JPH0843721A - Automatic focus detector - Google Patents

Abstract

PURPOSE:To provide an automatic focus detector capable of accurately deciding whether an object is a dynamic one or not regardless of a degree of photographing magnification. CONSTITUTION:The automatic focus detector is provided with a focus detecting means 1 repeatedly detecting the focus deviation amount of a lens with respect to a subject to be focused, an output means 2 outputting the information of the photographing magnification (beta), a dynamic body deciding means 3 comparing the result of the focus detection outputted by the focus detecting means 1 with a prescribed decision level, to decide whether the object is the dynamic one or not and a switching means 4 changing over the decision level used for the deciding operation of the dynamic body deciding means 3 in accordance with the information of the photographing magnification (beta) outputted from the output means 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focus detection device for detecting the focus state of a subject image in a device such as a camera.

[0002]

2. Description of the Related Art Conventionally, in Japanese Unexamined Patent Publication No. 62-125311, an automatic focus detection device for a camera determines that a subject is a dynamic subject when the previous and current defocus directions are the same. Is proposed. However, this conventional technique does not switch the level for determining whether or not the subject is a dynamic subject according to the photographing magnification.

[0003]

In the automatic focus detection device for detecting the focus state of a subject image, when the subject is a dynamic subject, the accuracy of focus detection is affected by:
It is the moving speed of the imaging position of the subject image rather than the actual moving speed of the subject. Therefore, when determining whether or not the subject is a dynamic subject, it is desirable to make a determination based on the moving speed of the imaging position of the subject image.

However, the moving speed of the image forming position largely changes depending on the photographing magnification. For example, even if the moving speed of the subject is the same, the closer the subject distance is, or the longer the focal length of the lens is, the higher the moving speed of the imaging position is. Therefore, when the subject distance is short or in the case of a telephoto lens having a large focal length, if the moving body determination is performed based on the moving speed of the imaging position, the detection sensitivity for the movement of the subject becomes too sensitive. For this reason, noise at the time of focus detection, variation in focus detection calculation, and the like are also determined to be movement of the subject, which causes malfunction.

The present invention has been made to solve the above-mentioned problems, and its purpose is to:
An object of the present invention is to provide an automatic focus detection device capable of accurately determining whether or not a subject is a dynamic subject, regardless of the magnitude of shooting magnification.

[0006]

In order to solve the above-mentioned problems, in the automatic focus detection device of the present invention, as shown in FIG. 1, the defocus amount of the lens for the object to be focused is repeated. By comparing the focus detection unit 1 for detecting, the output unit 2 for outputting the information of the photographing magnification β, and the focus detection result output by the focus detection unit 1 with a predetermined determination level, the subject is a dynamic subject. The moving body determination unit 3 for determining whether or not there is the switching unit 4 and the switching unit 4 for switching the determination level used for the determination operation of the moving body determination unit 3 according to the information of the photographing magnification β output from the output unit 2. It is characterized by having. Here, the moving body determination means 3 is, for example, the focus detection means 1
It is preferable that the means for determining whether or not the subject is a dynamic subject by detecting the amount of change in the defocus amount repeatedly output by and comparing the amount of change with the determination level. Further, the switching means 4 has at least two determination levels, and it is preferable to switch at least two determination levels according to the information of the photographing magnification β.

Further, the automatic focus detection device further comprises a correction amount calculation means 5 for calculating the amount of defocus caused by the movement of the subject based on a plurality of defocus amounts repeatedly output from the focus detection means 1. It is preferable to include a correction unit 6 that corrects the defocus amount detected by the focus detection unit 1 by the defocus amount calculated by the correction amount calculation unit 5. Here, it is preferable that the correction unit 6 does not correct the defocus amount when the photographing magnification β output from the output unit 2 is larger than a predetermined value.

[0008]

According to the configuration of FIG. 1, the focus detecting means 1
The defocus amount of the lens with respect to the subject to be focused is repeatedly detected. The moving body determination means 3 determines whether or not the subject is a dynamic subject by comparing the focus detection result output by the focus detection means 1 with a predetermined determination level. Specifically, the amount of change in the amount of defocus that is repeatedly output by the focus detection unit 1 is detected, and the amount of change is compared with the determination level to determine whether or not the subject is a dynamic subject. The determination level used for the determination operation of the moving body determination unit 3 is switched by the switching unit 4 according to the information of the photographing magnification β output from the output unit 2. The switching means 4 has at least two determination levels, and the photographing magnification β
It is preferable to switch the determination level in at least two steps or more in accordance with the above information.

As described above, by switching the determination level for determining whether or not the subject is a dynamic subject according to the photographing magnification,
Even when the subject distance is short or a telephoto lens is used, the detection sensitivity to the movement of the subject does not become too sensitive. Therefore, it is possible to accurately determine whether or not the subject is a dynamic subject regardless of the magnitude of the photographing magnification.

Further, the correction amount calculation means 5 calculates the amount of defocus caused by the movement of the subject based on the plurality of defocus amounts repeatedly output from the focus detection means 1, and the correction means 6 The focus shift amount detected by the focus detection unit 1 is corrected by the focus shift amount calculated by the correction amount calculation unit 5. As a result, it is possible to perform tracking correction on the dynamic subject. Here, when the photographing magnification β output from the output unit 2 is larger than a predetermined value, the correction unit 6 does not correct the amount of defocus. As a result, even when the subject distance is short or the telephoto lens is used, the detection sensitivity to the movement of the subject does not become too sensitive, and the tracking correction for the dynamic subject can be appropriately performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a focus detection area and a display in a finder for a photographing screen of a camera using the automatic focus detection device of the present invention. In this example, the three areas IS1 and IS indicated by the solid line in the center of the screen with respect to the shooting screen S are shown.
Focus detection can be performed on the subject of 2, IS3 (hereinafter referred to as the first island, the second island, and the third island, respectively). In the figure, a rectangular frame AF indicated by a dotted line is displayed to show the photographer the area in which focus detection is performed. A display portion Lb shown outside the photographing screen S indicates a focus detection state,
When focused, it is lit in green, and when focus cannot be detected, it is lit in red. La is a mark displayed when the tracking mode described later is set.

FIG. 3 is a diagram showing a schematic configuration of a multipoint focus detection module having the focus detection area. In the figure, 11 is a taking lens, 12 is a main mirror, 13 is a film surface, 14 is a sub-mirror, and 15 is a focus detection optical system. Reference numeral 22 is a field stop disposed near the focal plane, and has rectangular openings 22a, 22b, 22c. 21
Reference numerals a, 21b and 21c are condenser lenses, 20 is a module mirror, 18a, 18b and 18c are pairs of separator lenses, and 16a, 16b and 16c are CCD image pickup device arrays arranged on the focal plane 17 of the separator lenses. Reference numeral 19 denotes a diaphragm mask, which has circular or oval openings 19a, 19
b and 19c. The image whose field of view is limited by the rectangular opening 22a passes through the condenser lens 21a, and is projected as two images on the CCD image pickup device array 16a by the field stop 19a and the separator lens pair 18a. It is determined that the two images are in focus when the image interval is a predetermined interval, the front focus when the image interval is narrower than the predetermined interval, and the rear focus when the image interval is wider than the predetermined interval. Field diaphragms 19b and 19c
Similarly, the image is projected onto the CCD image pickup device rows 16b and 16c by the condenser lenses 21b and 21c and the separator lens pair 18b and 18c.

FIG. 4A shows a light receiving portion (including the light receiving portion, the storage portion, and the transfer portion, which will be referred to as a CCD) of the CCD image pickup element array used in this focus detection device. Figure 2
Each of the islands IS1, IS2, IS3 is provided with a standard portion and a reference portion, and C is provided on one of the side portions of the central island IS2 in the longitudinal direction.
A light receiving element MA for monitoring is provided to control the integration time of the CD into the storage section. Each island IS1, IS
2, the number of pixels (X, Y) in the standard part and the reference part of IS3 is
(34,44) for island IS1, island IS
2 (44, 52), island IS3 (34, 52)
44). These are all formed on one chip.

In the focus detecting apparatus of the present embodiment, the standard part of the above-mentioned three islands is divided into a plurality of blocks, and each block of the standard part thus divided is compared with all or part of the reference part to focus. Detect. Of the focus detection results in each block, the data of the rearmost pin is used as the focus detection data of each island, and the focus detection data of the camera is calculated based on the focus detection data of each island (details will be described later).

The dividing range and the defocusing range of the divided islands will be described with reference to FIGS. 5, 6 and 4B. FIG. 5 is an enlarged view of the focus detection area on the shooting screen shown in FIG. The islands IS1, IS2 and IS3 for focus detection are shown in FIG.
This is the area of the reference portion shown in (a). In addition, in FIG. 5, the numerical value shown in each island indicates the number of differences obtained by taking the difference data for every three pixels of the CCD shown in FIG. The difference data may be every two or every other data (however, at this time, the above numerical values are different). Therefore,
The number (X, Y) of the standard part and the reference part in each island is (30, 40) in the island IS1,
2 (40, 50), island IS3 (30,
40). The island IS1 is divided into two blocks, and the island IS1 is divided into two blocks, and the difference data at the upper end is set to (1 to 20) and (11 to 30), which are the first block BL1 and the second block BL2, respectively. . The island IS2 is divided into three blocks, and (1 to 20), (11 to 30), and (21 to 40) are selected from the difference data on the left end.
And the third block BL3, the fourth block BL4,
This is the fifth block BL5. In the island IS3, 2 of (1 to 20) and (11 to 30) are calculated from the difference data at the upper end.
The blocks are a ninth block BL9 and a tenth block BL10. Then, in the present embodiment, in the above-described second island, data in which the extraction frequency is changed for a low-frequency subject, specifically, every seventh difference data of the pixel data is calculated, and the sum is calculated. The focus detection calculation is performed using the minute data. The number of data is 35 in the standard part and 45 in the reference part. This block is referred to as a sixth block BL6. Then, by using the same data as the sixth block, the sixth block is divided into two blocks in order to perform focus detection in a wider range.
A block BL7 and an eighth block BL8 are set.

In the focus detection of this phase difference detection method, when the image interval when the images of the standard portion and the reference portion are coincident with each other is larger than a predetermined distance, the rear focus is used, when the image distance is smaller than the predetermined distance, the front focus is used, and the focus is adjusted with the predetermined distance. Becomes A specific description will be given with reference to FIG. 4B showing the state after the difference data is obtained.
Indicates the standard part and the reference part of the island IS2.
Consider the defocus range of the fourth block BL4 divided into blocks. At this time, the image is focused when the image of the 16th to 35th portions BL4 ′ from the left end and the image of the fourth block BL4 coincide with each other in the reference portion.
From this, when the image coincidence is at the left end of the reference portion, it becomes the front pin, and at this time, the maximum number of displacement data of the front pin (hereinafter referred to as displacement pitch) becomes 15. Further, when the image coincidence is on the right side of the reference portion with respect to the position shown in the drawing, the rear pin is formed, and at this time, the maximum rear pin shift pitch is 15. The same applies to the defocus range divided into blocks on each of the other islands. This is shown in FIG.
In L3, the front pin side displacement pitch is 5, the rear pin side displacement pitch is 25, and in the fifth block BL5, the front pin side displacement pitch is 25 and the rear pin side displacement pitch is 5. 1st, 3rd
Regarding the islands IS1 and IS3, the front pin side displacement pitch is 5, the rear pin side displacement pitch is 15, and the second and tenth blocks BL2 in the first and ninth blocks BL1 and BL9.
In BL10, the shift pitch on the front pitch side is 15, and the shift pitch on the rear pin side is 5. In the sixth block BL6, the shift pitches on the rear pin side and the front pin side are both 5. In the seventh block, the front pin side displacement pitch is 5, the rear pin side displacement pitch is 15, and in the eighth block, the front pin side displacement pitch is 15, and the rear pin side displacement pitch is 5.

FIG. 7 shows a block circuit diagram of the entire camera. μC is a microcomputer (hereinafter referred to as “microcomputer”) that performs calculations for sequence and exposure / focus detection of the entire camera, and LEC is a lens circuit of an interchangeable lens mounted on the camera body (not shown). Communicate information to the camera. The AFC is a focus detection data output circuit that includes a CCD that receives the light that has passed through the lens and converts the light into an analog electric signal, and is hereinafter referred to as an AF sensor. The AF sensor is a CC including a light receiving element array.
D circuit, light receiving element MA for monitoring used for controlling the integration time, integrating current IT from the light receiving element MA for monitoring, and outputting the integrated circuit ITG, and comparing the output of the integrating circuit ITG with a predetermined value. Comparator CMP, CCD
It is composed of an AGC circuit that amplifies the analog signal from the AGC circuit according to the output from the integrating circuit ITG. The operation will be briefly described. The microcomputer μC outputs the integration start signal ST. The CCD and the integration circuit ITG are reset and start integration respectively. When the integrated output of the integration circuit ITG becomes a predetermined value and the comparator CMP is inverted or the integration timer measured in the microcomputer μC becomes a constant value, the integration end signal SP is output. This allows CC
The integrated output in the D circuit is sent to the transfer register, and in sequence A
It is sent from the GC circuit to the microcomputer μC. On the other hand, the integration circuit ITG receives the integration end signal SP and holds the integration output. In response to this output, the AGC circuit amplifies the analog signal from the CCD circuit up to 8 times and outputs it to the microcomputer μC. The microcomputer μC incorporates an A / D converter that converts this analog data into digital data. Further, the AGC data is also output to the microcomputer μC.

The LMC measures the light passing through the lens,
This is a brightness detection circuit that detects the brightness of the subject, and outputs an apex digital signal Bvo corresponding to the brightness of the subject to the microcomputer μC. ISO is a film sensitivity reading circuit, which outputs an apex digital signal Sv corresponding to the film sensitivity to the microcomputer μC. The DISP is a display circuit and displays the exposure information and the focus state of the lens. ENC is an encoder that detects the amount of rotation of the motor M for driving the lens, and the lens control circuit LECON to be described later.
A pulse (a pulse output for a predetermined amount of rotation of the motor M) is output. The lens control circuit LECON inputs a motor rotation amount (number) signal and a motor (speed and direction) control signal from the microcomputer μC, and based on this,
While driving the motor M, a signal from the encoder ENC is input, it is detected whether the motor M has moved by a predetermined amount (motor rotation amount), and stop control of the motor M is also performed.
The microcomputer μC internally has a counter for knowing the lens position, and counts up or down the pulse from the encoder according to an internal command. The ILM is an auxiliary light circuit that irradiates the subject with AF auxiliary light when focus detection is not possible and the brightness is low.

BAT is a power supply battery and supplies power to all circuits. S _M is set to O by operating the main switch.
It is a switch that is turned on / off. One shot circuit O
S generates a pulse in conjunction with the turning on of the switch S _M. The microcomputer μC inputs this pulse and the INT
Execute the 0 interrupt flow. S _AF / _M is a switch for switching between the auto focus mode and the manual focus mode. In the auto focus mode, the lens is driven based on the focus detection result, and only the focus detection is performed in the manual focus mode. S1 is an image pickup preparation switch which is turned on by pressing the first stroke of the shutter button to start photometry and focus detection operations. S2 is a release switch that is turned on by pressing the second stroke (longer than the first stroke) of the shutter button to start the imaging operation. Ss / c is a switch for switching between the single shooting mode and the continuous shooting mode. Ss / w
Is a switch for switching between the spot AF mode and the wide AF mode.

Next, the operation of the camera will be described with reference to the flow chart of the microcomputer μC. Main switch S _M is O
If the answer is N, the "S _M ON" interrupt process shown in FIG. 10 is executed. In # 2, the determination reference value β with the larger imaging magnification
_{Let H} be 1/40. In # 4, the increase amount Δβ of the determination reference value having the smaller imaging magnification is set to 15. In # 6, it is determined whether or not the imaging preparation switch S1 is turned on. If the imaging preparation switch S1 is not turned on in # 6, the process proceeds to # 160, and if it is turned on, the process proceeds to # 8. # 8
Then, the free timer TM is reset and started. This is a timer used for moving object determination during focus detection. In # 10, various flags are reset. # 3
At 0, the variable N6 is set to 0. This variable N6 indicates the number of times the lens is driven during the follow-up determination in the out-of-focus state. # 4
At 0, lens-specific data is input from the lens circuit LEC. As the lens data, there are focal length data f, a conversion coefficient K _LR for converting the defocus amount DF into the lens driving amount Δn, a constant Dv∞, which will be described later, and an open F number. In # 50, the photometric circuit LMC is operated to input the photometric data Bvo from the photometric circuit LMC. # 60 is A
Control F. Details of the contents of the # 60 subroutine will be described later. In step # 70, exposure calculation is performed. In this exposure calculation, the photometric value Bvo from the measurement circuit LMC,
Film sensitivity reading circuit ISO film sensitivity Sv,
From the open aperture value A Vo of the lens to the exposure value Ev = Bvo + S
v + Avo is calculated, and the shutter speed Tv and the aperture value Av are calculated based on the determined diagram of the AE program.
In # 80, 2 after pressing down the first shutter button
The second step is pushed down and the release switch S2 is turned on.
It is determined whether or not. Release switch S2 with # 80
When is ON, the flag A indicating focus is displayed in # 90.
It is determined whether the FEF is set. When the flag AFEF is set in # 90, # 1
Exposure control is performed at 00. In step # 110, one frame of film is wound after the exposure control is completed. In step # 120, the switch Ss / c determines whether or not the continuous shooting mode is set.
When the continuous shooting mode is not set in # 120, the process waits until the shooting preparation switch S1 is turned off in # 130. When the shooting preparation switch S1 is turned off, the process proceeds to # 155. # 12
When the continuous shooting mode is 0, the continuous shooting flag VLYF is set in # 140 and the process returns to # 40.

When the release switch S2 is not turned on in # 80, it is determined in # 150 whether the photographing preparation switch S1 is turned off. When the photographing preparation switch S1 is turned off in # 150, the process proceeds to # 155. When the photographing preparation switch S1 is turned off in # 150, the process returns to # 40. In # 155, all the displays are turned off. In # 160, the main switch S _M is OF
It is determined whether or not F has been performed. When the main switch S _M is turned off in # 160, the process proceeds to # 165,
The free timer TM is stopped, the microcomputer μC stops the clock and enters the sleep state. When the main switch S _M is not turned off in # 160, the process returns to # 6 and the determination of the shooting preparation switch S1 is repeated.

Next, the # 60 AF subroutine is shown in FIG.
It is shown from 1 onwards. In # 200, it is determined whether or not the flag FLF indicating the focus lock is set. #
If the flag FLF is set at 200, A
Since it is not necessary to perform F, the process returns. When the flag FLF is not set in # 200, the time is read from the constantly operating free timer TM in # 202 and set as TM1. In step # 203, the lens extension amount is read from the lens position counter CT and is set as CT1. In # 205, it is determined whether or not the fill light prohibition flag NLF is set. When the flag NLF is not set in # 205, it is determined in # 210 whether or not the fill light flag ILMF indicating the fill light mode is set. This flag ILMF is set when the brightness is low and focus detection is impossible. Auxiliary light flag I in # 210
When the LMF is set, a signal indicating emission of auxiliary light is output at # 220. At this time, timing is started at the same time. In step # 230, the signal ST that causes the AF sensor to start integration is output. At # 240, it waits for 40 msec. When 40 msec has elapsed, a signal for stopping the auxiliary light emission is output at # 250. In step # 310, the signal SP indicating the end of integration is output to the AF sensor. #
When the auxiliary light flag ILMF is not set at 210, the process proceeds to # 260. Also, when the auxiliary light emission prohibition flag NLF is set in # 205, # 260
Proceed to. In step # 260, the signal ST that causes the AF sensor to start integration is output. At this time, timing is started at the same time. In # 270, it is determined whether or not a signal for ending the integration is input from the AF sensor. When the signal for ending the integration is not input in # 270, it is determined in # 280 whether 20 msec has elapsed from the start of the integration. #
If 20 msec has not elapsed at 280, # 27
Return to 0. # If 20 msec has passed in 280, #
At 290, the brightness is low, the low brightness flag LLF is set, and the process proceeds to step # 310. When the signal SP for ending the integration is input from the AF sensor in # 270, the flag LLF indicating low brightness is reset, and the process proceeds to # 310. In step # 310, a signal indicating the end of integration is output to the AF sensor.

At # 312, the time is read from the free timer TM and set as TM2. In # 313, the amount of lens extension is read from the lens position counter CT and C
T2. In # 314, the time TM1 of the previous integration center
Substitute 2 into TM12L. In # 315, the lens position CT12 at the previous integration center is substituted into CT12L. #
At 316, the average value of the times TM1 and TM2 read at the start of integration and at the end of integration, that is, the time (TM1 + TM2) / 2 of the current integration center is calculated and set as TM12. #
At 317, the average value of the lens extension amounts CT1 and CT2 read at the start of integration and at the end of integration, that is, the lens position (CT1 + CT2) / 2 at the center of integration is calculated, and CT is calculated.
12

In step # 320, integral data is input from the AF sensor. In # 325, AGC data is input from the AF sensor. In # 330, the island used for the previous lens drive, that is, the specific island is determined. This subroutine will be described with reference to FIG. # 40
At 0, the shift number Δn showing the maximum correlation used in the previous lens drive is compared with the shift number Δn11 showing the maximum correlation in the first island. At # 400, Δn = Δn1
If it is 1, the process proceeds to step # 410, and it is determined that the first island was selected last time, the variable AFIS indicating the specific island is set to 1, and the process returns. If Δn ≠ Δn11 in # 400, the process proceeds to # 420, and the shift number Δn is compared with the shift number Δn12 showing the maximum correlation in the second island. # 4
If Δn = Δn12 at 20, the process proceeds to step # 430. Since the second island was selected last time, the variable AFIS indicating the specific island is set to 2, and the process returns. If Δn ≠ Δn12 in # 420, the process proceeds to # 440, in which the third island is selected last time, the variable AFIS indicating the specific island is set to 3, and the process returns.

When the determination of the specific island is completed, the microcomputer μC returns to the flow of FIG. 11 and in the subroutine of # 340, the island IS (or block B) for focus detection is performed according to the condition such as the sequence state or the AF state.
L), the range for performing the correlation calculation (the range of the shift number j), and the algorithm for focus detection according to the above conditions are determined.

(A) Focus Detection Algorithm Type Before describing the subroutine of # 340, the focus detection algorithm type and its contents will be briefly described.

(I) Pattern Recognition Algorithm This algorithm recognizes the pattern of the distance distribution of the object based on the result of focus detection of the three islands, and adds conditions such as the photographing magnification and the focal length of the interchangeable lens to this. Then, the defocus amount for driving the lens is calculated from the focus detection results of the three islands. AR in the processing described below
= 1 indicates this algorithm.

(Ii) Minimum Defocus Algorithm This algorithm focuses on the object closest to the current focal position of the lens. AR = 2 to 4 in the processing described later indicates this algorithm. Of these, AR = 4 indicates the minimum defocus algorithm in the follow mode. AR = 3 indicates the minimum defocus algorithm when continuous shooting is not performed after focusing.
The difference from AR = 4 is that the offset amount ΔDF _R is added.

This offset amount ΔDF_RExplain about
It In the present invention, the state in which the lens remains stopped after focusing
Based on multiple focus detection results,
(Also called "body"), and if it is a moving body, 1
It takes some time to obtain the results of focus detection
It is moving, and in anticipation of this, the offset amount D
F_RIs attached to the side closer to the camera. In this example,
It doesn't consider the subject moving away from the camera,
If you know the moving direction or speed of the moving body,
Offset amount DF_RThe size and direction of
Yes. Then, this offset amount DF_RThe position including
Assuming the current lens focus position,
Use the defocus amount of the island that includes the closest subject
There is. Here, the offset amount DF_R= 50 μm
It AR = 2 is the minimum in continuous shooting mode after focusing
The algorithm is shown. In continuous shooting mode, the release operation
Since it enters, the time during which focus detection is not performed is increased. did
Therefore, the above offset amount DF _RAs 100 μm
There is.

(Iii) Specific Island Algorithm This algorithm uses the previously selected island again to drive the lens based on the defocus amount of the focus detected on this island. AR = 5 shows this algorithm.

(Iv) Always specific island (or block) algorithm Focus detection is always performed only on a specific block (fourth block) or a specific island (second island), and AR = 6 in the processing described later This algorithm is shown.

(B) Determination of Island (Block) and Shift Range Next, determination of the island (or block) for focus detection and the range (shift range) for correlation calculation will be described. In the process described later, these are determined using the variable B.

B = 1 indicates that there is no limitation on the shift range and the island (or block). B = 2 indicates that the blocks BL1, BL2 and BL4 are not used and there are no other restrictions. B = 3 indicates that the correlation calculation is performed only within the range of ± 4 pitches from the current focus position. B = 4 is
It indicates that the correlation calculation is performed only within a range of ± 2 pitches from the current focus position.

When B = 5, the correlation calculation is performed only in the range of -2 pitch from the current focus position to +2 pitch from the estimated focus position or from +2 pitch from the current focus position to -2 pitch from the estimated focus position. Indicates to do. Whether the former range or the latter range is selected depends on the driving direction of the lens, that is, the direction of the estimated focus position. B = 6
Indicates that the correlation calculation is performed only within a range of ± 4 pitches from the in-focus position. B = 7 indicates that the correlation calculation is performed only within the range of ± 4 pitches from the current focus position only for the island used for the previous lens drive, and there is no limit for other islands. B = 8 indicates that focus detection is performed only on the second island and there is no limitation on the shift range. B = 9 is the fourth block BL4
It indicates that the focus detection is performed only for No. 1 and there is no limit for the shift range. The processing for selectively using these will be described later.

Next, the subroutine of # 340 will be described with reference to FIGS. In # 500, manual focus mode (FA: Focu
sAid) is determined by the switch S _AF / _M. When the switch S _AF / _M is in the manual focus mode position, B = 1 (no limit) in # 590,
At # 600, AR = 1 (pattern recognition algorithm) is returned. Then, the second island is prioritized in # 4610 to # 4660 of the pattern recognition algorithm described later. That is, in the manual focus mode, since the photographer often brings the main subject to the center of the screen, the second island is prioritized. And
Only when the focus cannot be detected on this second island, the first
And the perspective of the subject on the third island are compared, and the defocus amount of the island including the subject close to the camera is used. The shift range of the correlation calculation cannot be limited because the lens is not driven and the defocus amount cannot be predicted.

When the switch S _AF / _M is in the auto focus mode position at # 500, whether or not the spot AF is selected is determined at # 520 by the switch Ss / w. When the spot AF is selected in # 520, B = 9 (spot AF) in # 530, # 555.
Then AR = 6 (always specified block) is returned.
This is the fourth block BL4 which is the area of the spot AF.
Only those that are selected. In spot AF, since AF is performed only in this block, focus detection time is short and it is not necessary to limit the shift range.

When the spot AF is not selected in # 520, whether or not the auxiliary light mode is set in # 540 is determined by whether or not the auxiliary light flag ILMF is set. When the auxiliary light flag ILMF is set in # 540, B = 8 (only the second island) is set in # 550, and AR = 6 (always specific island) is set in # 555. That is, in the fill light mode, only the second island is used. This includes at least the second island at the center of the screen among the three islands when the standard lens (focal length 35 mm to 105 mm) is attached to the range where the auxiliary light is irradiated, and the first and third islands are included. This is because there are things that do not exist. In this case, focus detection is performed only on the second island, so the focus detection time is short and there is no need to limit the shift range.

When the auxiliary light flag ILMF is not set in # 540, it is determined whether or not the flag FPF is set in # 560. This flag FPF is
This is a flag indicating that the pattern recognition algorithm is forcibly executed. When the flag FPF is set in # 560, B = 1 is set in # 590 to indicate that the shift range is not limited, and AR = 1 is set in # 600 to indicate that the pattern recognition algorithm is used.

When the flag FPF is not set in # 560, it is determined in # 570 whether the flag PA1PF is set. This flag PA1PF is
It is a flag indicating that the pattern recognition algorithm has been passed once. When the entire area is in low contrast and focus detection is impossible (hereinafter also referred to as "low contrast") during the first focus detection after the start of focus detection (hereinafter, also referred to as "low contrast"), an operation for searching for a focus detectable lens position while driving the lens ( Hereinafter, the "low-conscan" is performed, and the pattern recognition algorithm is selected during the low-con scan. As a result, when focus detection becomes possible, the flag PA1PF is set. The flag PA1P in # 570
When F is not set, it is determined at # 580 whether or not the flag LSF indicating the low contrast scan is set. When the flag LSF is not set in # 580, B = 1 in # 590 and AR = 1 in # 600.
To return.

If the flag LSF is set in # 580, it is determined in # 610 whether the conversion coefficient K _LR is larger than the predetermined value K1. The conversion coefficient K _LR is a coefficient for _obtaining the lens drive amount (AF motor rotation amount) per unit defocus amount. When K _LR ≦ K1 in # 610, the defocus amount per unit rotation amount of the AF motor becomes large, so that the time for focus detection calculation during lens driving becomes long, which causes the focus determined by the focus detection optical system. An area where the focus cannot be detected occurs because the area exceeds the detectable range.

This will be described with reference to FIG. In FIG. 8, the horizontal axis represents time t and the vertical axis represents the defocus amount DF. DF _EN is the focus detectable range determined by the number of data in the focus detection optical system and the reference unit. I ₁ , I ₂ , ... Are CCD integration times, and C ₁ , C ₂ ,. Considering the focus detectable range DF _EN from the defocus amount at the integration centers TM12L, TM12, ... When the conversion coefficient K _LR is large, the time required for one focus detection within the focus detectable range DF _EN (I ₁ + C ₁ ), (I ₂ +
Since the defocus amount driven by C ₂ ), ... Is included, the subject is never missed. However, the conversion coefficient K
_{When LR} is small, focus detection range DF _EN becomes (I ₁
Since the defocus amount driven during the time of + C ₁ ) does not enter, when the subject exists in this range DF _NO , the subject is missed. To prevent this, # 61
When K _LR ≦ K1 at 0, B = 2 at # 620 and the block BL is set to minimize the focus detection time.
The focus detection of 1, BL2 and BL4 is not performed.
In the case of a subject such as a horizontal line, focus detection cannot be performed on the second island, but focus detection can be performed on either the first island or the third island, so one is better, and in the embodiment, the first island (block BL1 and BL2) are omitted. The fourth block is omitted because the fourth block exists between the third block and the fifth block, the two blocks BL3 and BL5 cover the area of the fourth block BL4, and focus detection is performed. This is enough if you are looking for a possible subject. In order to show this, B = 2 in # 620. Also, # 61
When K _LR > K1 at 0, B = 1, # at # 590.
At 600, AR = 1 and the process returns.

When the flag PA1PF is set in # 570, it means that the pattern recognition algorithm has been passed once, and it is determined in # 630 whether or not the follow-up flag TRCF indicating the follow-up mode is set. . When the follow-up flag TRCF is set in # 630, it is determined whether or not the flag LCF is set in # 640. This flag LCF is a low contrast flag indicating that focus detection could not be performed on all islands last time. When the flag LCF is set in # 640, B = 1 is set in # 590 and AR = 1 is set in # 600 to return to focus detection from the beginning, and the process returns.

When the flag LCF is not set in # 640, it is determined that the object is continuously captured, and the correlation calculation is performed only in the shift range of ± 2 pitches from the previous in-focus position, in # 660. Then, set B = 4. Also,
Regarding the focus detection algorithm, to select the algorithm that selects the subject closest to the previous focus position,
At # 670, AR = 4 and the process returns. This is a follow-up mode, which has already captured the subject,
This is because it is assumed that the object does not deviate much from the in-focus position during one focus detection. The reason why all the islands are used is that it is a moving body, and the subject often moves left and right.

A follow-up flag T indicating a follow-up mode at # 630.
When the RCF is not set, it is determined at # 680 whether the flag AFPEF is set. This flag AFPEF is a flag that indicates that there was a previous focus. When the flag AFPEF is not set in # 680, the flag V1F is set in # 690 of FIG.
It is determined whether or not is set. This flag V1F
Is a flag that indicates focus detection during lens driving at the highest speed (free run). Flag V1 at # 690
When F is set, it is determined that focus detection is performed during free run, and -2 (or +) from the previous focus position.
2) In order to perform the correlation calculation in the range of +2 (or -2) pitch from the pitch and the estimated focus position, B = 5 is set in # 700. This is intended to shorten the calculation time, but the reason why a margin of 2 pitches is provided in the direction opposite to the defocus direction from the previous focus position is that a lens with a large exchange coefficient K _LR is mounted. In this case, even if the rotation amount of the AF motor in the camera is large, only a small defocus amount is moved. This is in consideration of the fact that a defocus amount may occur in the direction of (). This also applies to the case in which the subject moves more in the direction with a margin of 2 pitches than the change in the defocus amount due to the lens drive, and was obtained last time so that such a case can be dealt with. A margin of 2 pitches is provided in the direction opposite to the defocus amount. As for the focus detection algorithm, AR = 5 is returned at # 710 to select a specific island algorithm that uses the previously selected island. This is intended to shorten the time to focus and stabilize the driving of the lens by using the previously selected algorithm. This is because in this case, if an algorithm for selecting a subject from three islands such as a pattern recognition algorithm is used, and if another subject with a different defocus direction is mistakenly selected during lens driving, the lens will be driven by the current drive. This is because the lens is driven in the opposite direction and the lens drive becomes unstable. This also applies to the case of focus detection during low-speed driving which will be described later. In the latter case, when a subject with a large defocus amount is selected even if the defocus direction is the same, the driving speed is suddenly changed from low speed to high speed, and when a subject with a small defocus amount is selected during high speed driving, Instable lens drive such as low speed drive.

Further, by using the specific island algorithm as described above, the focus detection time can be shortened, and as a result, the number of times of focus detection within a predetermined time can be increased to improve the focus detection accuracy. In other words, when the lens driving speed is high, the defocus amount is large, and the value of the defocus amount includes a slight error, and if the lens stop position is determined accordingly, the defocus amount deviates slightly from the in-focus position. However, by increasing the number of times of focus detection and increasing the chances of detecting a small defocus amount, the error is reduced and the stop position of the lens is determined.

When the flag V1F is not set in # 690, it is determined that the focus detection is not performed during the free run, and it is determined in # 720 whether the flag LMVF is set. The flag LMVF is a flag that indicates focus detection during low speed driving. Flag L in # 720
When the MVF is set, it is determined that the focus detection is performed during low speed driving, and the defocus amount due to the focus detection result is smaller than the focus detection during the free run, and one pitch corresponds to the defocus amount of about 1 mm. However, since the pitch is usually ± 4 pitches or less, B = 6 is set in # 730 and AR = 5 is set in # 710 to return the correlation calculation only in the shift range of ± 4 pitches from the in-focus position.

When the flag LMVF is not set in # 720, it is determined that focus detection is not performed during low speed driving, and it is determined in # 740 whether the flag FRN1F is set. The flag FRN1F is a flag indicating that the focus is first detected when the lens is driven by the free run (highest speed) once and the lens is stopped. When the flag FRN1F is set in # 740, the flag FRN1F is reset in # 745. Next, in # 750, it is determined whether or not the flag NLCF is set. The flag NLCF is a flag indicating that there is an island in which focus cannot be detected by the pattern recognition algorithm performed before that. # 750
When the flag NLCF is set in, the correlation calculation is performed only for the ± 4 pitch shift range for the previously selected island, and B = 7 is set in # 760 in order to perform the correlation calculation without the other restrictions. , # 770 AR
Return as = 1. This is because in the previous pattern recognition algorithm, the pattern recognition algorithm is executed again in order to confirm that the subject to be recognized may have become unfocusable due to the relationship of the lens position at that time. However, the focus detection calculation is performed only in the ± 4 pitch shift range for the island selected last time so that the time can be shortened as much as possible, that is, the island for which focus detection is possible.

When the flag FRN1F is not set in # 740, it means that it is not the first focus detection after the lens is stopped from the free run, and when the flag NLCF is not set in # 750, the previous This is the case where there is no island whose focus cannot be detected by the pattern recognition algorithm. In these cases, the flag LCF is sent in # 780.
It is determined whether or not is set. This flag LC
As described above, F is a flag indicating that the result of the current focus detection is that focus detection cannot be performed on all islands.
If there is at least one focus-detectable island, that is, if the flag LCF is not set, the correlation calculation is performed only within the ± 4 pitch shift range of the current focus position.
In step # 790, B = 3 is set, and in step # 770, AR = 1 and the process returns. In addition, focus detection is not possible on all islands (LCF
= 1), in order to eliminate the restriction on the shift range, # 8
At 00, B = 1, and at # 770, AR = 1 and return.

Returning to the description of FIG. 13, when the flag AFPEF indicating that the focus was previously set in # 680 is set, it is determined in # 810 whether or not the continuous shooting flag VLYF is set. . This continuous shooting flag VLY
F is a flag that indicates the continuous shooting mode. # 8
When the continuous shooting flag is set at 10, # 82
When it is 0, it is determined whether or not the flag LCF indicating that focus detection is impossible in all islands is set. # 82
When the flag LCF is set to 0, # 59
When 0, B = 1, and when # 600, AR = 1 and the process returns. When the flag LCF is not set in # 820, B = 3 is set in # 830. This is the case where there is an island in which even one focus detection is possible during the previous focus detection during continuous shooting, so the correlation calculation is performed only within the shift range of ± 4 pitches from the current focus position. In other words, during continuous shooting, it takes time for exposure. Therefore, when the subject is moving, the defocus amount becomes larger than the previous time when the focus detection result is in focus, so the shift range is increased. Is what you are doing. Now, as the function of the camera, a focus priority method is used in which shooting is not possible unless the subject is in focus, so here, at least the last time, the subject is in focus.
Therefore, assuming that the subject is closest to the current focus position, AR = 2 is returned at # 840 in order to select the minimum defocus algorithm.
At this time, since the subject may be a moving body, an offset amount ΔDF _{R of} 100 μm is provided on the side closer to the camera, and this position is set as the in-focus position.

When the continuous shooting flag VLYF is not set in # 810, it is determined in # 850 whether or not the flag LCF is set in order to determine whether or not focus detection is not possible for all the islands. Flag L at # 850
When CF is not set, it means that there is at least one focus-detectable island, and the process proceeds to # 890. When the flag LCF is set in # 850, it means that the focus detection is not possible for all the islands. In # 860, the moving object determination flag MV is set.
It is determined whether F is set. The moving body determination flag MVF is a flag that is set when the moving body determination is in progress. If the moving object determination flag is not set in # 860, it is determined that the moving object determination is not in progress, and # 5
At B, B = 1, at # 600, AR = 1, and the process returns. When the moving object determination flag MVF is set in # 860, or when the flag LCF is not set in # 850, the correlation calculation is performed only in the shift range of ± 2 pitches from the current focus position in # 890. B = 4
And Further, in order to select the minimum defocus algorithm and set the offset amount ΔDF _R to 50 μm, # 90
When 0, AR = 3 and the process returns. This # 890 and #
It is during the moving object determination or in the continuous AF mode that the step 900 is passed. It is assumed that the subject may move during the focus detection during the moving body determination, and therefore the offset amount ΔDF _{R is set} to 50 μm. Further, here, it is set to +50 μm because only the moving subject that is approaching is determined. The island closest to this offset position is the subject position.
The same applies in the continuous AF mode. At this time (that is, during moving object determination or in continuous AF mode), the subject is likely to move in the optical axis direction or in the direction of a plane perpendicular to the optical axis, and focus detection is not possible for all islands. Even if it is temporary, ± 2 pitch correlation calculation, minimum defocus algorithm, offset amount ΔDF _R = 50
Select μm.

Returning to the explanation of FIG. 11, when the subroutine of # 340 is completed, the correlation of the subroutine of # 350 is made based on the selection of the range of the shift number j and the island IS (or the block BL) determined by the subroutine. Calculate. This subroutine will be described with reference to FIGS.

In # 1000, the variables Δn1 to Δn10,
Δn11 to Δn13, Δd1 to Δd10, Δd11 to Δ
A predetermined value K2 is set in d13. Δn1 to Δn10 are shift numbers indicating the maximum correlation in the correlation calculation in the blocks BL1 to BL10, and Δn11 to Δn13 are shift numbers selected in the islands IS1 to IS3. In each block, Δd1 to Δd10 are deviations from the in-focus position after the interpolation calculation, and Δd11 to Δd13 are deviations from the in-focus position after the islands IS1 to IS3. Further, K2 is a large negative value that cannot be the focus detection result, and is an initial value indicating the front focus side (far from the camera). In # 1005, each island IS
Difference data of 1 to IS3 is created. First Island I
The difference data of S1 is a _i (reference part) and a ′ _i (reference part), the difference data of the second island IS2 is b _i (reference part) and b ′ _i (reference part), the difference data of third island IS3. Are c _i (standard part) and c ′ _i (reference part).

Next, the correlation calculation on the second island is performed. First, in step # 1010, a flag LCF2 indicating that focus detection cannot be performed on the second island is set in advance. The flag LCF2 is reset when it is later determined that the focus detection of the second island is not possible.
Then, the correlation calculation of the third block in the second island is first performed. When the above variable B is B = 1, 2 or 8 #
1020, B = 3 to # 1040, B = 4 to # 1060, B = 5 to # 1080, B = 6 to # 1100, B = 7 to # 1120, B = When it is 9, proceed to # 1160. When the variable B is 1, 2 or 8,
Since there is no limitation on the number of shifts in the third block, the range of shift number j is set to 1 to 31 (# 1030). Variable B
When is 3, the shift range is ± 4 pitches from the current focus position. The number of shifts of the focus position in the third block is j
= 6, and the current focus position is (6 + Δn). Therefore, ± 4 pitches are added to this, and the range of the shift number j is Δ.
It is set to n + (2 to 10) (# 1050). When the variable B is 4, the shift range is ± 2 pitches from the current focus position. Similarly to the above, the number of shifts of the focus position in the third block is j = 6, and the current focus position is (6 + Δn)
Therefore, ± 2 pitches are added to this, and the range of the shift number j is set to Δn + (4 to 8) (# 1070). When the variable B is 5, whether or not it is a rear pin is determined in # 1085. When it is determined to be the rear focus, the shift range is set from the second pitch rear pin (+2) at the current focus position to the second pitch front pin (-2) at the focus position (j = 6),
The range of the shift number j is set to 4 to (Δn + 8) (# 1
090). When it is determined that the focus is not the rear focus, the shift range is changed from the front focus (-2) at the current focus position (Δn + 6) to the rear focus (+ = 2 pitch) at the focus position (j = 6).
Up to 2), the range of the shift number j is set to (Δn + 4) to 8 (# 1095). When the variable B is 6, the shift range is ± 4 pitches from the in-focus position. Since the number of shifts of the focus position is j = 6, add ± 4 pitches to this,
The range of the shift number j is set to 2 to 10 (# 111
0). When the variable B is 7, # 11 is used to determine whether the previously adopted island is the second island.
At 30, it is determined whether the variable AFIS = 2. # 1
When it is determined in 130 that AFIS = 2, the shift range is set to ± 4 pitches from the current focus position (6 + Δn), and ± 4 pitches are added to the current focus position (6 + Δn) to determine the number of shifts. The range of j is set to Δn + (2 to 10) (# 1140). When it is determined in # 1130 that AFIS = 2 is not satisfied, the range of the shift number j is set to 1 to 31 on the assumption that the shift number is not limited (# 1150). When the variable B is 9, it is only the fourth block, so # 1
At 170, the process proceeds to the fourth block.

When B = 1 to 8, # 1030 and # 1
050, # 1070, # 1090, # 1095, # 11
# 118 from any of 10, # 1140 and # 1150
In step 0, the low contrast determination level K _LC is set to a predetermined value K _LC1 . In # 1190, the reliability judgment level K
Set _YM / _C to a predetermined value _KYM / _C1 . In # 1195, the starting number of the reference portion for obtaining the correlation is k = 0. This start number k is later (in # 3010, # 3030) i =
1 is added so that i + k = 1 is actually the starting number of the reference part. In # 1200, focus detection impossibility determination and correlation calculation are performed.

The subroutine of # 1200 will be described with reference to FIG. First, in step # 3000, a flag LCFB indicating that the block for which the correlation calculation is currently performed (the third block when called from step # 1200) is incapable of focus detection is set. In # 3010, in order to obtain the contrast from the block (third block) in which the correlation calculation of the reference part is performed,

[0056]

[Equation 1] Ask in. In # 3020, it is determined whether the obtained contrast value C is larger than the predetermined value K _LC . When C ≦ K _LC, the process returns. In this case, the flag LCFB is set and returned. When C> K _LC ,
In # 3030, correlation calculation is performed by the following equation.

[0057]

[Equation 2] In # 3040, the minimum value MIN of the correlation calculation value M (j)
Find (M (j)). This minimum value MIN (M (j))
And the shift number j at that time is a coarse value obtained in units of 1 pitch, so in order to make this finer, # 3
At 050, interpolation calculation is performed. The minimum value of the correlation calculation values obtained by interpolation is YM, and the interpolated shift amount at that time is Δ
d. In # 3060, YM / C obtained by normalizing the minimum value YM of the correlation calculation values obtained by interpolation with the contrast C and the predetermined value K _YM / _C are compared to determine the reliability. When it is determined in # 3060 that YM / C ≧ K _YM / _C , the process returns with no reliability. In this case also, the flag LCFB is returned with the flag being set. When it is determined in # 3060 that YM / C < _KYM / _C, it is determined that there is reliability and focus detection is possible. Therefore, in # 3070, the flag LCF2 indicating that focus detection cannot be performed on the second island is set. After resetting, the flag LCFB indicating that focus detection cannot be performed on the block for which the correlation calculation is performed in # 3080 is reset and the process returns.

Returning to the flow of FIG. 15, in order to determine whether or not the block for which the correlation calculation is performed can detect the focus,
In # 1205, it is determined whether the flag LCBF has been reset. When the flag LCBF is reset in # 1205, a value obtained by subtracting the in-focus position 6 from j is substituted into the variable Δn3 indicating the shift shift number of the third block for which the correlation calculation has been performed (# 1207). Also, in order to obtain the amount of deviation from the in-focus position, the shift number Δd obtained by interpolation calculation
Then, the shift number j = 6 of the focus position is subtracted, and this is set as the shift number Δd3 of the third block (# 1209). # 120
When the flag LCBF is not reset in 5,
Since the third block has no focus detection,
# 1207 and # 1209 are skipped and the process proceeds to # 1210.

At # 1210, it is determined whether the variable B is 2. If the variable B is 2 in # 1210, the correlation calculation of the fourth block is omitted, and the process shifts from # 1220 to the correlation calculation of the fifth block. If the variable B is not 2 in # 1210, the process proceeds from # 1230 to the correlation calculation of the fourth block.

FIG. 17 shows the correlation calculation of the fourth block.
When the variable B is B = 9, go to # 1240, and when B = 3, go to # 1.
To 260, when B = 4 to # 1280, and when B = 5 to #
1300, when B = 6, proceed to # 1320; when B = 7, proceed to # 1340; otherwise, proceed to # 1375. When the variable B is 9, it is in the spot AF mode, so that there is no limitation on the number of shifts in the fourth block, the range of the number of shifts j is set to 1 to 31 (# 1030). When the variable B is 3, the shift range is ± 4 pitches from the current focus position, and when the variable B is 6, the shift range is ± 4 pitches from the focus position. The number of shifts of the focus position is j = 6 in the above-mentioned third block, but the number of shifts of the focus position is j = 16 in this fourth block. Therefore, when B = 3, the current focus position ( 16 + Δn), when B = 6, ± 4 pitches are added to the in-focus position 16 and the range of the shift number j is set to Δn + (12 to 20) (# 1).
270, # 1330). When the variable B is 4, the shift range is set to ± 2 pitches from the current focus position (16 + Δn), so the range of the shift number j is set to Δn + (14 to 18) (# 1290). When the variable B is 5, # 1305
Then, it is determined whether or not it is the rear pin. When it is determined to be the rear focus, the shift range is changed from the two-pitch rear pin (+2) at the current focus position to the two-pitch front pin (-2) at the focus position 16, so that the range of the shift number j 14 ~
(Δn + 18) is set (# 1310). When it is determined that it is not the rear focus, the shift range is set from the 2nd pitch front pin (−2) side of the current focus position (16 + Δn) to the 2nd pitch rear pin (+2) side of the in-focus position 16. The range of the shift number j is set as (Δn + 14) to 18 (#
1315). When the variable B is 7, in order to determine whether or not the previously adopted island is the second island,
In # 1350, it is determined whether the variable AFIS = 2. When AFIS = 2 in # 1350, the shift range is set to ± 4 pitches from the current focus position (16 + Δn). Therefore, ± 4 pitches are added to this, and the range of the shift number j is Δn + (12 to 20) (# 1360).
When it is determined in # 1350 that AFIS = 2 is not satisfied, the range of the shift number j is set to 1 to 31 on the assumption that the shift number is not limited (# 1370). In other cases, that is, when the variable B is 1 or 8, it is already (in # 1030).
Since it has already been set and there is no change, do not set it again. When the variable B is 2, the correlation calculation of the fourth block is not performed (∵ #
1210).

In any case, # 1250 and # 127
0, # 1290, # 1310, # 1315, # 133
From 0, # 1360, # 1370, or # 1375, the process proceeds to # 1380 to determine the low contrast determination level K.
_LC is set to a predetermined value K _LC1 . In # 1390, the reliability determination level K _YM / _C is set to a predetermined value K _YM / _C1 . # 13
In 95, the starting number of the reference part for obtaining the correlation is k = 10.
And In step # 1400, focus detection failure determination and correlation calculation are performed. Since this subroutine is the same as the subroutine called in # 1200, the duplicate description will be omitted. # 140 after returning from the subroutine
At 3, it is determined whether the flag LCBF has been reset. If it is determined in # 1403 that the flag LCBF has been reset, the value obtained by subtracting the in-focus position 16 from the shift number j before interpolation calculation showing the maximum correlation is determined in # 1405 assuming that focus detection is not possible for the fourth block. Substitute for the shift shift number Δn4 of the fourth block. In # 1407,
From the shift amount Δd after the interpolation calculation, the shift number of the in-focus position j =
16 is subtracted, and the defocus amount of the fourth block Δd4 = Δd
Calculate -16. When it is determined in # 1403 that the flag LCBF has not been reset, it is determined that focus detection cannot be performed on the fourth block, and # 1405 and # 140 are determined.
Skip step 7. In # 1410, B = 9
It is determined whether or not (Spot AF). # 1410
When B = 9 in step # 1415, Δd4 indicating the amount of deviation of the second island is set to Δd4, and only the focus detection of the fourth block is required, and the process returns. Shift to the correlation calculation of 5 blocks.

FIG. 18 shows the correlation calculation of the fifth block.
If the variable is B = 3, go to # 1460; if B = 4, go to # 14.
80, when B = 5, # 1500; when B = 6, # 1
520, to # 1540 when B = 7, and to # 1575 otherwise. When the variable B is 3, the shift range is ± 4 pitches from the current focus position, and when the variable is 6, the shift range is ± 4 pitches from the focus position. In the third and fourth blocks, the focus position shift numbers are j = 6 and j = 16, respectively, but in the fifth block, the focus position shift numbers are j = 26, so that B = In the case of 3, the current focus position (26 + Δn) is added by ± 4 pitches to the in-focus position 26 when B = 6, and the range of the shift number j is set as Δn + (22 to 30) (# 14
70, # 1530). When the variable B is 4, the shift range is set to ± 2 pitches from the current focus position (26 + Δn). Therefore, ± 2 pitches are added to the current focus position (26 + Δn) to obtain the range of the shift number j. Is set as Δn + (24 to 28) (# 1490). When the variable B is 5, # 1505
Then, it is determined whether or not it is the rear pin. When it is determined to be the rear focus, the shift range is changed from the two-pitch rear pin (+2) of the current focus position to the two-pitch front pin (-2) of the in-focus position 26. Therefore, the range of the shift number j is 24-
(Δn + 28) is set (# 1510). When it is determined that the shift is not the rear focus, the shift range is set from the two-pitch front pin (-2) of the current focus position to the two-pitch rear pin (+2) of the focus position 26, and thus the range of the shift number j is ( Δn + 24) to 28 are set (# 1515). When the variable B is 7, whether or not the variable AFIS = 2 is determined in # 1550 in order to determine whether or not the previously adopted island is the second island. # 1550 for A
When FIS = 2, the shift range is set to ± 4 pitches from the current focus position (26 + Δn). Therefore, ± 4 pitches are added to the current focus position (26 + Δn) to set the range of the shift number j. Set as Δn + (22 to 30) (# 156)
0). If it is determined in # 1550 that AFIS = 2 is not satisfied, the range of the shift number j is set to 1 to 31 because there is no limitation on the shift number (# 1570). In other cases, that is, when the variable B is 1, 2 or 8, (# 1
Since it has already been set and there is no change (in 030), it is not newly set. When the variable B is 9 (during spot AF), the correlation calculation of the fifth block is not performed (∵ # 1410).

In any case, # 1470 and # 149
0, # 1510, # 1515, # 1530, # 156
0, # 1570, or # 1575 to # 1580
Proceed to, and set the low contrast judgment level K _LC to the predetermined value K.
Set to _LC1 . In # 1590, the reliability judgment level K _YM
/ _C is set to a predetermined value K _YM / _C1 . In # 1595, the starting number of the reference portion for obtaining the correlation is k = 20. # 1
At 600, focus detection impossibility determination and correlation calculation are performed. Since this subroutine is the same as the subroutine called in # 1200, the duplicate description will be omitted. After returning from the subroutine, the flag L is returned in # 1602.
Determine if the CBF has been reset. # 16
When it is determined in 02 that the flag LCBF is reset, it is determined that the focus detection of the fifth block is not possible, and a value obtained by subtracting the in-focus position 26 from the shift number j before the interpolation calculation showing the maximum correlation in # 1605 is set. Store in variable Δn5. In step # 1607, the focus shift amount j = 26 is subtracted from the shift amount Δd after the interpolation calculation to calculate the defocus amount Δd5 = Δd−26 of the fifth block. If it is determined at # 1602 that the flag LCBF has not been reset, then it is determined that focus detection cannot be performed on the fifth block,
Steps # 1605 and # 1607 are skipped. #
At 1610, it is determined whether the flag LCF2 is reset. When the flag LCF2 is not reset in # 1610, it is determined that the focus detection of the second island is not possible at present, and the process proceeds from # 1620 to the correlation calculation of the sixth block. When the flag LCF2 is reset in # 1610, it means that at least one of the third to fifth blocks is capable of focus detection. Therefore, in # 1625, the focus from the in-focus position of the second island is detected. A subroutine for determining the deviation amount Δd12 is called.

This subroutine will be described with reference to FIG. In # 3200, the maximum value of the defocus amounts Δd3 to Δd5 in the third to fifth blocks is detected. This is for detecting the object on the rearmost pin side, that is, the object closest to the camera.

When the maximum value is Δd3, the process proceeds from # 3205 to # 3210, and the shift number Δn3 of the third block is set to the shift number Δ12 on the second island, and further, # 3.
At 220, the amount of defocus from the in-focus position in the third block Δ
The d3 is set as the defocus amount Δd12 from the in-focus position on the second island, and the process returns.

When the maximum value is Δd4, the routine proceeds from # 3205 to # 3230, and the shift number Δn4 of the fourth block is set as the shift number Δ12 on the second island. Further, in # 3240, the defocus amount Δd4 from the in-focus position in the fourth block is set as the defocus amount Δd12 from the in-focus position in the second island, and the process returns. When the maximum value is Δd5, the process proceeds from # 3205 to # 3250, and the shift number Δn5 of the fifth block is set as the shift number Δ12 on the second island. In addition, # 326
When 0, the defocus amount Δd5 from the in-focus position in the fifth block
Is the amount of defocus Δd from the in-focus position on the second island.
Set as 12 and return.

After returning from this subroutine,
The processing shifts from 1630 to the correlation calculation of the first island.

Before explaining the correlation calculation of the first island, the correlation calculation of the sixth block in the second island will be described with reference to FIG. The sixth block is a block for performing focus detection on a low-frequency subject. First, in # 1650, the difference data for every other three is set to the difference data for every other three so as to be suitable for the focus detection for the low-frequency subject, and consequently the difference data for every seven is created. Then, of these, calculation data is created by adding adjacent difference data. That is, the difference data of the standard part and the reference part are respectively a _i and a ′ _i.
Then, the second difference data is (a _i −a _{i + 3} ),
To become _{(a 'i -a' i +} 3). In addition, among the second difference data, operation data a ″ _i obtained by adding adjacent data,
a ″ ′ _i is as follows.

[0069]

(Equation 3) These are operated on the difference data of the second island to obtain the second operation data a ″ _i , a ″ ′ _i . The numbers of the standard portion and the reference portion are 35 and 45, respectively. # 16
After creating 50 operation data, the variable B is judged, and B = 1, 2
Or, if # 8, go to # 1660, and if B = 3, # 1680.
To # 1700 when B = 4 to # 1720 when B = 5
To # 1740 when B = 6, # 176 when B = 7
0, otherwise proceed to # 1795. Variable B is 1,
When it is 2 or 8, it is assumed that the sixth block has no limitation on the number of shifts, and the range of the number of shifts j is set to 1 to 11 (# 1
670). When the variable B is 3, the shift range is ± 4 pitches from the current focus position. Since the number of shifts of the focus position in the sixth block is j = 6, the current focus position (6
Add ± 4 pitch to + △ n) to set the range of shift number j to △
It is set as n + (2 to 10) (# 1690). When the variable B is 4, the shift range is ± 2 pitches from the current focus position. Similarly to the above, the number of shifts of the focus position in the sixth block is j = 6, so the current focus position (6 + Δ
n) is added with ± 2 pitches, and the range of the shift number j is Δn +
(4 to 8) is set (# 1710). When the variable B is 5, whether or not it is the rear pin is determined in # 1725. When it is determined to be the rear focus, the shift range is changed from the rear focus (+2) of the current focus position by 2 pitches to the focus position 6 of 2.
Since the pitch is up to the front pin (-2), the range of the shift number j is set to 4 to (Δn + 2) (# 1730). When it is determined that the focus is not the rear focus, the shift range is set from the front two pitches (-2) of the current focus position to the rear two pitches (+2) of the focus position 6, so that the range of the shift number j is ( Δn + 4) to 8 are set (# 1735). Variable B
When is 6, the shift range is ± 4 pitches from the in-focus position. Since the shift number of the focus position in the sixth block is j = 6, ± 4 pitches are added to this to set the range of the shift number j to 2 to 10 (# 1750). When the variable B is 7, the variable AFIS is determined in # 1770 to determine whether or not the previously adopted island is the second island.
= 2 is determined. AFIS = in # 1770
When it is determined to be 2, the shift range is set to ± 4 pitches from the current focus position (6 + Δn). Therefore, ± 4 pitches are added to the current focus position (6 + Δn) to obtain the shift number j. The range is set to Δn + (2 to 10) (# 178
0). When it is determined in # 1770 that AFIS = 2 is not satisfied, the range of the shift number j is set to 1 to 11 on the assumption that the shift number is not limited (# 1790). The variable B
When the number is 9, the spot AF is performed and only the fourth block is included. Therefore, in this embodiment, # 1795 is not passed.

When B = 1 to 8, # 1670 and # 1
690, # 1710, # 1730, # 1735, # 17
50 from # 1780 or 1790 to # 1800
Go to, low contrast judgment level K_LCIs a predetermined value K
_LC2(≠ K_LC1) Is set, and reliability is determined in # 1810.
Level K_YM/_CIs a predetermined value K_YM/_C2(≠ K_LC1)
It That is, in the sixth block, the third to fifth blocks
Since the number of data used is different,
Judgment level K_LCAnd reliability judgment level K_YM/ _CIs also the third
~ Different from the criterion of the fifth block. # 1820
Then, the focus detection inability determination and the correlation calculation are performed.

The subroutine of # 1820 will be described with reference to FIG. First, in # 3100, a flag LCFB indicating that focus detection cannot be performed on a block (sixth block) currently performing calculation for focus detection is set.
In # 3110, in order to obtain the contrast from the sixth block of the reference part,

[0072]

[Equation 4] Ask in. Since the number of data in the sixth block is different from that in the third to fifth blocks, the number of calculations for calculating the contrast C is also different from # 3010. #
In 3120, it is determined whether the obtained contrast value C is larger than the predetermined value K _LC . When it is less than a predetermined value (C ≦ K
Return to _LC ). The contrast value C is a predetermined value K
_When it is larger than _LC (C> K _LC ), the routine proceeds to # 3130, where the correlation calculation is performed by the following equation.

[0073]

(Equation 5) In the above equation, a ″ _i is the data of the reference part, and a ″ ′ _{i + j-1}
Is the data of the reference part. These data are # 165
It is obtained by calculating 0. In the 6th block, 3rd to 5th
Since the number of data is different from that of the block, the number of times of correlation calculation is different from that of # 3030. # 3140 to # 31
At 80, the minimum value MIN (M
(J)) is obtained, interpolation calculation is performed to determine the reliability of the correlation calculation, and when it is determined that the correlation is reliable, the flags LCF2 and LCFB are reset and the process returns. Since it is exactly the same as # 3040 to # 3080, duplicate description will be omitted.

Returning to the flow of FIG. 20, it is determined at # 1830 whether or not the flag LCBF is reset in order to determine whether or not the focus detection cannot be performed on the sixth block for which the correlation calculation is performed at # 1820. This flag LCBF is reset (in # 3180) when the block for which the correlation calculation has been performed cannot detect the focus. When the flag LCBF is reset in # 1830, that is, when the focus detection cannot be performed in the sixth block, the shift shift of the second island is performed so that the focus detection result of the sixth block becomes the focus detection result of the second island. Variable indicating the number Δn12
The value obtained by subtracting the in-focus position 6 from the shift number j of the sixth block obtained in # 3140 is substituted into (# 1840). Further, in order to obtain the shift amount from the in-focus position on the second island, the shift number Δd obtained by the interpolation calculation of # 3150
Then, the shift number j = 6 at the focus position of the sixth block is subtracted, and this is set as Δd12 (# 1850). And #
The operation shifts from 1855 to the correlation calculation of the first island. If the flag LCBF is not reset in # 1830, that is, if focus detection cannot be performed in the sixth block, the process proceeds from # 1860 to the correlation calculation of the seventh block.

A flowchart of the correlation calculation of the seventh block and the determination of focus detection failure is shown in FIG. 22 and will be described. When the variable B is B = 1, 2 or 8, the process proceeds to # 1870, when B = 7, the process proceeds to # 1890, and otherwise the process proceeds to # 1925. When the variable B is 1, 2 or 8, it is assumed that the shift number is not limited in the seventh block, and the range of the shift number j is set to 1 to 21 (# 1880). When the variable B is 7, whether or not the variable AFIS = 2 is determined in # 1900 in order to determine whether or not the previously adopted island is the second island. When AFIS = 2 in # 1900,
The shift range is ± 4 pitches from the current focus position (6 + Δn). The number of shifts of the focus position in the seventh block is j =
Since it is 6, add ± 4 pitches to this and shift number j
Is set to Δn + (2 to 10) (# 191).
0). If AFIS is not 2 in # 1900, it is assumed that the number of shifts is not limited, and the range of the number of shifts j is 1 to 21.
Is set (# 1920).

# 1880, # 1910, # 1920, #
From any of 1925, the process proceeds to # 1930, the low contrast determination level K _LC is set to a predetermined value K _LC3 , and # 1 is set.
At 810, the reliability determination level K _YM / _C is set to a predetermined value K _YM / _C3.
Set to. That is, in the seventh block, the number of data used is different from that in the third to fifth blocks and the sixth block, and the number of data in the reference portion is 26. Therefore, the determination level K _{LC of} low contrast and the reliability are low. Judgment level K _YM /
_C also differs from the judgment criteria of the third to fifth blocks and the sixth block. In # 1945, the starting number of the reference portion for obtaining the correlation is k = 0. This start number k is later (#
I = 1 is added (in 3310, # 3330), and i + k = 1 is actually the starting number of the reference part. In step # 1950, focus detection failure determination and correlation calculation are performed.

The subroutine of # 1950 will be described with reference to FIG. First, in step # 3300, a flag LCFB indicating that focus detection cannot be performed on a block currently being used for focus detection is set. In # 3310, in order to obtain the contrast from the block (7th block) in which the correlation calculation of the reference part is currently performed,

[0078]

(Equation 6) Ask in. In # 3320, it is determined whether the obtained contrast value C is larger than the predetermined value K _LC . When it is less than or equal to the predetermined value K _LC , the process returns. When C> K _LC , correlation calculation is performed by the following equation in # 3330.

[0079]

(Equation 7) In the above equation, a ″ _{i + k} is the data of the reference part, a ″ ′
_{i + j-1} is the data of the reference part. These data are #
It is obtained by the calculation of 1650. Third in block 7
Since the number of data is different from that of the fifth block and the sixth block, the number of times of correlation calculation is different from that of # 3030 and # 3130. In # 3340 to # 3380, the minimum value MIN (M (j)) of the correlation calculation value M (j) is obtained, the interpolation calculation is performed, the reliability of the correlation calculation is determined, and it is determined that there is reliability. At times, the flags LCF2 and LCFB are reset and then returned.
Since it is exactly the same as 3040 to # 3080, duplicate description will be omitted.

Returning to the flow of FIG. 22, it is determined in # 1960 whether or not the flag LCBF is reset in order to determine whether or not the focus detection cannot be performed on the seventh block subjected to the correlation calculation in # 1950. # 1960 flag L
When the CBF is reset, that is, when the focus detection cannot be performed in the seventh block, a variable Δ indicating the shift number of the second island so that the focus detection result of the seventh block becomes the focus detection result of the second island. to n12,
The value obtained by subtracting the in-focus position 6 from the shift shift number j of the seventh block obtained in # 3340 is substituted (# 1970). Also, the amount of deviation Δd from the in-focus position on the second island
In order to obtain 12, the shift number 6 at the in-focus position of the seventh block is subtracted from the shift number Δd obtained by the interpolation calculation of # 3350, and this is set to Δd12 (# 1975). And
The procedure proceeds from # 1980 to the first island correlation calculation.
If the flag LCBF is not reset in # 1960, that is, if focus detection is not possible in the seventh block, the process proceeds from # 1990 to the correlation calculation of the eighth block.

A flowchart of the correlation calculation of the eighth block and the determination of focus detection failure is shown in FIG. 24 and will be described. If the variable B is B = 3, go to # 2000, and if B = 4, go to # 202.
0, to B = 5 to # 2040, to B = 6 to # 20
60, # 2080 when B = 7, otherwise #
Proceed to 2115. When the variable B is 3, the shift range is ± 4 pitches from the current focus position, and when the variable B is 6, the shift range is ± 4 pitches from the focus position. Since the number of shifts of the focus position in the eighth block is j = 16, B =
When it is 3, B = 6 at the current focus position (16 + Δn)
In the case of, ± 4 pitches are added to the focusing position 16 and the range of the shift number j is set to Δn + (12 to 20) (#
2010, # 2070). When the variable B is 4, the shift range is set to ± 2 pitches from the current focus position, ± 2 pitch is added to the current focus position (16 + Δn), and the shift number j
Is set to Δn + (14 to 18) (# 203
0). When the variable B is 5, whether or not it is a rear pin is determined in # 2045. When it is determined to be the rear focus, the shift range is set to the rear focus 2 pitches (+) of the current focus position.
2) to the pin (-2) two pitches before the focus position 16, the range of the shift number j is set to 14 to (Δn + 18) (# 2050). When it is determined that it is not the rear focus, the shift range is set from the front focus (-2) of the current focus position two pitches to the rear focus (+2) of two pitches of the focus position 16, so that the range of the shift number j is ( △ n + 14) ~ 1
8 is set (# 2055). When the variable B is 7, whether or not the variable AFIS = 2 is determined in # 2090 in order to determine whether or not the previously adopted island is the second island. When it is determined that AFIS = 2 in # 2090, the shift range is set to the current focus position (1
Since 6 + Δn) is set to ± 4 pitches, ± 4 pitches are added to the current focus position (16 + Δn) and the range of the shift number j is set to Δn + (12 to 20) (# 2100).
When it is determined in # 2090 that AFIS = 2 is not established, the range of the shift number j is set to 1 to 21 on the assumption that the shift number is not limited (2110).

# 2010, # 2030, # 2055, #
2050, # 2070, # 2100, # 2110, # 2
From either 115, proceed to # 2120 and
Last judgment level K_LCIs a predetermined value K_LC3Set to # 18
In 10, the reliability determination level K _YM/_CIs a predetermined value K_YM/_C3To
Set. That is, in the 8th block, the data to be used
Is the same as the 7th block,
Judgment level K_LCAnd reliability judgment level K_YM/_CAlso
It is the same as the criterion for 7 blocks. However, the correlation
The starting number of the reference part for taking is different from the 7th block.
In step # 2135, k = 10. This starting number k
Is added with i = 1 later, and actually i + k = 11
It is the starting number of the reference part. Focus cannot be detected with # 2140
Judgment and correlation calculation are performed. This subroutine is the 7th block
23 used in the correlation calculation (# 1950) of the clock.
Brutin is used. However, in the 8th block
The number of shifts of the focal position is j = 16, and the shift of the reference part is opened.
These parameters are different because the starting number is k = 10.
Therefore, # 2140 is different from # 1950.
The calculation result is obtained. # 2140 which performed correlation calculation
It is necessary to judge whether 8 blocks are not focus-detectable.
First, the flag LCBF is reset at # 2150.
Or not. The flag LCBF is reset in # 2150.
Focus detection, that is, in the eighth block, focus detection fails.
If not, the focus detection result of the 8th block is
In order to obtain the focus detection result of the second island, the second air
In the variable Δn12 indicating the shift shift number of the band, # 3340
From the shift number j of the eighth block obtained in
The subtracted value is substituted (# 2160). Also, the second Islay
To obtain the amount of deviation Δd12 from the in-focus position
From the shift number Δd obtained by the interpolation calculation of # 3350,
Subtract the shift number 16 at the focus position of 8 blocks,
Δd12 is set (# 2170). And # 2180
To the correlation calculation of the first island. Also, # 21
If the flag LCBF is not reset at 50
If the focus cannot be detected even in the 8th block,
The process proceeds from # 2180 to the correlation calculation of the first island.
In this case, after all, the flag LCF2 is not reset.
It was hard.

The correlation calculation in the first island will be described with reference to FIG. First, in # 2200, a flag LCF1 indicating that focus detection cannot be performed on the first island is set in advance. This flag LCF1 is reset later when it is determined that the focus detection of the first island is not possible.

Next, the correlation calculation of the first block in the first island is first performed. When the variable B is B = 1, # 221
0, # 2344 when B = 2, # 22 when B = 3
30 to # 2250 when B = 4, # 2 when B = 5
270, # 2290 when B = 6, ## when B = 7
2310, and if B = 8, proceed to # 2348. When the variable B is 1, it is assumed that the number of shifts is not limited in the first block, and the range of the number of shifts j is set to 1 to 21 (# 222).
0). When the variable B is 2, focus detection is not performed on the first island, and # 2346 is set on the third island to proceed to the third island.
Move to island correlation calculation. When the variable B is 3, the shift range is ± 4 pitches from the current focus position, and when the variable B is 6, the shift range is ± 4 pitches from the focus position. The number of shifts of the focus position in the first block is j = 6
Therefore, when B = 3, the current focus position (6 + Δ
In n), when B = 6, ± 4 pitches are added to the focusing position 6 and the range of the shift number j is set to Δn + (2 to 10) (# 2240, # 2300). When the variable B is 4, the shift range is ± 2 from the current focus position (6 + Δn).
Since the pitch is set, the current focus position (6 + Δn) is ± 2
Add pitch to set the range of shift number j to Δn + (4 to 8)
Is set (# 2260). When the variable B is 5, # 2
At 275, it is determined whether or not it is the rear pin. When it is determined to be the rear focus, the shift range is changed from the two-pitch rear pin (+2) at the current focus position to the two-pitch front pin (-2) at the focus position 6, so that the range of the shift number j is 4-
(Δn + 8) is set (# 2280). When it is determined that the focus is not the rear focus, the shift range is set from the front two pitches (-2) of the current focus position to the rear two pitches (+2) of the focus position 6, so that the range of the shift number j is ( △ n
+4) to 8 are set (# 2285). When the variable B is 7, in order to determine whether or not the previously adopted island is the first island, the variable AFIS =
It is determined whether it is 1. AFIS = 1 in # 2320
If it is determined that the shift range is ± 4 pitches from the current focus position, the current focus position (6+
Add ± 4 pitch to △ n) to change the range of shift number j to Δn
It is set as + (2 to 10) (# 2330). # 2320
If it is determined that AFIS = 1 is not set, the range of the shift number j is set to 1 to 21 on the assumption that the shift number is not limited (# 2340). When the variable B is 8, the mode is the auxiliary light mode and only the focus detection of the second island is performed. Therefore, the focus detection of the first island and the focus detection of the third island are omitted, and the process returns.

# 2220, # 2240, # 2260, #
2280, # 2285, # 2300, # 2330, # 2
After setting the range of the shift number j with any of 340, #
At 2350, the low contrast judgment level K _LC is set to a predetermined value K.
Set to _LC1 . In # 2360, the reliability judgment level K _YM
/ _C is set to a predetermined value K _YM / _C1 . Since the first block has the same number of data in the reference portion as the third to fifth blocks, the same value is used as the determination criterion. # 2365
Then, the shift start number of the reference part for obtaining the correlation is k = 0.
And This start number k is later (# 3510, 353
I = 1 is added (in 0) so that i + k = 1 is actually the starting number of the reference part. In step # 2370, focus detection failure determination and correlation calculation are performed.

The subroutine of # 2370 will be described with reference to FIG. First, in step # 3500, a flag LCFB indicating that focus detection cannot be performed on a block for which focus calculation is currently performed is set. In # 3510, in order to obtain the contrast from the block currently performing the correlation calculation in the reference part,

[0087]

(Equation 8) Ask in. In step 3520, it is determined whether the obtained contrast value C is larger than the predetermined value K _LC . When C ≦ K _LC, the process returns. In this case, the flag LCFB is set and returned. When C> K _LC ,
In # 3530, correlation calculation is performed by the following equation.

[0088]

[Equation 9] In # 3540, the minimum value MIN of the correlation calculation value M (j)
Find (M (j)). This minimum value MIN (M (j))
And the shift number j at that time is a coarse value obtained in units of 1 pitch, so in order to make this finer, # 3
At 550, interpolation calculation is performed. The minimum value of the correlation calculation values obtained by interpolation is YM, and the interpolated shift amount at that time is Δ
d. In # 3560, the minimum value YM of the correlation calculation values obtained by interpolation is standardized with the contrast C and the value YM / C obtained by comparison with the predetermined value K _YM / _C to determine the reliability. If it is determined at # 3560 that YM / C ≧ K _YM / _C , the process returns with no reliability. In this case also, the flag LCFB is returned with the flag being set. When it is determined in # 3560 that YM / C < _KYM / _C, it is determined that there is reliability and focus detection is possible. After resetting, the flag LCFB indicating that focus detection cannot be performed on the block for which correlation calculation is performed in # 3580 is reset and the process returns.

Returning to the flow of FIG. 25, in order to judge whether the block for which the correlation calculation has been performed cannot detect the focus,
In # 2380, it is determined whether the flag LCFB has been reset. This flag LCFB is reset (at # 3580) when the block (first block) on which the correlation calculation is performed is not focus-detectable. When the flag LCFB is reset in # 2380, the focus position 6 is subtracted from the shift number j obtained in # 3540 as a variable Δn1 indicating the shift shift number of the block (first block) on which the correlation calculation is performed. A value is substituted (# 2382). Also,
The number of shifts at the focus position in the first block is calculated from the number of shifts Δd obtained by the interpolation calculation in # 3550 in order to obtain the shift amount Δd1 from the focus in the block (first block) on which the correlation calculation is performed. Subtract j = 6 and let this be Δd1 (#
2384). Note that when the flag LCFB is not reset in # 2380, it means that the focus detection of the first block cannot be performed. Therefore, # 2382, # 23.
Skip 84 and proceed to # 2386. The procedure proceeds from # 2386 to the second block correlation calculation.

The correlation calculation of the second block will be described with reference to FIG. When variable B is B = 3, go to # 2390, when B = 4, go to # 2410, when B = 5, go to # 2430, B = 6
If so, the process proceeds to # 2450, if B = 7, the process proceeds to # 2470, and otherwise, the process proceeds to # 2505. When the variable B is 3, the shift range is ± 4 pitches from the current focus position. When the variable B is 6, the shift range is ± 4 pitches from the in-focus position. In the first block described above, the number of shifts of the focus position is j = 6, but in this second block, the number of shifts of the focus position is j = 16. Therefore, when B = 3, the current focus position ( 16 + Δn), when B = 6, ± 4 pitches are added to the in-focus position 16 so that the range of the shift number j is Δ.
n + (12 to 20) is set (# 2400, # 246).
0). When the variable B is 4, the shift range is ± 2 pitches from the current focus position, so the current focus position (16+
Add ± 2 pitch to △ n) to change the range of shift number j to Δn
It is set to + (14 to 18) (# 2420). When the variable B is 5, whether or not it is a rear pin is determined in # 2435. When it is determined to be the rear focus, the shift range is changed from the two-pitch rear pin (+2) at the current focus position to the two-pitch front pin (-2) at the focus position 16, so that the range of the shift number j is 14 to (Δn + 16) is set (# 24)
40). When it is determined that it is not the rear focus, the shift range is set from the front focus (-2) of the current focus position two pitches to the rear focus (+2) of two pitches of the focus position 16, so that the range of the shift number j is ( Set as Δn + 14) to 18 (#
2445). When the variable B is 7, in order to determine whether or not the previously adopted island is the first island,
In # 2480, it is determined whether or not the variable AFIS = 1. When it is determined that AFIS = 1 in # 2480, the shift range is set to ± 4 pitches from the current focus position. Therefore, ± 4 pitches are added to the current focus position (16 + Δn) to change the shift number j. The range is set to Δn + (12 to 20) (# 2490). If it is determined in # 2480 that AFIS = 1 is not satisfied, the range of the shift number j is set to 1 to 21 on the assumption that the shift number is not limited (# 250).
0). In other cases, since it has already been set and there is no change, it is not newly set.

# 2400, # 2420, # 2440, #
2445, # 2460, # 2490, # 2500, # 2
The process proceeds from # 505 to # 2510 to set the low contrast determination level K _LC to a predetermined value K _LC1 . # 2
At 520, the reliability determination level K _YM / _C is set to a predetermined value K _YM / _C1.
Set to. That is, since the number of data in the second block is the same as that in the first block, the determination criterion is also the same as that in the first block. However, in the second block, the starting number k of the reference portion for obtaining the correlation is set to k = 10 in # 2525, unlike the first block. In step # 2527, focus detection failure determination and correlation calculation are performed. This subroutine is the same as the subroutine called in # 2370 described above, but since the range of the shift number j and the start number k in the second block are different from those in the first block, the calculation result is different from # 2370. After returning from the subroutine, it is determined at # 2530 whether or not the flag LCFB is reset. When the flag LCFB is reset in # 2530, it is determined that the focus detection of the second block is not possible, and the value obtained by subtracting the in-focus position 16 from the shift shift number j before the interpolation calculation showing the maximum correlation in # 2535 is set as the variable Δ. Substitute in n2. In # 2540, the shift amount j = 16 of the focus position is subtracted from the shift amount Δd after the interpolation calculation to calculate the defocus amount Δd2 = Δd-16 of the second block. If it is determined at # 2530 that the flag LCFB has not been reset, it is determined that focus detection cannot be performed on the second block, the steps of # 2535 and # 2540 are skipped, and the process proceeds to # 2545.

At # 2545, it is determined whether the flag LCF1 has been reset. # 2545 flag L
If CF1 is not reset, it is determined that focus detection cannot be performed on the first island, and the process proceeds from # 2550 to the correlation calculation of the third island. # 2545 flag LC
When F1 is reset, it means that at least one of the first and second blocks is capable of focus detection. Therefore, in # 2547, the amount of defocus Δd11 from the in-focus position of the first island. Call a subroutine that determines.

This subroutine will be described with reference to FIG. In # 3400, the maximum value of the defocus amounts Δd1 and Δd2 in the first and second blocks is detected. This detects the object on the rearmost pin side, that is, the object closest to the camera. When the maximum value is Δd1, # 3405 to # 3405
Proceeding to 3410, the shift number Δn1 of the first block is set as the shift number Δn11 on the first island. Further, in # 3420, the defocus amount Δd1 from the in-focus position in the first block is set as the defocus amount Δd11 from the in-focus position in the first island, and the process returns.

When the maximum value is Δd2, the routine proceeds from # 3405 to # 3430 and the shift number Δn2 of the second block is set as the shift number Δn11 of the first island. Further, in # 3440, the defocus amount Δd2 from the in-focus position in the second block is set as the defocus amount Δd11 from the in-focus position in the first island, and the process returns.

After returning from this subroutine,
The operation shifts from 2550 to the correlation calculation of the third island.

The correlation calculation of the third island is shown in FIGS. The third island is configured symmetrically with the first island and has the same amount of data, so the processing content is basically the same. However, the ninth block is replaced by the first block, the tenth block is replaced by the second block, Δn9 is replaced by Δn1, Δd9 is replaced by Δd1,
Δn10 instead of Δn2, Δd10 instead of Δd2, Δ
Δn13 instead of n11, Δd13 instead of Δd11,
Use flag LCF3 instead of flag LCF1,
The difference is that the range of AFIS = 3 is performed instead of the determination of AFIS = 1. Also, the contrast calculation formula of # 3610 and the correlation calculation formula of # 3630 are different from each other as follows.

[0097]

[Equation 10]

[0098]

[Equation 11] Further, in # 2570 and # 2580, the shift range is not limited even when B = 2, and after the processing of the third island is completed, the correlation calculation of other islands is not performed and the process returns. That is different. Therefore, only showing the above differences, the explanation about the correlation calculation of the first island is referred to the explanation about the correlation calculation of the third island, and the explanation about the correlation calculation and the focus detection non-determination processing in each island is described. Finish.

When the correlation calculation in # 350 of FIG. 11 is completed, the low contrast determination of # 360 is performed. This will be described with reference to FIG. In # 4000, the algorithm is AR =
It is determined whether or not it is 6 (auxiliary light mode or spot AF). # When AR is not 6 in 4000, #
At 4010, it is determined whether AR = 5 (specific island algorithm). When AR = 5 in # 4010, it is determined in # 4020 whether or not the variable AFIS = 1 in order to determine whether or not the specific island is the first island. The variable AFIS = 1 in # 4020
If it is, it is determined that the specific island is the first island, and it is determined whether or not the flag LCF1 is set in # 4030 in order to determine whether or not the focus detection of the first island is impossible. When the flag LCF1 is set in # 4030, it is determined that focus detection cannot be performed on the first island, and the flow proceeds to # 4072.
When the flag LCF1 is not set at # 4030, it is determined that the focus detection of the first island used in the specific island algorithm is not possible, and the process returns. When the variable AFIS = 1 is not set in # 4020, it is determined whether the variable AFIS = 2 is set in # 4040 in order to determine whether the specific island is the second island.

When the variable AFIS = 2 in # 4040, it is determined that the specific island is the second island, and the flag LCF2 is set in # 4050 to determine whether the focus detection of the second island is impossible. It is determined whether or not it is set. # 4050 flag LCF
When 2 is set, it is determined that focus detection cannot be performed on the second island, and the flow proceeds to # 4072. # 405
When the flag LCF2 is 0 and the flag LCF2 is not set, it is determined that the second island used in the specific island algorithm is not focus-detectable, and the process returns.

When the variable AFIS is not equal to 2 in # 4040, it is determined that the specific island is the third island. Therefore, the flag LCF3 is determined in # 4060 in order to determine whether the focus detection of the third island is impossible. It is determined whether or not is set. When the flag LCF3 is set in # 4060, it is determined that focus detection cannot be performed on the third island, and the flow proceeds to # 4072. #
When the flag LCF3 is not set in 4060, it is determined that the focus detection of the third island used in the specific island algorithm is not possible, and the process returns.

When AR = 6 in # 4000, it is determined that the auxiliary light mode or spot AF is in effect, and it is determined whether the second island used in the auxiliary light mode or spot AF cannot perform focus detection. Therefore, # 407
At 0, it is determined whether the flag LCF2 is set. When the flag LCF2 is not set in # 4070, it is determined that the focus detection of the second island used in the auxiliary light mode or the spot AF is not possible, and the routine returns. If the flag LCF2 is set in # 4070, the flag LCF2 is determined in # 4072 in order to determine whether or not the focus detection result of the previous focus detection was impossible.
It is determined whether or not is set. When the flag LCF is not set in # 4072, it is determined that the previous focus detection result is not the focus detection failure, and # 40
The flag LLCF is reset at 74, and the routine proceeds to # 4080. When the flag LCF is set in # 4072, it is determined that the focus detection result of the previous time is not focus-detectable, and the flag LLCF is set in # 4076.
Proceed to 080. In # 4080, the flag L indicating that the current focus detection result indicates that focus detection cannot be performed on all islands.
Set CF and return.

If AR = 5 (specific island algorithm) is not satisfied in # 4010, # 4090 and # 41 are used in order to determine whether or not focus detection is impossible in each island.
00, # 4110 for flags LCF1, LCF2, LCF
It is determined whether or not 3 is set. When the flag LCF1 is not set in # 4090, it is determined that the focus detection of the first island is not possible, and the process returns. When the flag LCF2 is not set in # 4100, it is determined that the focus detection of the second island is not possible, and the process returns. When the flag LCF3 is not set in # 4110, it is determined that the focus detection of the third island is not possible, and the process returns. # 4090 to # 41
When all the flags LCF1 to LCF3 are set at 10, it is determined that the focus detection cannot be performed on all the first to third islands, and the process proceeds to # 4072.

In FIG. 11, the low contrast judgment (# 36
After returning from the (0) subroutine, the flag LCF is determined in # 370 in order to determine whether or not focus detection is impossible.
It is determined whether or not is set. When the flag LCF is not set in # 370, it is determined that focus detection is not possible, the algorithm is determined in # 380, and the defocus amount is determined based on the algorithm.
After that, the process proceeds to # 390, the one-shot AF mode and the continuous AF mode are automatically selected, and the process returns. Normally, after focusing, the one-shot AF mode in which the AF operation is not performed is prioritized, and a tracking mode (including a continuous AF mode) that detects and only follows a subject when the subject is a moving body. ) Is being performed. In step # 370, focus detection is impossible (L
Even when it is determined that CF = 1), the processing of # 390 is started, but when the tracking mode is not set, control is performed when focus detection is impossible. This control is also included in the processing of # 390. include.

A subroutine for algorithm determination and defocus amount determination will be shown and described below with reference to FIG. # 420
At 0, the photographing magnification β _{N of the} subject closest to the camera is calculated. First, a general method for obtaining the photographing magnification β will be described.

General Method of Obtaining Shooting Magnification β The amount of extension of the lens from the infinity position to the current position is D
Letting F ₀ , the shooting distance at the current position be d, and the focal length of the lens be f, it can be approximately expressed as d = f ² / DF ₀ . Here, the value (N) of the pulse counter that monitors the state where the lens is extended from the extreme end position to the current position is generally proportional to the extension amount (DF ₀ ). = K _LR × DF ₀ (K _LR is a constant) _Therefore , the shooting distance at the current position of the lens is d = f ² K _LR / N, and if the logarithm of both sides of the above equation is taken, log ₂ d = log ^{_{2 f 2 K LR -log 2 N}} log 2 d 2 = Dv∞-2log 2 N ( here, to. the ^{_{Dv∞ = 2log 2 f 2 K LR}} ) becomes. If the shooting distance is an apex system and Dv = log ₂ d ² , then Dv = Dv ∞−2log ₂ N (*).

Now, the camera operation is performed in the apex system, and in the formula (*), Dv∞ is obtained as the lens-specific information in the apex system, and the pulse number N for lens extension is converted into the apex system. Then, the shooting distance Dv can be obtained by an apex system.

[0108] This amount N of extension is converted into an apex system.
The method is described below. First, log ₂N = D_VNGet / 2
Meru. As can be seen from this equation, when N = 1, that is, one parameter
When you roll out only Rus, D_VN/ 2 = 0,
From the equation (*), the distance Dv at this time is Dv∞.

When the number N of pulses for lens extension is 2 or more, the digit number N of the bit b _N in which 1 is set is counted as an integer value N from the maximum bit of the counter, and the lower 4 digits are respectively set. 1/2, 1/4, 1/8, 1/16
The fractional part with the weight of and the lower digits are ignored. For _{example, ... b 9 b 8 b 7} b 6 b 5 ... = ... 10111
If ... and (b ₁₀ or more bits 0), (9 + 7/1
6), and _{also, ... b 12 b 11 b 10} b 9 b 8 ... = ... 110
10 ... (bits _{13 and} above are 0), (12 + 1
0/16), and this value is log ₂ N. And
This value is doubled to obtain 2log ₂ N. In the above example, (9 + 7/16) is doubled to (18 + 7/8),
Double (12 + 10/16) to (24 + 10/8) =
It becomes (25 + 2/8). Then, Dv = D in the equation (*)
It suffices to obtain Dv based on v∞−2log ₂ N. At this time, there is a slight error (0.1 Dv) in the value of Dv, but it is a value that can be ignored. Next, regarding the value of Dv∞, when the pulse number N for lens extension is 2, that is, when 1 is set in bit b ₁ , the Dv value corresponding to the in-focus distance of the lens is set to 2. The value added may be used.

The value of the shooting distance Dv obtained as described above is information on the shooting distance (d) with respect to the current lens position. The distance (x) to the object having a certain defocus amount (DF) with respect to the current lens position is N = K, which indicates the lens drive amount, where N is the value of the counter indicating the current lens position. _{Calculate LR} × DF, N = N + ΔN
Then, the shooting distance (subject distance) at the object position of the lens is x = f ² K _LR / (N + ΔN), and if the logarithm of both sides of the above expression is log _{2 ^{x = log 2 f 2 K LR}} -log 2 (N + △ N) Dv = Dv∞-2log 2 (N + △ N) however, Dv = log ^₂ x _2, in Dv∞ = 2log ^₂ f ₂ K _LR subject position The imaging magnification is β = f / x, and log ₂ β = log ₂ f-log ₂ x 2log ₂ β = 2log ₂ f-Dv. Therefore, the focal length data may be stored as 2log ₂ f of the apex system.

Method for Obtaining Imaging Magnification β _N of Recent Subject Next, a method for obtaining the imaging magnification β _{N of the} object closest to the camera will be described with reference to FIG. In # 4500, the maximum value is obtained from the deviation amounts Δd11 to Δd13 from the in-focus position of each island. When the maximum value is Δd11, #
The process proceeds from 4501 to # 4502, and the maximum deviation amount Δdma
Substituting Δd11 for x, substituting the shift number Δn11 of the first island for the shift number Δn in # 4504, # 4514
Proceed to. When the maximum value is Δd12, the process proceeds from # 4501 to # 4506, and the maximum deviation amount Δdmax becomes Δd12.
Is assigned, the shift number Δn12 of the second island is substituted for the shift number Δn in # 4508, and the flow proceeds to # 4514. When the maximum value is Δd13, the process proceeds from # 4501 to # 4510, where Δd13 is substituted for the maximum deviation amount Δdmax, and #
4512 shift number Δn to third island shift number Δ
Substitute n13 and proceed to # 4514.

At # 4514, the maximum deviation amount Δdmax is multiplied by the defocus amount SA per pitch to calculate the defocus amount DF. Using this defocus amount DF, the photographing magnification β is obtained in the subroutine of # 4516, the obtained photographing magnification β is substituted for the closest magnification β _N of the latest subject in # 4518, and the process returns.

FIG. 36 shows a subroutine for calculating the photographing magnification, which will be described. This subroutine is the defocus amount D
After the photographing magnification β is calculated using F as an argument, the process returns. First, in # 4520, the defocus amount DF
_Is multiplied by the lens drive amount conversion coefficient K _LR to obtain the lens drive amount N
1 (the number of rotations of the AF motor) is calculated. In # 4530, the lens drive amount N2 is added to the current lens extension amount N2.
1 is added to calculate the lens extension amount N3 at the in-focus position. In # 4540, the lens extension amount N3 is converted into an apex system, and Dv ′ = 2log ₂ N3. In # 4550, the shooting distance Dv = Dv∞−Dv ′ is obtained as a difference from the lens-specific information Dv∞. # 4
At 560, the apex-system imaging magnification β is obtained by subtracting the apex-system imaging distance Dv from the apex-system focal length f.
And return.

As described above, the photographing magnification β can be obtained from the lens extension amount. As another method, the photographing distance x is obtained from the distance detecting means, and β = f / is calculated from the ratio with the focal length f. It may be calculated as x (non-apex system). Returning to the flow of FIG. 34, in # 4210, the flag LCF indicating that focus detection is impossible is reset. #
At 4220, the flag LCSF indicating low contrast search is reset.

Next, the variables for algorithm selection are
When AR = 1, go to # 4230; when AR = 2, go to # 4
260, when AR = 3, go to # 4280, when AR = 4, go to # 4300, when AR = 5, go to # 4330, and when AR = 6, defocus amount Δd is set to the second island. # 43 including the defocus amount Δd12
Proceed to 45.

First, when the variable AR is 1, # 4240
To run the pattern recognition algorithm. This is shown in FIG.
Will be explained. In # 4600, the pattern recognition algorithm
Set the flag PA1PF indicating that the rhythm has been passed
I do. In # 4610, the manual focus mode (F
A: Focus Aid) switch S _AF
/_MDetermined by Manual focus with # 4610
If it is a second mode, the second airer that is prioritized in this mode
The flag LCF2 determines whether or not the focus cannot be detected.
I do. # 4620 flag LCF2 is not set
When it is not, the second island is not not focus-detectable.
It is determined that the focus deviation amount Δd for focus determination is set to # 4630.
Substitute the defocus amount Δd12 of 2 islands and return
I do. This is because when you focus manually,
Do you often bring it to the center of the screen (second island)?
It is. The reason for this is that it has traditionally been installed in the center
Focus on the image of the split prism
Because there are many cases. Flag LC at # 4620
When F2 is set, the second island is out of focus.
It was judged that the point detection was impossible, and the first island was run at # 4640.
Defocus amount Δd11 and defocus amount of third island
Compare Δd13. With # 4640, Δd11 <Δd13
, The subject on the third island is the camera
It is determined that it is close to
Substitute Iland's defocus amount Δd13 and return
It When Δd11 ≧ Δd13 in # 4640,
It is determined that the subject on the first island is closer to the camera,
Defocus amount Δd for focus determination does not include the focus of the first island
Substitute the amount Δd11 and return.

If the manual focus mode is not set in # 4610, it is determined that the auto focus mode is set, and the flow shifts to # 4670 to set the focal length f of the interchangeable lens to 3
It is determined whether it is less than 5 mm. When the focal length f is less than 35 mm in # 4670, it is determined that the wide-angle lens is mounted, the defocus amount Δdmax of the object closest to the camera is adopted as the lens driving defocus amount Δd, and the return To do. This is because when using a wide-angle lens, it is likely that a landscape photo or a commemorative photo with a landscape in the background will be taken, and in such a case, the subject closest to the camera is often the main subject. Because.

When the focal length f is 35 mm or more in # 4670, it is determined in # 4690 whether or not the focus detection of the second island is impossible by the flag LCF2. #
When the flag LCF2 is set at 4690, it is determined that the focus detection cannot be performed on the second island,
In this case, since pattern recognition cannot be performed, the process proceeds to # 4680 to focus on the subject closest to the camera for the time being.

When the flag LCF2 is not set in # 4690, it is determined that the focus of the second island can be detected, and the determination criterion β _L of the smaller photographing magnification is calculated. This will be described with reference to FIG. In step # 4850, the denominator value β1 of the photographing magnification (1 / β1) corresponding to the focal length f read from the interchangeable lens is read from the ROM table. In # 4860, add Δβ to this β1,
Find β _L '. Δβ will be described later. # 4870
Then, the reciprocal of β _L 'is obtained, the above judgment criterion β _L is calculated, and the process returns.

Here, the determination criterion β of the smaller photographing magnification is used.
_The reason why _L is changed according to the focal length f of the interchangeable lens will be described. The criterion β _L is increased as the focal length f is smaller. Then, if the photographing magnification is smaller than the determination criterion β _L , the island of the subject is used recently. The shorter the focal length f is, the deeper the depth of field becomes, and the determined photographing magnification (for example, f = 35 mm, β = 1 /
Even if focus adjustment is performed on the island in which the recent subject in 50) exists, the probability that the background will be in focus increases.
Conversely, the larger the focal length f is, the shallower the depth of field becomes. If the focus is adjusted on a recent subject with the same shooting magnification as the above, the focus range is small and the focus is on the latest subject. Was not good. This has been confirmed by live action. Therefore, taking this depth of field into consideration, the criterion β _L is made smaller as the focal length becomes longer, and the probability of using the algorithm for selecting the island of the latest subject is made smaller than that when the focal length is short. There is.

[0121]

[Table 1] Table 1 shows an example of the ROM table used in # 4850.

Returning to FIG. 37, the control for determining the island to be selected according to the photographing magnification is performed from the next step # 4710. In the present invention, the photographing magnification to be used is determined using the focus detection result of the island in which the object closest to the camera among the three islands is detected. When the photographing magnification β _N is large, focus adjustment is performed using the focus detection result on the second island. This is because when the shooting magnification β _N is large, it is considered that the subject is large and the island where the shooting magnification is obtained is the second object.
This is because it is considered that the islands are always included. When the shooting magnification β _N is medium, the basic idea is the same as above. However, when the second island is farthest from the camera, a hollow or the like may be considered, and at this time it is difficult to select the subject, so an island having a defocus amount at the center of the distance distribution is used. When one of the islands other than the second island cannot detect the focus, the island in which the subject closest to the camera exists is used. When the shooting magnification β _N is small, the island closest to the camera is used because it is a landscape or a portrait including a landscape.

This will be described below with reference to the flowchart.
I do. In # 4710, the shooting magnification β _NJudgment is larger
Standard β_HIs greater than. # 4710
β_N> Β_HIf it is, # 4800 is the larger
Constant β_HTo 1/50 to add hysteresis. This
This reduces the frequency of switching algorithms depending on the shooting magnification.
However, the change in the amount of defocus at each focus detection is reduced and stable.
This is to obtain a focused focus detection operation. β_N> Β_HIs
The subject is relatively large, and only the second island is enough.
Since it is determined that it is
The defocus amount Δd is equal to the defocus amount Δd12 of the second island.
Substituting in # 4815, the number of shifts Δn becomes the second island
Substituting the shift number Δn12 of, the process returns.

When β _N ≤β _H in # 4710,
In # 4720, the determination criterion β _{H is set} to 1/40, and in # 4730
Then, it is determined whether or not β _H ≧ β _N ≧ β _L. # 473
When 0 and β _N <β _L , Δβ = 40 is set in # 4740 to add hysteresis to β _L similarly to the above, and hysteresis is added by changing the value of Δβ. In # 4750, the maximum defocus amount Δdmax is substituted for the lens driving defocus amount Δd.
This is because when β _N <β _L , there are many landscape photographs and commemorative photographs with the landscape in the background, and it is considered that there is a high probability that the main subject will be located closest to the camera.

When β _H ≧ β _N ≧ β _L in # 4730, Δβ = 15 is set in # 4760 to restore the original value. #
At 4770, it is determined whether the distribution of subjects is monotonic. This subroutine will be described with reference to FIG.
In # 4900, the defocus amounts Δd1 and Δd2 of the first island and the second island are compared. If Δd1 <Δd2, the process proceeds to # 4910, and if Δd1 ≧ Δd2, the process proceeds to # 4930. In # 4910, the defocus amounts Δd2 and Δd3 of the second island and the third island are compared, and Δd2 ≧ Δd.
If 3, then go to # 4920; if Δd2 <Δd3, go to # 4
Proceed to 940. # 4930: 2nd island and 3rd island
The amount of defocus of the islands Δd2 and Δd3 are compared, and Δd
If 2 <Δd3, the process proceeds to # 4920, and if Δd2 ≧ Δd3, the process proceeds to # 4940. In # 4920, the monotone flag MTF indicating that the subject has a monotone distribution is reset and the process returns. In step # 4940, the monotonic flag MTF indicating that the subject has a monotonic distribution is set and the process returns.

That is, # 4900, # 4910, # 49
Defocus amount Δd1 to Δ of each of the first to third islands at 30
d3 is compared, and the monotonic flag is set to # 492 according to the result.
0d or # 4940 reset or set, Δd
When 1 ≧ Δd2 ≧ Δd3, # 4900 and # 493
0, # 4940 to set the monotonic flag MTF,
When Δd1 <Δd2 <Δd3, # 4900, # 4
In step 910, # 4940, the monotonic flag MTF is set. If Δd1 ≧ Δd2, Δd2 <Δd3, the process proceeds to # 4900, # 4930, # 4920 to reset the monotone flag MTF, and Δd1 <Δd2, Δd2 ≧.
In the case of Δd3, # 4900, # 4910, # 4920
Then, the monotonic flag MTF is reset.

Returning to the flow of FIG. 37, it is determined at # 4780 whether the monotone flag MTF is set. #
When the monotonic flag MTF is set at 4780, the second island is at the center of the distance distribution, so # 4
At 785, the defocus amount Δd12 of the second island is substituted for the defocus amount Δd for driving the lens, and at # 4787, the shift number Δn12 of the second island is substituted for the shift number Δn, and the process returns. When the monotonic flag MTF is not set in # 4780, the center island of the distance distribution is detected in # 4790, and the defocus amount and shift number of the island are returned as the defocus amount and shift number for lens driving. A subroutine for detecting the center of this distance distribution will be described with reference to FIG.

At # 4950, the flag LCF1 is determined in order to determine whether the focus detection of the first island is impossible. If the flag LCF1 is set in # 4950, it is # 4960. If it is not set, # 4990.
Then, the flag LCF3 is determined in order to determine whether or not the focus detection of the third island is impossible. # 49
The flag LCF1 is set at 50, and # 4960 is set.
When the flag LCF3 is also set in, it is determined that focus detection cannot be performed on both the first and third islands,
In # 4970, the defocus amount Δd12 of the second island is substituted into the defocus amount Δd for driving the lens, in # 4975, the shift number Δn12 of the second island is substituted into the shift number Δn, and the process returns.

When the flag LCF1 is set in # 4950 and the flag LCF3 is not set in # 4960, focus detection cannot be performed on the first island,
It is determined that the focus detection of the third island is not possible, and #
At 4980, the defocus amount Δd12 of the second island and the third
The maximum value Δd of the defocus amount Δd13 of the island
Substitute max for the lens drive defocus amount Δd. This means that the island in which the subject closer to the camera exists is selected from the second island and the third island.

If the flag LCF1 is not set in # 4950 and the flag LCF3 is not set in # 4990, it is determined that the focus detection is not possible for both the first and third islands, and the first to third operations are performed in # 5000. An intermediate value Δdm of the defocus amounts Δd11, Δd12, and Δd13 of the third island is detected. Intermediate value Δdm is Δd1
If it is 1, the process proceeds from # 5010 to # 5011, and then # 50.
At 11, the defocus amount Δd11 of the first island is substituted for the defocus amount Δd for driving the lens, and at # 5012, the shift number Δn11 of the first island is substituted for the shift number Δn, and the process returns. If the intermediate value Δdm is Δd12, # 50
From # 10 to # 5013, the defocus amount Δd1 for the second island is added to the defocus amount Δd for driving the lens in # 5013.
2 is substituted, the shift number Δn12 of the second island is substituted for the shift number Δn in # 5014, and the process returns. If the intermediate value Δdm is Δd13, # 5010 to # 5015
Then, in # 5015, the defocus amount Δd13 of the third island is substituted into the defocus amount Δd for driving the lens, and then in # 50
16 shift number Δn to 3rd island shift number Δn1
Substitute 3 and return.

When the flag LCF1 is not set in # 4950 and the flag LCF3 is set in # 4990, focus detection cannot be performed on the first island,
It is determined that focus detection cannot be performed on the third island, and # 5
At 020, the maximum value Δdm of the defocus amount Δd12 of the second island and the defocus amount Δd11 of the first island.
Substitute ax for the lens drive defocus amount Δd. This means that the island in which the subject closer to the camera exists is selected from the second island and the first island.

As a modification, the above-mentioned # 49 is used.
In step 80, when the difference between the defocus amount Δd12 of the second island and the defocus amount Δd13 of the third island is less than or equal to a predetermined value determined by the depth of focus, the objects on both islands are focused. The average value (Δd12 + Δd13) / 2 of the defocus amount of both islands is substituted into the defocus amount Δd for lens driving, and when it is larger than the predetermined value, the larger defocus amount Δdmax for lens driving is substituted. It may be configured to substitute for the defocus amount Δd of. Also in step # 5020, the same modification as in step # 4980 can be made by replacing the third island with the first island and Δd13 with Δd11.

When the pattern recognition algorithm is finished as described above, the process returns to the flow of FIG. 34 and it is determined at # 4245 whether or not there is an island whose focus cannot be detected. A subroutine therefor is shown in FIG. 41 and will be described. # 5030 to # 5
At 040, it is determined by flags LCF1 to LCF3 whether focus detection cannot be performed on the first to third islands. If all the flags LCF1 to LCF3 are reset, # 5030, # 5035, # 504
The process proceeds from 0 to # 5045, sets a flag NLCF indicating that focus detection is possible on all islands, and returns. If any one of the flags LCF1 to LCF3 is set, # 5030, # 503
The process proceeds from # 5 or # 5040 to # 5050, resets the flag NLCF, and returns.

Returning to the flow of FIG. 34, when AR = 2 (minimum defocus algorithm), the process proceeds from # 4260 to # 4270, and the offset amount is set to ΔDF _R = 100 μ.
m. When AR = 3, # 4280 to # 42
At 90, the offset amount is set to ΔDF _R = 50 μm. When AR = 4, the process proceeds from # 4300 to # 4310, and the offset amount is set to ΔDF _R = 0. # 427
From 0, # 4290, # 4310 to # 4320, the minimum defocus algorithm is executed to determine the defocus amount.

This will be described with reference to FIG. # 5100
Then, the offset amount DF _R is divided by the defocus amount SA per pitch to obtain the pitch of the offset amount DF _R , and this is Δd _R. In # 510 to # 5140, the amount of defocus of each island (Δd11, Δd12,
Pitch Δd _{R of the} above offset amount from the absolute value of Δ13)
To subtract Δd11 ′, Δd12 ′, and Δd13 ′, respectively.
And In # 5140, the obtained Δd11 ′ and Δd1
The minimum value is obtained from 2'and Δd13 '. This is to obtain the value of the subject closest to the current focus position. When the minimum value is Δd11 ′, it is determined that the defocus amount of the first island is the minimum defocus amount, and the process proceeds from # 5145 to # 5150 to set the defocus amount Δd for lens driving to the first island. Defocus amount of Δd
11 is substituted, the shift number Δn11 of the first island is substituted for the shift number Δn in # 5155, and the process returns. When the minimum value is Δd12 ′, it is determined that the defocus amount of the second island is the minimum defocus amount.
Proceeding from 5145 to # 5160, the defocus amount Δd12 of the second island is substituted into the defocus amount Δd for driving the lens, and the shift number Δn12 of the second island is substituted into the shift number Δn in # 5165. And return. The minimum value is Δd
When it is 13 ′, it is determined that the defocus amount of the third island is the minimum defocus amount, and # 5145 is set.
To # 5170, the defocus amount for driving the lens Δ
Substituting the defocus amount Δd13 of the third island for d,
5180 shift number Δn to 3rd island shift number Δ
Substitute n13 and return.

Returning to the flow of FIG. 34, when AR = 5 (specific island algorithm), # 4330 to #
Proceed to 4340 to run the specific islands algorithm. This algorithm is shown in FIG. 43 and will be described.

In # 5200, the variable AFIS is set to 1 in order to determine whether or not the specific island is the first island.
Is determined. If AFIS = 1 in # 5200, it is determined that the specific island is the first island, and in # 5210, the first number is set to the lens driving shift number Δn.
The island shift number Δn11 is substituted, and the focus shift amount Δd11 of the first island is substituted for the lens drive focus shift amount Δd at # 5220, and the process returns. If AFIS = 1 in # 5200, the process proceeds to # 5230.

In # 5230, the variable AFIS is set to 2 in order to determine whether or not the specific island is the second island.
Is determined. If AFIS = 2 in # 5230, it is determined that the specific island is the second island, and in # 5240, the second number is set to the lens driving shift number Δn.
The shift number Δn12 of the island is substituted, and the focus shift amount Δd12 of the second island is substituted for the lens drive focus shift amount Δd in # 5250, and the process returns.

If AFIS = 2 is not satisfied in # 5230, it is determined that the specific island is the third island,
At 260, the shift number Δn13 of the third island is substituted for the shift number Δn for lens driving, and at # 5270, the defocus amount Δd of the third island is set as the defocus amount Δd for lens driving.
Substitute 13 and return.

Returning to the flow of FIG. 34, # 4245 and # 4
From any of 320, # 4340, and # 4343, # 4
Proceeding to 345, the defocus amount Δd for lens driving is multiplied by the defocus amount SA per pitch to obtain the defocus amount DF = Δd × SA. In step # 4350, the defocus amount DF is used as an argument to call a subroutine for calculating the photographing magnification, and the photographing magnification in the island of the detected subject is calculated. Since this only calls the subroutine shown in FIG. 36, its explanation is omitted. When this is finished, it returns.

Next, a flow chart of the one-shot AF / continuous AF automatic selection routine called in # 390 of FIG. 11 will be described with reference to FIG. # 53
At 00, it is determined whether or not the follow-up mode flag TRCF is set in order to determine whether or not the follow-up mode is set. If the follow-up mode flag is set in # 5300, the process proceeds to # 7500 (FIG. 55). # 5300
If the follow mode flag is not set in,
At 5330, it is determined whether or not the flag CNTF is set to determine whether or not the continuous AF mode is set. The continuous AF mode is a mode in which the lens is driven according to the defocus amount even after focusing. When the flag CNTF is set in # 5330, it is determined that the continuous AF mode is set, and it is determined in # 53 whether or not focus detection is impossible.
At 44, the flag LCF is determined. # 5344 flag L
When CF is set, it is determined that focus detection is impossible, and a subroutine for performing low-con control, that is, control when focus detection is impossible is called at # 5346, and then the process returns.

FIG. 45 shows the subroutine for this low-con control.
Will be explained. When this subroutine is called,
First, whether or not the manual focus mode is set is determined by the switch S _AF / _M. If the manual focus mode is set at # 5500, a flag P indicating that the pattern recognition algorithm has been passed once at # 5630.
The A1PF is reset, focus detection impossible display (low-con display) is performed at # 5640, and the process returns. When it is not in the manual focus mode in # 5500, it is determined in # 5510 whether or not the low brightness flag LLF is set in order to determine whether or not the subject has low brightness.
When the low brightness flag LLF is set in # 5510, it is determined whether or not the auxiliary light mode is set.
At 5520, it is determined whether the auxiliary light flag ILMF is set. If the fill light flag ILMF is set in # 5520, it is determined that the fill light mode is set. In this case, the focus cannot be detected even in the auxiliary light mode, and therefore it is useless to emit the auxiliary light. Therefore, in order to prohibit the auxiliary light emission, # 56
In step 20, the auxiliary light prohibition flag NLF is set, and similarly to the case of the manual focus mode, the process proceeds to # 5630. When the fill light flag ILMF is not set at # 5520, it is determined that the fill light mode is not set, and the fill light flag ILM is set to perform focus detection in the fill light mode.
Set F and return.

When the low brightness flag LLF is not set in # 5510, it is determined that the focus detection is not possible because of the low brightness, and it is determined in # 5520 whether or not the lens is being driven. If the lens is being driven in # 5520, the process returns to drive the lens based on the defocus amount obtained in the previous focus detection. # 5
When the lens is not being driven at 520, in order to perform a low contrast scan operation for searching for a lens position where focus can be detected,
The low-conscan flag LCSF is set at # 5530 and the process proceeds to # 5550. In # 5550, it is determined whether or not the flag FWF is set in order to determine whether or not the previous scan direction was the feeding direction. # 5
When the flag FWF is not set at 550, it is determined that the lens was previously stopped, and at # 5570, the current lens extension position N2 is subtracted from the maximum lens advance amount LNmax to obtain the lens drive amount LN. 55
The lens speed is determined at 80, and the process returns. # 5550
If the flag FWF is set in step # 55, it is determined that the previous scan direction was the feed direction, and # 55
At 90, including the maximum amount of lens extension and direction,
The lens drive amount LN is set to (-LNmax), and # 5580 is set.
Determine the lens speed with and return.

In # 5580, # 5570 or # 559.
The lens speed is determined according to the lens drive amount LN obtained by 0. This subroutine will be described with reference to FIG. First, in # 5600, a flag LMV indicating that the lens is being driven is displayed.
Set F. This step is performed once when the lens is driven. In # 5610, a predetermined value K _N (> 0) is subtracted from the absolute value | LN | of the lens drive amount to obtain the variable CT for determining the lens drive speed. Here, the predetermined value K _N is a value for determining whether to increase the lens driving speed with respect to the remaining lens driving amount. # 562
At 0, this variable CT is substituted into the counter CNT used for counter interruption. In # 5630, it is determined whether or not the variable CT is 0 or less. # ≦ 5630, CT ≦
When it is 0, the flag V1F indicating that the lens driving speed is the high speed mode is reset in # 5640, and
At 5650, the lens driving speed is set to the low speed V2 (<V1), and the process proceeds to # 5710. When CT> 0 in # 5630, the flag V1F indicating that the lens driving speed is the high speed mode is set in # 5680, the flag FRNF indicating free running is set in # 5690, and the lens is moved in # 5700. Drive speed is high speed V1 (> V
Set to 2) and proceed to # 5710.

At # 5710, it is determined whether the lens drive amount LN is positive. When LN> 0 in # 5710, the lens is driven in the feeding direction in # 5720, and
A flag FWF indicating the lens drive in the feeding direction at 725
Set and return. When LN ≦ 0 in # 5710, the lens is driven in the retreating direction in # 5730, and the flag FWF indicating the lens driving in the retreating direction is reset in # 5735 and the process returns.

Next, the above-mentioned counter interruption subroutine will be described with reference to FIG. This counter interruption subroutine is executed when the value of the counter CNT becomes zero. The counter CNT is an encoder EN that monitors the lens when it is driven.
Each time the pulse output from C is supplied to the microcomputer μC, it is decremented. In # 5760, the flag V1F is set in order to determine whether the lens driving speed is low when the counter interrupt occurs.
It is determined whether or not is reset. If the flag V1F is not reset in # 5760, it is determined that the lens was driven at a high speed when the counter interrupt occurs, and the lens drive speed is changed in # 5850 to switch the lens drive speed to a low speed. Low speed V2 (<
V1), reset the flag V1F indicating that the lens driving speed is high in # 5860, and then set # 587.
At 0, set the remaining drive amount K _N in the counter CNT,
Return to the step where the interrupt occurred.

When the flag V1F is reset in # 5760, it is determined that the lens driving speed is low when the counter interrupt occurs, and the above-mentioned # 58 is executed.
Assuming that the remaining drive amount K _N set in 70 has been driven, the motor for driving the lens is driven for a certain time T in # 5765.
Apply the brake 1 and then turn off the power supply to the motor in # 5770. Next, in # 5780, it is determined whether or not the flag FRNF is set to determine whether or not the free run has been performed. # 5780 for flag F
When the RNF is set, it is determined that the lens is stopped after the free run, and the flag FRN is set in # 5790.
At the same time as resetting F, the flag FRN1F indicating that the lens has just stopped after the free run is set in # 5800, and the flow proceeds to # 5810. # 5780 flag FRN
When F is not set, # 5790 and # 58
00 is skipped and the process proceeds to # 5810.

At # 5810, the flag LMVF indicating that the lens is being driven is reset. Next, # 5820
Then, in order to determine whether or not the low-con scan is being performed, it is determined whether or not the low-con scan flag LCSF is set. When the low contrast scan flag LCSF is not set at # 5820, the process returns. When the low-conscan flag LCSF is set in # 5820, it is determined that the low-con scan is in progress, and before the lens is stopped, the lens is moved out in the step 5830 to determine whether or not the lens is driven in the moving direction. It is determined whether the direction flag FWF has been reset. When the feeding direction flag FWF is not reset at # 5830, it is determined that the low-conscan in the feeding direction is performed, and the process returns. # 583
When the feed-out direction flag FWF is reset to 0, it is determined that the low-conscan in the feed-in direction has been performed, and it is determined that the focus cannot be detected even when the low-conscan in the feed-out direction and the feed-in direction is performed, and focus detection is performed from the next time. In order to prohibit the operation, the focus lock flag FLF is set at # 5840. Next, in # 5845, a focus detection impossible display (low contrast display) is performed and the process returns.

Returning to the flow of FIG. 44, when the flag CNTF is not set in # 5330, it is determined that the continuous AF mode is not set, and in # 5340, the moving object is being determined to determine whether or not the moving object is being determined. Flag MV
It is determined whether F is set. When the moving body determination flag MVF is not set in # 5340, it is determined that the moving body determination is not in progress, and the flag LCF is determined in # 5344 to determine whether focus detection is impossible. When the moving object determination flag MVF is set in # 5340, the variable N4 is incremented by 1 in # 5350 and the process proceeds to # 6300 (FIG. 51).

When the flag LCF is not set in # 5344, it is determined that the focus cannot be detected, and #
At 5360, it is determined whether the flag LMVF is set to determine whether the lens is being driven. # 53
When the flag LMVF is set at 60, it is determined that the lens is being driven, the lens driving subroutine is called at # 5490, and then the process returns. # 53
When the flag LMVF is not set at 60,
It is determined that the lens is not being driven, and it is determined in # 5370 whether the defocus amount DF is equal to or less than the predetermined value K _IF1 indicating the focusing allowable range. When DF ≦ K _IF1 in # 5370, it is determined that the focus is achieved, the focus display is performed in # 5380, and the flag A indicating that the focus is achieved in # 5390.
Set the FEF. Next, in # 5400, it is determined whether or not the auxiliary light flag ILMF is set in order to determine whether or not the auxiliary light mode is set. If the fill light flag is set in # 5400, fill light mode I
Since it is determined to be LMF and neither the focus detection operation nor the follow-up determination is performed, the focus lock flag FLF is set in # 5410, and the process returns. # 5400
If the auxiliary light flag ILMF is not set at, it is judged that the auxiliary light mode is not set, and # 5420, #
At 5430, variables N4 and N5 are reset, and at # 5434, a flag MVF indicating that the moving object is being determined is set. As a result, the moving object determination will be performed from the next time. Next, # 5436
In step # 5437, a flag AEPEF indicating that focusing has been performed once is set, and in step # 5437, a flag TLCF indicating that focus detection is impossible during moving object determination is set.
Then, the flag T1STF indicating the first transition to the moving body determination mode is set, and the process returns.

When DF> K _IF1 in # 5370, it is determined that the subject is not in focus, and the process for determining the moving object is performed even if the focus is not reached even once. This is based on the assumption that the moving speed of the subject is so fast that focusing cannot be achieved only by normal focus detection. The control in this case will be described based on the following flowchart.

At # 5440, the variable N6 is incremented by one. This variable N6 will indicate the number of times this step has been passed. # 5442, # 5446, # 5
At 447, DF3 is set to DF2, DF2 is set to DF1, and D
By substituting DF into F1 in the same order, the latest 3
The focus detection data DF3, DF2, and DF1 of the times are stored. In # 5448, it is determined whether or not the automatic gain control data AGC is 8 in order to determine whether or not the brightness is low. When AGC = 8 in # 5448, it is determined that the luminance is low, the noise from the data from the CCD is large, the focus detection accuracy is poor, and the integration time is long. Cannot be ignored, and this will reduce the focus detection accuracy.
Without performing the moving body determination, the variable N6 is set to 0 in # 5485, and the lens drive is performed in # 5490.

If # 5448 does not indicate AGC = 8,
In order to determine whether or not it is the fill light mode, # 5450
Then, it is determined whether or not the auxiliary light flag ILMF is set. When the auxiliary light flag ILMF is set in # 5450, it is determined that the auxiliary light mode is set, and the moving object determination is not performed for the same reason as above, and the auxiliary light flag ILMF is set in # 548.
In step 5, the variable N6 is set to 0, and the lens drive of # 5490 is started. If the fill light flag ILMF is not set in # 5450, it is determined that the fill light mode is not set, and the flow proceeds to # 5460. In # 5460, it is determined whether or not the shooting magnification β of the island for which the defocus amount is obtained is larger than 1/20. When β> 1/20 in # 5460, a small movement of the subject appears as a large change in the focal plane, and it is determined that the subject cannot follow, and the variable N6 is set in # 5485 without performing the moving body determination. As 0,
The lens drive of # 5490 is started. # ≦ 5460 with β ≦
When it is 1/2, it is determined whether or not the lens has been driven (# 5490) three times or more in # 5470, that is, # 5440.
It is determined whether or not the value of the variable N6 is 4 or more in order to determine whether or not the vehicle has passed 4 times or more. # 5470 N6 <
When it is 4, it is determined that the number of times of lens driving is less than 3, and it is determined that there is insufficient data to obtain the speed of the subject, and the process proceeds to lens driving of # 5490. # 54
When N6 ≧ 4 in 70, it is determined that the number of times of lens driving is three times or more, and in # 5480, the latest three defocus amounts DF1, DF2, and DF3 have the same sign (defocus amount in the same direction). Determine if there is. # 548
0 for the latest three defocus amounts DF1, DF2, DF
When 3 is not the same sign, it is determined that tracking is impossible, the variable N6 is set to 0 in # 5485, and the lens drive is performed in # 5490. In this case, the determination to enter the follow-up mode is performed again from the beginning. When the latest three defocus amounts DF1, DF2, and DF3 have the same sign in # 5480, the tracking mode is entered, and the tracking correction is performed in # 5486 to re-determine the defocus amount.
The lens driving subroutine of 90 is executed, and the process returns. That is, when the moving speed of the subject is high and the object is moving in the same direction, the tracking mode is entered in order to immediately perform the tracking correction with the result of the focus detection performed three times.
Note that focus detection may be performed four times or more when the free run or the lens driving at low speed is long.

A subroutine for follow-up correction is shown in FIG. 48 and will be described. In # 6000, the flag TRCF indicating the follow-up mode is set. In # 6010, the time of the free timer TM is read and stored as TM3. In # 6020, the lens extension amount is read from the lens position counter CT and stored as CT3. #
At 6030, it is determined whether or not the flag MVF is set in order to determine whether or not the moving body determination is being performed. # 60
When the flag MVF is set at 30, it is determined that the moving body determination is being performed, and the processing proceeds to the processing of # 6040 to # 6060 (described later). When the flag MVF is not set in # 6030, it is determined that the moving body is not being determined, and the moving body speed is detected in # 6080.

The direction of this moving body speed detection will be described with reference to FIG. 9, and the flow chart of the microcomputer μC for that purpose will be described with reference to FIG. In FIG. 9, I ₁ is the previous integration time, and C
₁ is the time required for the previous focus detection calculation, I ₂ is the current integration time, C ₂ is the time required for the current focus detection calculation, and E is the time required between the end of the previous focus detection calculation and the current integration start. This is the time taken for the exposure calculation, including the time for exposure calculation. TM1 is the integration start time, TM2 is the integration end time, TM12 is the midpoint of the integration time, and TM3 is the calculation end time. Further, Ov is the defocus amount according to the movement of the moving body, and L _E is the lens drive amount converted into the defocus amount. Here, the speed of the moving body is expressed as a change in the defocus amount per unit time, and the previous defocus amount LDF is subtracted from the current defocus amount DF to obtain the time required for the focus detection from the previous time. It can be obtained by dividing by ΔT (= TM12-TM12L). However, if the lens is moving at this time, this must be taken into consideration. That is, the amount DF ′ obtained by subtracting the previous defocus amount LDF from the sum of the lens drive amount DF _CT and the current defocus amount DF may be divided by the time required for one focus detection. The time when the defocus amounts LDF and DF are obtained is the time when the calculation ends, and time has passed from the midpoint of integration (the midpoint of the integration time) when the defocus amount is obtained, and the amount of movement DF _CT is calculated during this time. It may be added to the obtained defocus amount DF.

Referring to FIG. 49, first in # 6150,
The time ΔT required for one focus detection is calculated by the following formula. ΔT = TM12-TM12L # 6160, the movement of the lens that moved during this ΔT time
The quantity ΔCT is calculated by the following equation. ΔCT = CT12-C
In T12L # 6170, the moving amount ΔCT of this lens is calculated by the following equation.
Defocus amount DF _CTConvert to. DF_CT= ΔCT / K_LR

At # 6180, the current defocus amount D
Add the defocus amount DF _CT due to lens movement to F,
The value obtained by subtracting the previous defocus amount LDF is the time Δ
Dividing by T, the moving body speed is calculated by the following formula. In V = {(DF + DF _CT ) −LDF} / ΔT # 6190, the current defocus amount DF is substituted for the previous defocus amount LDF, and the process returns.

Returning to the flow of FIG. 48, in # 6090, the time To from the midpoint TM12 of the integration time to the calculation end time TM3 is calculated. To = (TM3-TM2) + (TM2-TM1) / 2 In # 6100, the defocus amount ΔDF of the subject moving during the time To is calculated by the following equation. ΔDF = V × To

In # 6110, the defocus amount DF obtained by moving the subject is added to the obtained defocus amount DF.
Is added and DF = DF + ΔDF is returned as the true defocus amount.

Next, the lens driving subroutine is shown in FIG.
Will be explained. In # 6210, the lens drive amount LN obtained by multiplying the obtained defocus amount DF by the lens drive amount conversion coefficient K _LR is obtained. In # 6220, the midpoint TM1 of the integration time
The required lens drive amount LN = LN− (CT3−CT3-CT12) is subtracted from the lens drive amount LN from 2 to the calculation end time TM3.
CT12) is obtained. C when the lens is stopped
T3 = CT12. In # 6230, a lens speed determination subroutine is executed, and the process returns.

Returning to the flow of FIG. 44, when the flag MVF is set in # 5340, it is determined that the moving body is being determined, and the flow proceeds to # 5350. At this time, a subject having a relatively slow speed and in a direction (rear focus) approaching the camera is detected and corrected. For a fast-moving subject, the following mode is entered from # 5480. Further, in the case of a relatively slow moving object moving away, it is considered that the change in the focal plane becomes even slower and correction is not necessary. In addition, this allows the microcomputer μ
The number of steps of C can be reduced. In # 5350,
The variable indicating the number of times of focus detection executed to obtain one average defocus amount (described later) is incremented by 1, and the process proceeds to # 6300 (FIG. 51).

51, in # 6300, it is determined whether or not the low contrast flag LCF is set in order to determine whether or not the focus detection result of this time is focus detection impossible. # 6300 low contrast flag L
When CF is not set, it is determined that the focus detection result of this time is not focus detection impossible, and a flag TL indicating that focus detection cannot be performed during moving object determination in # 6310.
Reset CF. Next, in # 6320, it is determined whether or not the flag DFNF is set in order to determine whether or not all the focus detections for obtaining the average defocus amount once have been impossible. # 6320 flag DFN
When F is set, it is determined that all focus detection results in the past are focus detection impossible, and the current defocus amount DF is substituted into DF4 to DF1 indicating four defocus amounts, and # 6435 is set. move on. When the flag DFNF is not set in # 6320, it is determined that focus detection was possible even once to obtain the average defocus amount, and in DF4 to DF3 in DF4 in # 6340 to # 6370.
, DF3 to DF2, DF2 to DF1 and DF1 to D
By substituting F in the same order, the latest four defocus amounts are updated, and the process proceeds to # 6435.

When the low contrast flag LCF is set at # 6300, it is determined that the result of the focus detection this time is not focus detectable, and it is determined whether or not the average defocus amount has been obtained so far. Therefore, it is determined at # 6380 whether or not the flag MDFF is set. #
When the flag MDFF is set at 6380, it is determined that the average defocus amount has been obtained so far, and at # 6390, the previously obtained average defocus amount DF _AV1 is set as the current defocus amount DF. , # 63
Proceed to 40. The reason why the previous average defocus amount DF _AV1 is used instead of the previous defocus amount DF1 is that the average defocus amount DF _{AV1 is} a more stable defocus amount and is considered to be more likely. .
When the flag MDFF is not set in # 6380, it is determined that the average defocus amount has not been obtained so far, and it is determined whether or not it is the first focus detection for obtaining the average defocus amount. Therefore, in # 6400, it is determined whether or not the value of the variable N4 is 1. If N4 = 1 is not set in # 6400, it is determined that the focus detection is not the first time, and the flag TLCF is set in # 6410 to determine whether or not the defocus amount has been obtained in the past in order to obtain the average defocus amount. Determine if it has been reset.
When the flag TLCF is reset in # 6410, it is determined that the defocus amount has been obtained in the past, and
At 6420, the previous defocus amount DF1 is set as the current defocus amount DF, and the process proceeds to # 6340. When the flag TLCF is not reset in # 6410, it is determined that the defocus amount has not been obtained in the past, and the process proceeds to # 6430. If N4 = 1 in # 6400, it is determined that the focus detection is the first time, and the process proceeds to # 6430. #
In the 6430, the flag DFNF indicating that all the focus detection results up to now are focus detection impossible is set,
Go to # 6435.

At # 6435, a subroutine for calculating the speed obtained by one focus detection is executed, and the routine proceeds to # 6440. This subroutine will be described with reference to FIG. # 71
At 00, the time ΔT required for one focus detection is calculated by the following equation. ΔT = TM12-TM12L In the above formula, TM12 is the time at the midpoint of the current integration time, and TM12L is the time at the midpoint of the previous integration time. In # 7105- # 7130, TM6 is added to TM7,
TM5 is substituted into TM6, TM4 is substituted into TM5, and ΔT is substituted into TM4 in the same order, and the time ΔT is newly updated by one. In # 7140, the sum TM47 = (TM4 + TM5 + TM6 + TM7) of the times required for the past four focus detections is obtained. # 7150, # 7160, # 7270, # 728
In 0, TM474 is TM473 and TM473 is TM.
472, TM472 to TM471, TM471 to T
Substituting M47 in the same order, the time TM47 is newly updated by one. Next, in order to determine whether or not the focus detection for obtaining the average defocus amount is the first time, # 72
At 82, it is determined whether the variable N4 is 1. # 728
When N4 = 1 in 2 is not determined to be the first focus detection, the previous defocus amount DF2 is subtracted from the current defocus amount DF1, and the defocus amount DF1 = ( DF1-DF2) is obtained and the process proceeds to # 7290. When the variable N4 is 1 in # 7282, # 7284 is skipped and the process proceeds to # 7290. In # 7290, the speed V is calculated by the following equation. V = DF1 / ΔT

In # 7300, it is determined whether or not the flag DFNF is set in order to determine whether or not all the focus detection results up to the previous time for obtaining the average defocus amount are focus detection impossible. # 7300 for flag D
When FNF is set, it is determined that focus detection is not possible, the speed V is substituted for the speeds V1 to V4 in # 7310, the flag DFNF is reset in # 7320, and the process returns. When the flag DFNF is not set in # 7300, it is determined that focus detection is possible, and in # 7330 to # 7360, the speed V4 is the speed V3, the speed V3 is the speed V2, and the speed V2 is the speed V1.
, The velocity V is substituted for the velocity V1 in the same order, the velocity V for four times is newly updated by one, and the process returns.

Returning to the flow of FIG. 51, in # 6440,
Automatic gain control data AG to determine whether the brightness is low
It is determined whether C is 8. # 6440 = AGC =
When the value is 8, the reliability of the focus detection result data is low.
Since it is difficult to determine the moving body, it is possible to focus on # 6600.
Set the flag FLF and return. # 6440
When AGC is not 8, the shooting magnification β is 1/20.
It is determined in # 6550 whether or not it is larger than that. # 6550
When β> 1/20, it is difficult to determine the moving body.
Therefore, in # 6600, set the focus lock flag FLF.
And return. # 6550 and β ≦ 1/20
If it is, determine whether it is the first motion determination
In order to do so, the flag T1STF is set in # 6560.
Is determined. # 6560 flag T1ST
When F is set, it is the first motion determination.
It is determined that the flag T1STF is reset in # 6570.
The focal length f of the lens at this time
Fixed lens focal length f ₀In # 6580,
f₀Substitute f for #, and proceed to # 6610. # 6560
When lag T1STF is not set, this time
The focal length f of the lens is the focal point of the lens when the first moving object is determined.
Distance f₀It is determined whether or not is equal to. # 6
F at 590₀When ≠ f, the focal length is
It is determined that the separation has been changed, and focus is performed at # 6600.
Set the lock flag FLF and return. this
Will detect focus if the focal length is changed during motion detection.
The size of the image on the CCD for performing changes and the correct data
It may not be possible to obtain the focus amount, so use this data.
If you try to calculate the speed of the moving object, it may be an incorrect speed.
Because it is done. # 6590 f₀When = f
Proceeds to # 6610. In # 6610, one average data
Whether focus detection is performed 4 times to obtain the focus amount
To determine whether the variable N4 is 4.
It If N4 = 4 in # 6610,
Make a turn. When N4 = 4 in # 6610
Is the result of all four focus detections during this moving object determination.
In order to determine whether detection is impossible, a flag T is set in # 6612.
Determine if the LCF has been reset. # 66
When the flag TLCF is not reset at 12
Is determined to be incapable of focus detection, and the focus is detected in # 6614.
Set the circus lock flag FLF and return.
When the flag TLCF is reset in # 6612
, It is determined that focus detection is not possible, and the
The number N4 is set to 0, and the focus detection during moving object determination in # 6630
Reset the flag TLCF indicating that it is not possible.
In # 6640, the defocus amount DF1 obtained four times,
Average value DF of DF2, DF3, DF4_AV= (DF1 + D
F2 + DF3 + DF4) / 4 is calculated. # 6650 ~ #
In 6680, DF_AV4To DF_AV3The DF_AV3To DF
_AV2The DF_{AV 2}To DF_AV1The DF_AV1To DF_AVTo
Substituting each in the same order, update the value of the average defocus amount four times.
To be new. In # 6690, the average defocus amount is obtained.
The flag MDFF indicating that it has been set is set. Next, # 6
In 694 and # 6666, constants a and b described later are respectively set.
Set to 200 μm and 400 μm. # 6700
Is a variable N5 indicating the number of times the average defocus amount is obtained.
Is incremented by 1. In # 6710, the variable N5 is
It is determined whether or not 1. If N5 = 1 in # 6710,
It was judged that the first average defocus amount was obtained,
Average defocus amount DF_AV1# 6720 for the first time
Average defocus DF₀As a memory, # 67
Proceed to 30. If N5 = 1 in # 6710,
Average defocus amount DF₀From the value obtained by subtracting the constant a from
Also, the average defocus amount DF this time_AV1Whether or not
To judge. Where a (200 μm) is subtracted
After focusing, the camera is shaken and another subject is detected.
This is to determine that there is. In addition, a positive value a (>
Since 0) is drawn, the camera is aimed at a distant subject.
It is to detect that it has been shaken. If DF> 0
Rear pin, front pin if DF <0. DF₀And DF
_AV1Are the same rear pin direction, DF_AV1＞ DF₀−
a. Here, the speed of the moving subject is almost constant
I believe. DF_AV1≦ DF₀-A is far away
It is thought that you saw another subject of # 6600.
To lock the focus. In this example, comparison
Objects that move toward the rear pin as quickly as possible are not detected. ratio
If the subject moves relatively quickly in the front pin direction, the motion
DF immediately after entering fixed mode_AV1<DF₀-A,
Since the camera moves away from the camera quickly,
Such a subject is not detected, and
No, go to # 6600. Also very slow front pin direction
If the detection time is long,
Since the amount of waste increases in the negative direction, # 6600
Go to focus lock. In this embodiment, four times of focus
Using the average defocus amount of the detection result, the moving object after focusing
By making a judgment, the error due to one focus detection is suppressed.
The subject in the front pin direction appears due to the error.
But I'm trying not to go to focus lock immediately
It # 6740 DF_AV1＞ DF₀If -a, flat
It should be judged whether or not the uniform defocus amount is obtained four times or more.
First, it is determined whether or not N5 ≧ 4 in # 6750. #
If N5 <4 at 6750, the process proceeds to # 6730. # 6
If N5 ≧ 4 at 750, then at # 6760, the current average
Focus amount DF_AV1Is the average defocus amount D three times before
F _AV4It is determined whether it is greater than the value obtained by subtracting the predetermined value a from
Set. As a result, a subject that moves during four focus detection times
You have information about. In this step, I got 4 times
Detects the speed of the subject moving in the front focus direction during the focus detection time
are doing. The present invention does not detect a moving object.
I haven't done so, so DF at # 6760_AV1≦ DF _AV4-A
If there is, go to focus lock (# 6600). # 6
DF at 760 _AV1＞ DF_AV4If -a, go to # 6730
move on. # 6730 detects the average speed of the moving object,
Proceed to 6770 (Fig. 54).

The subroutine for detecting the average velocity of the moving body, which is shown at # 6730, will be described with reference to FIG. # 73
At 70, the average speed V _AV = (V1 + V2 + V3 + V4)
Calculate / 4. In # 7380 to # 7410, V _AV4
To V _AV3 , V _AV3 to V _AV2 , V _AV2 to V _AV1 , V
By substituting V _AV into _AV1 in the same order, the average speed for four times is updated, and the process returns.

After detecting the average speed (# 6730), FIG.
No. 6770. In # 6770, it is determined whether or not the current average defocus amount DF _AV1 is equal to or larger than a predetermined value b (400 μm). This is to determine whether or not the speed at which the subject approaches the camera is high.

If DF _AV1 ≤b in # 6770, # 6
In step 780, it is determined whether or not the variable N5 is 3 or more in order to determine whether or not the average defocus amount of three times or more is obtained. If N5 ≧ 3 is not satisfied in # 6780, it is determined that the average defocus amount of three times or more is not obtained, and the process returns. If N5 ≧ 3 in # 6780, it is determined that the average defocus amount of three times or more is obtained, and in # 6790, it is determined whether or not the photographing magnification β is larger than 1/30. # 679
If 0 and β ≦ 1/30, # 6800 sets the predetermined value c to 1
00 μm and proceed to # 6840. # 6790 β> 1
If it is / 30, it is determined in # 6810 whether the shooting magnification β is larger than 1/25. # 6810 with β ≤ 1/2
If 5, then the predetermined value c is set to 140 μm in # 6820,
Go to # 6840. If β> 1/25 in # 6810, the predetermined value c is set to 200 μm in # 6830, and # 684 is set.
Go to 0. Here, the predetermined value c is a reference value for determining whether or not the subject is a moving body, and the larger the photographing magnification β, the larger the defocus amount on the focal plane with respect to the movement of the subject. The value c is set larger as the photographing magnification β increases.

In # 6840, the average defocus amount is 3 times.
Whether the variable N5 is 3 to determine whether or not it is obtained
Determine whether or not. If N5 = 3 in # 6840, # 6
Two consecutive average defokers at 850 and # 6860
Difference in amount (DF_AV2-DF _AV1), (DF_AV3-DF
_AV2) Is greater than or equal to the predetermined value c, and
If any one of them is less than the predetermined value c, the process returns.
In # 6850 and # 6860, both differences are the predetermined value c
If it is above, the average value of the average speed for three times in # 6870
(V_AV1+ V_AV2+ V_AV3) / 3 as the object velocity Vc
I do. Also, the time required Tc = TM471 + TM472
+ TM473 is calculated in # 6880 and added from # 6890.
Enter any mode. If N5 = 3 in # 6840, 4
It is judged that the average defocus amount more than once is obtained.
And every 6th average # 6900 and # 6910 average
Difference in circus amount (DF_AV1-DF_AV3), (DF_AV2−
DF _AV4) Is greater than or equal to the predetermined value c, respectively.
However, if either one is less than the predetermined value c, return
I do. # 685 using the average defocus amount of 3 times
Every other average differential compared to 0 and # 6860
The difference in the amount of focus is compared with the same predetermined value c is
You can follow fast subjects as quickly as possible
As well as possible for slow subjects
In order to detect accurately, every other averaged difference is used.
It is the one that detects the body. This allows you to move the subject
You can ignore a slight change in velocity. # 6900 and # 69
If both differences are equal to or greater than the predetermined value c in # 10, # 692
0 for every second difference (DF_AV1-DF_AV4) Is a predetermined value c
It is determined whether or not the above. This is a slower subject
About the deformation according to the averaged subject movement,
By judging by the amount of scrap, accuracy is important.
is there. When the difference is less than the predetermined value c in # 6920,
To return. In # 6920, the difference is equal to or larger than the predetermined value c.
Sometimes, in # 6930, the average value (V
_AV1+ V_AV2+ V_AV3+ V_AV4) / 4 is the speed V of the subject
Let be c. Also, the time required Tc = TM471 + TM4
72 + TM473 + TM474 is calculated in # 6940,
The follow mode is entered from # 6890.

If DF _AV1 > b in # 6770, follow-up correction is performed in order to follow the subject. First, in order to determine whether or not the average defocus amount is obtained for the first time, #
At 6950, it is determined whether the variable N5 is 1. # 6
If N5 = 1 at 950, it is determined that the average defocus amount is obtained for the first time, and V _AV1 is substituted for the velocity Vc of the control subject at # 6960. In # 6970, TM471 is substituted for the time Tc required at this time. And
The follow mode is entered from # 6980.

The follow-up correction during the moving object determination shown in FIG. 48 will be described. When the tracking mode is entered, this tracking correction is first executed. # 6000 to # 6030 are as already described. When the flag MVF is set in # 6030, it is determined that the moving body determination is in progress, and this moving body determination is exited next. Therefore, in # 6040, the flag MV is set.
Reset F. In # 6050, the time Tc required during the moving object determination is changed from the time of the current integration midpoint to the current (TM
3) time required (TM3-TM2) + (TM2-
Add TM1) / 2 to get the time To. In # 6060, the speed Vc is multiplied by the time To to obtain the defocus amount DF, and the process returns.

Returning to FIG. 54, if N5 = 1 is not satisfied in # 6950, it is determined that the average defocus amount is not the first time, and it is determined whether or not the average defocus amount is obtained for the second time. At 6990, it is determined whether the variable N5 is 2. If N5 = 2 in # 6990, it is determined that the average defocus amount is obtained for the second time.
At 00, the object velocity Vc = (V _AV1 + V _AV2 ) / 2 is obtained. In # 7010, the time required at this time Tc = T
Calculate M471 + TM472. And # 7020
To follow mode.

If N5 = 2 is not satisfied in # 6990, it is determined that it is not the average defocus amount of the second time, and it is determined whether or not the average defocus amount is obtained for the third time.
At 030, it is determined whether the variable N5 is 3. # 70
If N5 = 3 in 30, it is determined that the average defocus amount has been obtained for the third time, and it is determined from # 7040 to # 68.
Proceed to 70. Unless N5 = 3 in # 7030, it is determined that the average defocus amount has not been obtained for the third time, and the process proceeds from # 7050 to # 6930.

In FIG. 55, the follow-up mode is executed at # 5300 in FIG.
Flow when the flag TRCF indicating the flag is set
A chart is shown and demonstrated. # 7500 is the focus test
In order to determine whether the result of the output is focus detection impossible,
It is determined whether the flag LCF is set. #
When the flag LCF is not set at 7500
Detects the moving body speed in # 7510 and proceeds to # 7540.
Mu. When the flag LCF is set in # 7500
Has determined that the result of this focus detection is that focus detection is not possible.
The result of the previous focus detection was that the focus could not be detected.
In order to determine whether or not the flag LLCF is set in # 7520.
It is determined whether or not it is set. # 7520
When GLLCF is not set, the previous focus
The result of the detection was determined not to be undetectable focus,
The previous speed V to the speed V_AV1And substitute # 7540
Proceed to. In # 7540 to # 7570, V_AV4To V_AV3
To V _AV3To V_AV2To V_AV2To V_AV1To V_AV1To V
Are respectively substituted in the same order to update the average speed. Average speed
Is the speed of one focus detection in the following mode. next,
In # 7590, get the average speed (average defocus amount).
The variable N5, which indicates the number of times it has performed, is incremented by 1. # 7
At 600, it is determined whether or not the value of the variable N5 is 2.
It If N5 = 2 in # 7600, control in # 7610
Calculate the speed Vc used for the following formula and proceed to # 7650.
Mu. Vc = (V_AV2+ V_AV1) / 2

If N5 = 2 in # 7600, # 76
At 20, it is determined whether the value of the variable N5 is 3. # 7
If N5 = 3 in 620, the speed Vc used for control is calculated by the following equation in # 7630, and the process proceeds to # 7650. Vc = (V _AV3 + V _AV2 + V _AV1 ) / 2 If N5 = 3 is not satisfied in # 7620, the speed Vc used for control is calculated in the following formula in # 7640, and the process proceeds to # 7650. Vc = (V _AV4 + V _AV3 + V _AV2 + V _AV1 ) / 2

In # 7650, follow-up correction is performed based on the obtained speed Vc to obtain the defocus amount DF for lens driving. In # 7660, it is determined whether the absolute value of this defocus amount | DF | is equal to or less than a predetermined defocus amount K _IF2 . Here, K _{IF 2} is set to a value larger than the in-focus determination level K _IF1 at the lens stop. This takes into account variations in speed detection.

If | DF | ≦ K _IF2 in # 7660, it is considered to be in-focus, the flag AFEF indicating this is set in # 7670, the in-focus display is performed in # 7680, and # 7700 is displayed.
Proceed to. If | DF |> K _IF2 in # 7660, it is considered as out-of-focus, and the focus display is erased in # 7685.
Then, the flag AFEF indicating focus is reset with # 7700.
Proceed to.

At # 7700, it is determined whether the current speed V _AV1 and the previous speed V _AV2 are in the same direction. # 77
At 00, if the speeds V _AV1 and V _AV2 are in the same direction, # 765
# 771 based on the defocus amount DF obtained at 0
At 0, the lens is driven and the process returns. If the speeds V _AV1 and V _AV2 are not in the same direction in # 7700, the follow-up display is erased in # 7720 to exit the follow-up mode, and then in # 7730.
Sets the flag CNTF, resets the follow-up flag TRCF in # 7740, and returns. Here, the continuous flag CNTF is set because the subject is not moving in one direction, so that the subject is in focus no matter which direction the subject moves after that. Is. However, in the continuous mode, the lens cannot be driven by predicting the movement of the moving body (the defocus amount according to the movement).

When the flag LLCF is set in # 7520, it is determined that the focus detection was not possible in the previous time, and in order to follow the subject, the movement of the subject is predicted based on the focus detection results obtained two times before. Therefore, in order to exit the follow-up mode, the flag AFEF indicating the focus is reset at # 7750, the focus display is erased at # 7760, and the process proceeds to # 7720 and thereafter.

[0181]

[Effects] According to the present invention, the determination level for determining whether or not a subject is a dynamic subject is switched according to the shooting magnification. Therefore, even when the subject distance is short or a telephoto lens is used, the movement of the subject is prevented. The detection sensitivity does not become too sensitive. Therefore, it is possible to accurately determine whether or not the subject is a dynamic subject regardless of the magnitude of the photographing magnification.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a diagram showing a display in a finder according to an embodiment of the present invention.

FIG. 3 is a perspective view of a focus detection optical system according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing details of a CCD chip according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a divided area of a reference portion in the above-mentioned CCD chip.

FIG. 6 is an explanatory diagram showing a shift amount for a divided area of the above.

FIG. 7 is a circuit diagram of a control circuit used in an embodiment of the present invention.

FIG. 8 is an operation explanatory diagram of the embodiment of the present invention.

FIG. 9 is an operation explanatory diagram of the embodiment of the present invention.

FIG. 10 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 11 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 12 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 13 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 14 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 15 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 16 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 17 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 18 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 19 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 20 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 21 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 22 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 23 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 24 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 25 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 26 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 27 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 28 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 29 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 30 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 31 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 32 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 33 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 34 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 35 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 36 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 37 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 38 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 39 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 40 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 41 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 42 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 43 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 44 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 45 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 46 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 47 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 48 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 49 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 50 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 51 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 52 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 53 is a flow chart for explaining the operation of the embodiment of the present invention.

FIG. 54 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 55 is a flowchart for explaining the operation of the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 focus detection means 2 output means 3 moving body determination means 4 switching means 5 correction amount calculation means 6 correction means

Claims (5)

[Claims] 1. A focus detection unit that repeatedly detects a focus shift amount of a lens with respect to an object to be focused, an output unit that outputs information on a photographing magnification, and a focus detection result output by the focus detection unit to a predetermined value. By comparing with the determination level, the moving body determination unit that determines whether or not the subject is a dynamic subject, and the determination level used in the determination operation of the moving body determination unit, the imaging magnification output from the output unit. An automatic focus detection device comprising: a switching unit that switches in accordance with information. 2. The moving body determining means detects a change amount of the defocus amount repeatedly output by the focus detecting means, and compares the change amount with a determination level to determine whether the subject is a dynamic subject. The automatic focus detection device according to claim 1, wherein it is determined whether or not it is. 3. The automatic focus according to claim 1, wherein the switching means has at least two determination levels, and switches the determination levels in at least two stages in accordance with information on the photographing magnification. Detection device. 4. The automatic focus detection device further comprises correction amount calculation means for calculating a focus shift amount caused by movement of the subject based on a plurality of focus shift amounts repeatedly output from the focus detection means. 2. The automatic focus detection device according to claim 1, further comprising: a correction unit that corrects the focus shift amount detected by the focus detection unit by the focus shift amount calculated by the correction amount calculation unit. 5. The automatic focus detection device according to claim 4, wherein the correction means does not correct the amount of defocus when the photographing magnification output from the output means is larger than a predetermined value. .