JP5984595B2 - Automatic focusing apparatus, control method therefor, and imaging apparatus - Google Patents

Description

  The present invention relates to an automatic focusing device and a control method thereof. The present invention also relates to an imaging device including an automatic focusing device.

  2. Description of the Related Art Conventionally, an electronic still camera or the like uses an automatic focusing (AF) device that focuses on a subject by moving a focus lens position based on a luminance signal obtained from an image sensor such as a CCD.

  The automatic focusing device has, for example, a focus lens drive range (hereinafter referred to as a scan range) that is predetermined for each shooting mode. Then, the focus lens position at which the focus evaluation value calculated from the image signal sampled at a predetermined period while the focus lens is driven within the scan range is maximized is detected as the in-focus position (this focus lens operation is performed). Hereinafter referred to as AF scan).

  When performing an AF scan, first, the focus lens is driven to a predetermined AF scan start position. The AF scan start position is usually one end of the scan range. After the focus evaluation value is acquired at the AF scan start position, the focus lens starts to be driven in a predetermined direction. Immediately after the focus lens is driven to the AF scan start position, as shown in FIG. During this time, the focus lens vibrates. Therefore, the focus evaluation value calculated from the image signal sampled during the vibration of the focus lens is lower than the focus evaluation value calculated from the image signal sampled in a state where the focus lens is not oscillating due to vibration and focus fluctuation due to vibration. Value. On the other hand, in the AF scan operation executed thereafter, since the focus lens is not stopped, the focus evaluation value does not receive the lens vibration at the time of stop as described above.

  Although the focus lens is moving during AF scanning, if the lens is driven at a constant speed, the influence of the lens drive on the image signal is almost uniform for each image signal sampled at each lens position. Therefore, the influence of lens driving on the peak position of the focus evaluation value calculated from the focus evaluation value acquired for each image signal is small.

  As described above, among the focus evaluation values acquired in the AF scan operation, only the focus evaluation value acquired at the AF scan start position is a value acquired during lens behavior different from other lens positions. Since the lens position from which the focus evaluation value is acquired is discrete, the focus lens position at which the focus evaluation value reaches a peak is often obtained using an interpolation curve of the focus evaluation value. When the focus evaluation value acquired at the AF scan start position is different from the original value due to the influence of lens vibration, for example, as shown in FIG. 8, the shape of the interpolation curve is affected, and the peak position of the focus evaluation value is actually Will shift from the in-focus position.

  Further, as shown in FIG. 9, immediately after the focus lens is started to be driven at a predetermined speed Vs from the stop state (between the start of driving 0 and time AcT), the state is accelerating. The speed is slower than the speed Vs (for example, Vf). When the speed of the focus lens during AF scanning is different, the influence on the sampled image signal due to lens driving is different. For example, as shown in FIG. 10, the focus evaluation value sampled during driving at a predetermined focus lens speed Vs is lower than the focus evaluation value sampled during driving at a focus lens speed Vf slower than Vs. This is because the focus evaluation value depends on the high-frequency component, and the faster the focus lens speed, the higher the low-pass effect due to lens driving.

  If the speed during AF scanning varies depending on the lens position, the influence of lens driving on the focus evaluation value is not uniform. Therefore, when the peak position is obtained by using the focus evaluation value obtained while the focus lens is moving at a speed different from the predetermined focus lens speed for the interpolation calculation, as shown in FIG. End up. In FIG. 10, as in FIG. 8, the initial focus evaluation value differs from the original value due to the influence of lens vibration.

  In Patent Document 1, in a camera that employs a quick return type mirror, the start of the AF operation is waited until the vibration of the focus lens due to the mirror bounces, thereby preventing a decrease in AF accuracy due to the vibration of the focus lens.

JP 2010-128273 A

  However, in the method of Patent Document 1, the AF operation is not started until the vibration of the focus lens is settled. Therefore, if the method of Patent Document 1 is applied to wait for the start of AF scan until the vibration after driving the focus lens to the above-described AF scan start position is settled, the AF time becomes longer by the waiting time. There is a problem that it ends up. In Patent Document 1, no consideration is given to the influence of the difference in driving speed of the focus lens on the focus evaluation value.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an automatic focusing device, a control method, and an imaging device capable of improving at least one of AF accuracy and AF operation speed. To do.

The above-described object is an automatic focusing device that drives a focus lens from an AF scan start position and calculates a peak position of a focus evaluation value from a focus evaluation value based on image data captured at different focus lens positions. The start position of the AF scan is located outside the start position of the predetermined initial scan range, and at least one focus evaluation is performed until the focus lens reaches the start position of the initial scan range from the start position of the AF scan. setting means for setting a position value is calculated, when the focus lens is Ru is driven to the start position of the AF scan and control means for starting the AF scan, the focus evaluation values obtained until AF scanning is completed And a peak calculation means for calculating a peak position of the focus evaluation value without using the focus evaluation value calculated first. It is achieved by an automatic focusing device, characterized in that.

  With such a configuration, according to the present invention, it is possible to improve at least one of AF accuracy and AF operation speed.

1 is a block diagram showing a functional configuration example of a digital camera as an example of an imaging apparatus to which an automatic focusing device according to an embodiment of the present invention is applied. The flowchart which shows the relationship between the state of SW1 119 and SW2 120, AE process, AF operation | movement, and imaging | photography operation | movement in the digital camera 100 which concerns on embodiment of this invention. Flowchart for explaining the details of the AF operation in S203 in FIG. Flowchart for explaining the details of the AF scan start position StartPos calculation process performed in S303 of FIG. It is a figure which shows typically the specific example of AF operation | movement in embodiment of this invention. FIG. 3 is a flowchart for explaining details of the focus evaluation value peak position calculating operation in S314 in FIG. The figure explaining the lens vibration state immediately after driving the focus lens to the AF scan start position The figure explaining the influence which the vibration of the focus lens gives to the focus evaluation value The figure which shows the example of the speed change of the focus lens immediately after AF scan drive start The figure explaining the influence which the speed change of the focus lens immediately after AF scan drive starts has on a focus evaluation value

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating a functional configuration example of a digital camera as an example of an imaging apparatus to which an automatic focusing apparatus according to an embodiment of the present invention is applied. The automatic focusing device according to the present invention can be applied not only to an imaging device such as a digital camera or a digital video camera, but also to any device in which the imaging device can be incorporated or connected. Such devices include various devices such as mobile phones, computers, game machines, tablet terminals, home appliances, and vehicles.
Note that the automatic focusing device only needs to have a function of controlling the driving of the focus lens, and the focus lens and its driving mechanism need not be included.

  The digital camera 100 includes a photographic lens 101 including a zoom mechanism, a diaphragm and shutter 102 for controlling the amount of light, a focus lens 104 for focusing the photographic lens 101 on the imaging surface of the image sensor 107, and a motor for driving the focus lens 104. 105. The image sensor 107 is, for example, a CCD or CMOS image sensor, and converts a subject image into an electrical signal in units of pixels. The A / D conversion unit 108 applies noise removal to the output signal of the image sensor 107 or applies nonlinear amplification processing, and then converts the signal into a digital signal.

  The AE processing unit 103 controls the operation of the aperture and shutter 102 according to the control of the system control unit 113. The AF processing unit 106 controls the motor 105 according to the control of the system control unit 113 and drives the focus lens 104. Further, the position of the focus lens 104 is detected and notified to the system control unit 113. The image processing unit 109 applies image processing such as color interpolation processing and white balance adjustment processing to the digital signal output from the A / D conversion unit 108 to generate image data.

The format conversion unit 110 converts image data in RGB format into YCrCr format.
The DRAM 111 is a high-speed built-in memory, and is used as a high-speed buffer as temporary image storage means or a working memory for image compression / decompression.

  The image recording unit 112 includes a recording medium such as a memory card and its interface, and records image data according to a predetermined file system. The system control unit 113 is a programmable processor such as a CPU or MPU, and controls the overall operation of the digital camera 100 including automatic focusing control described later by executing a program stored in advance. An image display memory (hereinafter referred to as VRAM) 114 is a memory for storing image data for display. In addition to image display, the image display unit 115 displays a shooting screen and an index representing a focus detection area at the time of shooting, in addition to display for operation assistance and camera status.

  The operation unit 116 is an input device group for giving instructions to the digital camera 100 from the outside, such as a switch, a button, and a touch panel. The operation unit 116 includes the following, for example. A menu switch that performs various settings such as the shooting function of the imaging device and settings for image playback, a zoom lever that instructs the zoom operation of the shooting lens, and an operation mode switch between the shooting mode and the playback mode. The shooting mode switch 117 is used to designate a shooting mode that the digital camera 100 has, such as a macro mode, a distant view mode, and a sports mode. In the digital camera 100 of the present embodiment, the distance range for focus detection, the AF operation, and the like may be changed according to the shooting mode.

  The main switch 118 is used to turn on or turn off the digital camera 100. SW1 119 and SW2 120 are switches that are turned on when the release switch is pressed, for example. For example, SW1 119 is turned on when the release switch is half-pressed, and SW2 120 is turned on when the release switch is fully pressed. The ON of SW1 119 is an instruction to start a shooting standby operation such as AF or AE, and the ON of SW2 120 is a shooting instruction. The conditions for turning on SW1 119 and SW2 120 are not limited to the state where the release button is pressed, but the operation for instructing the start of the shooting standby operation of the input device included in the operation unit 116 and the start of shooting are instructed. It may be an operation.

(Operation overview of the digital camera 100)
FIG. 2 is a flowchart showing the relationship between the state of SW1 119 and SW2 120 and the AE processing, AF operation, and photographing operation in the digital camera 100. Here, when the power is turned on, moving image shooting is started by the image sensor 107, and the shot moving image is displayed on the image display unit 115 so that the image display unit 115 functions as an electronic viewfinder. The moving image shooting is continued at a predetermined frame rate until the shooting operation is started.

  First, in S201, the AE processing unit 103 performs AE processing for determining an exposure condition according to a preset program diagram or the like based on subject brightness obtained from the output of the image processing unit 109. In step S202, the system control unit 113 checks the state of the SW1 119. If ON, the process proceeds to step S203. If not, the process proceeds to step S201. In S203, the system control unit 113 performs an AF operation described later. Here, the exposure conditions (shutter speed, aperture, sensitivity) during the AF operation are determined by the AE process in S201 immediately before. In step S204, the system control unit 113 checks the state of the SW1 119. If it is ON, the process proceeds to step S205. If not, the process proceeds to step S201. In step S205, the system control unit 113 checks the state of the SW2 120. If ON, the process proceeds to step S206. If not, the process proceeds to step S204. In step S206, the system control unit 113 performs a shooting operation and advances the process to step S201.

(Overall AF operation)
FIG. 3 is a flowchart for explaining the details of the AF operation in S203 in FIG.
First, in S301, the system control unit 113 sets a focus detection area in a predetermined area in the screen. For example, the focus detection area can be set to a predetermined area, or can be set to an area corresponding to a specific subject such as a human face.

In step S <b> 302, the system control unit 113 sets an initial scan range according to the shooting mode set by the shooting mode switch 117 and the focal length (field angle) of the shooting lens 101.
In step S303, the system control unit 113 calculates an AF scan start position StartPos described later.
In step S304, the system control unit 113 operates the motor 105 through the AF processing unit 106 to drive the focus lens 104 to the AF scan start position StartPos calculated in step S303.

In step S305, the system control unit 113 checks whether the lens driving wait Flg (flag) set in the AF scan start position StartPos calculation process in step S303 is TRUE. If TRUE, the system control unit 113 proceeds to step S306. If not, the process proceeds to step S307. Proceed.
In step S306, the system control unit 113 stops the focus lens 104 for a predetermined time. This is a process for preventing the focus lens vibration from affecting the focus evaluation value acquired in S307 described later after the focus lens 104 is driven to the AF scan start position StartPos and stopped in S304. is there. Here, the predetermined time may be, for example, a time measured in advance until the vibration width of the focus lens 104 falls within a predetermined range. Alternatively, it may be a time until it can be determined that the position of the focus lens 104 is within a predetermined range from the AF scan start position StartPos for a predetermined time.

  In step S307, the system control unit 113 acquires a focus evaluation value from the image data in the focus detection area set in step S301 in a state where the focus lens 104 is stopped at the AF scan start position StartPos. There is no restriction | limiting in particular in the acquisition method of a focus evaluation value, A suitable thing can be used from a well-known method.

In step S <b> 308, the system control unit 113 acquires the current position of the focus lens 104 through the AF processing unit 106.
In step S309, the system control unit 113 instructs the AF processing unit 106 to drive the focus lens 104 in a predetermined direction at a predetermined speed Vs set in advance. The AF processing unit 106 controls the motor 105 to drive the focus lens 104 at the instructed direction and speed.

In step S310, the system control unit 113 acquires a focus evaluation value from the image data in the focus detection area set in step S301.
In step S <b> 311, the system control unit 113 acquires the current position of the focus lens 104 through the AF processing unit 106.
In step S312, the system control unit 113 checks whether the current position of the focus lens 104 acquired in step S311 is within the AF scan range set in step S302. If it is within the AF scan range, the process proceeds to step S310. The process proceeds to S313.

  Here, it is assumed that the series of operations from S310 to S312 is performed in a time corresponding to one frame at the current frame rate. In addition, the system control unit 113 associates the focus evaluation value acquired in S307 with the lens position acquired in S308, the focus evaluation value acquired in S310, and the lens position acquired in S311. Used in peak position calculation. For example, the system control unit 113 sets the focus evaluation value and lens position acquired i-th (i is an integer of 0 or more) as the afVal [i] and Pos [i], respectively, and is equal to the total number of acquired focus evaluation values DataCnt. For example, it is stored in the DRAM 111.

  During the AF operation, the focus lens 104 moves continuously. Therefore, the system control unit 113 calculates the position of the focus lens 104 at the timing of the center of the exposure time when the corresponding frame is captured and associates it with the focus evaluation value.

In step S <b> 313, the system control unit 113 stops driving the focus lens 104 through the AF processing unit 106.
In step S314, the system control unit 113 serving as a peak calculation unit calculates the peak position of the focus evaluation value using the focus evaluation value acquired in steps S307 and S310 and the position of the corresponding focus lens 104 (obtained in steps S308 and S311). To do. Details of calculation of the peak position of the focus evaluation value will be described later.
In step S315, the system control unit 113 performs in-focus determination.
In step S316, the system control unit 113 instructs the AF processing unit 106 to drive the focus lens 104 to the lens position corresponding to the peak position of the focus evaluation value obtained in step S314, and ends the AF operation.

(Calculation process of AF scan start position StartPos)
FIG. 4 is a flowchart for explaining the details of the AF scan start position StartPos calculation process performed in S303 of FIG.
Here, the AF operation will be described by taking as an example a case where the AF scan start position StartPos is in the far side direction from the current focus lens position and the lens driving direction during AF scan in S309 is the near side direction.

  First, in step S401, the system control unit 113 acquires the far end lens position PosF and the near end lens position PosN in the initial scan range set in step S302. These lens positions can be stored in advance if the initial scan range is fixed. If the initial scan range is a relative range with respect to the current focus lens position, for example, it can be calculated from the current focus lens position. Of course, you may acquire by another method.

  In S402, the system control unit 113 acquires MaxDelPoint, which is the number of focus evaluation values not used for peak position calculation (the number of scan points to be deleted) among the focus evaluation values acquired in S307 and the focus evaluation values sequentially acquired in S310. . Here, the number of scan points MaxDelPoint to be deleted is set in advance from the length of the period affected by the vibration after the driving of the focus lens 104 is stopped, the driving speed less than the predetermined driving speed, and the sampling cycle. Can do.

  For example, the number of focus evaluation values (the number of scan points) affected by a drive speed that does not satisfy a predetermined drive speed is calculated and set in advance using AcT in FIG. 9 and the focus evaluation value sampling period. Alternatively, the lens acceleration or lens speed is calculated from the lens position detected during the AF scan, and the period until the lens acceleration reaches near zero, the period until the lens speed reaches a predetermined speed, and the sampling period are used. Also good. Note that the number of focus evaluation values affected by the vibration after the driving of the focus lens 104 is stopped is 0 when the lens driving wait Flg = TRUE, and is 1 when the lens driving wait Flg = FALSE. Therefore, when processing S402 for the first time, the number of focus evaluation values that are affected by the vibration after the driving of the focus lens 104 is stopped is determined according to the initial value of the lens driving wait Flg. The system control unit 113 sets the number of scan points MaxDelPoint to be deleted as the sum of the number of focus evaluation values that are affected by the drive speed that is less than the predetermined drive speed and the number of focus evaluation values that are affected by the vibration after the drive is stopped. Can be set.

In step S403, the system control unit 113 acquires an AF scan interval (interval of focus lens positions for obtaining focus evaluation values) ScanInt from, for example, a built-in nonvolatile memory.
In step S <b> 404, the system control unit 113 acquires FarLimitPos that is the end of the driveable range of the focus lens 104 from, for example, a built-in nonvolatile memory.
In step S405, the system control unit 113 sets the far-end lens position PosF in the initial scan range as the AF scan start position StartPos.
In S406, the system control unit 113 initializes the lens vibration waiting Flg to TRUE.
In step S407, the system control unit 113 initializes the number of scan points DelPoint to be actually deleted to 0.

In step S408, the system control unit 113 checks whether the actual deletion scan point number DelPoint is greater than or equal to the deletion scan point number MaxDelPoint. If so, the process advances to step S412; otherwise, the process advances to step S409.
In step S409, the system control unit 113 checks whether StartPos−ScanInt × (DelPoint + 1) is equal to or greater than FarLimitPos. If so, the process proceeds to step S410. If not, the process proceeds to step S413.
In S410, the system control unit 113 increments (increases by 1) the actual deletion scan point DelPoint.
In step S411, the system control unit 113 sets StartPos−ScanInt × DelPoint as the scan start position StartPos, and the process proceeds to step S408.

If the actual deletion scan point DelPoint is equal to or larger than the deletion scan point MaxDelPoint, the system control unit 113 sets the lens vibration waiting Flg to FALSE in S412.
In S413, the system control unit 113 sets a range from the scan start position StartPos set at this time to the near end lens position PosN of the initial scan range as the scan range, and advances the process to S304. In this way, the AF scan start position is set so that it does not exceed the movable range of the focus lens, is outside the initial scan range, and is equal to or less than the maximum number of deleted scan points, DelPoint, below the maximum number of deleted scan points. To do.

  FIG. 5 schematically shows an example of the AF operation when the number of deleted scan points MaxDelPoint = 2, (a) when the actual deleted scan points DelPoint is 2, and (b) when the actual deleted scan points DelPoint is 0. . As shown in FIG. 5A, when the actual number of deleted scan points is equal to or greater than the number of deleted scan points, the system control unit 113 starts the AF scan immediately after driving the focus lens 104 to the AF scan start position StartPos.

Here, “immediately” means to start an AF scan within the period of StT in FIG.
-Without waiting for the vibration of the focus lens 104 to settle,
・ Before the predetermined time for the vibration of the focus lens 104 to settle,
In response to detecting that the focus lens 104 has reached the AF scan start position StartPos,
Means either.
“Start of AF scan” is at least one of the calculation start of the focus evaluation value and the drive of the focus lens 104 (AF scan drive).
As will be described later, the focus evaluation value obtained first (in S307) and the second focus evaluation value obtained first after the start of AF scan driving are not used for peak position calculation.

  Thus, according to this embodiment, the AF scan start position is a position outside the initial scan range, and at least one focus evaluation value is obtained before the focus lens reaches the start position of the initial scan range. Set to position. Alternatively, the scan range is widened so that the focus evaluation value affected by the vibration of the focus lens or the lens behavior during acceleration is not included in the focus evaluation value obtained in the initial scan range. Thereby, even if the AF scan operation is started without waiting until the vibration of the focus lens is settled, it is possible to suppress the focus evaluation value affected by the vibration from being used for calculating the peak position. Therefore, the time required for the AF operation can be reduced and the accuracy of the peak position can be improved.

  On the other hand, if the scan range cannot be expanded due to restrictions on the drive range of the focus lens, the lens vibration wait Flg remains TRUE and the lens is stopped for a predetermined time in S306. Accordingly, priority is given to preventing the lens vibration from affecting the focus evaluation value in S307 rather than reducing the waiting time until the lens vibration is settled.

(Peak position calculation operation)
FIG. 6 is a flowchart for explaining the details of the focus position calculation operation of the focus evaluation value in S314 in FIG.
First, in step S601, the system control unit 113 initializes a variable i to 0.
In step S602, the system control unit 113 checks whether the variable i is greater than or equal to the actual deletion scan point DelPoint determined in step S303. If so, the process proceeds to step S604. If not, the process proceeds to step S603.
In step S603, the system control unit 113 increments the variable i and advances the process to step S604.

In S604, the system control unit 113 sets the focus evaluation value afVal [i] in the variable AFValue [i-DelPoint] and the lens position Pos [i] corresponding to the variable FocusPos [i-DelPoint].
In step S605, the system control unit 113 checks whether the variable i is equal to or greater than (the total number of acquired focus evaluation values DataCnt) −1. If so, the process advances to step S607; otherwise, the process advances to step S606.

In step S606, the system control unit 113 increments the variable i and proceeds to step S605.
In S607, the system control unit 113 performs interpolation calculation of the peak position of the focus evaluation value using AFValue [i] and FocusPos [i] (i = 0,..., DataCnt-DelPoint-1), and the process proceeds to S315. Proceed.
Thereby, it is possible to prevent the deleted focus evaluation value from being used for peak position calculation.

  The effect of the present embodiment is greatest when the actual deletion scan point number DelPoint ≧ the deletion scan point number MaxDelPoint. However, if the actual deletion scan point number DelPoint ≧ 1, the effect of shortening the AF time and improving the AF accuracy is as follows. Can be obtained. This is because the focus evaluation value obtained in the initial stage is greatly affected by the vibration of the lens and the behavior during lens acceleration.

  According to the present embodiment, the AF scan start position is set to a position where at least one focus evaluation value is obtained before the focus lens reaches the start position of the initial scan range, and the focus lens is driven to the AF scan start position. Immediately, the AF scan operation is started. Since the AF scan operation is started immediately after driving to the AF scan start position, the AF operation time can be shortened and the AF operation speed can be improved as compared with the case where the focus lens vibration is settled after the drive. Also, the focus evaluation value is affected by the focus lens vibration immediately after driving to the AF scan start position and the lens behavior when accelerating to the driving speed at the time of AF scan by setting the AF scan start position. The influence on the peak position calculation result can be reduced. As a result, AF accuracy can be improved.

  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 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)

An automatic focusing device that drives a focus lens from an AF scan start position and calculates a peak position of the focus evaluation value from a focus evaluation value based on image data captured at different focus lens positions,
The start position of the AF scan is a position outside a start position of a predetermined initial scan range, and the focus lens is at least from the start position of the AF scan to the start position of the initial scan range. Setting means for setting a position at which one focus evaluation value is calculated;
And a control means for the focus lens starts the AF scan and Ru is driven to the start position of the AF scan,
Peak calculation means for calculating a peak position of the focus evaluation value without using the focus evaluation value calculated first among the focus evaluation values obtained until the AF scan ends. Features an automatic focusing device.   The setting means sets the start position of the AF scan to a position where a predetermined number of focus evaluation values are calculated from the start position of the AF scan to the start position of the initial scan range. The automatic focusing device according to claim 1, wherein:   3. The automatic focusing apparatus according to claim 2, wherein the predetermined number is determined based on a number of focus evaluation values obtained during acceleration of the focus lens. The predetermined number is determined based on the number of the focus evaluation values calculated from when the focus lens is stopped until reaching a predetermined driving speed. The automatic focusing device according to 2 or 3.   5. The automatic focusing apparatus according to claim 1, wherein the setting unit sets the start position of the AF scan within a range that does not exceed a driveable range of the focus lens. 6.   6. The control unit according to claim 1, wherein the control unit starts the AF scan without waiting for the vibration of the focus lens to settle after the focus lens is driven to the start position of the AF scan. The automatic focusing device according to any one of claims.   2. The control unit according to claim 1, wherein after the focus lens is driven to the start position of the AF scan, the AF scan is started before a predetermined period of time during which the vibration of the focus lens is settled. 6. The automatic focusing device according to any one of 5 above.   The said control means starts the said AF scan according to having detected that the said focus lens reached the start position of the said AF scan, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. Automatic focusing device. When the setting unit cannot set the start position of the AF scan to a position where at least one focus evaluation value is calculated from the start position of the AF scan to the start position of the initial scan range. , Set the start position of the AF scan to the start position of the initial scan range,
The control means starts the AF scan after the focus lens is driven to the AF scan start position and waits for the vibration of the focus lens to stop,
The peak calculation means calculates the peak position of the focus evaluation value using the focus evaluation value obtained until the AF scan is completed, including the first calculated focus evaluation value; The automatic focusing apparatus according to claim 1, wherein the automatic focusing apparatus is characterized.   An image pickup apparatus comprising the automatic focusing device according to claim 1 and driving a focus lens of a photographing lens to a position corresponding to a peak position of the focus evaluation value calculated by the peak calculation unit. . A method for controlling an automatic focusing device that drives a focus lens from an AF scan start position and calculates a peak position of the focus evaluation value from a focus evaluation value based on image data captured at different focus lens positions,
The setting means sets the start position of the AF scan to a position outside a predetermined start position of the initial scan range, and the focus lens moves from the start position of the AF scan to the start position of the initial scan range. A setting step for setting at a position where at least one of the focus evaluation values is calculated,
Control means, and a control step of the focus lens is to start the AF scan and Ru is driven to the start position of the AF scan,
A peak calculating step in which a peak calculating means calculates a peak position of the focus evaluation value without using the focus evaluation value calculated first among the focus evaluation values obtained until the AF scan is completed; And a method of controlling the automatic focusing device.

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