S504, since Pos5 is already stored in the buffer at the lens position, the flow proceeds to S505. In S505, the oldest lens position, that is, the current Pos5 is taken out. In S506, exposure is performed using the lens position extracted in S505 (StdPos = Pos5) and the previous lens position (BefPos = Pos3: see S711 in FIG. 7) previously stored in a storage unit different from the buffer. A central lens position is calculated. As a result, the corresponding focus evaluation value Eva5 and the exposure center lens position calculated from Pos5 and Pos3 are aligned, and are associated with each other.

  Thereafter, the above is repeated, and the focus evaluation value and the exposure center lens position corresponding to the focus evaluation value are successively associated.

  As described above, in the present embodiment, even when the communication of the focus lens position from the interchangeable lens 100 to the digital camera body 200 is shifted and the lens position cannot be acquired, the lens position and the focus evaluation value are aligned. Make a correspondence. Therefore, it is possible to prevent erroneous distance measurement due to incorrect association.

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

(Other embodiments)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

100: interchangeable lens, 102: photographing lens, 103: focus lens, 106: lens mount, 200: digital camera body, 201: image sensor, 208: system control unit

Claims (13)

An imaging device in which a photographic lens is interchangeably mounted,
Based on the image data obtained by capturing the subject image formed by the photographing lens while moving the focus lens provided in the photographing lens in the optical axis direction, a focus evaluation value indicating the contrast of the focus detection region is calculated, Focus adjusting means for adjusting the position of the focus lens so that the focus evaluation value is maximized;
First acquisition means for acquiring the focus evaluation value from an image captured at a first timing;
Second acquisition means for acquiring a position of the focus lens by communication with the photographing lens at a second timing;
In each of the first acquisition unit and the second acquisition unit, a storage unit that stores the focus evaluation value and the position of the focus lens in the acquisition order;
When the position of the focus lens and the focus evaluation value are stored in the storage unit at the first timing or the second timing, the position of the focus lens and the focus evaluation value are Control means for associating
An imaging apparatus comprising:   The control means uses the position of the focus lens acquired by the second acquisition means and the position of the focus lens acquired last time by the second acquisition means, so that the control means at the center of the exposure period. The imaging apparatus according to claim 1, wherein the position of the focus lens is calculated.   If the position of the focus lens cannot be acquired at the second timing, the control means notifies that the position of the focus lens cannot be acquired at the next second timing. The imaging apparatus according to claim 1 or 2.   The control unit does not use the oldest focus evaluation value stored in the storage unit at the timing when the position of the focus lens cannot be acquired at the second timing. Item 4. The imaging device according to any one of Items 1 to 3.   The control means calculates the position of the focus lens at the center of the exposure period using the position of the focus lens last time when the position of the focus lens could not be acquired at the second timing. The imaging device according to any one of claims 2 to 4. An imaging system having a photographic lens and an imaging device to which the photographic lens is attached,
The taking lens is
A focus lens that focuses the subject image;
Driving means for driving the focus lens;
The imaging device
A focus evaluation value indicating the contrast of the focus detection area is calculated based on image data obtained by capturing the subject image formed by the photographing lens while moving the focus lens in the optical axis direction. Focus adjusting means for adjusting the position of the focus lens so that
First acquisition means for acquiring the focus evaluation value from an image captured at a first timing;
Second acquisition means for acquiring a position of the focus lens by communication with the photographing lens at a second timing;
In each of the first acquisition unit and the second acquisition unit, a storage unit that stores the focus evaluation value and the position of the focus lens in the acquisition order;
When the position of the focus lens and the focus evaluation value are stored in the storage unit at the first timing or the second timing, the position of the focus lens and the focus evaluation value are Control means for associating
An imaging system comprising:   The control means uses the position of the focus lens acquired by the second acquisition means and the position of the focus lens acquired last time by the second acquisition means, so that the control means at the center of the exposure period. The imaging system according to claim 6, wherein the position of the focus lens is calculated.   If the position of the focus lens cannot be acquired at the second timing, the control means notifies that the position of the focus lens cannot be acquired at the next second timing. The imaging system according to claim 6 or 7.   The control unit does not use the oldest focus evaluation value stored in the storage unit at the timing when the position of the focus lens cannot be acquired at the second timing. Item 9. The imaging system according to any one of Items 6 to 8.   The control means calculates the position of the focus lens at the center of the exposure period using the position of the focus lens last time when the position of the focus lens could not be acquired at the second timing. The imaging system according to any one of claims 7 to 9. A method for controlling an imaging device in which a photographic lens is interchangeably mounted,
Based on the image data obtained by capturing the subject image formed by the photographing lens while moving the focus lens provided in the photographing lens in the optical axis direction, a focus evaluation value indicating the contrast of the focus detection region is calculated, A focus adjustment step of adjusting the position of the focus lens so that the focus evaluation value is maximized;
A first acquisition step of acquiring the focus evaluation value from an image captured at a first timing;
A second acquisition step of acquiring a position of the focus lens by communication with the photographing lens at a second timing;
In each of the first acquisition step and the second acquisition step, a storage step of storing the focus evaluation value and the position of the focus lens in the order of acquisition;
When the position of the focus lens and the focus evaluation value are stored in the storing step at the first timing or the second timing, the position of the focus lens and the focus evaluation value are A control process to associate with
An image pickup apparatus control method comprising:   The program for making a computer perform each process of the control method of Claim 11.   A computer-readable storage medium storing a program for causing a computer to execute each step of the control method according to claim 11.

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