JP2010169882A - Digital camera and optical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a more compact, high speed digital camera and optical equipment for making high precision AF control with respect to an object moving in an optical axis direction, wherein so-called mountain climbing AF is performed by driving an imaging element and high precision AF is performed at a high speed. <P>SOLUTION: The digital camera comprises: a photographing lens 20 including a focus lens 21, a lens driving part 22 and a lens control part 23; and a camera body 30 including a body control part 31, the imaging element 32 and an imaging element driving part 33. The body control part 31 is configured to calculate the focusing degree of the object image captured by the imaging element 32 as a focus evaluation value, then, control the movement of the focus lens 21 and the movement of the imaging element 32 based on the focus evaluation value so as to adjust the focus. The main control part 31 is configured to finely drive the imaging element 32 in the optical axis direction and detect the defocusing amount of the object upon the continuous AF of continuously performing the focus control during a release operation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement in automatic focusing in an optical apparatus such as a digital camera or a video camera.

  A conventional single-lens reflex camera (hereinafter abbreviated as a single-lens reflex camera) has a main mirror 2 and a sub mirror 3 in a camera body 1 as shown in FIG. In such a camera, when autofocus (hereinafter referred to as AF) is performed, a finder having a screen mat 6, a pentaprism 7, an eyepiece 8 and the like is caused to emit a light beam 17 from a subject (not shown) by these mirrors. Focus adjustment is performed by dividing the optical system 5 into a phase difference AF optical system 10 including a condenser lens 11, re-imaging lenses 12a and 12b, line sensors 13a and 13b, and the like. Further, at the time of shooting, these mirrors are retracted from the optical path, and a subject image is formed on the film or the image sensor 15.

  In the case of the above-described configuration, since the finder optical system 5 and the AF optical system 10 exist, there is a disadvantage that the camera becomes large. In the case of a digital single-lens reflex camera, the following method is adopted as a method for eliminating this drawback and reducing the size of the camera.

  In other words, using an imaging device such as a CCD for photographing, the focus lens in the photographing lens is driven at a predetermined interval to detect the high-frequency component of the subject image as the focus evaluation value, and the focus that maximizes the focus evaluation value The AF optical system 10 and the finder optical system 5 are abolished by performing focus adjustment by so-called hill-climbing AF for obtaining a lens position and displaying a photographed image on a liquid crystal monitor or the like disposed on the back surface of the camera. is there.

  However, in such a method, the conventional interchangeable lens is not configured to perform minute driving of the focus lens during hill-climbing AF. There is a problem that detection cannot be performed.

  In addition, even if the lens driving mechanism is an interchangeable lens suitable for the above-described hill-climbing AF, the apparatus becomes complicated due to an increase in control signal lines between the camera body and the interchangeable lens, or in the case of a large interchangeable lens. Since a large driving force is required, there arises a problem that power consumption increases.

  As an example of a method for solving such a problem, for example, as disclosed in Patent Document 1 below, an imaging unit including an imaging element is detected after a rough focus position is detected by driving a lens during focus adjustment. An autofocus method is known in which focus adjustment is performed by driving in the optical axis direction of a photographing lens.

JP 2008-46417 A

  However, in Patent Document 1 described above, both the focus lens and the imaging unit are driven, but focus control can be performed only on a stopped subject. Therefore, there is a problem that the control for performing the focus control continuously during the release operation cannot be realized.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a hill-climbing AF by driving an image pickup device in order to reduce the size of an optical device, increase the speed of AF, and increase the accuracy. A digital camera and an optical device capable of realizing AF control with high accuracy even for a subject moving in the optical axis direction in a smaller, faster, and higher-precision AF device. There is.

  That is, according to the first aspect of the present invention, a photographic lens having a focus lens for focus adjustment, a lens driving means for moving the focus lens in the optical axis direction, and a subject image formed through the photographic lens are obtained. Based on the focus evaluation value, an imaging unit driving unit that moves the imaging unit to be imaged in the optical axis direction, a focus evaluation unit that outputs the degree of focus of the subject image captured by the imaging unit as a focus evaluation value, and A focus control unit that performs focus adjustment by controlling the movement of the focus lens by the lens driving unit and the movement of the imaging unit by the imaging unit driving unit, and the focus control unit controls the imaging unit. A focus evaluation value is acquired by the focus evaluation means while being finely driven in the optical axis direction, and a focus shift amount of a moving object is detected based on the focus evaluation value.

  According to a second aspect of the invention, in the first aspect of the invention, the focus control means adjusts the focus by controlling the position of the focus lens in accordance with the amount of focus deviation. To do.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the focus control means is based on a plurality of point focus evaluation values obtained by minutely driving the imaging unit in the optical axis direction. Approximate calculation of the amount of focus deviation.

  The invention according to claim 4 is the invention according to claim 2 or 3, wherein the focus control means stores history information of the position and time of the focus lens by the focus adjustment operation, and the history information. Is used to perform a moving object prediction calculation and to adjust the focus of a moving subject.

  According to a fifth aspect of the present invention, there is provided a photographic lens unit having a focus lens for focus adjustment, a lens driving unit capable of moving the focus lens in the optical axis direction, and the photographic lens unit. An imaging unit that captures the subject image formed through the imaging lens unit, an imaging unit drive unit that moves the imaging unit in the optical axis direction, and focusing of the subject image captured by the imaging unit Is calculated as a focus evaluation value, and focus adjustment is performed by controlling movement of the focus lens by the lens driving unit and movement of the imaging unit by the imaging unit driving unit based on the focus evaluation value. A control unit that obtains a focus evaluation value by the focus evaluation unit while finely driving the imaging unit in the optical axis direction, and detects a focus deviation amount of a moving object based on the focus evaluation value. Characterized by comprising a main body portion that, the.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the control unit performs focus adjustment by controlling the position of the focus lens in accordance with the amount of focus deviation. .

  The invention according to claim 7 is the invention according to claim 5 or 6, wherein the control unit is based on a plurality of point focus evaluation values obtained by minutely driving the imaging unit in the optical axis direction. Approximate calculation of the amount of focus deviation.

  The invention according to claim 8 is the invention according to claim 6 or 7, wherein the control unit stores history information of the position and time of the focus lens by the focus adjustment operation, and stores the history information. It is characterized in that a moving object prediction calculation is performed to adjust the focus of a moving subject.

  According to the present invention, in order to reduce the size of an optical device, increase the speed and accuracy of AF, and perform hill-climbing AF by driving an image pickup device, a smaller, faster, and more accurate AF is performed. In the apparatus, it is possible to provide a digital camera and an optical apparatus capable of realizing AF control with high accuracy even for a subject moving in the optical axis direction.

It is a schematic diagram for demonstrating the autofocus operation | movement of the camera which concerns on one aspect | mode of this invention. It is a block diagram which shows the structure of the camera which concerns on one Embodiment of this invention. It is a flowchart for demonstrating one operation example of the imaging | photography sequence of the camera which concerns on one Embodiment of this invention. FIG. 3 illustrates an example of a relationship between a focus lens operation during hill-climbing AF and an imaging unit operation and a focus evaluation value according to an embodiment of the present invention, and (a) illustrates an example of a relationship between the focus lens operation and a focus evaluation value. FIG. 4B is a diagram illustrating an example of the relationship between the imaging unit operation and the focus evaluation value. It is the figure which showed the relationship between a focus evaluation value and an image pick-up element drive position. It is a figure for demonstrating AF operation | movement with respect to a moving subject. It is the figure which showed the drive condition of the focus lens when a focus detection operation | movement is carried out. It is a schematic diagram which shows the structure of the conventional single-lens reflex camera.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In this embodiment, when the first release switch is pressed, the focusing operation is performed. Even if it is determined that the focus is once in focus, if the movement of the subject is detected, the focus position is corrected according to the movement of the subject. A mode called normal continuous AF will be described.

  FIG. 1 is a schematic diagram for explaining an autofocus operation of a camera according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of the camera according to an embodiment of the present invention. FIG. 3 is a flowchart for explaining an example of the operation of the imaging sequence of the camera according to the embodiment of the present invention. FIG. 4 is a focus lens operation and imaging unit during hill-climbing AF according to the embodiment of the present invention. 2A and 2B illustrate an example of a relationship between an operation and a focus evaluation value. FIG. 3A illustrates an example of a relationship between a focus lens operation and a focus evaluation value. FIG. 3B illustrates an example of a relationship between an imaging unit operation and a focus evaluation value. FIG.

  In FIG. 1, a camera according to an embodiment of the present invention includes a photographic lens 20 and a camera main body 30 as a main body portion on which the photographic lens 20 is mounted.

  The photographic lens 20 includes various photographic optical systems, a focus lens 21 and the like, and is used to form a subject image on an image sensor 32 which is an imaging unit described later. The photographing lens 20 includes a focus lens 21, a lens driving unit (lens driver) 22 that is a lens driving unit for driving the focus lens 21, and a lens control unit 23 that is a lens control unit. Yes.

  The focus lens 21 is a focus adjusting lens that is moved in the direction of the optical axis 25 of the photographing lens 20 by the lens driving unit 22. The lens driving unit 22 is a lens driving unit that has an actuator such as a motor and drives the focus lens 21. The lens control unit 23 controls the movement of the lens driving unit 22 to move the focus lens 21 in accordance with an instruction from a main body control unit 31 described later.

  On the other hand, in the camera main body 30, a main body control unit 31 that is a control means (focus control means, focus evaluation means) that controls the entire camera operation, and an imaging means that can move in the direction of the optical axis 25 of the photographing lens 20. And an imaging element driving unit (imaging element driver) 33 which is an imaging element driving means for driving the imaging element 32, and the like. The main body control unit 31 performs operation control of various cameras such as drive control and calculation of the image sensor 32 and the focus lens 21.

  The image pickup device 32 is an image pickup means including a CCD sensor or the like for picking up a subject image formed by the taking lens 20. The image sensor 32 includes a position detection unit that detects the current position and transmits position information to the main body control unit 31. The image sensor 32 can be moved in the direction of the optical axis 25 of the photographic lens 20 by the image sensor drive unit 33. It has become. Further, the image sensor driving unit 33 has an actuator such as a motor, and controls the driving of the image sensor 32 by a control signal from the main body control unit 31.

  FIG. 2 is a block diagram showing a basic configuration of such a camera. In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 2, the camera body 30 includes a CPU (Central Processing Unit) 34, an A / D converter 35, an image processor 36, in addition to the image sensor 32 and the image sensor drive unit 33. A display unit 37 and a storage unit 38 are provided.

  The CPU 34 corresponds to the control unit (control means, focus control means) 31 and mainly manages all control operations in the camera body 30. The A / D conversion unit 35 is conversion means for converting an analog image signal output from the image sensor 32 into a digital image signal. Based on the digital image signal output from the A / D conversion unit 35, the image processing unit 36, which is an image processing unit, generates image data by image processing such as white balance correction, distortion correction, and image compression. A focus evaluation value is calculated by detecting a high frequency component of the signal (focus evaluation means). In accordance with an instruction from the CPU 34, the image data is displayed on the display unit 37, stored in the storage unit 38, re-image processing of the stored image data, and the like.

  The display unit 37 displays the live view image processed by the image processing unit 36 and the image data stored in the storage unit 38, and includes a liquid crystal panel, for example. The storage unit 38 is a storage unit for storing the image data processed by the image processing unit 36.

  In the camera having such a configuration, when the autofocus operation is started, first, as shown in FIG. 4A, the focus lens 21 in the photographing lens 20 is brought close by the lens driving unit 22. From the end position to the infinite position side, the photographing lens 20 is moved and stopped at a rough interval in the optical axis 25 direction. The focus evaluation value at each stop position is obtained from the high-frequency component of the subject image signal, and the lens drive is stopped when the peak of the focus evaluation value is detected.

  Next, as shown in FIG. 4B, when the above-described lens driving is performed along the optical axis 25 of the photographing lens 20 in the direction in which the imaging element 32 in the camera body 30 has a peak of the focus evaluation value. Moving and stopping are performed at finer intervals. Then, the focus evaluation value at each stop position is obtained, and finally, hill-climbing AF in which the image sensor 32 is driven to the peak position of the focus evaluation value is performed.

  Next, with reference to the flowchart of FIG. 3, the photographing operation of the camera according to the embodiment of the present invention will be described. The operation of the camera is mainly performed by the control of the CPU 34.

  This sequence is started when a power switch of a camera (not shown) is turned on. First, in step S1, an image (subject image) of a subject (not shown) formed on the image sensor 32 by the focus lens 21 is photoelectrically converted by the image sensor 32 and converted into an analog image signal. . Then, through image data is generated by the image processing unit 36 from the digital image signal obtained by A / D converting the analog image signal by the A / D conversion unit 35, and the generated through image is generated. An image corresponding to the data is displayed on the display unit 37.

  Next, in step S2, the focus lens 21 is driven by the lens driving unit 22, and the driving pitch when the focus evaluation value is detected depends on the shooting mode of the camera and the type of the shooting lens 20 (for example, focal length and Fno ( F number)). For example, regarding the shooting mode, in the portrait mode, the driving pitch is made fine to give priority to focusing accuracy, and in the continuous shooting mode, the driving pitch is made coarse to give priority to the focusing speed. Regarding the focal length of the photographic lens 20, the driving pitch is made finer on the wide angle side where the driving range of the focus lens 21 for adjusting the focus is narrow, and the driving pitch is made coarse on the telephoto side where the driving range is wide. Regarding the Fno of the photographing lens 20, in the case of a bright Fno lens, the drive pitch of the focus lens 21 is made finer, and in particular, the drive pitch of the image pickup device 32 which is an image pickup unit is made finer to improve the accuracy.

  In step 3, it is determined whether the power is turned off by a power switch (not shown) of the camera body 30. If the power is on, the process proceeds to step S4. If the power is turned off, the process proceeds to step S17.

  In step S4, it is determined whether or not a release switch (not shown) is turned on, that is, whether or not the first release switch (1st release SW) is turned on. If the first release switch is turned on, the process proceeds to step S5. If the first release switch remains off, the process proceeds to step S4.

  In step S5, the wobbling operation of the image pickup unit (detecting the in-focus direction by finely vibrating the image pickup device 32 as the image pickup unit in the optical axis direction) is performed, and the subject will be present. Direction is detected. For example, as shown in FIG. 5, the focus evaluation value at the current focus lens position and the focus when the image sensor 32 is moved back and forth by performing a wobbling operation from the closest side to the infinity side. An evaluation value can be calculated.

  If the focus evaluation value on the front side (infinite side) of the image sensor 32 is high (the state shown in FIG. 5), the subject position with respect to the subject that is not aimed at the current focus lens position is It is determined that there is an object to be aimed at on the rear side (infinite side), and the focus lens is driven to the rear feeding side (infinity side) (arrow in FIG. 5). Is done. If there is no clear difference in the focus evaluation values, first, the focus drive value is driven to the closest side.

  Next, in step S6, the imaging unit is set to the initial position. In this operation, the imaging unit is applied to either the closest end or the infinite end so that the entire driveable range of the imaging element 32 as the imaging unit can be driven only in one direction. The abutting side is based on the result of step S5, and is set in the direction in which the focus lens is driven in step S7 (when the focus lens is moved from the closest side to the infinite side, it is applied to the infinite end). .

  By doing so, the moving range of the imaging unit can be sufficiently taken, and the overshoot amount of the focus lens can be increased in step S7. That is, since the movement pitch of the focus lens can be made coarse, the focus time can be shortened.

  In Step S7, as shown in FIG. 4A, the lens control unit 23 and the lens driving unit 22 are controlled by the CPU 34, so that the focus lens 21 is moved in Step S6 at the driving pitch set in Step S2. It is moved in the detected direction. In step S7, the high frequency component of the image signal at each stop position is detected by the image processing unit 36 to obtain a focus evaluation value, and it is determined that the focus evaluation value at each stop position exceeds the peak. For example, the lens drive is stopped when the focus evaluation value at the current position becomes smaller than the focus evaluation value at the previous position, or when the focus evaluation value decreases two times in succession. With respect to the lens drive stop timing, the timing at which the imaging unit at the time of first focusing comes to the center of the movable range is targeted so as to facilitate the wobbling operation of the imaging unit performed in step S9 described later.

  Next, in step S8, as shown in FIG. 4B, the image pickup device driving unit 33 is controlled by the CPU 34, so that the image pickup device 32 has a finer pitch than that when the focus lens 21 is driven. It is driven from the infinite position side toward the closest position side. Then, when the high-frequency component of the image signal at each stop position is detected by the image processing unit 36 and a focus evaluation value is obtained, and it is determined that the focus evaluation value at each stop position exceeds the peak, the image sensor The image pickup device 32 is driven in the reverse direction by the drive unit 33 and stopped at a position where the focus evaluation value reaches a peak (mountain climbing AF). As a result, the subject is once focused. However, when the first release switch is turned off between steps S6 to S8 described above, the focus position detection operation is stopped, and although not shown, the process returns to step S4.

  Here, the reason why the image pickup device 32 is driven in order to obtain the final in-focus position is that the movement control of the image pickup device 32 can be performed by the camera body 30, and therefore the image pickup device 32 is moved at a constant speed. The focus evaluation value can be obtained in synchronization with the vertical synchronization signal of the image sensor 32 while acquiring the image sensor position in real time. Therefore, high-speed and high-precision AF is possible. In order to control the focus lens in the photographic lens, communication processing is required between the camera body 30 and the photographic lens 20, so the focus lens can be driven at a high speed, but the lens must be stopped once. This is because it is difficult to obtain highly accurate position information in real time.

  Next, processing for following the movement of the subject will be described in detail with reference to steps S9 to S14.

  In step S9, it should have been in focus in step S8 immediately before that, but when the subject is moving, it is necessary to correct the focus position. Therefore, the wobbling operation of the imaging unit is performed at regular time intervals, and the movement of the subject is detected from the result of the focus evaluation value.

  With reference to FIG. 6A, an AF operation for a moving subject will be described.

  First, AF is performed in the subject state immediately after the first release switch is turned on (the state indicated by the broken line in FIG. 6A) by the processing up to step S8. After that, when the subject comes to the photographer side, in FIG. 6A, the state is shown by a one-dot chain line, and is slightly out of focus.

  Therefore, a wobbling operation is performed, focus evaluation values at a plurality of front and rear positions are acquired, and the focus evaluation value is approximated by a quadratic expression, whereby the peak position of the current focus evaluation value is calculated.

  The calculation method is as follows.

To obtain a quadratic curve F = az ² + bz + c that passes closest to a plurality of points (F _i , z _i ) (i = 1, 2, 3,..., N), What is necessary is just to calculate each coefficient a, b, c which becomes the minimum. That is, it is only necessary to solve simultaneous equations obtained by setting the value of each expression obtained by partial differentiation of the residual sum of squares by each coefficient to 0. Here, z is the amount of movement of the imaging unit in the optical axis direction, and F is the focus evaluation value. In order to calculate the peak of the focus evaluation value, it is sufficient to have information on the focus evaluation value of about five points, so here n = 5.

The residual sum of squares S is
S = Σ (F _i −az _i ² −bz _i −c) ²
Therefore, when this is partially differentiated by each coefficient a, b, c,
∂S / ∂a = Σ (−2 (F _i −az _i ² −bz _i −c)) z _i ²
∂S / ∂b = Σ (−2 (F _i −az _i ² −bz _i −c)) z _i
∂S / ∂c = Σ (−2 (F _i −az _i ² −bz _i −c))
(I = 1 to n)
If the value of each expression is 0,
Σ (z _i ² F _i ) = aΣ (z _i ⁴ ) + bΣ (zi ³ ) + cΣ (z _i ² )
Σ (z _i F _i ) = aΣ (z _i ³ ) + bΣ (z _i ² ) + cΣ (z _i )
Σ (F _i ) = aΣ (z _i ² ) + bΣ (zi) + cn
In the above formula,
Σ (z _i ) = A, Σ (F _i ) = B, Σ (z _i F _i ) = C, Σ (z _i ² ) = D
Σ (z _i ³ ) = E, Σ (z _i ⁴ ) = F, Σ (z _i ² F _i ) = G
Then,
G = aF + bE + cD
C = aE + bD + cA
B = aD + bA + cn
Solving the above simultaneous equations for a, b, and c,
a = ((AB-Cn) (D 2 -AE) - (DC-AG) (A 2 -Dn))
/ ((AD-En) ( D 2 -AE) - (DE-AF) (A 2 -Dn))
b = ((DC-AG) -a (DE-AF)) / (D 2 -AE))
c = (B−bA−aD) / n
It becomes.

  The defocus amount is directly used as the defocus amount by calculating the position Z of the imaging unit where the focus evaluation value reaches a peak.

  Here, since Z = b / 2a, by substituting the values of a and b in the above equation, it is possible to calculate the imaging unit position Z at which the focus evaluation value peaks.

  In step S10, the defocus amount is calculated by the above-described method, whereby the difference (defocus amount) between the first AF element position that is first AF and the current focus position can be calculated. Here, in order to accurately calculate the defocus amount, it is desirable that the driving method has no backlash. Therefore, it is desirable to use an ultrasonic motor capable of linear driving with less backlash as the motor for driving the image sensor.

  Next, in step S11, since the subject position has changed by this defocus amount, the focus lens is driven by the amount of deviation (in this embodiment, it is driven to the nearest side).

  Here, the reason why the focus lens is driven to cope with the change in the subject position is that the imaging element can move at high speed and with high accuracy, but the movement range is very small. Therefore, the driving of the moving subject is realized by moving the focus lens capable of moving at a high speed and in a wide range.

  Further, as shown in FIG. 6B, even when the amount of movement of the subject is large and the peak position of the focus evaluation value cannot be calculated, the focus evaluation value is approximated by a quadratic expression to obtain the peak position of the focus evaluation value. By calculating, the defocus amount is calculated, and the focus lens is driven in step S11 to perform focusing.

  In step S12, the driving amount of the focus lens driven in step S11 and the time for wobbling are stored. By repeating the control operations in steps S9 to S12, the driving history of the focus lens when the focus detection operation is performed can be left as shown in FIG.

  If the second release switch (2nd release SW) is pressed in step S13, the process exits the loop of steps S9 to S12 described above and proceeds to step S14. However, there is a possibility that the subject has already moved when the imaging operation is performed, and the focus lens position is not appropriate. Therefore, in accordance with the drive history stored in step S12, the optimum focus lens position at the imaging timing is predicted in step S14, and the focus lens is predicted to be driven.

  Thereafter, when the second release switch is pressed, in step S15, imaging is performed at the stop position of the image sensor 32 detected by the hill-climbing AF in step S8. By this imaging, an analog image signal obtained by photoelectric conversion in the image sensor 32 is converted into a digital image signal by the A / D converter 35, and further, various filter processes and white balance are performed in the image processor 36. Image processing such as correction and image compression is performed to generate image data. In step S16, the image data generated in step S8 is stored in the storage unit 38. Thereafter, the process shifts to step S4, and shifts to the photographing standby state again.

  On the other hand, when the power is turned off in step S3, the process proceeds to step S17, and predetermined end processing such as saving various data and disconnecting the power supply system is executed. Thereafter, this sequence ends.

  In the present embodiment, the predicted focus lens position is calculated based on the history information of the focus lens position, but the history information of the imaging unit position Z (defocus amount) is stored and predicted based on this. The defocus amount may be calculated, and the moving body prediction drive may be performed based on the predicted defocus amount in step S14 of FIG.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, or some constituent requirements shown in the embodiment are combined, it is described in the column of the problem to be solved by the invention. When the problem can be solved and the effect described in the column of the effect of the invention can be obtained, the configuration from which this constituent requirement is deleted can be extracted as the invention.

  According to the present invention, in order to reduce the size of an optical device, increase the speed and accuracy of AF, and perform hill-climbing AF by driving an image pickup device, a smaller, faster, and more accurate AF is performed. In the apparatus, AF control can be realized with high accuracy even for a subject moving in the optical axis direction.

  DESCRIPTION OF SYMBOLS 20 ... Shooting lens, 21 ... Focus lens, 22 ... Lens drive part (lens driver), 23 ... Lens control part, 30 ... Camera body, 31 ... Main body control part, 32 ... Imaging element, 33 ... Imaging element drive part (Imaging) (Element drivers), 34... CPU (central processing unit), 35... A / D converter, 36... Image processor, 37.

Claims (8)

A photographic lens with a focus lens for focus adjustment;
Lens driving means for moving the focus lens in the optical axis direction;
An image pickup unit driving means for moving an image pickup unit for picking up a subject image formed through the photographing lens in the optical axis direction;
Focus evaluation means for outputting the degree of focus of the subject image captured by the imaging unit as a focus evaluation value;
A focus control means for performing focus adjustment by controlling movement of the focus lens by the lens driving means and movement of the imaging section by the imaging section driving means based on the focus evaluation value;
Comprising
The focus control unit is configured to acquire a focus evaluation value by the focus evaluation unit while finely driving the imaging unit in the optical axis direction, and detect a focus deviation amount of a moving object based on the focus evaluation value. A digital camera.   The digital camera according to claim 1, wherein the focus control unit performs focus adjustment by controlling a position of the focus lens in accordance with the focus shift amount.   3. The digital image according to claim 1, wherein the focus control unit approximately calculates a focus shift amount from a plurality of focus evaluation values obtained by minutely driving the imaging unit in the optical axis direction. camera.   The focus control unit stores history information of the position and time of the focus lens by the focus adjustment operation, performs a moving object prediction calculation using the history information, and performs focus adjustment of a moving subject. The digital camera according to claim 2 or 3. A photographic lens unit having a focus lens for focus adjustment, and a lens driving unit capable of moving the focus lens in the optical axis direction;
An imaging unit that mounts the imaging lens unit and that captures a subject image formed through the imaging lens unit, an imaging unit drive unit that moves the imaging unit in the optical axis direction, and the imaging The focus degree of the subject image captured by the image pickup unit is calculated as a focus evaluation value, and the focus lens is moved by the lens drive unit based on the focus evaluation value, and the image pickup unit is moved by the image pickup unit drive unit. The focus evaluation value is acquired by the focus evaluation means while finely driving the imaging unit in the optical axis direction, and the amount of focus deviation of the moving subject is determined based on the focus evaluation value. A main body having a control unit for detecting;
An optical apparatus comprising:   The optical apparatus according to claim 5, wherein the control unit performs focus adjustment by controlling a position of the focus lens in accordance with the focus shift amount.   The optical control according to claim 5 or 6, wherein the control unit approximately calculates an amount of focus deviation from a plurality of focus evaluation values obtained by minutely driving the imaging unit in the optical axis direction. machine.   The control unit stores history information of the position and time of the focus lens by the focus adjustment operation, performs moving object prediction calculation using the history information, and performs focus adjustment of a moving subject. Item 8. The optical device according to Item 6 or 7.

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