JPS63262611A - Automatic focusing device - Google Patents

Abstract

PURPOSE:To obtain a true focused position by executing a contrast detection with regard to each corresponding position, when plural pieces of phase difference data exist. CONSTITUTION:When a phase difference detecting means 2 detects a phase difference data from an output data of a focus detecting sensor 1, this phase difference data is stored in a storage means 3. When plural phase difference data stored in the storage means 3 exist, a sequence control means 4 moves a focusing lens 7 by a lens driving means 6 to plural scheduled focal positions related to each phase difference. Subsequently, by operating a contrast detecting means 5 in each scheduled focal position, a position of the highest contrast is selected from in such scheduled focal position, and by deciding this position to be a true focal position, the focusing lens 7 is brought to a driving control in the end. In such a way, focusing can be executed to the true focusing position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic focus adjustment device, more specifically, an automatic focus adjustment device that detects the amount of deviation of an object from the expected focus position and moves the lens to the in-focus position based on this. The present invention relates to a driven automatic focusing device.

[Prior Art] Focus detection methods for conventional cameras include phase difference detection methods, contrast detection methods, etc. Among them, the phase difference detection method has the highest practicality, and its principle is explained in Figs. 10 to 12. Explain using.

FIG. 10 shows the positional relationship between the focus detection sensor 00 and the imaging optical system (taking lens) 101. - In the case of an eye reflex camera, if it is a TTL method (a method in which focus is detected using light passing through a lens), the focus detection sensor 00 is placed at a position equivalent to the film surface. The focus detection sensor 00 is shown in FIG. 12 (A), (B),
As shown in (C), each pair (al and b tr
a2 and b2..., an and b) CD consisting of a group and b group arranged to form photoelectric conversion cords a1 to an formed of CD and the like.

b1 to bn (see Figure 12 (A)) and each pair thereof (
a 1 and b t + "a 2 and b2..., a
It is composed of lenslets c1 to c (see FIG. 12(B)) arranged corresponding to lenses (n and bn), respectively.

The lenslet cl-cn directs the light that passes through the exit pupil of the photographing lens 101 and reaches the focus detection sensor 00 from the upper A.
It splits the light flux into the lower B light flux and guides them to the 8th group detection sensor and the 5th group detection sensor (Figure 12 (C).
)reference).

Now, as shown in FIG.
2 is formed, the photoelectric conversion cord a1 at this time
The output values and element numbers of ~an, b1~bn are shown in FIG. At this time, the curve formed by the detection sensors of group b is shifted from the curve formed by the detection sensors of group a by a phase difference ΔX. This phase difference ΔX and the amount of deviation Δg from the actual focal plane can be linearly approximated via a certain coefficient. In other words, Δl-k・ΔX (1) (k: variable magnification coefficient) Here, whether the focus is the front focus or the in-focus state,
Or, whether it is a rear pin can be determined by the following evaluation formula.

・・・・・・・・・・・・・・・(2) (N: Number of sensor pairs) Here, F>0 focuses on the front, and F-0 focuses.

When F<0, rear pin is established.

Next, a method for determining the phase difference ΔX using equation (2) will be described with reference to FIGS. 13 and 14.

Since the outputs from the focus detection sensor 100 have the same corresponding subscripts, they form a pair, so by shifting the subscripts one by one and calculating the evaluation formula, the position of F and 0 can be found in terms of calculation. In other words, the number of times the subscript is shifted corresponds to ΔX.

Now, creating a pair in which the subscript of group b becomes smaller than the subscript of group a is defined as a positive shift, and the opposite is defined as a negative shift.The shift is performed in order from the negative side to the positive side, and the above (2) )
Evaluate expressionExecute expression. If we change this evaluation formula into a general formula that is a function of the number of shifts, we get:

The number of sensor pairs, the dimensions between sensor pairs, etc. are determined by the sensitivity of the detection sensor, the manufacturing limit of lens red, etc. Therefore, the shift number S is such that F(So)-0 can be obtained only by calculation using the evaluation formula F (S). is difficult to find. Therefore, it is necessary to interpolate intermediate values from the results of adjacent F(S). That is, in this interpolation, if the result of the evaluation formula in a certain shift is F(S)>0 and the result in the next shift is F(S,+1)×0, the phase difference ΔX is expressed by.

In order to move the photographic lens to the in-focus point, that is, the position where the amount of deviation is 0, perform calculations to convert ΔX obtained by equation (5) into the amount of lens extraction (or amount of retraction), and calculate that amount. Move the take lens.

[Problems to be Solved by the Invention] However, when detecting a phase difference using the focus detection principle described above, the above-mentioned equations (8) and (4) can be calculated from the output values of the 8th group sensor and 5th group sensor. When a shift operation is performed, a plurality of points may occur where the value of the resulting evaluation formula F (S) is reversed from positive to negative. In other words, there are multiple points that are expected to be in focus.

This phenomenon occurs when the contrast of the subject is periodic (
For example, it is more likely to occur with patterns of vertical stripes at regular intervals, etc.
a7! The output waveforms of the '¥ sensor and the 5th group sensor are as shown in FIG.

In this way, multiple phase differences (ΔXt+ ΔX2+...
For a subject where ΔX) occurs, for example, if the photographing lens is driven with a phase difference other than the correct phase difference, a focus signal is output even though the viewfinder image is blurred (so-called (false focus), and if you continue shooting in this state, the photo will naturally be out of focus.

By the way, the contrast of a finder image in an out-of-focus state is generally extremely low compared to the contrast in an in-focus state. Even in the case of false focus described above, the contrast at the false focus position is lower than the contrast at the true focus position. This situation will be explained using FIGS. 16 and 17.

FIG. 16 shows the relationship between the shift number S and the shift calculation value F (S), where -S shift -82 shift.

Assuming that F(S)=0 at +S shift and +84 shift, and assuming that -S2 shift is the true shift number, the contrast distribution will be as shown in FIG. 17.

The starting point 0 is the current lens position, and e, f, g, and h are positions corresponding to -S shift, -82 shift 1-, +s3 shift, and +84 shift. As you can see, the contrast is at its peak at the true focus position.

Focusing on this point, the present applicant filed the patent application No. 61-17462.
In No. 7, when multiple planned focus positions occur, false focusing is avoided by driving the lens in a predetermined direction, stopping the lens near the position of maximum contrast, and determining the final focus position at that position. Suggests ways to avoid it. According to this method, the contrast level is determined while driving the lens, so depending on the subject situation, it may be difficult to determine the position of maximum contrast.

In view of the above-mentioned problems, the present invention provides an automatic focus adjustment device that obtains a true in-focus position by performing contrast detection for each corresponding position when a plurality of pieces of phase difference data exist. The purpose is to

[Means and operations for solving the problems] As the concept of the automatic focus adjustment device of the present invention is shown in FIG. Once detected, this phase difference data is stored in the storage means 3.

If there is a plurality of phase difference data stored in the storage means 3, the sequence control means 4 controls the focusing lens 7 by means of a plurality of predetermined focus position Herens driving means 6 associated with each phase difference.
move. Then, the contrast detection means 5 is further operated at each planned focus position to select the position with the highest contrast from among each planned focus position, and this position is determined to be the true focus position and the focusing lens 7 is activated. Finally, the drive is controlled.

[Example] Next, an example of the present invention will be described with reference to FIG. 2 and the following drawings.

FIG. 2 is a block diagram of the entire electric circuit mainly focused on the power supply of the camera system to which the present invention is applied.

The voltage ■co of the power supply battery 11 is stepped up by the DC/DC converter 13 when the power switch 12 is opened, and the voltage between the lines Ω0 and Ω1 is regulated to a voltage VDD. Line Ω. , MAINCPU14 during 91, bipolar ■
Circuit 15, bipolar 1 circuit 16, lens data circuit 1
7 is connected, power supply control of the bipolar ■ circuit 15 is performed by a signal from the power control circuit of the MAIN CPU, and power supply control of the bipolar 1 circuit 16 and the lens data circuit 17 is connected to the bipolar ■ circuit 1.
This is done by the power control signal from 5.

CCD line sensor 20. Interface IC2 1,
The autofocus circuit section consisting of the AFCPU 22 is connected to the line ρ via a power supply control transistor 23. . AF
The CPU 22 is a central processing unit for performing autofocus algorithm calculations, and is connected to an autofocus (AF) display circuit 24 that displays in-focus/out-of-focus status. The MAIN CPU 14 is a central processing unit for controlling the entire sequence of the camera, such as film winding, rewinding, and exposure sequences, and is connected to a display circuit 25 that performs displays other than the focus display. The bipolar circuit 15 is a circuit that includes various drivers necessary for camera sequences such as winding and rewind motor control, lens drive and shutter control, and includes a motor drive circuit 26 and an autofocus (AF) auxiliary light circuit 27. It is connected. The bipolar 1 circuit 16 is a circuit mainly responsible for photometry, and has a photometry element 28. The lens data circuit 17 is a circuit that stores unique lens data that differs for each interchangeable lens and is necessary for autofocus, photometry, and other camera control. Among the lens data contained in this lens data circuit 17, the data necessary for autofocus includes a lens magnification coefficient (zoom coefficient), a macro identification signal, a lens rotation direction, an aperture F value, an autofocus accuracy threshold, etc. .

The above bipolar ■circuit 15 monitors the state of the power supply voltage ■DD, and when the power supply voltage drops below the specified voltage, M
Sends a system reset/reset signal to the AINCPU 14, supplies power to the bipolar circuit 15 to lens data circuit 17, and supplies power to the CCD line sensor 20. Interface I
The power supply to the autofocus circuit section consisting of C21 and AFCPU22 is cut off. MAINCP
Power is supplied to U14 even if the voltage is below the specified voltage.

FIG. 3 is a schematic block diagram of an autofocus circuit part of the electrical circuit shown in FIG. 2.

AF-12, a central processing unit for autofocus
= Data is exchanged between the CPU 22 and the MAIN CPU 14 via a serial communication line. and,
The communication direction is controlled by a serial control line. The content of this communication is lens data specific to the interchangeable lens. Also, MAINC
Each camera mode (autofocus, single mode or other mode) is sent from PU14 to AFCPU22.
Each piece of information is decoded through the model line.

Furthermore, A from MAINCPU14 to AFCPU22
The FENA (autofocus enable) signal is output in response to half-pressing the release button, and is a signal that controls the start and stop of autofocus.
The AF (end-off autofocus) signal is a signal that is emitted at the end of autofocus operation to permit transition to an exposure sequence.

In addition, the bipolar circuit 15 receives A from the AFCPU 22.
Decodes the F motor control line signal and performs AF
The motor drive circuit 26 is driven. Motor drive circuit 2
When the lens drive motor 31 is rotated by the output of 6, slits 32 provided at equal intervals in the rotating member of the lens barrel
rotates, and the light emitting part 33a is placed across the passage of the slit 32.
A photo ink printer 33, which includes a light receiving section 33b and a light receiving section 33b arranged opposite to each other, counts the number of slits 32. That is, the slit 32 and the photo interrupter 33 are connected to the address generator 34.
The address signal (count signal of the slit 32) generated from the address generation section 34 is waveform-shaped and taken into the AFCPU 22.

The sub lamp (hereinafter abbreviated as S lamp) signal sent from the AF CPU 22 to the bipolar circuit 15 is a signal that controls the AF auxiliary light circuit 27, and turns on the S lamp 27a when the subject is in low light (low brightness). .

The AF display circuit 24 connected to the AFCPU 22 is an LED (light emitting diode) that lights up when the focus is OK to indicate that the focus is OK.
24a and an out-of-focus indicator LED 2 that lights up when out of focus
4b. Note that this AFCPU 22 includes a clock oscillator 35. A reset capacitor 36 is connected.

Further, the AFcPU 22 and the interface IC 21 exchange data through a path line, and the direction of the data transmission is controlled by a path line control signal. A sensor switching signal and a system clock signal are sent from the AFCPU 22 to the interface IC 21.

For example, the interface IC 21 sends a CCD drive clock signal and a COD control signal to the CCD line sensor 20, reads a CCD output from the CCD line sensor 20, converts the read CCD output of an analog value into a digital value, and sends it to the AFCPU 22.

Next, regarding the camera to which the present invention is applied, the AFCPU2
2 will be explained using FIGS. 4 to 9.

When the power switch 12 is turned on, the DC/DC converter 1
3 starts operating, the MAIN CPU 14
Turn on power supply to U22.

Then, a power-on reset is applied to the AFCPU 22, and the flow of "power-on reset" shown in FIG. 4 is executed.

First, all I10 ports are initialized, followed by clearing the AFOK flag (described below). Then, wait for the AFENA signal from the MAINCPU 14 to become H".Now, when the photographer presses the relay button halfway to instruct the start of autofocus operation, the MAINCP
The U14 detects this and then notifies the AFCPU 22 of this by setting the AFENA signal to "H". Upon receiving this signal, the AFCPU 22 calls the <AF> routine. The <AF> routine is a routine in which /l111 distance and lens drive are performed, and when the photographic lens is guided to the in-focus position, the AFOK flag is set to H''.
If it is not possible to focus, the AFOK flag will remain at "L" and return.

Therefore, after executing the <AF> routine, AF
Check the OK flag, and if it is "H", the focus is displayed on the AFOK display LED 24a, and if it remains "L", the non-focus display is displayed on the non-focus display LED 24b.Focus is displayed After that, the EOFAF signal is set to "L" to notify the MAIN CPU 14 of the end of the autofocus operation, and then the MAIN CPU 14 waits for the AFENA signal to become "L".The MAIN CPU 14 detects the "L" level of the EOFAF signal. Then, check the release switch (not shown), and if the switch is on, that is, if the photographer has pressed the release button deeply, the exposure operation will be performed. If you let go,
Or, if you release your finger after the exposure operation is complete, the AFE
The NA signal changes from "H" to "L". When the AFCPU 22 detects that the AFENA signal becomes "L", it waits for the next autofocus operation.

On the other hand, if focusing is not possible, the AF is displayed after the out-of-focus display.
It checks the ENA signal, waits for the photographer to release the release button, and when the AFENA signal becomes "L", turns off the out-of-focus display and waits for the next autofocus operation.

Next, the <AF> routine shown in FIG. 5 will be explained. First, the LC count flag (described later) is cleared, and then the routine ``Distance Measurement'' is called. In the <distance measurement> routine, the amount and direction of focus deviation are measured. Here, if a plurality of pieces of phase difference data exist, all the data are stored in the RAM (random access memory) of the AFCPU 22. Furthermore, if the contrast level of the object is below a predetermined value, the LC flag is set to "H" and the process returns. Therefore, <distance measurement>
When returning from the router, the LC flag is checked, and if it is "H", the process proceeds to the low contrast operation.

The operation at low contrast is to first check the LC count flag, and if it is "H", that is, the same operation has already been performed once, return to the original routine without doing anything, and when it is "L", the flag is checked. If so, set the LC count flag to “
"H" and call the <LC scan> routine.

The <LC scan> routine is an operation in which the photographic lens is forcibly moved from the current position to the closest end to the 100th (infinity) end, and distance measurement is performed continuously to search for a position that is not in low contrast. be. The conditions for returning from the <LC scan> routine are when the contrast is no longer low or when the photographic lens reaches its open end. When returning from the <LC scan> routine, the AFENA signal is checked, and if it is "H", the distance measuring operation is performed again, and if it is #L, the process returns to the power-on reset> routine.

On the other hand, if it is determined that the subject does not have low contrast by checking the LC flag after distance measurement, the lens data circuit 17 provided in the lens stores information necessary for autofocus operation. Read in.

Here, this information includes the lens' open F-number, lens magnification coefficient, autofocus accuracy threshold, and the like.

Next, a focus tolerance range is set in <ERRORTH> in a routine. The allowable focus range is a range within which the human eye cannot determine that the object is out of focus, and even if the photographic lens is deviated from the true focus position, it can be recognized that the object is in focus as long as it is within this range. This range removable lens ROM
It is determined from the open F value read in the routine above.

Next, it is checked whether a plurality of pieces of phase difference data have been calculated, and if not, it is then checked whether the current photographing lens is at the in-focus position. Specifically, it is checked whether the phase difference data is within the above-mentioned focus tolerance range, and if it is, it is determined that the focus is in focus and the AFOK flag is set to H" and the return is made. If it is not, the corresponding phase difference data is checked. The data is converted into the number of pulses corresponding to the amount of rotation of the lens drive motor using the routine ``Pulse calculation'', and the photographing lens is moved by the number of pulses using the routine ``Lens drive''. Pulses are generated with the rotation of the motor, and by counting the number of these pulses, the amount of rotation of the motor can be determined. In the pulse calculation routine, the phase difference data is multiplied by the lens magnification coefficient. to find the number of pulses.

The lens drive routine is a routine that rotates the motor by the number of pulses mentioned above to guide the lens to the in-focus position.The direction of rotation of the motor is determined by the sign of the phase difference data. If the value is positive (+), the motor is rotated in the lens retracting direction.

After returning from the lens drive routine, continue with L.
Check the STOP flag. In the LSTOP flag and lens drive routine, this flag is set when the lens hits the close end before reaching the in-focus point, and when this flag is "H", the lens is out of focus. , returns as is, and if the value is "L", it is assumed that the lens has been guided to the in-focus point, and the AFOK flag is set to "H" before returning.

On the other hand, going back to the previous step, if there are multiple pieces of phase difference data, the routine ``Phase Difference Scan'' is called. The phase difference scan routine selects true phase difference data from among a plurality of pieces of phase difference data and guides the lens to the true in-focus position. After returning from this routine, the AFOK flag is set to "H" and the process returns to the <power-on reset> routine.

Here, the routine of distance measurement in the routine of <AF> will be explained with reference to FIG. In the distance measurement routine, first, lighting of the auxiliary light is prohibited, and then the CCD integration routine is called. This<CCD
In the routine of ``Integration'', electric power ff1 (CCD output) corresponding to the subject brightness is read out from the CCD line sensor 20 and stored as a digital value. Next, the contrast level of the subject is measured in the routine Contrast Calculation. In this contrast calculation routine,
As shown in FIG. 7, the sum of absolute values of differences between adjacent elements is calculated for each of groups a and b of the output data of the CCD line sensor 20. These are assumed to be Ca and cb, respectively, and their average value C is used as contrast data.

Here, the contrast measurement value of the subject or the reference value Cref
If it is smaller than , even though the auxiliary light is turned on, the LC flag is set to "H" and the process returns. On the other hand, if the auxiliary light is not turned on,
It is possible that the brightness of the subject is too low, resulting in low contrast, so the auxiliary light is allowed to turn on and <CCD integration> is executed again.

Go back, low con!・If not, a <shift operation> routine is called to calculate phase difference data.

The routine for the shift operation will be explained with reference to FIG.

The shift calculation is the calculation shown in equations (3) and (4) above, and each F (S) is obtained by changing the shift number S from -(N-2) to +(N-2). Here, N is the number of sensor pairs.

Once all F (S) has been calculated, next, in order to find the S at which F (S) crosses zero, we can calculate F (S) without changing S from -(N-2) to +(N-3). F(S+
1) and search for S where there is a zero cross point between the two. After finding S that satisfies this condition, phase difference data is calculated as DX (m) using equation (5). Here m
is a variable that indicates the number of phase difference data; if it is a single phase difference data, m = 1; if it is plural, m = 2.3.4...
...and increases.

Next, the phase difference scan routine in the AF routine will be explained with reference to FIG.

First, all m phase difference data are converted into the number of moving pulses from the current position (starting point). This is the same as the routine for pulse calculation described above, and P (R) (N-1,2
,...m). Then, ρ=1
The lens is moved to the first planned focus position based on the first phase difference data, and the <CCD integration> routine and the <contrast calculation> routine are executed at that position to calculate the contrast at the first planned focus position. is set and stored in register LASTC. Subsequently, the difference between the second planned focus position and the first planned focus position based on the second phase difference data is stored in DP(ρ) (at this time g-2). After this, the lens is moved by DP(ρ) (Ω=2) and stopped at the second planned focal position, and the first
<CCD integration> and contrast calculation> are performed in the same way as for the planned focal position. Here, compare the contrast data C obtained this time and the previous contrast data LASTC,
If C>LASTC, it can be determined that the first expected focus position was not the true focus position, since the contrast level has improved compared to the previous time. Therefore, this time, the contrast data at the second expected focus position is stored in the register LASTC, and a similar determination operation is performed with respect to the third expected focus position. The above operation is C>LASTC
This is performed sequentially until Ω>m is reached. Contrast changes are continuous, so for example, if the nth contrast data is smaller than the n-1st contrast data, the n-1st contrast is m
This is the one with the highest contrast among the planned focus positions. In other words, the n-1st position is the true focus position. Therefore, if the lens is returned from the current position -25= to the previous position, the lens will have stopped at the true focus position. If the position where the contrast is maximum is not found and Q>m, the m-th position is regarded as the true in-focus position and the process returns.

To summarize the explanation so far, when the photographer presses the release button halfway to start autofocus operation, distance measurement is performed on the subject, and as a result, it is determined that there are multiple pieces of phase difference data. If so, the photographing lens is moved to the planned focal position closest to the closest end, and from there the lens is sequentially moved toward each planned focal position toward the country. During this time, the contrast is measured at each planned focus position, and if the current contrast is higher than the previous one, the lens advances to the next planned focus position, and if it is lower, the lens is returned to the previous planned focus position. In other words, the returned position is the position with the highest contrast among the plurality of planned focus positions, and is the true focus position.

Of course, this embodiment is not the only method for selecting the position where the contrast is maximum, and several lens movement algorithms can be considered. For example, there are methods that temporarily store contrast data at all planned focal positions, calculate the position with the highest contrast level among them, and finally drive the lens to that position; Instead of comparing the contrast levels at , a comparison may be made at a position that is slightly displaced from an arbitrarily selected planned focal position. In other words, in FIG. 17, if the contrast level at the starting point (0) is compared with the contrast level when the lens is moved to the adjacent planned focus position g on the lens extension side, and the contrast level is lower at position g, then It is determined that the true in-focus position is on the lens renormalization side than the starting point, and then the lens is moved to the adjacent planned focal position f on the renormalization side, and if the contrast level here is higher than the starting point, Further, the contrast level is slightly moved to an arbitrary position f' on the renormalization side, the contrast level is determined here as well, and if the contrast level is lower than that at position f, this position f is determined to be the true in-focus position. If the contrast level at position f' is higher, the lens is moved to the intended focal position e and the same process is performed.

This method eliminates the need for the lens to move at every predetermined focus position, so the time required to find the true focus position is shortened.

Note that the same effect can be obtained even if the contrast detection means has a node-like circuit configuration.

[Effects of the Invention] As described above, according to the present invention, when focusing on a subject whose contrast is periodic, the focus detection sensor can maintain focus even though the viewfinder image is blurred. Even if a plurality of pieces of false focus data are generated, it is possible to detect the position where the contrast is maximum and focus on the true focus position.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an automatic focus adjustment device that explains the present invention in detail. FIG. 2 is a block diagram of an electric circuit mainly for power supply of a camera system to which the device of the present invention is applied. 10 is a schematic block diagram showing the transmission and reception of signals in the autofocus circuit section in FIG. 2, FIGS. 11 are a schematic configuration diagram of an optical system and a detection output diagram for explaining the principle of the phase difference detection method used in the present invention, and FIG. 12 (A) to ('C) are "2" 10 is a schematic diagram for explaining the configuration and operation of the focus detection sensor, FIGS. The diagram is
A diagram of the evaluation formula when multiple pieces of phase difference data are generated. Figure 16 is a diagram showing the calculated values for the number of shifts. Figure 17 is a diagram of the lens corresponding to the diagram shown in Figure 16 above. FIG. 3 is a diagram showing the relationship between position and contrast. 1... Focus detection sensor 2... Phase difference detection means 3... Memory means 4... Sequence control means 5... Contrast detection means 6...Lens driving means 7...Focusing lens 20...CCD line sensor (focus detection sensor) 22
...AFCPU (phase difference detection means, storage means, sequence control means, contrast detection means)

Claims (1)

[Scope of Claims] A focus detection sensor that receives light from the same part of an object as a luminous flux having parallax through different optical apertures and paths, and detects phase difference data of the illuminance distribution of the received luminous flux from this focus detection sensor. a storage means for storing at least one piece of the phase difference data; a lens drive means for electrically driving the focusing lens; a contrast detection means for detecting a contrast level from the illuminance distribution; The lens driving means is controlled to move the focusing lens to a predetermined focus position related to the phase difference data stored in the storage means, and when there is a plurality of phase difference data, each phase difference data is By operating the contrast detection means at each related planned focus position and comparing the contrast levels at each of the planned focus positions, it is possible to detect the highest contrast among the plurality of planned focus positions corresponding to the plurality of phase difference data. automatic focus adjustment characterized by comprising: sequence control means for selecting a predetermined focus position and controlling the lens driving means using the predetermined focus position as the final movement target position of the focusing lens; Device.