JP2003302571A - Method and device for automatic focus adjustment and imaging unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an adjusting speed from decreasing while improving focusing precision and to make fast the focusing adjustment, specially, in micro defocusing. <P>SOLUTION: A method for automatic focus adjustment which uses a 1st focus adjustment part (6) roughly adjusting a focal length and a 2nd focus adjustment part (4) finely adjusting the focal length comprises: detecting a focusing state (S105); judging whether a focusing point is in the range of the focal length adjustable by the 2nd focus adjustment part (S107); and adjusting the focal length by the 2nd focus adjustment part while fixing the 1st focus adjustment part when it is judged that the focusing point is within the range of the focal length adjustable by the 2nd focus adjustment part. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focusing device such as a digital still camera or a video camera.

[0002]

2. Description of the Related Art Conventionally, a TTL (Through The Lens) phase difference autofocus has been used as an autofocus mechanism of an interchangeable lens type autofocus single lens reflex camera using a silver salt film.

In this autofocus mechanism, the camera body is provided with a defocus detection mechanism for autofocus, and the focus adjustment lens of the interchangeable lens is used for focus adjustment operation by a motor in the lens or in the camera.

Further, in a video camera or the like, so-called hill-climbing AF is performed in which contrast detection is performed by the high frequency component of the signal of the image pickup device.

The TTL phase difference autofocus and the contrast detection autofocus have their respective characteristics, and are used properly according to the application.

In Japanese Laid-Open Patent Publication No. 5-64056, it is not possible to know the defocus direction and the defocus amount by one-time focus detection only with contrast detection autofocus.
A technique for combining phase-difference autofocus is disclosed.

Further, in Japanese Unexamined Patent Publication No. 6-225198, a focus motor control means for coarse adjustment and a focus motor control means for fine adjustment are separately used for lens control by contrast detection autofocus, and quick and stable focus control is performed. Techniques for doing so are disclosed.

Further, Japanese Laid-Open Patent Publication No. 7-284502 discloses a technique for smoothly performing coarse and fine adjustment of a focus by linking a means for performing coarse adjustment at high speed and a means for performing fine adjustment at low speed.

[0009]

However, the above-mentioned conventional example has the following drawbacks, and it is difficult to achieve both high-speed and high-precision focusing adjustment at the time of minute defocus and at the time of large defocus.

In the conventional examples described in JP-A-5-64056 and JP-A-6-225198, in order to improve the final accuracy of focus adjustment, the resolution of focus position adjustment is made sufficiently fine. Therefore, the focus adjustment mechanism must be finely controlled for that purpose, and there is a problem that the adjustment speed is inevitably sacrificed and the adjustment speed becomes low.

Further, the technique disclosed in Japanese Patent Application Laid-Open No. 7-284502 does not show a method for linking with autofocus.

The present invention has been made in view of the above problems, and it is an object of the present invention to prevent a decrease in adjustment speed while improving focusing accuracy, and particularly to speed up focusing adjustment at the time of minute defocus.

[0013]

To achieve the above object, the automatic focusing of the present invention using a first adjusting means for roughly adjusting the focal length and a second adjusting means for finely adjusting the focal length. The adjusting method determines whether or not the in-focus point exists within the range of the focal length adjustable by the second adjusting means, based on the detection step of detecting the in-focus state and the detection result in the detecting step. In the judging step, and in the judging step, when it is judged that the in-focus point exists within the range of the focal length adjustable by the second adjusting means, the first adjusting means is fixed and the second adjusting means is fixed. And a fine adjustment process for adjusting the focal length.

Further, the automatic focus adjusting device of the present invention comprises first adjusting means for roughly adjusting the focal length, second adjusting means for finely adjusting the focal length, and detecting means for detecting the in-focus state. Based on the detection result of the detection means, the second
Determining means for determining whether or not the in-focus point is within the range of the focal length adjustable by the adjusting means, and the in-focus point is within the range of the focal length adjustable by the second adjusting means. When it is determined that the first adjusting means is present, the first adjusting means is fixed, and the second adjusting means controls the focal length to be adjusted.

Further, the image pickup apparatus of the present invention has the above-mentioned automatic focus adjusting apparatus, a camera body, and a lens unit detachable from the camera body.

According to the above arrangement, the focus adjustment is performed only by the fine adjustment means within the range adjustable by the second adjustment means for finely adjusting the focal length.
Since it is possible to reduce as much as possible the use of adjusting means for coarse adjustment, which takes time from start to stop, it is possible to shorten the focusing time at the time of minute defocus.

Preferably, the detecting step further includes a contrast detecting step of detecting a focus state based on contrast, and the second adjusting means determines the focal length on the basis of the detection result in the contrast detecting step. Make adjustments. Further, the detection means further has a contrast detection means for detecting a focus state based on the contrast,
The second adjusting means adjusts the focal length based on the detection result of the contrast detecting means.

According to the above arrangement, since the contrast AF using the image pickup device for obtaining the final image signal is performed, the focusing precision can be improved.

Further, as a result of the adjustment of the focal length based on the detection result of the contrast detecting step or the contrast detecting means, when the reliability of the focal point is low, the phase difference detecting step or the detection result by the phase difference detecting means is used. To adjust the focal length.

According to the above construction, it is possible to improve the focusing reliability by adopting the result of the higher reliability of the contrast AF and the phase difference AF.

Further, preferably, by mounting the lens unit of the image pickup device on the first and second adjusting means, a single moving member can be used to simplify the structure.

According to another configuration, the first adjusting means is mounted on the lens unit of the image pickup apparatus, and the second adjusting means is mounted on the camera body of the image pickup apparatus, thereby providing a total. The cost of the system can be reduced.

[0023]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. (First embodiment)

FIG. 1 is a view showing the arrangement of a lens interchangeable digital still camera according to the first embodiment of the present invention.
An example is shown in which both the coarse adjustment actuator and the fine adjustment actuator of the present invention are mounted on an interchangeable lens.

In FIG. 1, 1 is a digital still camera body, and 2 is an interchangeable lens. The interchangeable lens 2 includes a focus lens 3, and the focus lens 3 adjusts the focus. Although only one lens is shown in FIG. 1, the interchangeable lens 2 is actually composed of a plurality of lenses.

Reference numeral 6 is a first focus adjusting section for adjusting the focus lens barrel 5 in the optical axis direction, and 4 is a second focus adjusting section for adjusting the focus lens 3 in the focus lens barrel 5 in the optical axis direction. The focus lens 3 and the second focus adjustment unit 4 are held by the focus lens barrel 5. In the present embodiment, the first focus adjustment unit 6 is for coarse adjustment and the second focus adjustment unit 4 is for fine adjustment, each of which is composed of an actuator or the like. Therefore, in the above configuration, the focus lens 3 can be adjusted by both the first and second focus adjustment units 6 and 4. The second focus adjustment unit 4 also has a position encoder that indicates the relative positional relationship between the focus lens barrel 5 and the focus lens 3. A lens control circuit 7 communicates with the digital still camera body 1 and controls the first focus adjustment unit 6 and the second focus adjustment unit 4.

Reference numeral 8 is a half mirror, 9 is an image pickup element, and 10 is a phase difference AF sensor.

The half mirror 8 divides the photographing light beam into an image sensor 9 and a phase difference AF sensor 10. With this configuration,
The imaging operation and the phase difference AF detection operation can be performed at the same time. 11 is an LCD panel for an electronic viewfinder having a built-in backlight, 12 is a finder optical system for observing the LCD panel 11, and 13 is a phase difference A.
The first focus evaluation unit 14 that calculates the amount of defocus from the output of the F sensor 10 is an image processing unit. Image processing unit 1
Reference numeral 4 processes the output signal of the image sensor 9, extracts the contrast information of the image, and performs white balance, γ processing, color matrix processing and the like to form a photographed image and an image for a finder. The viewfinder image formed by the image processing unit 14 is sent to the LCD panel 11, and the viewfinder image displayed on the LCD panel 11 is observed through the viewfinder optical system 12.

Reference numeral 15 denotes a second focus evaluation section, which is the image processing section 1.
The focus evaluation value is output by determining the history of contrast information obtained from No. 4. A camera control circuit 16 controls the entire digital still camera body 1. 1
A lens interface circuit 7 exchanges signals with the lens control circuit 7 of the interchangeable lens 2. Reference numeral 18 is a release switch. The image captured in response to the depression of the release switch 18 is stored in a non-volatile memory (not shown) or the like.

Next, the operation of the digital still camera having the above configuration will be described with reference to the flowchart of FIG.

When a power source (not shown) is turned on, step S
At 101, the camera control circuit 16 starts the initialization operation and sends an initial reset command to the lens control circuit 7 via the lens interface circuit 17. Upon receiving the initial reset command, the lens control circuit 7 moves the focus lens 3 to a predetermined position Xini (hereinafter, referred to as “reset position”) of the focus lens barrel 5 by the second focus adjustment unit 4. In this embodiment, it has moved to the center position. In step S102, the focus lens barrel 5
The position Xini of the focus lens 3 inside is stored in a memory (not shown) as the current position Xp of the focus lens. Here, it is remembered that it is the center.

In step S103, the release switch 18
The switch SW1 is turned on by pressing the button halfway or the like, and waits for an instruction to prepare for shooting. When the switch SW1 is turned on, the process proceeds to step S104, and the current position Xp of the focus lens 3 in the focus lens barrel 5 (Xp = Xini immediately after the power is turned on) is acquired, and the infinite
The range of movement in the closest direction is calculated. Here, the movable distance from the current position Xp of the focus lens 3 to the end of the infinite direction is Xinf, and the movable distance to the end of the closest distance is Xnear.

Next, in step S105, a signal is acquired from the phase difference AF sensor 10, and the first focus evaluation unit 13 calculates the defocus amount. From the defocus amount obtained in step S106, which is obtained when the first focus adjustment unit 6 and the second focus adjustment unit 4 perform individual focus adjustments to bring the defocus amount into the in-focus state? Calculate whether only drive is required. The calculated drive amount of the first focus adjustment unit 6 is X1, and the calculated drive amount of the second focus adjustment unit 4 is X2.

In step S107, the required drive amount X2 of the second focus adjustment unit 4 calculated in step S106 is added to the assumed error amount Xd of the phase difference AF and the confirmation amount Xaf corresponding to half of the range in which the contrast AF is performed. Then, by determining whether the value is within the movable range of the focus lens 3 in the focus lens barrel 5, it is determined whether or not focusing can be surely performed within the fine adjustment range. Here, when the value of X2 is in the infinite direction, (X2 + Xd + Xaf) <Xinf, X2
When the value of is in the close direction, it is determined whether or not (X2 + Xd + Xaf) <Xnear ”is movable.

The second focus adjusting unit 4 which satisfies the above relational expression
If the drive amount X2 of is included in the fine adjustment range, the process proceeds to step S114, and if it exceeds the fine adjustment range, the process proceeds to step S108.

In step S108, the focus lens barrel 5
The drive amount of X1 is corrected by the difference between the predetermined position (reset position) Xini of the focus lens 3 inside and the current position Xp inside the focus lens barrel 5. The final drive amount thus obtained is X1 '. In step S109, the final drive amount X1 ′ is sent to the lens control circuit 7. The lens control circuit 7 causes the first focus adjusting unit 6 to start driving the focus lens barrel 5.

If the second focus adjusting section 4 for fine adjustment is in the reset position Xini in step S110, step S1
Proceed to 13. On the other hand, if it is not at the reset position Xini, the process proceeds to step S111, and the lens interface circuit 17
A command for initial reset is sent to the lens control circuit 7 via. Upon receiving the initial reset command, the lens control circuit 7 moves the focus lens 3 to the reset position Xini of the focus lens barrel 5 by the second focus adjustment unit 4.

By the above operation, the reset operation of the focus lens 3 to the reset position Xini of the focus lens barrel 5 is performed in parallel while the focus lens barrel 5 is being driven. Further, since the drive amount X1 ′ of the focus lens barrel 5 takes into consideration the movement amount of the focus lens 3 due to the reset operation,
It also prevents the drive amount from becoming improper due to the reset operation. Next, in step S112, the current position Xp of the focus lens 3 in the focus lens barrel 5 (here,
Xp = Xini) is stored.

In step S113, if the drive of the drive amount X1 'is completed, the process returns to step S105, and if not completed, the drive is continued.

On the other hand, if it is determined in step S107 that the focus can be adjusted only by the fine adjustment, step S11
4, the range of ΔX before and after the detected final focus position is searched by the second focus adjustment unit 4, and the contrast AF is performed.
Of the second focus adjustment unit 4 at the optimum position.
To stop. Here, the search range is ΔX = Xd + Xaf, and is set to the minimum area that covers the detection error of the phase difference AF and that the peak can be confirmed during the contrast AF. The details of the fine adjustment processing in step S114 will be described later in detail with reference to the flowchart in FIG.

In step S115, it is judged whether or not the peak evaluation value obtained by the process shown in FIG. 3 which will be described later is a value obtained by contrast AF, and if it is a value obtained by contrast AF, it is obtained by contrast AF in step S117. If not, the process proceeds to step S116.

In step S116, for example, as shown in FIG. 5, a display indicating that the focus is achieved only by the phase difference AF is displayed.

In FIG. 5, reference numeral 24 is a shutter speed display, 25 is an aperture value display, 26 is a distance measurement area display, and 27 is a display showing that focusing is performed only by phase difference AF.

On the other hand, in step S117, for example, as shown in FIG.
A display indicating that focusing is performed by the contrast AF is performed as shown by. In FIG. 4, 20 is a shutter speed display, 21 is an aperture value display, 22 is a distance measurement area display, and 23 is
Is a display indicating that the image is focused by the contrast AF.

After the display in steps S116 and S117, the process proceeds to step S118.

Next, in step S118, the current position X of the focus lens 3 in the focus lens barrel 5 is determined.
Remember p.

After focusing according to the procedure described above, when photographing is instructed by fully pressing the release switch 18 or the like, photographing is performed in a normal photographing sequence in step S119. After the shooting is completed, the process returns to step S103.

FIG. 3 shows the second operation performed in step S114.
6 is a flowchart showing a procedure of a focus detection operation by the focus adjustment unit 4 of FIG.

First, in step S201, the contrast A
Set the F search range. Search range is step S
The lens position after the focus lens 3 is driven by the drive amount X2 obtained by the phase difference AF in 105 is set as the center position and ΔX before and after that. Note that ΔX is as described above.

In step S202, the second focus adjusting section 4 is controlled to move the focus lens 3 from the current position to the side closer to the end of the search range, and in step S203, the evaluation value of contrast AF is obtained at the position after the movement. take in.

In step S204, the evaluation value obtained in step S203 and the position of the focus lens 3 are stored as an evaluation value history.

In step S205, reference is made to the evaluation value history to check whether the focal point (peak value of evaluation values) has been passed. If it has passed, the process proceeds to step S208, and if it has not passed, the process proceeds to step S206.

In step S206, it is determined whether or not all the search range set in step S201 has been searched. If completed, the process proceeds to step S210. If there is a region to be searched, the process proceeds to step S207, and the second focus The position of the focus lens 3 is updated by controlling the adjusting unit 4. After updating, the process returns to step S203.

Steps S203 to S207
The peak search for contrast AF is performed by repeating the above process.

In step S208, the second focus adjusting section 4 is moved to the position showing the peak position from the evaluation value history,
In step S209, the peak evaluation value that is the result of the contrast AF is stored, the processing is terminated, and the process returns to the main routine.

On the other hand, if the process within the search range is completed (NO in step S206) without obtaining the in-focus point (peak value) (NO in step S205), step S2 is performed.
10, the center position of the search range, that is, the driving amount X
The focus lens 3 is moved by the second focus adjustment unit 4 to the position moved by 2. This is equivalent to moving to the position of the center value as a result of the phase difference AF.

In step S211, the fact that the contrast AF is disabled is stored, the processing is terminated, and the process returns to the main routine.

When the second and subsequent frames are photographed while the power is on, the determination in step S107 is made based on the current lens position Xp stored in step S118. Therefore, if the subject (or the camera) moves back and forth within a certain range, focus adjustment is possible only within the range of the second focus adjustment unit 4.

As described above, the first focus adjustment section 6 performs rough adjustment up to the vicinity of the in-focus position, and the second focus adjustment section 4 is used for the fine adjustment operation for final focus.

In the configuration of this embodiment, the first and second focus adjusting sections 6 and 4 are provided with different characteristics in order to achieve the above function. The second focus adjustment unit 4 eliminates the influence of backlash by performing biasing and finely sets the focus adjustment pitch. On the other hand, the first focus adjusting section 6 is set with high speed operation as the highest priority, and there is a large amount of backlash in order to reduce the driving load. The focus adjustment pitch is also coarse. Therefore, the amount of backlash when reversing is large,
Also, fine adjustment is no longer possible.

In the present invention, the first focus adjusting section 6 for coarse adjustment is used.
In order to properly use the second focus adjustment unit 4 and the second focus adjustment unit 4 for fine adjustment, the necessary movement amount detected by the phase difference AF means capable of detecting the absolute amount up to the expected focus position, and the stored fine adjustment possible range. When it is possible to make a fine adjustment, the second focus is adjusted without using the first focus adjusting unit 6 for coarse adjustment.
Focusing is attempted only by the focus adjustment unit 4 of. For this reason, it becomes possible to dispense with the use of the first focus adjusting section 6 which takes a longer drive time at the time of the small drive, at the time of the small drive, and the focusing time of the small drive is improved.

Further, in the first embodiment, the phase difference AF and the contrast AF are used together to increase the speed and accuracy, but when the contrast AF cannot be performed depending on the subject, the phase difference AF is performed. The focus is moved to the target position and the focus display mode is changed to notify the user. This allows the user to accurately determine the current focus state.

In the first embodiment, the current position of the focus lens 3 in the lens barrel 5 is stored, but the present invention is not limited to this, and the positive direction of the focus lens 3 in the lens barrel 5, The finely adjustable range due to movement in the opposite direction may be stored. (Second embodiment)

Next, a second embodiment of the present invention will be described. In the first embodiment, the fine adjustment is performed by driving the focus lens 3 inside the lens barrel 5.
In the second embodiment, the focus is finely adjusted by minutely driving the position of the image sensor, that is, the focal plane.

FIG. 6 is a view showing the arrangement of a lens-interchangeable digital still camera according to the second embodiment of the present invention.
The coarse adjustment actuator of the present invention on the interchangeable lens side,
An example in which a fine adjustment actuator is mounted on the camera body side is shown.

In FIG. 6, reference numeral 51 is a digital still camera body, and 52 is an interchangeable lens. The interchangeable lens 52 includes a focus lens 53, and the focus lens 53
Focus adjustment is performed by.

Reference numeral 54 is a first focus adjusting section for adjusting the focus lens 53 in the optical axis direction, and 55 is a lens control circuit for communicating with the digital still camera main body 51 and controlling the first focus adjusting section 54.

56 is a half mirror, 57 is an image sensor, and 5
A second focus adjustment unit 8 adjusts the image sensor 57 in the optical axis direction. Reference numeral 59 is a phase difference AF sensor. The half mirror 56 splits the photographing light flux into a light flux to the image sensor 57 and a light flux to the phase difference AF sensor 59. With this configuration, the imaging operation and the phase difference AF detection operation can be performed at the same time.

In the second embodiment, the first focus adjusting section 54 on the interchangeable lens side is used for coarse adjustment, and the second focus adjusting section 58 on the digital still camera body side is used for fine adjustment.

Reference numeral 60 is an LCD panel for an electronic viewfinder, which has a built-in backlight, 61 is a viewfinder optical system for observing the LCD panel 60, and 62 is a viewfinder optical system.
Is a first focus evaluation unit that calculates the amount of defocus from the output of the phase difference AF sensor 59, and 63 is an image processing unit.
The image processing unit 63 processes the output signal of the image sensor 57,
While taking out the contrast information of the image, white balance, γ processing, color matrix processing and the like are performed to form a photographed image and an image for a finder. The finder image formed by the image processing unit 63 is sent to the LCD panel 60, and the finder image displayed on the LCD panel 60 is observed via the finder optical system 61.

Reference numeral 64 denotes a second focus evaluation section, which is the image processing section 6
The focus evaluation value is output by determining the history of the contrast information obtained from No. 3.

A camera control circuit 65 controls the entire digital still camera body 51.

Reference numeral 66 is a lens interface circuit for exchanging signals with the lens control circuit 55 of the interchangeable lens 52. 67 is a release switch. The image taken in response to the depression of the release switch 66 is stored in a non-volatile memory (not shown) or the like.

The operation of the digital still camera having the above-mentioned structure is performed by the position sensor of the focus lens 3 in the lens barrel 5 among the operations described with reference to FIGS. 2 and 3 in the first embodiment. Since it is replaced with the position drive of No. 57, detailed description is omitted here.

Although the focus detection device and method in the digital still camera have been described in the first and second embodiments, the present invention is not limited to this, and the focus detection device and method of the present invention are not limited thereto. , Video cameras, video still cameras, single-lens reflex cameras, lens shutter cameras, surveillance cameras, and other types of imaging devices,
Furthermore, the invention can be applied to devices and methods applied to those imaging devices.

[0076]

Other Embodiments Even when the present invention is applied to a system including a plurality of devices (for example, a camera body, a lens unit, etc.), an apparatus including one device (for example,
It may be applied to a lens-integrated type digital camera or the like).

Further, an object of the present invention is to supply a storage medium (or recording medium) recording a program code of software for realizing the functions of the above-described embodiment to a system or apparatus, and to supply a computer of the system or apparatus ( Alternatively, by the CPU or MPU) reading and executing the program code stored in the storage medium,
It goes without saying that it will be achieved. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also based on the instruction of the program code,
An operating system (OS) running on the computer does some or all of the actual processing,
It goes without saying that the processing includes the case where the functions of the above-described embodiments are realized. Here, as the storage medium for storing the program code, for example, a floppy (registered trademark) disk, a hard disk, a ROM,
RAM, magnetic tape, non-volatile memory card, CD-
ROM, CD-R, DVD, optical disk, magneto-optical disk, MO, etc. are considered.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion card inserted in the computer or the function expansion unit connected to the computer, based on the instruction of the program code. , The CPU provided in the function expansion card or the function expansion unit performs some or all of the actual processing,
It goes without saying that the processing includes the case where the functions of the above-described embodiments are realized.

When the present invention is applied to the above storage medium, the storage medium stores the program code corresponding to the flowcharts shown in FIGS. 2 and 3 described above.

[0080]

As described above, according to the present invention, it is possible to prevent the adjustment speed from decreasing while improving the accuracy of focusing, and to speed up the focusing adjustment especially at the time of minute defocus.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an interchangeable lens type digital still camera according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the digital still camera according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a fine adjustment operation in the first embodiment of the present invention.

FIG. 4 is a diagram showing an example of an in-focus display according to the first embodiment of the present invention.

FIG. 5 is a diagram showing an example of a focus display according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of an interchangeable lens type digital still camera according to a second embodiment of the present invention.

[Explanation of symbols]

1,51 Digital still camera body 2,52 interchangeable lens 3,53 Focus lens 4, 58 Second focus adjustment unit 5 Focus barrel 6, 54 1st focus adjustment part 7,55 lens control circuit 8,56 Half mirror 9,57 Image sensor 10, 59 Phase difference AF sensor 11,60 LCD panel 12, 61 finder optical system 13, 62 First Focus Evaluation Section 14, 63 Image processing unit 15, 64 Second focus evaluation unit 16,65 Camera control circuit 17,66 lens interface circuit 18, 67 Release switch

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Claims (33)

[Claims] 1. An automatic focus adjusting method using a first adjusting means for coarsely adjusting a focal length and a second adjusting means for finely adjusting a focal length, which comprises a detection step of detecting a focused state. A determination step of determining whether or not an in-focus point exists within the range of the focal length adjustable by the second adjustment means based on the detection result of the detection step; and the second adjustment in the determination step. A fine adjustment step of fixing the first adjusting means and adjusting the focal length by the second adjusting means when it is determined that the in-focus point exists within the range of the focal length adjustable by the means. An automatic focus adjustment method characterized by the above. 2. The automatic focusing method according to claim 1, wherein the first adjusting unit moves a position of an optical element for focusing. 3. The automatic focus adjusting method according to claim 2, wherein the second adjusting means moves a position of an optical element for focus adjustment. 4. A step of storing the position of the optical element is further included, and a range of the focal length adjustable by the second adjusting means is moved from the position of the optical element stored in the step of storing. The automatic focusing method according to claim 3, wherein the range is a range obtained by subtracting a predetermined range from the possible range. 5. The method further comprises a storage step of storing a range of focal lengths adjustable by the second adjusting means, wherein the range of focal lengths adjustable by the second adjusting means is the current range of the optical element. From the range that can be moved from the position,
4. A range obtained by subtracting a predetermined range.
The automatic focus adjustment method described in. 6. The automatic focus adjusting method according to claim 2, wherein the second adjusting means moves a position of an image pickup device for converting an optical image of a photographing target into an electric signal. 7. A storage step of storing the position of the image pickup element, wherein a range of the focal length adjustable by the second adjusting means is moved from the position of the image pickup element stored in the storage step. 7. The automatic focus adjustment method according to claim 6, wherein the range is a range obtained by subtracting a predetermined range from the possible range. 8. The method further comprises a storage step of storing a range of focal lengths adjustable by the second adjusting means, wherein a range of focal lengths adjustable by the second adjusting means is a current range of the image pickup device. From the range that can be moved from the position,
7. A range obtained by subtracting a predetermined range.
The automatic focus adjustment method described in. 9. The detection step includes a phase difference detection step of detecting a focus state based on a phase difference, and the determination step makes a determination based on a detection result in the phase difference detection step. 9. The automatic focusing method according to claim 1, wherein: 10. The detecting step further includes a contrast detecting step of detecting a focused state based on contrast, and the second adjusting means adjusts a focal length based on a detection result in the contrast detecting step. The automatic focus adjustment method according to claim 9, wherein: 11. If the result of adjusting the focal length based on the detection result of the contrast detecting step is that the in-focus point reliability is low, the focal length is adjusted based on the detection result of the phase difference detecting step. The automatic focusing method according to claim 10, wherein 12. The automatic focus adjustment according to claim 10, further comprising a notification step of notifying which of the phase difference detection step and the contrast detection step the focal length is adjusted. Method. 13. The focal length is adjusted by the first adjusting means when the judging step judges that the in-focus point does not exist within the range of the focal length adjustable by the second adjusting means. The automatic focus adjustment according to any one of claims 1 to 12, further comprising a coarse adjustment step, wherein the detection by the detection step and the determination by the determination step are performed again after the execution of the coarse adjustment step. Method. 14. A first adjusting means for coarsely adjusting a focal length, a second adjusting means for finely adjusting a focal length, a detecting means for detecting an in-focus state, and a detecting result by the detecting means. Determining means for determining whether or not a focal point exists within the range of the focal length adjustable by the second adjusting means, and the determining means within the range of focal length adjustable by the second adjusting means. When it is determined that there is a focal point in
An automatic focus adjusting device, comprising: a control unit that fixes the first adjusting unit and controls the focal length by the second adjusting unit. 15. The first adjusting means moves the position of an optical element for focus adjustment.
4. The automatic focusing device according to 4. 16. The second adjusting means moves the position of an optical element for focus adjustment.
5. The automatic focusing device according to item 5. 17. A storage means for storing the position of the optical element is further provided, and the range of the focal length adjustable by the second adjusting means is moved from the position of the optical element stored in the storage means. The automatic focus adjustment device according to claim 16, wherein the range is a range obtained by subtracting a predetermined range from the possible range. 18. A storage means for storing a range of focal lengths adjustable by the second adjusting means, wherein the range of focal lengths adjustable by the second adjusting means is the current range of the optical element. From the range that can be moved from the position,
A range obtained by subtracting a predetermined range.
6. The automatic focusing device according to item 6. 19. The automatic focusing apparatus according to claim 15, wherein the second adjusting unit moves a position of an image pickup element for converting an optical image of a photographing target into an electric signal. 20. A storage unit that stores the position of the image sensor is further provided, and the range of the focal length adjustable by the second adjusting unit is moved from the position of the image sensor stored in the storage unit. 20. The automatic focus adjustment device according to claim 19, wherein the range is a range obtained by subtracting a predetermined range from the possible range. 21. A storage unit for storing the range of the focal length adjustable by the second adjusting unit, wherein the range of the focal length adjustable by the second adjusting unit is the current range of the image pickup device. From the range that can be moved from the position,
A range obtained by subtracting a predetermined range.
9. The automatic focusing device according to item 9. 22. The detecting means includes a phase difference detecting means for detecting a focus state based on a phase difference, and the judging means makes a judgment based on a detection result by the phase difference detecting means. Claims 14 to 2
1. The automatic focusing device according to any one of 1. 23. The detecting means further comprises a contrast detecting means for detecting an in-focus state based on a contrast, and the second adjusting means adjusts a focal length based on a detection result by the contrast detecting means. 23. The automatic focus adjustment device according to claim 22, wherein: 24. As a result of adjusting the focal length based on the detection result of the contrast detecting means, if the reliability of the in-focus point is low, the focal length is adjusted based on the detection result of the phase difference detecting means. 24. The automatic focus adjustment device according to claim 23. 25. The automatic focus adjustment according to claim 23, further comprising a notification unit for notifying which of the phase difference detection unit and the contrast detection unit the focal length is adjusted. apparatus. 26. When the determination means determines that there is no in-focus point within the range of the focal length adjustable by the second adjusting means, the control means causes the focal length by the first adjusting means. 26, and after the execution, the detection by the detecting means and the judgment by the judging means are controlled to be executed again.
The automatic focusing device according to any one of 1. 27. An image pickup apparatus, comprising: the automatic focus adjustment device according to claim 14; a camera body; and a lens unit detachable from the camera body. 28. The image pickup apparatus according to claim 27, wherein the first and second adjusting means are mounted on the lens unit. 29. The image pickup apparatus according to claim 28, wherein the first and second adjusting means move a position of an optical element for focus adjustment. 30. The image pickup apparatus according to claim 27, wherein the first adjusting means is mounted on the lens unit, and the second adjusting means is mounted on a camera body. 31. The camera body has an image sensor for converting an optical image of an object to be photographed into an electric signal, and the first adjusting means moves a position of the optical element for focus adjustment, 31. The image pickup apparatus according to claim 30, wherein the second adjusting unit moves a position of the image pickup element. 32. A program executable by an information processing device, having a program code for implementing the automatic focusing method according to claim 1. Description: 33. A storage medium storing the program according to claim 32.