JP6351310B2 - Imaging apparatus, control method therefor, program, and storage medium - Google Patents

Description

  The present invention relates to an imaging apparatus that performs focus detection using an image signal acquired by an imaging element.

  In digital cameras and video cameras, a contrast detection type autofocus (hereinafter referred to as AF) that uses an output signal from an image sensor such as a CCD or CMOS sensor to detect and focus a signal according to a focus evaluation value of a subject. ) The method is common. In this focus detection system, the focus evaluation value of the object is sequentially detected (AF scan operation) while moving the focus lens in the optical axis direction over a predetermined movement range, and the focus lens position where the focus evaluation value is maximized is determined as the in-focus position. Detect as.

  However, the actual best image plane of the photographing optical system (imaging plane having the maximum luminous flux concentration or resolving power at the frequency felt by the observer: best focus position) and the focus position calculated by the focus detection system will be described later. There are many cases where a difference occurs due to the reason.

  The reason why the above best focus position correction is necessary will be described. The best image plane of the photographing optical system exists at a position shifted from the paraxial image plane due to the influence of spherical aberration, chromatic aberration, astigmatism and the like. On the other hand, because there is a difference between the spatial frequency band perceived by humans and the spatial frequency band used for focus detection, the focus position obtained by the focus detection system depends on the change in focus position for each spatial frequency caused by spherical aberration. A difference from the best image plane is created. In addition, since there is a difference in spectral sensitivity between the film or image sensor arranged on the imaging surface and the light receiving element of the focus detection system, the focus obtained by the best image plane of the imaging optical system and the focus detection system is also caused by chromatic aberration. There is a difference in position. Furthermore, when the evaluation direction of the focus detection system is only one direction, a difference is produced when a human determines the focus position from all directions of the captured image. Therefore, the best image of the photographing optical system is also caused by astigmatism. There is a difference between the surface and the in-focus position obtained by the focus detection system. The best focus correction amount is for correcting the driving amount of the focus lens in consideration of this difference.

  However, even if the drive amount of the focus lens is calculated using the best focus correction amount before the focus drive, the aberration of the photographing optical system may change due to the movement of the focus lens. In this case, since there is a difference between the best focus correction amount before the focus drive, if the focus position correction after the focus drive is performed using the best focus correction amount at the position before the focus drive, the degree of focus is sufficient. Or AF may need to be redone. For this reason, in the imaging device disclosed in Patent Document 1, based on the focus defocus amount obtained in advance by the focus detection system, the best focus correction at the focus lens position after the focus drive is performed before the focus drive. Find the amount. Then, a focus drive amount for focus drive is obtained.

JP 2008-241733 A

  However, in the conventional focus detection system based on the contrast detection method, since the focus drive amount cannot be obtained in advance, the best focus correction amount after the focus drive cannot be obtained. Further, in the case of the contrast detection method, the focus drive amount from the focus lens position that has passed the best image plane to the detected best image plane having the maximum focus evaluation value is obtained. However, if communication is performed again from that position and the best focus correction amount is calculated, it takes time to detect the focus.

  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 can accurately detect a focus by predicting the best focus correction amount at the best image plane position. is there.

An imaging apparatus according to the present invention includes a control unit that controls a driving unit that drives a part of a photographing optical system to adjust a focus, an imaging element that photoelectrically converts a subject image formed by the photographing optical system, From the signal obtained from the image sensor, an evaluation value calculation unit that calculates a focus evaluation value, a focus position calculation unit that calculates a focus position from the focus evaluation value, and the focus position calculation unit calculates the focus. Acquiring the correction amount at each position of the imaging optical system from a correction amount storage unit that stores the correction amount of the in-focus position for each imaging parameter of the imaging apparatus, before calculating the position; and Determination means for determining whether or not the correction amount is acquired by the acquisition means based on a focus evaluation value, and the control means calculates the focus position calculated by the focus position calculation means. , Get the above It corrected using the correction amount obtained by the step, characterized in that operating the driving unit.
In addition, an imaging apparatus according to the present invention includes a control unit that controls a driving unit that drives a part of a photographing optical system for focusing, and an imaging element that photoelectrically converts a subject image formed by the photographing optical system. A focus position calculating means for performing a scanning operation for obtaining a focus evaluation value from a signal obtained from the image sensor and calculating a focus position based on the focus evaluation value; and An acquisition unit that acquires the correction amount at each position of the photographing optical system from a correction amount storage unit that stores a correction amount of the focusing position for each photographing parameter of the imaging apparatus, before calculating the in-focus position; Determination means for determining whether or not to acquire the correction amount by the acquisition means based on the mode of the scanning operation, and the control means is calculated by the in-focus position calculation means The focus position is corrected using the acquired correction amount by the acquisition unit, and wherein the operating the drive means.

  According to the present invention, it is possible to provide an imaging apparatus that can accurately detect a focus by predicting the best focus correction amount at the best image plane position.

1 is a block diagram showing a schematic configuration of an imaging apparatus according to a first embodiment of the present invention. 5 is a flowchart showing an AF operation procedure in the first embodiment. The figure which showed the relationship between the focus evaluation value and BP correction value in the 1st method of 1st Embodiment. The figure which showed the relationship between the focus evaluation value and BP correction value in the 2nd method of 1st Embodiment. The figure which showed the relationship between the focus evaluation value and BP correction value in the 3rd method of 1st Embodiment. FIG. 5 is a diagram illustrating a focus lens driving amount in the first embodiment. 9 is a flowchart showing an AF operation procedure in the second embodiment. The figure which showed the relationship between the lens position and BP correction value in the 1st method of 2nd Embodiment. The figure which showed the relationship between the lens position and BP correction value in the 2nd method of 2nd Embodiment.

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

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of an imaging apparatus having a focus adjustment apparatus according to the first embodiment of the present invention. The imaging device includes, for example, a digital still camera and a digital video camera, but is not limited thereto. The present invention can be applied as long as an incident optical image is acquired as an electrical image by photoelectric conversion using a two-dimensionally arranged solid state sensor such as an area sensor.

  In FIG. 1, A is a camera, and B is an interchangeable lens that is detachably attached to the camera A. Reference numeral 2 denotes a zoom lens group, and reference numeral 3 denotes a focus lens group, which constitutes a photographing optical system 31. Reference numeral 4 denotes a light amount adjusting means for controlling the amount of light flux that passes through the photographing optical system, and an aperture that is an exposure means. A photographing optical system (lens barrel) 31 includes a zoom lens group 2, a focus lens group 3, a diaphragm 4, and the like.

  Reference numeral 5 denotes an image pickup device such as a CCD for photoelectrically converting a subject image that has passed through the photographing optical system. The image sensor may be a CMOS sensor. An image sensor unit including an image sensor composed of an optical low-pass filter, an infrared cut filter, and a CCD sensor or a CMOS sensor is disposed in the vicinity of the planned imaging plane. L is an optical axis of the photographing optical system 31 provided in the photographing lens B.

  Reference numeral 6 denotes an image pickup circuit that receives an electric signal photoelectrically converted by the image pickup device 5 and performs various image processing to generate a predetermined image signal. Reference numeral 7 denotes an A / D conversion circuit that converts an analog image signal generated by the imaging circuit 6 into a digital image signal.

  The SDRAM 8 is a memory such as a buffer memory that temporarily stores a digital image signal output from the A / D conversion circuit 7. The SDRAM 8 can record an output signal of a partial area of the imaging area of the imaging element 5. From the output signal recorded by the SDRAM 8, focus detection can be performed by the scan AF processing circuit 14 described later via the camera CPU 15.

  Reference numeral 12 denotes a recording memory that records image data including a semiconductor memory or the like. Image data that has been subjected to compression processing and encoding processing by the compression circuit and image data that has been subjected to decompression processing in an optimal form for performing reproduction display are stored in the recording memory 12.

  Reference numeral 13 denotes an AE processing circuit that receives an output from the A / D conversion circuit 7 and performs automatic exposure (AE) processing. Reference numeral 14 denotes a scan AF processing circuit that receives an output from the A / D conversion circuit 7 and performs autofocus (AF) processing.

  Reference numeral 15 denotes a camera CPU with a built-in memory for controlling the image pickup apparatus. In this embodiment, the camera CPU has storage means for storing current shooting conditions (for example, shooting parameters such as a focus state, a zoom state, an F value, and an AF image height).

  Reference numeral 17 denotes an image sensor driver. Reference numeral 40 denotes a lens CPU with a built-in memory for controlling the lens. When the photographing lens B is attached to the camera A, the lens CPU 40 communicates with the camera CPU 15. Reference numeral 21 denotes an aperture drive motor that drives the aperture 4. Reference numeral 18 denotes a first motor driving circuit for driving and controlling the diaphragm driving motor 21. A focus drive motor 22 drives the focus lens group 3. In the present embodiment, the lens CPU 40 operates the focus drive motor 22 to form lens drive means. Reference numeral 19 denotes a second motor drive circuit that drives and controls the focus drive motor 22. A zoom drive motor 23 drives the zoom lens group 2. Reference numeral 20 denotes a third motor drive circuit for driving and controlling the zoom drive motor 23.

  An EEPROM 25 is an electrically rewritable read-only memory in which programs for performing various controls, data used for performing various operations, and the like are stored in advance.

  The operation switch 24 includes a main power switch, a release switch, a reproduction switch, a zoom switch, a switch for turning on / off the display of the AF evaluation value signal on the monitor, and the like. The main power switch is for starting up the camera A and supplying power.

  The release switch starts a shooting operation (storage operation) and the like. The reproduction switch starts a reproduction operation. The zoom switch moves the zoom lens group 2 of the photographing optical system to perform zooming. The release switch then performs a first stroke (hereinafter referred to as SW1) for generating an instruction signal for starting an AE process and an AF process performed prior to a photographing operation and a second stroke (hereinafter referred to as an instruction signal for starting an actual exposure operation). SW2) and a two-stage switch.

  In the present embodiment, the memory in the lens CPU 40 or the EEPROM 25 on the camera A side has a correction amount storage unit and stores a BP (best focus) correction table for each focus state.

  Next, the focusing operation (AF operation) of the imaging apparatus having the above configuration will be described with reference to FIG. FIG. 2 is a flowchart illustrating an AF operation procedure of the imaging apparatus. A control program related to this operation is executed by the camera CPU 15.

  In step S1, the camera CPU 15 starts focus detection in accordance with the operation of SW1 of the operation SW 24 provided on the camera body, and simultaneously communicates with the lens CPU 40. Through this initial communication, for example, the camera CPU 15 acquires the name of the attached lens (serial information) and optical information of the photographing optical system (for example, focus sensitivity information of the focus lens group 3), and the lens CPU 40 acquires the current photographing condition ( For example, the focus state, zoom state, F value, AF image height, etc.) are acquired.

  In step S2, AF scan (focus detection operation) is performed. Here, the second motor drive circuit 19 is operated to drive the focus lens 3, thereby performing AF scan at the focus lens position LP [n] for n times of scan drive times.

  In step S3, the second motor drive circuit is operated to move the focus lens group 3 by a predetermined amount from the scan start position to the scan end position. Then, while driving this predetermined amount, the scan AF processing circuit 14 calculates a focus evaluation value M [n] at the position LP [n] of each focus lens group and stores it in the camera CPU 15. In this embodiment, this operation forms a focus evaluation value calculation unit.

  In step S4, it is determined whether the number of loops n set in step S2 is the second or more. If n is 2 or more, the process proceeds to step S6, and if n = 1, the next loop calculation is started.

  In step S6, lens information is communicated between the camera CPU 15 and the lens CPU 40, and the BP correction amount BP at the current focus lens position LP [n] is obtained from the BP (best focus) correction value table in the correction amount storage unit. To do. This operation forms correction amount acquisition means in the present embodiment. In step S6, the BP correction value BP is updated to the BP correction amount BP [x] at the current focus lens position LP [n].

  A method of selecting x in step S6 will be described. Hereinafter, three methods will be described, but various modifications and changes can be made within the scope of the gist.

  First, as a first method, x = n−OP. OP here refers to the amount of overshoot from the in-focus position to the focus lens stop position that occurs when performing contrast AF scanning. An illustration is given using FIG.

  FIG. 3A is a diagram illustrating an example of a change in the focus evaluation value M when the focus lens position LP is taken on the horizontal axis. FIG. 3B is a diagram illustrating a change example of the BP value BP [n] to be acquired by lens communication when the focus lens position LP is taken on the horizontal axis. In the drawing, an image having a BP correction value BP [n] is shown for each focus lens position, but each order term is stored as a function form of BP_C as information on the acquired BP correction value. It does not matter if you keep it.

  Assume that the initial focus lens position is LP1 and the contrast AF scan is performed in the direction from LP1 to LP7. Then, the focus lens performs an operation like I + II and returns to the focus position LP4. When scanning in the I direction, the focus evaluation value M takes the maximum value in the vicinity of M [4] and is found to be in the vicinity of the in-focus position. However, in actuality, after taking into account the influence of noise, etc., after evaluating some points from the evaluation value peak and determining whether the focus evaluation value curve AF_C has a reliable mountain shape, Reverse drive is performed up to the focal position. Although details of the reliability determination method at this time will not be described here, it is conceivable to perform determination based on the gain of the evaluation value, the degree of decrease in the left and right evaluation values from the maximum focus evaluation value, and the like. That is, in the contrast AF scan, the focus lens overshoot amount OP for II in FIG. 3 occurs. Since the amount of OP at this time is a value determined by the above-described reliability determination, it is a known number. In FIG. 3, OP = 3P with respect to the focus lens scan interval P. That is, if the BP correction value BP [n] at the position three points before is acquired, the BP correction value [n] in the vicinity of the in-focus position can be acquired. Therefore, x = n−OP. . In this way, when BP correction value acquisition communication is performed at each focus lens position, as shown in FIG. 3C, the BP correction value at the focus lens LP7 becomes BP [4], which will be described later. The focus lens drive amount calculation in step S11 can be performed correctly.

  Next, as a second method, in order to perform BP correction with higher accuracy than the first method, the BP value acquired for each driving direction of the focus lens is changed. An illustration is given using FIG.

  FIG. 4A is a diagram showing a change example of the focus evaluation value M when the focus lens position LP is taken on the horizontal axis. FIG. 4B is a diagram illustrating a change example of the BP correction value BP [n] to be acquired by lens communication when the focus lens position LP is taken on the horizontal axis. In the figure, an image having a BP correction value BP [n] is shown for each focus lens position. However, as the BP correction value information, each order term is stored as a function form of BP_C. It doesn't matter.

  BP [n] represents a BP correction value when the focus scan direction is the I direction, and BP ′ [n] represents a BP correction value when the focus scan direction is the II direction. Depending on the driving direction of the focus lens, tilting of the lens surface, decentration, etc. may change the way in which optical aberrations occur, and the BP correction value may change. Therefore, in the second method, as shown in FIG. 4B, a BP correction value is provided for each driving direction.

  Also in the second method, as in the first method, the BP correction value BP [x] at each focus lens position LP is acquired. The difference from the first method is that the acquired BP correction value is changed depending on whether the contrast AF scan direction and the final lens driving direction are the same. FIG. 4A is an illustration when the contrast AF scan direction is different from the final lens drive direction. Normally, the contrast AF scan direction and the final lens drive direction are different as shown in FIG. 4A. However, depending on the lens, the lens stop direction is limited to one direction in order to improve the lens stop position accuracy. In some cases, a drive like III in FIG. This is known information in advance and can be acquired at the time of initial communication in step S1.

  That is, in the second method, in addition to x = n−OP, the BP correction value can be acquired with higher accuracy by performing communication for acquiring the BP correction value in consideration of the lens driving direction. It is. In this way, when BP correction value acquisition communication is performed at each focus lens position, as shown in FIG. 4C, the BP correction value at the focus lens LP7 becomes BP ′ [4], which will be described later. The focus lens drive amount calculation in step S11 can be performed correctly.

  Finally, as a third method, x is updated to the current focus lens position n only when the evaluation value increases. This will be described in detail with reference to FIG. 2B and FIG.

  FIG. 5A is a diagram showing a change example of the focus evaluation value M when the focus lens position LP is taken on the horizontal axis. FIG. 5B is a diagram illustrating a change example of the BP correction value BP [n] to be acquired by lens communication when the focus lens position LP is taken on the horizontal axis. In the figure, an image having a BP correction value BP [n] is shown for each focus lens position. However, as the BP correction value information, each order term is stored as a function form of BP_C. It doesn't matter.

  This operation will be described with reference to FIG. First, in step S21, lens information communication is started between the camera CPU 15 and the lens CPU 40.

  Next, in step S22, it is determined whether or not the focus evaluation value M [n] obtained in step S3 has increased. If it is determined in step S22 that the focus evaluation value has increased, the process proceeds to step S23, and otherwise, the process proceeds to step S24.

  In step S23, x = n, and the BP correction value is updated to the BP correction value at the current focus lens position n. In step S24, x = n−1, the BP correction value remains the BP correction value at the previous focus lens position, and no update is performed. In step S25, the lens information communication operation is terminated, and the process returns to step S7.

  In this way, when BP correction value acquisition communication corresponding to each focus lens position is performed, as shown in FIG. 5C, the BP correction value in the focus lens LP7 becomes BP [4], which will be described later. The focus lens drive amount calculation in step S11 can be performed correctly. Even in the operation of the third method, different BP values may be acquired for each lens driving direction as in the second method.

  In step S7, it is determined whether or not to end scanning. For example, if the change in the focus evaluation value M [n] obtained in step S3 is a change as shown in FIG. 3A, the focus evaluation is sufficient if the scan is performed up to the focus lens position LP7 (n = 7). The focus position can be detected by capturing the value peak. Although details of the reliability determination method will not be described here, it is possible to determine whether or not to end the contrast AF scan based on the evaluation value gain, the degree of decrease in the left and right evaluation values from the maximum focus evaluation value, and the like. Conceivable. For example, when the focus evaluation value decreases three times in succession, the AF scan may be terminated. If it is determined in step S7 that the AF scan has ended, the process exits the loop from step S2 and proceeds to step S10. If it is not determined in step S7 that the AF scan has ended, the process proceeds to step S8, and loop processing is repeatedly performed. Step S8 is an iterative loop process from step S2.

  In step S9, the in-focus position is calculated. The in-focus position calculation here is to calculate the position of the focus lens position LP_P that maximizes the focus evaluation value from the result of the focus evaluation value M [n] obtained up to step S8. For example, the focus lens position LP [max] where the focus evaluation value M [n] takes the maximum value may be used as the position. Further, it is also possible to obtain a focus lens position LP_P having a maximum value by linear interpolation using a point near the maximum value or high-order approximation of the change AF_C of the focus evaluation value M [n].

  In step S10, the focus lens drive amount LP_M_BP is calculated. Here, the sum of the focus lens drive amount LP_M from the current focus lens position to LP_P obtained in step S9 and the BP correction value BP obtained in step S6 is calculated, and the focus lens drive amount LP_M_BP is calculated. In this embodiment, the operation for calculating LP_M of this operation forms a focus position calculation means.

As shown in FIG. 6, when the AF scan advances from the focus lens position LP1 to LP7 and the focus lens position LP_P obtained in step S9 is detected at the position LP7, the focus lens drive amount LP_M_BP to be obtained in step S11 is
LP_M_BP = LP_P-LP7 + BP
It becomes.

  In step S11, the focus lens is driven by the focus lens drive amount obtained in step S10, and the focus lens is stopped at the in-focus position.

  As described above, in the present embodiment, the best focus correction amount at the best image plane position is predicted based on the focus evaluation value signal of the output signal obtained by the image sensor or the focus lens driving interval, and the best focus correction. Get quantity. As a result, it is possible to provide an imaging apparatus that enables accurate focus detection without re-communication. Further, when the photographing optical system in the present embodiment is a zoom lens, it is preferable that the zoom position can be detected by a zoom position detector such as an encoder. Then, the range from the wide-angle end to the telephoto unit is divided into a plurality of zoom zones, and a focus correction amount corresponding to the zoom zone and the focus zone may be stored in the correction amount storage means.

  In the above embodiment, the change in the focus state of the subject is realized by the movement of the focus lens. However, the method for realizing the change in the focus state is not limited to this. For example, it may be realized by moving a sensor instead of the focus lens. In addition, the imaging apparatus that can acquire the incident angle information (light field information) of the light beam may realize the change of the in-focus state by reconstruction processing.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. The main difference from the first embodiment is that it is determined whether or not to perform lens communication provided in step S5. In the first embodiment described above, since it is necessary to perform BP correction value acquisition communication for each lens position, there is a possibility that communication takes time and AF scanning is delayed. Further, since BP correction value acquisition communication is required only in the vicinity of the in-focus position, it is not necessary to perform BP correction value acquisition communication for each lens position.

  Therefore, in the second embodiment, it is determined whether or not the BP acquisition communication is necessary, and only when necessary, the BP acquisition communication after step S6 described above is performed, so that it is faster than the first embodiment. In addition, AF scanning becomes possible.

  Since the same operation is performed except for step S5 and the flowchart for explaining the AF scan of FIG. 2 in the first embodiment, detailed description of the operation is omitted.

  A method for determining whether or not to perform lens communication performed in step S5 of FIG. 7 in which the processing content performed in the second embodiment is different from that in the first embodiment will be described with reference to FIG.

  In step S5, it is determined whether to perform BP correction value acquisition communication. Here, the BP correction value acquisition communication is communication for the camera CPU 15 to acquire a BP correction value from the lens CPU 40 when the BP correction value is stored on the lens side. As another case, when the BP correction value is stored in the camera-side EEPROM 25, the communication for the camera CPU 15 to acquire the BP correction value from the EEPROM 8 is performed. This is communication for obtaining a BP correction value from a memory in which the BP correction value is stored. Note that the operation in step S5 forms the correction determining means in the present embodiment.

  As a method for selecting the presence or absence of BP correction value acquisition communication, for example, if the focus evaluation value calculated in step S4 is increased (based on the amount of change), it is determined that lens communication is performed. For example, as shown in FIG. 5A, when the focus evaluation value M [n] has been acquired, the focus lens positions LP1 to LP4 are more focused than the evaluation value M [n] at the previous focus lens position. The focus evaluation value M at the lens position increases. On the other hand, the focus lens positions LP5 to LP7 are decreased. That is, since it is determined that it is not necessary to perform BP correction value acquisition communication after LP5, the necessity of BP correction value acquisition communication at each focus lens position LP is as shown in FIG. In the first embodiment, n = 7 BP correction value acquisition communication is required for each lens position, but in the second embodiment, four communication operations are sufficient. As the BP correction value at the position where communication is not performed, it is only necessary to acquire the BP correction value obtained at the end. Therefore, after the focus lens position LP5, the BP correction value acquired through the lens acquisition communication is finally acquired. [4] may be used as a correction value.

  In addition, if the focus evaluation value is equal to or greater than a certain threshold value K, it is possible to perform lens communication assuming that the focus position is close. Since it is desirable that the focus evaluation value at this time does not change depending on the subject, it is desirable to normalize the focus evaluation value M by the maximum value-minimum value of the image sensor signal. If the threshold value K is set as shown in FIG. 9A, the BP correction value acquisition communication is performed only at the focus lens positions LP3, LP4, and LP5 where the focus evaluation value M exceeds K. The relationship between BP and used BP is as shown in FIG. In this case as well, the BP correction can be performed with the number of times of communication three times compared to the first embodiment that required seven times of BP acquisition communication, so the communication time can be reduced and the AF scan can be performed at high speed. Can be done. Similarly, when the primary differential amount of the focus evaluation value M [n] decreases, communication may be performed assuming that the focus evaluation value M [n] is close to the in-focus position.

  Alternatively, the determination may be made based on the AF scan mode stored in the camera CPU 15. When performing the determination in the scan mode, in the case of a rough scan (AF scan that roughly finds the focus position from the scan start position to the end position), the final focus detection is not performed, so the lens communication is not performed and the fine scan is performed. In the case of (AF scan in which the focus lens is finely moved to find the focus position in the vicinity of the focus position found by the coarse scan), lens communication may be performed. Further, it may be determined that lens communication is not performed before SW1.

  If it is determined in step S5 that communication is performed, the process proceeds to step S6, and BP acquisition communication is performed. If it is determined that lens communication is not performed, the process proceeds to step S17.

  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.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (11)

Control means for controlling drive means for driving a part of the photographing optical system for focusing;
An image sensor that photoelectrically converts a subject image formed by the imaging optical system;
Evaluation value calculation means for calculating a focus evaluation value from a signal obtained from the image sensor;
A focus position calculating means for calculating a focus position from the focus evaluation value;
Before calculating the in-focus position by the in-focus position calculating means, the correction amount at each position of the imaging optical system is stored as the correction amount for the in-focus position for each imaging parameter of the imaging apparatus. Obtaining means for obtaining from the storage means;
Determination means for determining whether or not to acquire the correction amount by the acquisition means based on the focus evaluation value ;
Said control means, said in-focus position calculated by said focus position calculating means, corrected using the obtained the amount of correction by the acquisition unit, shooting you characterized by operating the drive means Image device. The imaging apparatus according to claim 1 , wherein the determination unit determines to acquire the correction amount when the focus evaluation value is greater than a predetermined threshold. The imaging apparatus according to claim 1 , wherein the determination unit determines whether or not to acquire the correction amount based on a change amount of the focus evaluation value. Control means for controlling drive means for driving a part of the photographing optical system for focusing;
An image sensor that photoelectrically converts a subject image formed by the imaging optical system;
A focus position calculating means for performing a scanning operation for acquiring a focus evaluation value from a signal obtained from the image sensor and calculating a focus position based on the focus evaluation value;
Before calculating the in-focus position by the in-focus position calculating means, the correction amount at each position of the imaging optical system is stored as the correction amount for the in-focus position for each imaging parameter of the imaging apparatus. Obtaining means for obtaining from the storage means;
Determination means for determining whether or not the correction amount is acquired by the acquisition means based on the mode of the scanning operation ;
Said control means, said in-focus position calculated by said focus position calculating means, corrected using the obtained the amount of correction by the acquisition unit, shooting you characterized by operating the drive means Image device. It said acquisition means, image pickup according to any one of claims 1 to 4, characterized in that obtaining the correction amount corresponding to the position of different ones of the photographic optical system of the position of the current of the imaging optical system apparatus. The acquisition unit determines whether or not to acquire a correction amount corresponding to a current position of the photographing optical system as the correction amount based on a change in the focus evaluation value. 5. The imaging device according to any one of items 4 to 4 . The correction amount storage means for each drive direction of the drive means, the imaging apparatus according to any one of claims 1 to 6, characterized in that for storing the correction amount. A method for controlling an image pickup apparatus including an image pickup device that photoelectrically converts a subject image formed by a photographing optical system,
An evaluation value calculation step of calculating a focus evaluation value from a signal obtained from the image sensor;
An in-focus position calculating step of calculating an in-focus position from the focus evaluation value;
Before calculating the in-focus position in the in-focus position calculating step, the correction amount for each position of the imaging optical system is stored as the correction amount for the in-focus position for each imaging parameter of the imaging apparatus. An acquisition step of acquiring from the storage means;
A determination step of determining whether or not to acquire the correction amount in the acquisition step based on the focus evaluation value;
A control step of controlling a driving means for driving a part of the photographing optical system for focusing, and
In the control step, the in-focus position calculated in the in-focus position calculation step is corrected using the correction amount acquired in the acquisition step, and the driving unit is operated. Control method. A method for controlling an imaging device including an imaging device that photoelectrically converts a subject image formed by the imaging optical system,
A focus position calculation step of performing a scan operation for acquiring a focus evaluation value from a signal obtained from the image sensor, and calculating a focus position based on the focus evaluation value;
Before calculating the in-focus position in the in-focus position calculating step, the correction amount for each position of the imaging optical system is stored as the correction amount for the in-focus position for each imaging parameter of the imaging apparatus. An acquisition step of acquiring from the storage means;
A determination step of determining whether or not to acquire the correction amount by the acquisition unit based on a mode of the scan operation;
And a control step for controlling a driving means for driving a part of the photographing optical system for focusing.
In the control step, the in-focus position calculated in the in-focus position calculation step is corrected using the correction amount acquired in the acquisition step, and the driving unit is operated. . The program for making a computer perform each process of the control method of Claim 8 or 9. A computer-readable storage medium storing a program for causing a computer to execute each step of the control method according to claim 8 or 9.

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