JPH0321911A - Automatic focus adjusting device - Google Patents

Abstract

PURPOSE:To accurately follow up the movement of an object even if the movement is complicate and sudden and to enable photography in focus detecting operation reasonably by driving and controlling a photographic lens according to lens movement pattern information which is stored in advance and calibrating the driving control with focusing lens position information which is generated intermittently. CONSTITUTION:This device is provided with a decision means 4 which decides the position of the photographic lens to be put in focus according to a defocusing quantity and a lens position and a storage means 6 for storing the relation between the position of the photographic lens to be put in focus on a specific moving subject and the time as lens movement pattern information. Further, the means is provided with a lens driving control means 7 which drives and controls the photographic lens according to the lens position, focusing lens position, and lens movement pattern information. Here, the lens driving control means 7 controls the lens position so that the position of the photographic lens coincides with the lens movement pattern information and the lens position is calibrated every time a focusing lens position is generated. Consequently, the automatic focus detecting device which puts the photographic lens accurately in focus on the moving subject is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic focus adjustment device for a camera or the like that is driven to focus on a moving subject.

[Prior Art] Conventionally, a technique called tracking, moving object prediction, or predictive driving is known as a technique for driving and controlling a photographing lens without delay so as to focus on a moving subject.

For example, in the automatic focus adjustment device disclosed in Japanese Patent Application Laid-Open No. 60-214325 by the present applicant, the future lens position is predicted from the latest defocus amount obtained from the focus detection means and the defocus amount from multiple past times, and the image is taken. The lens is driven and controlled.

[Problems to be Solved by the Invention] However, in an automatic focus adjustment device that performs drive control by predicting the future lens position from the latest defocus amount and multiple past defocus amounts, If the lens position changes almost linearly on the time axis, prediction accuracy is high and accurate drive control can be performed, but if the lens position does not change linearly, the prediction will not be successful and the lens will not reach the true focus point. However, there was a problem with overruns and underruns.

For example, as shown in Figure 15, a car (
When focusing is performed with the closest distance of the camera to D (a constant-velocity moving object), ideally the solid line L in Fig. 13
A pattern of the focusing lens position along the time axis shown in is obtained.

That is, in FIG. 13, the vertical axis is the lens position Z (+),
The horizontal axis is time t, and the lens position is expressed by the amount of lens extension based on the position of ■. Further, Zd is the lens position relative to the closest distance D.

FIG. 14 shows a case in which the conventional apparatus for performing linear prediction is applied to the object shown in FIG. 15 that produces the lens movement pattern shown in FIG. 13.

In FIG. 14, a broken line M indicates the relationship between lens position and time when drive control is performed using the conventional technique.

At lens positions Z (N) and Z (+2), the solid line L indicating the ideal pattern changes rapidly, so if the conventional device performs prediction based on previous data, an overrun will occur.

In particular, when the subject brightness is low and the accumulation time of the sensor used as the focus detection means becomes long, or when the exposure operation occurs during the focus detection operation, the time interval at which the defocus amount can be obtained becomes wider. , the prediction accuracy further deteriorates, the overrun becomes more pronounced, and in the worst case, the amount of movement of the subject during the time interval during which the amount of defocus is obtained increases, making focus detection impossible and lens drive impossible. Situations also occur.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an automatic focus detection device that can accurately track and focus on a moving subject.

[Means for solving the problem] In order to achieve this object, the automatic focus adjustment device of the present invention has the following features:
a photographic lens for forming a subject image on a predetermined film equivalent surface; a focus detection means for detecting the amount of defocus of the image plane of the photographic lens with respect to the film equivalent surface;
lens position detection means for detecting the lens position of the photographing lens; focusing lens position determining means for determining the focusing lens position at which the photographing lens should focus from the defocus amount and the lens position; and a specific moving subject. lens movement pattern storage means for storing, as lens movement pattern information, the relationship between the lens position and time for the photographing lens to focus on; It is composed of a lens drive control means for driving and controlling the photographing lens; and;

Here, the lens drive control means is configured to control the lens position so that the position of the photographing lens matches lens movement pattern information, and to calibrate the lens position every time a focusing lens position occurs. . That is, the lens movement pattern information with the first in-focus lens position as the initial position is read out over time, and control is performed so that the actual lens positions match, and during this control, the new in-focus lens position is When the position is obtained, the lens position is updated to the lens position of the lens movement pattern information that matches this focused lens position for calibration, and reading of the lens movement pattern information is restarted from this updated position.

Further, the lens drive control means is provided with a starting means for instructing the start of control that follows the lens movement pattern information, and when a predetermined photographing condition is obtained, the lens drive according to the lens movement pattern information is started. good.

[Function] In the focus detection device of the present invention having such a configuration, lens movement pattern information, which is the relationship between lens position and time, is stored in advance in accordance with the type of moving subject, etc. Since the driving of the photographic lens is controlled based on this, the lens can be driven to focus more accurately following the moving subject.

In addition, the error between the lens position according to the lens movement pattern information and the focused lens position with respect to the actual movement of the subject is
Since the calibration is performed sequentially based on the focusing lens position of the moving object that occurs intermittently, errors with respect to the actual movement of the moving object can be minimized.

[Embodiment] FIG. 1 is a block diagram showing a first embodiment of an automatic focus adjustment device of the present invention.

In FIG. 1, a luminous flux from a subject 1 passes through a photographic lens 2 to form a subject image on the film surface, but is branched from the photographing optical axis by a sub-mirror of a known configuration, and a focal point placed at the bottom of the camera, etc. It is guided to the detection means 3. The focus detection means 3 is composed of a known focus detection optical system, an image sensor, and a focus detection calculation device, and receives the light flux from the subject 1 and detects the deviation between the subject image plane and the film plane, that is, the direction and amount (hereinafter referred to as "deviation"). (referred to as "focus amount"). The amount of defocus is generated at certain time intervals because the focus detection means 3 requires charge accumulation time by the sensor and focus detection calculation time. Furthermore, when a camera photographing operation is performed, the interval between occurrences becomes even longer because focus detection cannot be performed during that time.

The lens position detection means 5 is a means for detecting the absolute position of the photographic lens 2, for example, the amount of lens extension when the set position of the photographic lens 2 is set to the reference O position, and corresponds to a predetermined movement amount of the photographic lens 2. It consists of an encoder that generates a predetermined number of pulses, a counter that adds or subtracts encoder output pulses depending on the direction of movement, and a reset means that initializes the counter. In other words, an automatic focus adjustment device? When the power is turned on, the taking lens 2 is retracted to ω, the counter is reset, and subsequent decoder output pulses are counted, so that the contents of the counter become information corresponding to the absolute position of the taking lens 2.

The focusing lens position determining means 4 converts the amount of defocus generated by the focus detection means 3 into the amount of movement of the photographing lens 2, and also sets the amount of movement based on the amount of defocus to the lens position at the time when the amount of defocus occurs. By adding , a lens position (hereinafter referred to as a "focusing lens position") for focusing the photographic lens 2 on the current subject is determined.

If the photographic lens is moving during the focus detection operation time (sensor accumulation time, calculation time) of the focus detection means 3,
A correction is applied to the defocus amount or the in-focus lens position according to the amount of movement during the focus detection operation time.

The lens movement pattern storage means 6 is a means for storing in advance lens movement pattern information, which is the relationship between the lens position and time corresponding to the movement of a specific moving subject.

For example, if the lens movement pattern information corresponding to the shooting situation of a moving subject is shown by the solid line L in FIG.
Time t and lens position Z (1) are stored in a memory such as ROM or RAM at addresses X, X+1, X+2, etc. as shown in Figure 2.
- - - and contents Zo, Zl, Z2, ...
It is stored in the relationship as follows, and addresses X, X+1, X+
2. ... is determined by a value that is an integral multiple of the time interval ΔT. In FIG. 2, X represents a reference address, ΔT represents a time interval, and 2 represents a lens position.

Referring again to FIG. 1, the lens drive control means 7 causes the photographic lens 2 to focus on and follow a specific moving subject based on the lens movement pattern information, focusing lens position information, and lens position information. to drive and control its position and time relationship.

The control operation of the lens drive control means 7 will be explained using FIGS. 3 and 4.

In FIG. 3A, a solid line L indicates a lens movement pattern that is the relationship between the lens position and time corresponding to the movement of a specific moving subject. This lens movement pattern L searches for a point P1 at which the lens movement pattern L becomes 21 when focused lens position information z1 (initial position) occurs at a certain time t1. Here, lens movement pattern L
is a bivalent function that has two values on the time axis for lens position 2, but point P1 is uniquely determined by selecting the one for which time t is small.

Once the first point P1 is determined, the lens drive control means 7 sets the lens movement pattern L in which the relationship between the lens position of the photographing lens 2 and time starts from the point P1 until the focused lens position information Z2 is generated at the next time t2. Drive control is performed using part L1 of the lens position information.

Therefore, the lens position that is the actual control target is indicated by the solid line L1 in FIG. 3B.

Here, the broken line L' in FIG. 3B shows the relationship between the lens position and time in a case that strictly corresponds to the actual movement of the subject.

This broken line L゜ varies depending on the subject, and to be more precise, it is the third A.
Although it does not match the lens movement pattern L shown in the figure, it is expected that the error will be small. Therefore, from time t1 to t2
As long as the time until t2 is not extremely long, the error at time t2 will be small even if lens drive control is performed with the solid line L+ as the target.

When the focused lens position information Z2 is newly generated at time t2, the lens movement pattern L is changed to 22 in the same way as the previous time.
The relationship between the lens position of the photographing lens 2 and time is found until the focused lens position information Z3 is generated at the next time t3. Driving control is performed using lens position information so that part L2 of the lens movement pattern L starts from point P2. Therefore, the error between the solid line L' indicating the lens position corresponding to the actual object and the control target Li that occurred at time t2 is corrected at this point.

Hereinafter, time t3, t'4, t5. . . , the control targets L3, L4, L5, . . . shown in FIG. ...is required.

Control targets Ll, L2, . . . are at times tl, t2, .
Since the actual movement of the photographing lens 2 does not match Ll, L2 ・●・ at this point, it can be controlled to match Ll and L2 at other times, and the final movement is discontinuous. There is little difference between the relationship L' between the lens position and time when the lens position corresponds strictly to the movement of the actual object, and the lens position when it is actually controlled.

In addition, the focusing lens position information that is generated at time intervals is not used to directly control the drive of the photographing lens 2, but is only used to calibrate the lens movement pattern, so even if the time intervals that occur are long, the lens Drive control error does not increase.

Furthermore, in order to reduce errors at times tl, t2, . Expanding the time axis for control,
It can also be reduced.

For example, the difference Δ2 between the focused lens position Z2 that occurred at time t2 in FIG. 3B and the control target L1 at time t2 is 0 in this case, and the lens movement direction is also +, so the actual movement speed of the subject is faster than expected. In other words, considering that the actual lens movement pattern L° is smaller than the stored lens movement pattern L in the time axis direction, the control target L2 from time t2 is reduced according to the amount of the difference ΔZ (time rate of change is reduced). By doing so, the error at time t3 can be reduced.

An embodiment in which the driving of the photographing lens 2 is controlled based on the above concept will be described with reference to FIGS. 4A and 4B. In FIG. 4A, at time t1, lens position Zl
The lens movement pattern Z = F I (
When lens drive control is started according to 1) and focused lens position information z2 is obtained at time 12, function Z =
A time S2 at which the lens position z2 is reached when the lens movement continues along F I (1) is determined as shown in the figure. The error in the lens position Z that occurs at time t2 is caused by the fact that the actual movement of the subject is performed according to a lens movement pattern Z = F 2 (t) that is different from the previously stored lens movement pattern Z = F I (1). The lens movement pattern Z=F2(1), which can be considered to be due to the lens movement pattern Z=F2(1), can be expressed as the following equation since it can be assumed that the lens movement pattern Z=F1) is reduced/enlarged on the time axis and moved in parallel.

F2(+)=F1(a2*t+b2) ●●●
(A) Also, time tl, 12, S 2, lens position z
1. The conditions for z2 are as shown in the following equation.

F2(It) =FI[1) =ZI F2(S2) =F](t2) =22 ・
●・ (B) From equation (B), the coefficients a2 and b2 of equation (A) can be determined as shown in the following equation.

a2 = (82-N)/(12 glances) b2 = +(
12- 82)/(12 bites)}*tl ・●● (
C) Therefore, from time t2, the driving of the photographing lens may be controlled according to the lens movement pattern Z = F 2 m determined from (A) and (C).

Next, in FIG. 4B, lens drive control is started according to lens movement pattern Z=F2 (1) from lens position Z2 at time +2, and when focused lens position information Z3 is obtained at time t3, function Z=F2( Time S when lens position 23 is reached when lens movement continues along 1)
3 is obtained as shown in the figure. Based on the same idea as above, from time 12 to t3, the lens movement pattern Z=F3
Assuming that the process is carried out according to (1), F30) can be expressed as in the following equation, assuming that the lens movement pattern Z = F 2 (1) is reduced/enlarged on the time axis and translated in parallel.

F 3 (+) = F 2 (a 3 net t + b3) = F
1 (a2 pieces a3tt + b2 + a2tb3) = F 1
(A 3s++B 3) --- (D) Time 12. 13. S3. lens position 22,
The conditions for z3 are as shown in the following equation.

F3(+2) =F2(+2) =22F3(S3)
=F2(13) =23... (E
) (E), the coefficients a3, b3, A3, and B3 of equation (D) can be determined as shown in the following equation.

a3 = (S3-t2) / (t3-t2)b
2 = t(t3 - S3)/ (t3 - t2)) *
+2A3 =a2 *a3 B3 =a2 *b3 +b2 ● ●
● (F) Therefore, from time 13, (D). (F)
Lens movement pattern determined by Z = F 3 (1)
The driving of the photographic lens may be controlled accordingly.

Generally, when the focused lens position information Zn is obtained at time tI1, the lens movement pattern immediately before time tn z = F
The time Sn at which the lens reaches the lens position rI1zn is determined from n-1 (1) D, and then the lens drive control is performed from time 1+ according to the lens movement pattern Z=FJl (1) expressed by the following equation.

Fn(+)=Fn-1(an*t+bn)-F
l(An * t + Bn) However, an = (Sn-tn-1)/ (tn -tn-1
)bn=i(tn-Sn)/(tn-t
n-1)) *t n-1An −=anxAn−
1 = alXa2X @ @ # xanBn = Bn
-1 +An-I Xbn @●●(G
) AI = 1, Bl = 0, at-1. bl=0
Further, the time axis is fixed without being scaled up or down, and the time change rate K of the error is determined from the error ΔZ at time t2 in FIG. control target L2 of L2
It may be corrected as =L2+K (+-+2).

In general, the lens movement pattern L is a multivalued function that has multiple time axis values for lens position 2, as shown in Figure 5, but the search for the point corresponding to focusing lens position 2 starts from the smaller time axis. After that, it is only necessary to select the closest point after the previous point and the same moving direction.

In addition, if the subject shifts to a distance other than the expected distance and the point corresponding to the focused lens position Z that occurs does not exist on the lens movement pattern L, then the time axis from the previous point on the lens movement pattern L Then, a point with the least difference from the focusing lens position Z is selected in the vicinity separated by the elapsed time from the previous time to the current time.

Further, if the focus cannot be detected at a certain time, or if the difference between the focused lens position Z and the current lens position is larger than a predetermined value, the drive control continues based on the previous control target. You can do it like this. This continuous control prevents the photographing lens from focusing on the background even if the moving subject moves out of the distance measurement area and the focus is detected on the background.

FIGS. 6 and 7 are flowcharts in the case where the first focusing lens position determining means 4 and the lens drive control means 7 are configured by a microcomputer.

First, in FIG. 6, when the focus detection means 3 determines the amount of defocus, an interrupt is generated in step 81.

In step S2, the in-focus lens position is determined from the defocus amount and the lens position, and in step S3, an interrupt is generated. This is the operation of the focusing lens position determining means 4.

Next, when the focusing lens position determination means 4 generates an interrupt in step S4 of FIG. 7, corresponding points are determined in step S5 by the method shown in FIG. 4 based on the focusing lens position and lens movement pattern information, and step S6 The driving of the photographing lens 2 is controlled according to the lens movement pattern L after the point. The above is the lens drive control means 7
This is the operation.

FIG. 8 shows a second embodiment of the present invention, and this embodiment is characterized in that the stored contents of the lens movement pattern storage means 6 can be set from the outside. In this example, lens movement pattern external setting means 9 and storage control means 8 are added.

The storage control stage 8 is a control means for resetting and updating the memory contents of the lens movement pattern storage means 6, and allows writing in the memory of the lens movement pattern storage means 6 when updating the lens movement pattern. At the same time, the operation of the lens drive control means 7 is prohibited. The lens movement pattern external setting means 9 writes new lens movement pattern information into the memory of the lens movement pattern storage means 6 when memory writing is permitted. When the writing is completed, the storage control means 8 once again prohibits writing into the memory of the lens movement pattern storage means 6, and permits the operation of the lens drive control means 7.

The photographer may directly provide desired lens movement pattern information to the lens movement pattern external setting means 9, or select a desired pattern from a plurality of pieces of lens movement pattern information prepared in advance in the lens movement pattern external setting means 9. You may choose.

Further, by providing information on photographing conditions (distance, speed, etc.) by the photographer, corresponding lens movement pattern information may be calculated within the lens movement pattern external setting means 9. For example, under the photographing conditions shown in FIG. 15, the close distance D and the initial distance D are used. Lens movement pattern information can be calculated by inputting the vehicle speed V and the vehicle speed V.

First, the movement pattern d(1) of the subject distance is expressed by the following equation.

d(+)=x t−Zo +D −(
1) However, zo'' o1-: 10,000T Next, the lens movement pattern Z (+) is the focal length of the photographing lens f1 The distance from the film surface to the subject is the distance from the film surface to the subject (
Applying the lens formula as d (1) in equation 1) gives the following equation.

Z (+) Yo (d(1)/21) - d. l
2-1 2-f2... (2) This 'th equation (2) is approximated as Z(.+)=f2/ (d(t)-2 f)...
・It can be treated as (3).

FIG. 9 shows a third embodiment of the present invention, which is characterized in that the stored contents of the lens movement pattern storage means 6 can be set by the output of the focusing lens position determination means 4, The configuration is such that a storage control means 8 is added to the embodiment shown in FIG.

The storage control means 8 is a control means for resetting and updating the memory contents of the lens movement pattern storage means 6, and when updating the lens movement pattern, it permits writing to the memory of the lens movement pattern storage means 6 and also , prohibits the operation of the lens drive control means 7. When memory writing is permitted, the focusing lens position determining means 4 writes the focusing lens position information into the memory of the lens movement pattern storage means 6 as new lens movement pattern information.

When the writing is completed, the storage control means 8 once again prohibits writing into the memory of the lens movement pattern storage means 6, and permits the operation of the lens drive control means 7.

FIG. 10 shows how the focusing lens position determination means 4 writes lens movement pattern information into the lens movement pattern storage means 6. That is, the focusing lens position determining means 4 uses the writing permission time as a reference time, and the focusing lens position determining means 4 determines the time tl, t2...t n, t n+I after writing permission.
The in-focus lens position information Z(+) (indicated by x) generated at ● is paired with time t and written into the lens movement pattern storage means 6. If the time interval Δt is large, the lens position information in between may be interpolated and written.

In the case of FIG. 10, collection and writing of lens movement pattern information is performed with the photographing lens 2 in a stopped state in order to shorten the time interval Δt, but the driving operation of the photographing lens 2 and the operation of the focus detection means 3 are overlapping. If wrapping is possible, it may be performed while driving the photographing lens 2. Further, the lens movement pattern information may be obtained as an average of multiple detections instead of being detected only once, or after writing the lens movement pattern information once, the lens drive control means 7 is operated accordingly. The in-focus lens position information captured while moving may be fed back to the lens movement pattern information.

Furthermore, it is generally difficult for a lens with a long focal length to capture a moving subject, and the amount of extension is large, making it difficult to collect lens movement pattern information when the focus cannot be detected. Therefore, when collecting lens movement pattern information, use a lens with a short focal length, and after converting the lens position information into object distance information using equation (2) above, use the focal length f of the lens used. Alternatively, the lens position information may be converted again into lens position information.

FIG. 11 shows a fourth embodiment of the present invention, and this embodiment is characterized in that the activation of the lens drive control means 7 can be controlled by the activation means 10. The configuration includes an additional means 1o.

By providing the activation means 10, the photographer can activate the operation of the lens drive control means 7 at a desired time or from a desired subject distance.

For example, if it is desired to operate the lens drive control means 7 for a desired period of time, the activation means 10 may be a simple switch, and the operation of the lens drive control means 7 may be permitted or prohibited depending on the state of the switch.

Further, when starting from a desired distance, the photographer sets the distance in the starting means 10. For example, with the settings shown in Figure 15, the photographer is at a distance D. If you want to start the lens drive control means 7 when the distance is below, set the distance D. The following information is set in the activation means 10. The starting means 10 has a distance D. is converted into the lens position Zo using the above equation (2), and the focused lens position information generated at time intervals is monitored. As a result, as shown in Figure 12, the subject is at a distance of D
If it is farther than 0, the focusing lens position is 2.

Since the following is the case, the activation means 10 does not activate the lens drive control means 7. The focusing lens position information Z (tn+1) generated at time tn+1 when the subject approaches is 2. When the value exceeds the threshold value, the activation means 10 activates the lens drive control means 7. distance D
. The setting may be made by manually setting the photographing lens 2 to the distance DO, and then importing the set lens position into the activation means 1o via the lens position detection means 5.

Further, before the lens drive control means 7 is activated by the activation means 10, the photographing lens 2 may be stopped.
The photographic lens may be driven according to the amount of defocus as in conventional lens drive control.

In the above embodiment, the lens movement pattern storage means 6
used to store lens movement pattern information in the form of time t and lens position Z (t), but using equation (2) above, lens movement pattern information is stored in the form of time t and subject distance d (+). You can leave it there.

In this way, even for a lens whose focal length changes, such as a zoom lens, the lens position at each 'X-me position can be converted according to the focal length using equation (2).

In addition, the driving of the photographing lens 2 was mainly controlled based on lens movement pattern information, and the focusing lens position information or defocus amount was used for calibration or correction. The lens drive control may be performed, and the lens drive control may be switched to the lens drive control according to the embodiment of the present invention when the focus cannot be detected or when it is determined that the conventional predictive drive is difficult due to the close distance.

Also number 1. 8, 9. In the embodiments shown in FIG. 11, the focus detection means 3 detects the defocus amount of the photographic lens 2 using TTL, but the object distance may also be directly measured using an active triangulation method.

[Effects of the Invention] As explained above, according to the present invention, the drive control of the photographing lens is performed according to lens movement pattern information stored in advance, and the drive control is calibrated using intermittently generated focusing lens position information. Because of this, even if the movement of the subject is complex or rapid, it can be accurately followed. Furthermore, since the interval between occurrences of the focusing lens position information can be made longer, the photographing operation can be easily performed between the focus detection operations.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the automatic focus adjustment device according to the present invention; Fig. 2 is an explanatory diagram of a storage method for lens movement patterns; Fig. 3
A. 3B. 4A. 4B. FIG. 5 is an explanatory diagram of the operation of the lens movement control means; FIG. 6 is an operation flowchart of the focusing lens position determination means; FIG. 7 is an operation flowchart of the lens drive control means.
; FIG. 8 is a block diagram of another embodiment of the automatic focus adjustment device according to the present invention; FIG. 9 is a block diagram of another embodiment of the automatic focus adjustment device according to the present invention; FIG. 10 is a block diagram of another embodiment of the automatic focus adjustment device according to the present invention; Explanatory diagram of information; 11th
The figure is a block diagram of another embodiment of the automatic focusing device according to the present invention; Figure 12 is an explanatory diagram of the operation of the activation means; Figure 13 is an explanatory diagram of lens movement pattern information; Figure 14 is an illustration of the conventional tracking operation. Explanatory diagram; FIG. 15 is an explanatory diagram of a moving subject photographing situation. [Description of symbols of main parts] 1: Subject 2: Photographic lens 3: Focus detection means 4: Focusing lens position determination means 5: Lens position detection means 6: Lens movement pattern storage means 7: Lens drive control means 8: Memory Control means 9: Lens movement pattern external setting means 10: Starting means FIG.

Claims (2)

[Claims] (1) A photographic lens for forming a subject image on a predetermined film equivalent surface; a focus detection means for detecting the amount of defocus of the image surface of the photographic lens with respect to the film equivalent surface; and a lens of the photographic lens. lens position detection means for detecting a position; focusing lens position determining means for determining a focusing lens position at which the photographing lens should focus based on the defocus amount and the lens position; a lens movement pattern storage means for storing the relationship between the lens position and time for the lens to focus as lens movement pattern information; driving and controlling the photographing lens based on the lens position, focusing lens position, and lens movement pattern information; and a lens drive control means, wherein the lens drive control means reads out the lens movement pattern information with the initially obtained in-focus lens position as the initial position over time and determines the actual lens position. When a new focused lens position is obtained during this control, the lens position of the lens movement pattern information is updated and calibrated to match the focused lens position, and the updated position is An automatic focus adjustment device characterized in that reading of the lens movement pattern information is restarted from . (2) The automatic focusing device according to claim 1, wherein the lens drive control means includes a starting means for instructing the start of drive control of a lens position that matches the lens movement pattern.