JP2014102298A - Imaging apparatus, control program for imaging apparatus, and method for controlling imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which is capable of obtaining a focused image at high probability, without being affected by a photographing condition, while performing high-speed consecutive photographing, without reducing a consecutive photographing speed, when an object is consecutively photographed.SOLUTION: In the consecutive photographing of a camera system, time-series data 151 of a focusing position based on a range-finding result is collected to determine a prediction straight line L, while a release button is half-depressed (T<t<T) and a prediction focusing position 152 is determined based on the prediction straight line Land exposure timings (Tto T), after the release button is fully depressed (T<t), to perform the consecutive photographing, so that it is not necessary to perform focusing arithmetic operation during the consecutive photographing and when the object is consecutively photographed, the focused image is obtained at the high probability, without being affected by the photographing condition, while performing the high-speed consecutive photographing, without reducing the consecutive photographing speed.

Description

  The present invention relates to an imaging apparatus, an imaging apparatus control program, and an imaging apparatus control method.

Conventionally, as a function to be used when it is difficult to obtain an image in focus at the position desired by the photographer with normal autofocus or manual focus, the position of the focus adjustment lens is changed by a predetermined amount. However, a focus bracket function that performs continuous shooting is known.
In addition, when performing conventional focus bracket shooting, it is necessary for the photographer to manually set shooting conditions such as the amount of change of the focus adjustment lens position and the number of shots. As a measure for eliminating the complexity of the setting operation, Patent Document 1 describes the amount of change in the focus adjustment lens position and the number of shots in consideration of the depth of field determined by the subject distance range, the aperture value, and the like. A method of automatically performing focus bracket shooting with automatic determination on the side is disclosed.

JP 2004-333924 A

However, the conventional focus bracket shooting and the techniques disclosed in the above prior art assume that the subject is stationary, and the shooting is performed when the subject is moving or under shooting conditions such as camera shake. There is a technical problem that it is difficult to take an image as intended by a person.
In addition, as a shooting mode for continuously shooting a moving subject, a continuous autofocus (AF) continuous shooting mode is known. When this shooting mode is set, the release button of the imaging device is used. The focusing lens position based on the distance measurement result is stored as time-series data during half-pressing or continuous shooting, and the focusing lens position at the time of exposure is predicted from this time-series data, and the focus adjustment lens Since shooting is performed while driving the image, it is possible to acquire an image in which the moving subject is in focus.
However, in the above-described conventional continuous shooting mode, the distance measurement operation is performed even during continuous shooting, so the focus adjustment lens position is fixed when the release button is fully pressed without performing the distance measurement operation during continuous shooting. Thus, there is a technical problem that the continuous shooting speed is reduced as compared with the case where continuous shooting is performed.
An object of the present invention is to obtain a focused image with high probability without being affected by shooting conditions, while performing high-speed continuous shooting without reducing the continuous shooting speed when continuously shooting a subject. It is to provide possible technology.

According to a first aspect of the present invention, there is provided a focus detection means for detecting a focus position of the focus adjustment lens based on an image of a subject by a light beam transmitted through a photographing lens including a focus adjustment lens;
In-focus position detection instruction means for instructing the focus detection means to detect the in-focus position;
Photographing instruction means for instructing execution of photographing of the subject by causing the light flux transmitted through the photographing lens to enter an imaging element;
When the detection of the in-focus position is instructed by the in-focus position detection instructing means, the in-focus position of the focus adjustment lens continuously detected by the focus detecting means and the detection timing of the in-focus position are time-series. Storage means for storing in,
Predicting means for predicting a focus position at the time of exposure to the image sensor after an instruction for photographing is performed by the photographing instruction means based on the in-focus position stored in the storage means and the detection timing; ,
With
The predicting means corresponds to the in-focus position and the detection timing of the focus adjustment lens stored in the storage means in correspondence with a period in which the in-focus position detection instruction means instructs the detection of the in-focus position. Predicting a focus position at the time of exposure of the image sensor based on at least a part of the focus position and the detection timing,
The shooting instruction unit drives the focus adjustment lens to the in-focus position predicted by the prediction unit every time shooting is performed, and instructs shooting.
An imaging device is provided.

According to a second aspect of the present invention, there is provided a focus detection means for detecting a focus position of the focus adjustment lens based on an image of a subject by a light beam transmitted through a photographing lens including a focus adjustment lens,
In-focus position detection instruction means for instructing the focus detection means to detect the in-focus position;
Photographing instruction means for instructing execution of photographing of the subject by causing the light flux transmitted through the photographing lens to enter an imaging element;
Control means for controlling focus bracket shooting for shooting the subject while changing the in-focus position;
A control program for a photographing apparatus including:
The control program is
The focus position of the focus adjustment lens and the detection timing of the focus position continuously detected by the focus detection means within a period instructed to detect the focus position by the focus position detection instruction means. A prediction step for generating prediction information for predicting a focus position at the time of exposure to the image sensor after an instruction for shooting is performed based on the shooting instruction unit;
Taking the shooting instruction from the shooting instruction unit as a trigger, shooting for instructing shooting by driving the focus adjustment lens to the in-focus position based on the prediction information every time the exposure of the focus bracket shooting is performed. Steps,
Causing the control means to execute,
A control program for an imaging apparatus is provided.

According to a third aspect of the present invention, there is provided a focus detection means for detecting a focus position of the focus adjustment lens based on an image of a subject by a light beam transmitted through a photographing lens including a focus adjustment lens,
In-focus position detection instruction means for instructing the focus detection means to detect the in-focus position;
Photographing instruction means for instructing execution of photographing of the subject by causing the light flux transmitted through the photographing lens to enter an imaging element;
Control means for controlling focus bracket shooting for shooting the subject while changing the in-focus position;
A method of controlling an imaging apparatus including:
The control means includes
The focus position of the focus adjustment lens and the detection timing of the focus position continuously detected by the focus detection means within a period instructed to detect the focus position by the focus position detection instruction means. Generating prediction information for predicting the in-focus position at the time of exposure to the imaging device after the shooting instruction is given by the shooting instruction means based on
Triggered by the shooting instruction from the shooting instruction means, the focus adjustment lens is driven to the in-focus position based on the prediction information every time the focus bracket shooting is performed, and shooting is performed.
A method for controlling an imaging apparatus is provided.
According to a fourth aspect of the present invention, there is provided a control method for an image pickup apparatus, wherein preparation for shooting is performed by half-pressing a release button, and exposure is performed by full-pressing the release button,
A first step of generating prediction information of the in-focus position based on a plurality of in-focus positions and a distance measurement timing based on a distance measurement result during a half-press period of the release button;
A second step of performing continuous shooting by repeating a plurality of exposures while changing a focus position of the focus adjustment lens based on the prediction information and an execution time of the exposure when the release button is fully pressed; ,
A method for controlling an imaging apparatus including the above is provided.

  According to the present invention, when continuously shooting a subject, it is possible to obtain a focused image with high probability without being affected by shooting conditions while performing high-speed continuous shooting without reducing the continuous shooting speed. Possible technology can be provided.

It is a conceptual diagram of the structural example of the camera system as an imaging device which concerns on this invention. It is a block diagram which shows the structural example of the control system of the camera system as an imaging device which concerns on this invention. It is a conceptual diagram which shows the structural example of AF unit with which the camera system as an imaging device was equipped. It is a conceptual diagram which shows the exit pupil plane in AF unit of a photographic lens. It is a front view of the visual field mask which comprises AF unit. It is a front view of the separator stop which comprises AF unit. It is a front view of the separator lens which comprises AF unit. It is a front view of the AF sensor which comprises AF unit. It is a conceptual diagram which shows the example of arrangement | positioning of the ranging area in the imaging | photography screen of the camera using the AF unit which concerns on embodiment of this invention. It is a flowchart for demonstrating an example of imaging | photography operation | movement of the camera system as an imaging device which concerns on this invention. It is a diagram for demonstrating an example of the moving body prediction and imaging | photography sequence in the imaging device which concerns on this invention. It is an image figure for demonstrating an example of an operation | movement in case the focus position detection in the imaging device which concerns on this invention is performed by hill-climbing AF. It is explanatory drawing of an example of the focus position detection method in hill-climbing AF in the imaging device which concerns on this invention. It is a diagram for demonstrating an example of the imaging | photography sequence based on the back-and-forth blur prediction in the imaging device which concerns on this invention. It is a flowchart for demonstrating an example of the imaging | photography operation | movement which concerns on Embodiment 3 of this invention.

In the embodiment of the present invention exemplified below, as one aspect, in a camera system having a release button that is a two-stage switch composed of a general 1R switch and 2R switch, when the release button is half-pressed (1R is ON) Based on the in-focus position of the focus adjustment lens obtained continuously during the period (2), the in-focus position in each frame in continuous shooting after the release button is fully pressed (2R is ON) is predicted. A technique for performing continuous shooting for a preset number of frames while driving a focus adjustment lens to a focal position is disclosed.
In addition, it is estimated whether the change in focus position during the period when 1R is ON is due to movement of the subject or due to camera shake (position shift of the camera system in the optical axis direction), and a prediction method according to the estimation result Is switched.
Further, if the focus evaluation value becomes a predetermined value or less during continuous shooting, the continuous shooting operation is stopped.
In addition, the photographer can arbitrarily select the number of continuous frames to be executed when 2R is turned on.
As a result, according to the present embodiment, when a moving subject is continuously shot, it is possible to obtain a focused image with high probability while performing high-speed continuous shooting (as compared to the normal continuous AF continuous shooting mode). A possible imaging device can be provided.
In addition, an imaging apparatus capable of obtaining a focused image with high probability while performing continuous shooting at a high speed (in comparison with the normal continuous AF continuous shooting mode) even if camera shake occurs during continuous shooting. Can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
In the first embodiment, as an example, continuous shooting is performed by predicting a change in the focus position of the moving subject by linear approximation or the like from the focus position of the focus adjustment lens 203 continuously acquired when the release button 106 is half-pressed. The case where it performs is demonstrated.
FIG. 1 is a conceptual diagram of a configuration example of a camera system as an imaging apparatus according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a control system of a camera system as an imaging apparatus according to the present invention.
As illustrated in FIG. 1, a camera system 100 (imaging device) according to the present embodiment includes a camera body 101 and an interchangeable lens 201 (photographing lens) connected to the camera body 101 in an interchangeable manner. .

  The camera body 101 includes a camera control circuit 102, an image sensor 103, a focal plane shutter 104, a display monitor 105, a release button 106, a battery 107, a main mirror 108, a sub mirror 109, and a focus detection unit (hereinafter referred to as an AF unit) 110. , A screen mat 111, a finder optical system 112, an eyepiece lens 113, and the like.

  The camera control circuit 102 controls the image sensor 103, the focal plane shutter 104, the main mirror 108, the sub mirror 109, and the AF sensor in the AF unit 110 (focus detection means) according to the operation of the release button 106 by the photographer. At the same time, a shooting operation is executed by performing various drive controls of the interchangeable lens 201 through the lens control circuit 202, and display control of the display monitor 105 is performed according to various camera operations.

  The imaging element 103 is configured by a CCD, a CMOS sensor, or the like, and captures a subject image formed on the imaging surface by the optical system of the interchangeable lens 201.

  The focal plane shutter 104 performs an exposure operation on the image sensor 103 by opening and closing in accordance with an instruction from the camera control circuit 102 according to the operation of the release button 106 by the photographer. In a through image display described later, the focal plane shutter 104 is opened.

  The display monitor 105 is composed of a liquid crystal, an organic EL, or the like, and displays a through image display at the time of moving image shooting, a display of a playback image, setting information, etc. according to an operation of a playback button (not shown) and various setting means by the photographer. .

The release button 106 is operated by a photographer to cause the camera system 100 in which the interchangeable lens 201 is mounted on the camera body 101 to perform photographing operations such as automatic exposure (AE), automatic focusing (AF), and exposure. It is a switch.
The battery 107 is a power source that supplies power to the camera body 101 and the interchangeable lens 201.

  The main mirror 108 is composed of a half mirror, transmits a part of the light beam from the subject to the image sensor 103 side, reflects a part to the viewfinder optical system 112 side, and at the time of exposure to all the subjects. The light beam can be rotated and retracted in the direction indicated by the arrow in FIG. 1 so that the light beam enters the imaging surface of the image sensor 103.

  The sub mirror 109 is configured by a total reflection mirror, reflects a part of the light beam from the subject transmitted through the main mirror 108 to the AF unit 110 side, and the total light beam of the subject is reflected on the imaging surface of the image sensor 103 at the time of exposure. In order to enter, the main mirror 108 is integrally rotated with the direction shown by the arrow in FIG.

The AF unit 110 re-images the subject light beam reflected by the sub mirror 109 on the internal AF sensor light receiving unit. A detailed configuration example of the AF unit 110 will be described later.
The screen mat 111 is an optical member on which a subject image is formed by a subject light beam reflected by the main mirror 108.

The finder optical system 112 is an optical system such as a prism for guiding the subject image formed on the screen mat 111 to the finder eyepiece.
The eyepiece 113 magnifies and displays the subject image guided to the finder eyepiece by the finder optical system 112 at a predetermined magnification.

On the other hand, the interchangeable lens 201 includes a lens control circuit 202, a focus adjustment lens 203, a zoom lens 204, a diaphragm 205, and the like.
The lens control circuit 202 performs drive control of the focus adjustment lens 203, the zoom lens 204, and the diaphragm 205 according to an instruction from the camera control circuit 102.

  The focus adjustment lens 203 moves in the direction of the optical axis O in response to an instruction from the lens control circuit 202 according to a focus ring operation (not shown) by the photographer or a request from the camera control circuit 102, and the focus state of the interchangeable lens 201 Adjust.

  The zoom lens 204 moves in the direction of the optical axis O according to a zoom ring operation (not shown) by the photographer or an instruction from the lens control circuit 202 in response to a request from the camera control circuit 102, and the focal length of the interchangeable lens 201 is changed. Make a change.

  The aperture 205 adjusts the amount of subject light incident on the camera body 101 by changing the aperture area according to an aperture operation (not shown) by the photographer or an instruction from the lens control circuit 202 in response to a request from the camera control circuit 102. To do.

On the extension of the optical axis O of the interchangeable lens 201, the main mirror 108, the focal plane shutter 104, and the image sensor 103 are positioned.
An example of a control system of the camera system 100 of the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration example of a control system of the camera system according to the present invention.

  The main body CPU 121 (control means) includes a flash ROM 122, a RAM 123 (storage means), an image sensor control circuit 124, an image processing circuit 125, a shutter control circuit 126, a display circuit 127, a strobe control circuit 128, an operation switch detection circuit 129, and a power supply circuit. 130, a camera main body communication circuit 131, an AF sensor control circuit 134, and the like are connected to control the entire camera system 100.

The flash ROM 122 is a rewritable nonvolatile semiconductor memory, and stores a control program 121P (prediction means) for the main body CPU 121 (hereinafter referred to as FROM).
The RAM 123 is configured by a semiconductor memory such as a DRAM, for example, and provides a storage area for temporarily storing various information of the main body CPU 121.

  The imaging element control circuit 124 performs an imaging operation for converting a subject image formed on the imaging element 103 into an image signal when performing an operation of a process that requires image data such as through image display and exposure. 103.

The image processing circuit 125 performs processing such as generation of image data that is subjected to image processing such as A / D conversion and filter processing on the image signal output from the image sensor 103 and stored as a captured image.
The shutter control circuit 126 controls the opening / closing operation of the focal plane shutter 104.

The display circuit 127 performs display control for displaying a through image, a captured image, various types of captured information, a menu, and the like on the display monitor 105.
The strobe control circuit 128 controls charging and light emission of a built-in strobe (not shown).

  The operation switch detection circuit 129 includes a switch (not shown) that switches the shooting mode of the camera of the camera body 101 operated by the photographer, a first release switch 132 that operates by operating the release button 106, a second release switch 133, and the like. Various operation switches are connected, and the state of each switch is detected and transmitted to the main body CPU 121.

The power supply circuit 130 supplies power to the camera by smoothing or boosting the voltage of the loaded battery 107.
The camera body communication circuit 131 implements a communication interface for communicating with the lens CPU 221 via the lens communication circuit 231.

  A first release switch 132 (hereinafter referred to as a 1R switch) is turned on by half-pressing a release button 106 which is a general two-stage switch. When the operation switch detection circuit 129 detects the ON state of the first release switch 132, the main body CPU 121 executes AE, AF operation, and the like.

  The second release switch 133 (hereinafter referred to as a 2R switch) is turned on when the release button 106, which is a general two-stage switch, is fully pressed. When the ON state of the second release switch 133 is detected by the operation switch detection circuit 129, the main body CPU 121 executes an exposure operation such as retraction of the main mirror 108 and the sub mirror 109 from the optical path and opening / closing of the focal plane shutter 104. .

  The AF sensor control circuit 134 controls the AF sensor 148 in accordance with an instruction from the main body CPU 121, and executes an imaging operation for converting the subject image formed on the AF sensor 148 into an image signal. Thus, the subject image data to be used for the distance measurement calculation is acquired.

  On the other hand, on the interchangeable lens 201 side, the lens CPU 221 includes a FROM 222, a RAM 223, a focus adjustment lens drive circuit 224, a focus adjustment lens position detection circuit 225, a zoom lens drive circuit 226, a zoom lens position detection circuit 227, and an aperture drive circuit 228. And a lens communication circuit 231 and the like are connected.

  The lens CPU 221 performs various drive controls such as lens drive and diaphragm drive, and communicates with the main body CPU 121 via the lens communication circuit 231 and the camera main body communication circuit 131 to receive an operation command and the lens of the interchangeable lens 201. The operating state and optical data stored in the FROM 222 are transmitted.

  The flash ROM 222 is a rewritable nonvolatile semiconductor memory, and stores lens data such as lens identification data and optical data to be transmitted to the control program 221P of the lens CPU 221 and the main body CPU 121.

The RAM 223 is configured by a semiconductor memory such as a DRAM, and provides a storage area for temporarily storing various information of the lens CPU 221.
The focus adjustment lens drive circuit 224 includes an actuator such as a stepping motor, a motor driver, and the like, and performs drive control of the focus adjustment lens 203.

  The focus adjustment lens position detection circuit 225 converts the rotation amount of the drive motor included in the focus adjustment lens drive circuit 224 into the number of pulses, and the absolute position of the focus adjustment lens 203 is the number of pulses from a reference position such as an infinite end. A position of a focus adjustment lens 203 that is configured to include a photo interrupter (PI) circuit and the like that is driven by a focus adjustment lens drive circuit 224 is detected.

  The zoom lens driving circuit 226 includes an actuator such as a stepping motor, a motor driver, and the like, and controls driving of the zoom lens 204.

  The zoom lens position detection circuit 227 includes a linear encoder, an A / D conversion circuit, and the like, and the position of the zoom lens 204 driven by the zoom lens drive circuit 226 based on the A / D conversion result of the encoder value. Perform detection.

  The diaphragm drive circuit 228 includes an actuator such as a stepping motor, a motor driver, and the like, and controls the opening operation of the diaphragm 205.

  The lens communication circuit 231 has a communication connection terminal provided outside the interchangeable lens 201. The lens communication circuit 231 receives a drive command for the focus adjustment lens 203, the zoom lens 204, and the diaphragm 205 from the main body CPU 121, lens position information, an operation state, A communication interface for transmitting lens data or the like to the main body CPU 121 is realized.

Next, a configuration example of the AF unit 110 provided in the camera system 100 of the present embodiment will be described.
FIG. 3A is a conceptual diagram illustrating a configuration example of an AF unit provided in a camera system as an imaging apparatus. FIG. 3B is a conceptual diagram showing an exit pupil plane in the AF unit of the photographing lens. FIG. 3C is a front view of a field mask constituting the AF unit. FIG. 3D is a front view of a separator diaphragm constituting the AF unit. FIG. 3E is a front view of a separator lens constituting the AF unit. FIG. 3F is a front view of the AF sensor constituting the AF unit.

  As illustrated in FIG. 3A, the AF unit 110 of the present embodiment includes a field mask 142, a condenser lens 143, a total reflection mirror 144, an infrared cut filter 145, a separator diaphragm 146, a separator lens 147, and an AF sensor 148. Including a focus detection optical system.

The primary imaging plane 141 immediately before the field mask 142 is at a distance equivalent to the imaging plane of the imaging element 103.
As illustrated in FIG. 3C, the field mask 142 has an opening 142a for narrowing the subject light beam 301 guided through the sub mirror 109 and transmitting the light beam 302 (dotted line in the drawing) necessary for focus detection. Have.

The condenser lens 143 is disposed corresponding to the position of the opening 142 a of the field mask 142 in order to collect the light that has passed through the field mask 142.
The total reflection mirror 144 is installed so as to reflect the light beam collected by the condenser lens 143 and guide it toward the separator diaphragm 146.

The infrared cut filter 145 cuts an infrared light component harmful to focus detection included in the light beam condensed by the condenser lens 143.
As illustrated in FIG. 3D, the separator diaphragm 146 has four openings 146a, 146b, 146c, and 146d for dividing the light beam collected by the condenser lens 143 into four light beams.

  As illustrated in FIG. 3E, the separator lens 147 re-images the light beam divided by the separator diaphragm 146 on the light receiving unit 148a, the light receiving unit 148b, the light receiving unit 148c, and the light receiving unit 148d of the AF sensor 148. The four light receiving lenses 147a, 147b, 147c, and 147d.

  As illustrated in FIG. 3F, the AF sensor 148 includes a light receiving unit 148a including a plurality of photoelectric conversion element arrays that output a light intensity signal corresponding to the light intensity distribution of the subject image re-imaged by the separator lens 147. 148b, 148c, and 148d.

  The photoelectric conversion element arrays of the light receiving units 148a and 148b of the AF sensor 148 are arranged in a direction corresponding to the horizontal direction of the imaging screen, and the photoelectric conversion element arrays of the light receiving units 148c and 148d correspond to the vertical direction of the imaging screen. This is a so-called cross sensor type configuration that is arranged in a direction and can detect a subject pattern in the horizontal and vertical directions within one distance measuring area.

  As illustrated in FIG. 3B, the exit pupil plane 241 of the photographing lens (interchangeable lens 201) is a pupil region through which the focus detection light beams incident on the light receiving portions 148a, 148b, 148c, and 148d of the AF sensor 148 pass. 241a, pupil region 241b, pupil region 241c, and pupil region 241d are included.

  That is, in the focus detection optical system of the AF unit 110 configured as described above, different pupil regions 241a and 241b on the exit pupil plane 241 of the photographing lens (interchangeable lens 201) as shown in FIG. The focus detection light fluxes that pass through the region 241c and the pupil region 241d are received by the light receiving unit 148a, the light receiving unit 148b, the light receiving unit 148c, and the light receiving unit 148d, respectively, and converted into electrical signals indicating the light intensity distribution pattern of the image. Is done. Using this light intensity signal, focus detection is performed by a TTL phase difference method which is one method of focus detection.

FIG. 4 is a conceptual diagram showing an example of the arrangement of distance measurement areas in the shooting screen of the camera using the AF unit according to the embodiment of the present invention.
When the photographer looks through the eyepiece lens 113, focus detection area marks 149 corresponding to a plurality of focus detection areas of the AF sensor 148 are displayed in the viewfinder. Note that the example of FIG. 4 shows an example of multi-AF having 11 distance measuring areas.

Next, an example of the photographing operation of the camera system 100 according to the present embodiment will be described with reference to FIGS.
FIG. 5 is a flowchart for explaining an example of the photographing operation of the camera system as the imaging apparatus according to the present invention.
FIG. 6 is a diagram for explaining an example of a moving object prediction and imaging sequence in the imaging apparatus according to the present invention.

FIG. 6 shows a two-dimensional coordinate space in which the vertical axis indicates the lens position in the optical axis direction of the focus adjustment lens 203 and the horizontal axis indicates the time axis, and the meanings of the reference numerals are as follows.
T _1R : ON time of the 1R switch 132 (focus position detection instruction means) detected by the operation switch detection circuit 129.
T _2R : ON time of the 2R switch 133 (photographing instruction means) detected by the operation switch detection circuit 129.
T _{1 to} T ₁₀ : The center time of the accumulation period of the AF sensor 148 in the distance measuring operation executed at a predetermined cycle while the 1R switch 132 is on.
T _{E1 to} T _E5 : Exposure period center time in each frame of continuous shooting.
L _E : A predicted straight line calculated by the least square method or the like based on the in-focus position (white circle in the figure) of the focus adjustment lens 203 obtained from the times T _{1 to} T ₁₀ and the defocus amount detected at that time.
An example of the photographing operation of the camera system 100 according to the present embodiment will be described with reference to the above-described reference numeral in FIG. 6 and the flowchart in FIG.
The following processing is realized by the main body CPU 121 executing the control program 121P and the lens CPU 221 executing the control program 221P.

First, in step S101, when the power of the camera body 101 is turned on, the body CPU 121 determines whether or not the interchangeable lens 201 is attached by detecting a mount switch state (not shown) with the operation switch detection circuit 129. If the interchangeable lens 201 is attached, the process proceeds to step S202. If the interchangeable lens 201 is not attached, a standby operation such as periodically detecting attachment is performed until it is attached.
When the photographer performs an operation for changing the photographing parameter or an operation for reproducing an image photographed in the past during the standby, the instructed operation is executed.

  In step S102, when it is confirmed that the interchangeable lens 201 is attached, the main body CPU 121 communicates with the lens CPU 221 via the camera main body communication circuit 131 and the lens communication circuit 231, and the operation parameters such as the focus adjustment lens 203, chromatic aberration data, and the like. Lens data such as optical data is acquired and stored in the RAM 123.

  In step S103, the main body CPU 121 detects whether or not the interchangeable lens 201 is mounted by detecting a mount switch state (not shown) in the operation switch detection circuit 129. If it is removed, the process returns to step S101 and is mounted. If yes, the process proceeds to step S104.

  In step S104, it is confirmed whether the power of the camera body 101 is turned on. If it is turned off, the process proceeds to step S121. If it is turned on, the process proceeds to step S105.

  In step S105, if the operation switch detection circuit 129 detects that the 1R switch 132 is turned on, the process proceeds to step S106, and if it is off, the process returns to step S103.

  If the photographer performs an operation for changing a shooting parameter, a playback operation for an image shot in the past, or the like while the processes in steps S103 to S105 are repeatedly executed, the instructed operation is executed.

  In step S106, the main body CPU 121 determines whether or not the shooting mode is the high-speed continuous shooting mode with prediction (predictive continuous shooting mode). If the shooting mode is the high-speed continuous shooting mode with prediction (predictive continuous shooting mode), the process proceeds to step S107. If it is another mode, the process proceeds to step S122.

  In step S107, the AF sensor 148 in the AF unit 110 accumulates charges obtained by photoelectrically converting subject images formed on the light receiving units 148a to 148d in accordance with an instruction from the AF sensor control circuit 134, and the accumulation level becomes a predetermined level. And a signal obtained by converting the accumulated charge into a voltage is output as an image signal.

  The main body CPU 121 communicates with the lens CPU 221 during the accumulation, acquires the number of pulses at the position of the focus adjustment lens 203 being accumulated detected by the focus adjustment lens position detection circuit 225, and uses it as a reference position for focus position detection. Therefore, it is temporarily stored in the RAM 123. In addition, as data for performing the prediction calculation in step S111 (prediction step), the time at this time (for example, the elapsed time since the 1R switch 132 is turned on) is also stored in the RAM 123.

  The AF sensor control circuit 134 performs A / D conversion on the image signal output from the AF sensor 148, acquires it as subject image data, and stores it in the RAM 123.

  The main body CPU 121 performs a known correlation operation and interpolation operation from a pair of pupil-divided data of the subject image data stored in the RAM 123 (output data from the light receiving units 148a and 148b and 148c and 148d of the AF sensor 148). As shown in FIG. 4, the horizontal and vertical two image interval values of each of the eleven distance measuring points are obtained, and one of them is selected by a predetermined selection method (for example, comparing the contrast levels to select the higher one). A two-image spacing value is selected. Subsequently, the defocus amount is calculated from the two-image interval value of each distance measuring point selected using a conversion formula corresponding to the optical design, and is specified if the distance measuring point selection mode of the camera is the spot AF mode. A defocus amount of a distance measuring point is selected, and in the multi-point AF mode, a defocus amount of one distance measuring point is selected by a predetermined selection method such as closest selection.

  Then, the main body CPU 121 transmits the selected defocus amount and the acquired number of pulses of the position of the focusing lens 203 to the lens CPU 221 to instruct the calculation of the number of pulses of the focus position.

  The lens CPU 221 uses the received pulse number at the position of the focus adjustment lens 203 during the accumulation operation as a reference, obtains the pulse number at the position shifted from the position by the received defocus amount as the in-focus position, and transmits it to the main body CPU 121.

The main body CPU 121 stores the acquired number of pulses at the in-focus position in the RAM 123 as time series data in association with the time stored during the accumulation operation.
The main body CPU 121 performs photometry and exposure calculation in parallel with the above-described focus position detection.

In step S108, the main body CPU 121 transmits the defocus amount calculated in step S107 to the lens CPU 221 to instruct driving of the focus adjustment lens 203 by the defocus amount.
The drive instruction here may be performed simultaneously with the focus position calculation instruction in step S107.

  Further, when the calculated defocus amount is equal to or less than a predetermined value, for example, within the in-focus range, the drive restriction according to the defocus amount may be performed such that the focus adjustment lens 203 is not driven.

  In step S109, if the operation switch detection circuit 129 detects that the 1R switch 132 is turned off, the process returns to step S103, and if it is on, the process proceeds to step S110.

  In step S110, if the operation switch detection circuit 129 detects that the 2R switch 133 is turned on, the process proceeds to step S111, and if it is off, the process returns to step S107.

  In step S111, based on the time-series data of the focus position stored in the RAM 123 in step S107, the number of pulses at the focus position at each exposure time to be executed thereafter is obtained by the following prediction calculation.

As shown in FIG. 6, at the time of 2R switch 133 is turned on at time _{T 2R,} focus position of the step S107 executed at time _T 1 _{through T 10} from 1R switch 132 is turned on at time _{T 1R} Time series data 151 (white circles in FIG. 6) acquired by the detection process is stored in the RAM 123.
A prediction line L _E (prediction information) (P = at + b) is obtained from the number of pulses at the in-focus position associated with the accumulation time of the AF sensor 148 of the time series data 151 by a least square method or the like, and continuous shooting is performed on this line equation. Each of the exposure times (T _{E1 to} T _E5 ) is substituted to obtain the predicted in-focus positions 152 (black circles in FIG. 6) corresponding to the preset number of continuously shot frames. In addition, when the number of continuous shooting frames set is large, calculating all the predicted in-focus positions 152 at this time may increase the time lag until shooting of the first frame. In consideration of the case, it may be performed before the focus adjustment lens 203 is driven in each frame.
In the description of the prediction calculation, a linear expression is used as a prediction expression. However, the prediction expression is not limited to this, and a secondary expression or a higher order expression may be used.
Also, all the time-series data 151 using that to determine a prediction equation, but a memory for time-series data storing the inter time T _1R through T _2R becomes long between the time T _1R through T _2R in the above description increase in the prediction calculation time due to lack or data increase in area, since deterioration of the prediction accuracy of the data is out of date occurs, if a long between the time T _1R through T _2R than the predetermined time, the latest time-series data The prediction formula may be obtained by excluding data from 151 before a predetermined number of times (for example, 10 times) or a predetermined time (for example, 0.5 seconds).
Furthermore, the number of frames for continuous shooting need not be fixed, and can be switched according to the focal length, aperture value, etc. of the photographic lens (in this case, the smaller the focusing range is set, the smaller the number of frames set). The photographer may be able to set an arbitrary number of frames using a menu or the like.

In step S112, the main body CPU 121 instructs the lens CPU 221 to drive the focus adjustment lens 203 to the predicted in-focus position 152 calculated in step S111 and drive the diaphragm 205 based on the exposure calculation result in step S107. Mirror up drive of the mirror 108 and the sub mirror 109 is performed.
The lens CPU 221 drives the focus adjustment lens 203 and the aperture 205 to the designated target positions by the focus adjustment lens drive circuit 224, the focus adjustment lens position detection circuit 225, and the aperture drive circuit 228.

  In step S113, the main body CPU 121 drives the focal plane shutter 104 by the shutter control circuit 126 based on the exposure calculation result in step S107 after driving the focus adjustment lens 203, the diaphragm 205, the main mirror 108, and the sub mirror 109 in step S112. The image processing circuit 125 controls the image sensor 103 by the image sensor control circuit 124, and the image processing circuit 125 generates image data that is a photoelectric conversion output of the subject image formed on the light receiving surface of the image sensor 103. After the processing, the captured image data is stored in a nonvolatile external storage means such as the RAM 123 or Compact Flash (registered trademark), and the captured image is displayed on the display monitor 105 by the display circuit 127.

  In step S114, if the operation switch detection circuit 129 detects that the 2R switch 133 is turned off, the process proceeds to step S120, and if it is turned on, the process proceeds to step S115.

In step S115, the main body CPU 121 instructs the lens CPU 221 to drive the focus adjustment lens 203 to the predicted in-focus position 152 calculated in step S111, and performs mirror-down driving of the main mirror 108 and the sub mirror 109.
The lens CPU 221 drives the focus adjustment lens 203 to the designated target position by the focus adjustment lens drive circuit 224 and the focus adjustment lens position detection circuit 225.

In step S116, the main body CPU 121 instructs the lens CPU 221 to drive the focus adjustment lens 203 to the predicted in-focus position 152 calculated in step S111, and performs mirror-up driving of the main mirror 108 and the sub mirror 109.
The lens CPU 221 drives the focus adjustment lens 203 to the designated target position by the focus adjustment lens drive circuit 224 and the focus adjustment lens position detection circuit 225.

The focus adjustment lens 203 in step S115 and step S116 may be driven in either one of the periods depending on the required lens drive amount or the like, or both by adjusting the drive speed or dividing the drive amount. You may make it carry out in the period.
In step S117 (imaging step), exposure processing similar to that in step S113 is performed.

In step S118, it is determined whether or not the number of continuously shot frames has reached the set number of frames. If it has reached, the process returns to step S103, and if not, the process proceeds to step S119.
The set number of frames may be stored in the camera body 101 in advance, or the photographer may be able to set an arbitrary number of frames by shooting menu setting or the like.

  In step S119, if the operation switch detection circuit 129 detects that the 2R switch 133 is turned off, the process proceeds to step S120, and if it is turned on, the process returns to step S115.

  In step S120, if the operation switch detection circuit 129 detects that the 1R switch 132 is turned off, the process returns to step S103, and if it is on, the process returns to step S107.

In step S121, if it is determined in step S104 described above that the power is OFF, predetermined end processing such as saving of various data, reset operation, and power supply system disconnection processing is executed.
In step S122, when it is determined in step S106 described above that the mode is not the predictive continuous shooting mode, processing according to a setting mode such as normal single shooting is performed.
As described above, according to the first embodiment, it is possible to perform continuous shooting at a speed higher than that in the normal continuous AF continuous shooting mode when the moving subject is continuously shot. It is possible to provide an imaging apparatus capable of obtaining a focused image with higher probability than high-speed continuous shooting with a fixed position.
That is, according to the first embodiment, when continuously shooting a subject, high-speed continuous shooting is performed without decreasing the continuous shooting speed, and without being affected by the movement of the subject. A technique capable of obtaining a focused image can be provided.
(Modification 1)
In the above description, continuous shooting is performed for the preset number of frames, but there is a difference between the focus position predicted during continuous shooting (predicted focus position 152) and the actual focus position. When it becomes larger (when the focus evaluation value decreases), processing may be performed such that continuous shooting is stopped at that time.
For example, a high-frequency component is extracted from the captured image data as an AF evaluation value for each frame of continuous shooting, and the AF evaluation value is smaller than a predetermined threshold value or smaller than a predetermined ratio than the AF evaluation value up to the previous frame. In this case, it is determined that the deviation of the predicted focus position 152 from the actual focus position is large, and the continuous shooting operation is stopped.
At this time, the photographer may be notified that the continuous shooting is stopped by a monitor display on the display monitor 105 or the like.
Thereby, useless continuous shooting of a defocused image can be suppressed, the storage area of the image recording medium can be saved, and the battery 107 can be made longer by saving power consumption.
(Modification 2)
In the above description, the example in which the phase difference AF for obtaining the defocus amount from the parallax of the subject image divided into pupils is employed as the AF method in the AF unit 110 has been described, but the AF method of the first embodiment is the same. The focus position is not limited, and the position where the high-frequency component (AF evaluation value) of the subject image signal acquired from the image sensor at a predetermined interval while driving the focusing lens is maximized. The detection may be applied when so-called hill-climbing AF is employed.

FIG. 7 is an image diagram for explaining an example of the operation when the focus position detection is performed by hill-climbing AF in the imaging apparatus according to the present invention.
FIG. 7 shows a two-dimensional coordinate space in which the vertical axis indicates the lens position in the optical axis direction of the focus adjustment lens 203 and the horizontal axis indicates the time axis, and the meanings of the respective symbols are as follows.
Ot: Focus position change locus according to the movement of the subject.
Lt: scan drive locus for detecting the in-focus position.

FIG. 8 is an explanatory diagram illustrating an example of a focus position detection method in hill-climbing AF in the imaging apparatus according to the present invention.
The meanings of the symbols in FIG. 8 are as follows.
T _P : Time when the focusing position of the focus adjustment lens 203 is P _P.
P _P: focus position of the focusing lens 203 at time _{T P.}

C _P : AF evaluation value when the focus position of the focus adjustment lens 203 is P _P.
T ₁ : Evaluation value acquisition time one time before the maximum value of the evaluation value is acquired.
T ₂ : Evaluation value acquisition time when the maximum value of the evaluation value is acquired.
T ₃ : Evaluation value acquisition time one time after the maximum value of the evaluation value is acquired.
P ₁ : Evaluation value acquisition position of the focus adjustment lens 203 one time before the maximum value of the evaluation value is acquired.
P ₂ : Evaluation value acquisition position of the focus adjustment lens 203 at the time of acquiring the maximum value of the evaluation value.
P ₃ : Evaluation value acquisition position of the focus adjustment lens 203 once after the maximum value of the evaluation value is acquired.
C ₁ : The evaluation value acquired one time before the maximum value of the evaluation value is acquired.
C ₂ : Maximum value of the evaluation value.
C ₃ : Acquired evaluation value one time after obtaining the maximum value of the evaluation value.

Hereinafter, the second modification will be described with reference to FIGS.
FIG. 7 shows an image of driving of the focus adjustment lens 203 and detection timing of the AF evaluation value for detecting a focus position that changes in accordance with the movement of the subject while the release button 106 is half-pressed (while the 1R switch 132 is on). Is shown.
When the operation switch detection circuit 129 detects that the 1R switch 132 is turned on, the main body CPU 121 executes normal hill-climbing AF to drive the focus adjustment lens 203 near the in-focus position.
Subsequently, as shown in FIG. 7, the main body CPU 121 instructs the lens CPU 221 about the driving direction and the driving speed of the focus adjustment lens 203 in accordance with the change of the focus position according to the movement of the subject, and the position of the focus adjustment lens 203 is adjusted. Control to change before and after the focal position.

The main body CPU 121 causes the imaging element control circuit 124 to execute an imaging operation at a predetermined frame rate, for example, 120 frames per second (fps) together with the driving of the focus adjustment lens 203, and the AF evaluation value acquisition timing 161 The high-frequency component of the image signal output from the image sensor 103 is extracted by the image processing circuit 125 and the AF evaluation value is calculated. As shown in FIG. 7, the focus position (focus position change locus O _t (prediction information)) is calculated. ), For example, the detected in-focus position 162 and the elapsed time at that time are calculated by a method as shown in FIG. 8 and stored in the RAM 123 as time series data 151.

FIG. 8 shows the relationship between the elapsed time, the lens position, and the AF evaluation value with respect to the AF evaluation value acquisition timing in the A part of FIG. 7, and three points showing the relationship between the lens position and the AF evaluation value in the drawing. _{, (P 1, C 1)} , (P 2, C 2), calculates the position _{P P} focusing from the data of _{(P 3, C} 3).
Assuming that the slope of the straight line passing through the points (P ₂ , C ₂ ) and (P ₃ , C ₃ ) is a, the intercept is b, the lens position, and the variables indicating the AF evaluation values are x and y _C , respectively, the formula of this straight line Is
y _C = ax + b (1)
The equation of a straight line passing through the point (P ₁ , C ₁ ) and having an inclination opposite to that of the equation (1) and the intercept c is
y _C = −ax + c (2)
If the straight lines represented by the equations (1) and (2) intersect at a point (P _P , C _P ),
C _P = aP _P + b (3)
C _P = −aP _P + c (4)
(3) by substituting equation (4) into equation and solving for _{P P,}
P _P = (c−b) / 2a (5)
here,
_{a = (C 3 -C 2)} / (P 3 -P 2) ··· (6)
b = C ₂ −aP ₂ (7)
c = C ₁ + aP ₁ (8)
Since it is, (5) to (8), it is possible to obtain the focus position _{P P.}
Also, for the time _{T P} in which the focus position is _{P P,} point 2 indicating the elapsed time related to the lens position in FIG. _{(P 1,} T _1), is calculated from the data of _(P 2, _{T 2)} .
Assuming that the slope of the straight line passing through the points (P ₁ , T ₁ ) and (P ₂ , T ₂ ) is d, the intercept is e, and the variable indicating the elapsed time is y _T , the equation of this straight line is
y _T = dx + e (9)
If the point (P _P , T _P ) is a point on the straight line of the equation (9),
T _P = dP _P + e (10)
here,
d = (T ₂ −T ₁ ) / (P ₂ −P ₁ ) (11)
e = T ₁ −dP ₁ (12)
Since it is, (10) to (12), can be determined time _{T P} in which the focus position is _{P P.}
Focus position at the exposure time of each frame after the full press (after on the 2R switch 133) of the release button 106 by using the time series data 151 of the in-focus position P _P and the time T _P determined as described above ( Prediction focus position 152) is predicted.

(Embodiment 2)
In the second embodiment, a focus position change due to blurring in the optical axis direction of the photographing lens is predicted by sine wave approximation from the focus position of the focus adjustment lens 203 continuously acquired when the release button 106 is half-pressed, and continuously. An example of shooting is shown.
The basic configuration and photographing operation of the interchangeable lens according to the second embodiment and the camera body are the same as those of the first embodiment.
The overall shooting operation of the second embodiment is the same as that of the first embodiment illustrated in the flowchart of FIG. 5, but the processing is different for the prediction calculation in step S111. explain.

Based on the time-series data of the focus position stored in the RAM 123 in step S107, the number of pulses at the focus position at each exposure time to be executed thereafter is obtained by the following prediction calculation.
FIG. 9 is a diagram for explaining an example of an imaging sequence based on the forward / backward blur prediction in the imaging apparatus according to the present invention.
FIG. 9 shows a two-dimensional coordinate space in which the vertical axis indicates the lens position in the optical axis direction of the focus adjustment lens 203 and the horizontal axis indicates the time axis, and the meanings of the symbols are as follows.
T _1R : ON time of the 1R switch 132 detected by the operation switch detection circuit 129.
T _2R : ON time of the 2R switch 133 detected by the operation switch detection circuit 129.
T _{1 to} T ₁₄ : The center time of the accumulation period of the AF sensor 148 in the distance measuring operation executed at a predetermined cycle while the 1R switch 132 is on.
T _{S1 to} T _S5 : Time between inflection points of the focus position of the focus adjustment lens 203 stored in the RAM 123 of the camera body 101 as time series data 171.
T _{E1 to} T _E4 : exposure period center time in each frame of continuous shooting.
T _E : Prediction period of back-and-forth blur obtained by taking the average of times T _{S1 to} T _S5 between a plurality of inflection points.
P _Ec : Predicted center position of front / rear blur obtained by taking the average of the focus positions of the focus adjustment lens 203 stored in the RAM 123 of the camera body 101 as the time series data 171.
P _Ea : Predicted amplitude of front / rear shake obtained by taking the difference between the maximum position and the minimum position of a plurality of inflection points within a predetermined range with reference to the predicted center position P _Ec of front / rear shake.
C _E : Sinusoidal approximate curve obtained from the prediction period, the prediction center position, and the prediction amplitude of front and rear blur

As shown in FIG. 9, at the time of 2R switch 133 is turned on at time _{T 2R,} if in step S107 that the 1R switch 132 at time _{T 1R} is executed at time _T 1 _{through T 14} from being turned on focus Time series data 171 (white circles in the figure) acquired by the position detection process is stored in the RAM 123.
First, an inflection point at the in-focus position is detected from the number of pulses at the in-focus position associated with the accumulation time of the AF sensor 148 in the time series data 171, and the time T _{S1 to} T _S5 between the detected inflection points is detected. an average value, this value and shake period T _E.
Next, an average value of each in-focus position of the time series data 171 is obtained, and this value is set as the center position P _Ec of the shake amplitude.

Subsequently, a maximum value and a minimum value within a predetermined range from each focus position of the time series data 171 with reference to the center position P _Ec of the shake amplitude, for example, twice the focus range, are detected. The difference is obtained, and this value is set as the shake amplitude P _Ea .

The following sine wave approximation formula (sine wave approximation curve C _E (prediction information)) is obtained from the shake period T _E , the center position P _{Ec of} the shake amplitude, and the shake amplitude P _Ea obtained above.
P = (P _Ea / 2) sin (2π / T _E ) t + P _Ec (13)
Substituting the difference time from the reference time point T _D for blur prediction to each exposure time (T _{E1 to} T _E4 ) for continuous shooting into the equation (13), the predicted in-focus positions 172 corresponding to the number of continuous shooting frames set in advance. (Black circle in the figure) is obtained.
The reference time T _D of the blur prediction involves using the time closest focus position in the central position P _Ec shake amplitude is detected by the ON just before the 2R switch 133.
If the number of continuous shooting frames set is large, calculating all of the predicted in-focus positions 172 at this time may increase the time lag until the start of shooting for the first frame. In consideration of the case, it may be performed before the focus adjustment lens 203 is driven in each frame.
In the above description of the prediction calculation using the prediction equation including the sine function (sin) as the prediction expression, the prediction type is not limited thereto, the reference time T _D of the blur prediction of 2R switch 133 on just before A prediction formula including a cosine function (cos) may be used as the time when the inflection point at the in-focus position is detected.

Further, all the time-series data 171 using that to determine a prediction equation, but a memory for time-series data storing the inter time T _1R through T _2R becomes long between the time T _1R through T _2R in the above description increase in the prediction calculation time due to lack or data increase in area, since deterioration of the prediction accuracy of the data is out of date occurs, if a long between the time T _1R through T _2R than the predetermined time, the latest time-series data The prediction formula may be obtained by excluding data from 171 a predetermined number of times (for example, 20 times) or a predetermined time (for example, 1 second).

Furthermore, when the variation in the time T _{S1 to} T _S5 between the inflection points of the detected in-focus position is large, or when the variation in the in-focus position is larger than the amount of change caused by normal camera shake or the like, The prediction of the focus position during the continuous shooting may be stopped, and for example, the focus adjustment lens 203 may be fixed to the average position of the focus position and the continuous shooting may be performed.

As described above, according to the second embodiment, high-speed continuous shooting with the focus adjustment lens position fixed when a change in position (such as camera shake) occurs in the optical axis direction of the shooting lens. In contrast, it is possible to provide an imaging apparatus that can obtain a focused image with higher probability without reducing the continuous shooting speed.
That is, according to the second embodiment, when the subject is continuously photographed, high-speed continuous photographing is performed without lowering the continuous photographing speed, and the subject is not affected by camera shake, and is focused with high probability. A technique capable of obtaining an image can be provided.

(Embodiment 3)
In the third embodiment, a change in the focus position due to the movement of the subject is predicted according to the change in the focus position of the focus adjustment lens 203 continuously acquired when the release button 106 is half-pressed, or the light of the photographing lens A case will be described in which it is determined whether or not a focus position change due to axial back-and-forth blur is predicted, and continuous shooting is performed by predicting the focus position change by a selected prediction method.

The basic configuration and photographing operation of the interchangeable lens according to the third embodiment and the camera body are the same as those of the first embodiment.
Hereinafter, an example of the photographing operation of the third embodiment will be described with reference to the flowchart of FIG. FIG. 10 is a flowchart for explaining an example of the photographing operation according to Embodiment 3 of the present invention.

In steps S201 to S210, similarly to steps S101 to S110, processing corresponding to the camera operation of the photographer from when the camera body 101 is turned on until the 2R switch 133 is turned on is performed.
If the power is turned off during the process, the process proceeds to step S224, and if a shooting mode other than the predicted continuous shooting mode is selected, the process proceeds to step S225.

In step S211, a prediction straight line L _E (P = at + b) as shown in FIG. 6 is obtained by the least square method using the time series data of the in-focus position acquired while the 1R switch 132 is on, whether to motion prediction according to the magnitude of the slope a of the expected line L _E, selects whether to perform back and forth motion prediction.
For example, when the inclination a is equal to or less than a predetermined value, for example, when the in-focus position change is within the in-focus range while shooting the set number of consecutive frames, the forward / backward blur prediction is selected. Select.

In step S212, if moving object prediction is selected in step S211, the process proceeds to step S213, and if front / rear blur prediction is selected, the process proceeds to step S214.
In step S213, the predicted in-focus positions for the preset number of continuously shot frames are calculated by the same method as the moving object prediction calculation in the first embodiment.

In step S214, the predicted in-focus positions for the preset number of continuously shot frames are calculated by the same method as the forward / backward blur prediction calculation in the second embodiment.
In steps S215 to 223, as in steps S112 to S120, a continuous shooting operation for a preset number of frames is executed.
When shooting for the set number of frames is completed, or when both the 1R switch 132 and 2R switch 133 during continuous shooting are turned off, the process returns to step S203. When only the 2R switch 133 is turned off, the process returns to step S207. .

In step S224, similar to step S121, predetermined termination processing such as saving various data, resetting operation, and power supply system disconnection processing is executed.
In step S225, similarly to step S122, processing according to a setting mode such as normal single shooting is performed.
As described above, according to the third embodiment, it is automatically determined whether the subject is moving or whether there is a back-and-forth blur, and the focus position during continuous shooting is determined by an appropriate prediction method. Since the prediction is performed, it is possible to provide an imaging apparatus that can obtain a focused image with a higher probability regardless of shooting conditions during high-speed continuous shooting.

(Modification example of prediction method selection method)
In the above description, as a method for selecting a prediction method of the in-focus position during continuous shooting, the inclination of the approximate straight line obtained from the time-series data of the in-focus position of the focusing lens 203 continuously acquired when the release button 106 is half-pressed. However, the selection method of the prediction method according to the third embodiment is not limited to this, and other methods, for example, the occurrence frequency of moving subject shooting and the focus position of the front / rear blur In consideration of the degree of influence on the fluctuation, the selection may be performed according to the perspective of the time-series data of the in-focus position.

  As a specific example, the average value of the time-series data of the in-focus position or the in-focus position detected immediately before the release button 106 is fully pressed is a predetermined selection determination distance L0 (for example, L0 = 1 meter ( m)) If the subject distance is longer than the subject distance L1 (> L0), the moving object prediction is selected. If the subject distance L2 is shorter than the selection determination distance L0 (≦ L0), the selection is made to select the forward / backward blur prediction. A method is conceivable.

In addition, since the frequency of moving subject shooting and the degree of influence of back-and-forth blur vary depending on the focal length and aperture value of the taking lens, the selection determination distance L0 may be switched accordingly.
Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, although the case where the interchangeable lens 201 is provided as an example of the configuration of the camera system 100 is illustrated, a configuration in which the photographic lens is integrally fixed to the camera body 101 may be used.
(Appendix)
(Appendix 1). A focus detection means for detecting a focus position of the focus adjustment lens based on a subject image by a light beam transmitted through the photographing lens;
A focus position detection instructing means for instructing the focus detection means to execute focus position detection;
Photographing instruction means for instructing execution of photographing of a subject image by causing a light beam transmitted through the photographing lens to enter the imaging element;
Storage means for storing the focus position and the focus position detection timing of the focus adjustment lens continuously detected by the focus detection means at the time of the focus position detection instruction by the focus position detection instruction means in time series;
A prediction unit for predicting a focus position at the time of exposure to the image sensor after a shooting instruction is given by the shooting instruction unit based on a focus position stored in the storage unit and a focus position detection timing;
In an imaging apparatus capable of continuous shooting, in-focus position detection and shooting are performed by the focus position detection instruction means and the shooting instruction means in a mode in which high-speed continuous shooting is performed by predicting a focus position at the time of shooting. Is instructed to detect the focus position by the focus position detection instruction means, all of the focus position and the focus position detection timing of the focus adjustment lens stored in the storage means, or Based on a part, the in-focus position at the time of exposure of the image sensor in each frame of a preset number of continuous shooting frames is predicted by the prediction unit, and the prediction unit predicts every time shooting is performed in each frame An imaging apparatus that performs continuous shooting by driving a focus adjustment lens to a focused position.
(Appendix 2). The imaging apparatus according to (Appendix 1), wherein the prediction method performed by the prediction means predicts a change in the in-focus position due to movement of the subject.
(Appendix 3). The image pickup apparatus according to (Appendix 1), wherein the prediction method performed by the prediction means predicts a change in the in-focus position due to back-and-forth movement in the optical axis direction of the photographing lens.
(Appendix 4). Based on the focus position of the focus adjustment lens stored in the storage means and the focus position detection timing during the period when the focus position detection instruction means instructs the detection of the focus position, the change tendency of the focus position is detected. The imaging apparatus according to (Appendix 1), wherein the prediction method of the prediction unit is switched according to the change tendency.

DESCRIPTION OF SYMBOLS 100 Camera system 101 Camera main body 102 Camera control circuit 103 Image pick-up element 104 Focal plane shutter 105 Display monitor 106 Release button 107 Battery 108 Main mirror 109 Sub mirror 110 AF unit 111 Screen mat 112 Viewfinder optical system 113 Eyepiece 121 Main body CPU
121P Control program 122 Flash ROM
123 RAM
124 Image sensor control circuit 125 Image processing circuit 126 Shutter control circuit 127 Display circuit 128 Strobe control circuit 129 Operation switch detection circuit 130 Power supply circuit 131 Camera body communication circuit 132 1R switch (first release switch)
133 2R switch (second release switch)
134 AF sensor control circuit 141 Primary imaging plane 142 Field mask 142a Opening 143 Condenser lens 144 Total reflection mirror 145 Infrared cut filter 146 Separator diaphragms 146a to 146d Opening 147 Separator lens 147a Light receiving lens 147b Light receiving lens 147c Light receiving lens 147d Light receiving Lens 148 AF sensors 148a to 148d Light receiver 149 Focus detection area mark 151 Time series data 152 Predicted focus position 161 AF evaluation value acquisition timing 162 Detection focus position 171 Time series data 172 Predictive focus position 201 Interchangeable lens 202 Lens control circuit 203 Focus Adjustment Lens 204 Zoom Lens 205 Aperture 221 Lens CPU
221P Control program 222 Flash ROM
223 RAM
224 Focus adjustment lens drive circuit 225 Focus adjustment lens position detection circuit 226 Zoom lens drive circuit 227 Zoom lens position detection circuit 228 Aperture drive circuit 231 Lens communication circuit 241 Exit pupil planes 241a to 241d Pupil region 301 Subject light flux 302 Light flux for AF

Claims (13)

Focus detection means for detecting a focus position of the focus adjustment lens based on an image of a subject by a light beam transmitted through a photographing lens including a focus adjustment lens;
In-focus position detection instruction means for instructing the focus detection means to detect the in-focus position;
Photographing instruction means for instructing execution of photographing of the subject by causing the light flux transmitted through the photographing lens to enter an imaging element;
When the detection of the in-focus position is instructed by the in-focus position detection instructing means, the in-focus position of the focus adjustment lens continuously detected by the focus detecting means and the detection timing of the in-focus position are time-series. Storage means for storing in,
Predicting means for predicting a focus position at the time of exposure to the image sensor after an instruction for photographing is performed by the photographing instruction means based on the in-focus position stored in the storage means and the detection timing; ,
With
The predicting means corresponds to the in-focus position and the detection timing of the focus adjustment lens stored in the storage means in correspondence with a period in which the in-focus position detection instruction means instructs the detection of the in-focus position. Predicting a focus position at the time of exposure of the image sensor based on at least a part of the focus position and the detection timing,
The shooting instruction unit drives the focus adjustment lens to the in-focus position predicted by the prediction unit every time shooting is performed, and instructs shooting.
An imaging apparatus characterized by that. The prediction means executes a first prediction method for predicting a change in the in-focus position due to the movement of the subject.
The imaging apparatus according to claim 1. The predicting means executes a second prediction method for predicting a change in the in-focus position due to a blur in the optical axis direction of the photographing lens;
The imaging apparatus according to claim 1. The predicting means is based on the in-focus position and the detection timing of the focus adjustment lens stored in the storage means during a period when the in-focus position detection instruction means instructs the detection of the in-focus position. Detecting the change tendency of the in-focus position,
A first prediction method for predicting a change in the in-focus position due to the movement of the subject according to the change tendency, and a second prediction method for predicting a change in the in-focus position due to blurring in the optical axis direction of the photographing lens. And switch
The imaging apparatus according to claim 1. Focus detection means for detecting a focus position of the focus adjustment lens based on an image of a subject by a light beam transmitted through a photographing lens including a focus adjustment lens;
In-focus position detection instruction means for instructing the focus detection means to detect the in-focus position;
Photographing instruction means for instructing execution of photographing of the subject by causing the light flux transmitted through the photographing lens to enter an imaging element;
Control means for controlling focus bracket shooting for shooting the subject while changing the in-focus position;
A control program for a photographing apparatus including:
The control program is
The focus position of the focus adjustment lens and the detection timing of the focus position continuously detected by the focus detection means within a period instructed to detect the focus position by the focus position detection instruction means. A prediction step for generating prediction information for predicting a focus position at the time of exposure to the image sensor after an instruction for shooting is performed based on the shooting instruction unit;
Taking the shooting instruction from the shooting instruction unit as a trigger, shooting for instructing shooting by driving the focus adjustment lens to the in-focus position based on the prediction information every time the exposure of the focus bracket shooting is performed. Steps,
Causing the control means to execute,
A control program for an image pickup apparatus. In the prediction step, the control means generates first prediction information for predicting a change in the in-focus position due to the movement of the subject.
The control program for an imaging apparatus according to claim 5, wherein In the predicting step, the control means generates second predictive information for predicting a change in the in-focus position due to blurring in the optical axis direction of the photographing lens.
The control program for an imaging apparatus according to claim 5, wherein In the prediction step, the in-focus position is determined based on the in-focus position and the detection timing of the focus adjustment lens detected during a period in which the in-focus position detection instruction means instructs the detection of the in-focus position. Detect change trends,
According to the change tendency, generation of the first prediction information for predicting a change in the in-focus position due to the movement of the subject, and a change in the in-focus position due to blurring in the optical axis direction of the photographing lens are predicted. Causing the control means to execute a process of switching generation of the second prediction information;
The control program for an imaging apparatus according to claim 5, wherein Focus detection means for detecting a focus position of the focus adjustment lens based on an image of a subject by a light beam transmitted through a photographing lens including a focus adjustment lens;
In-focus position detection instruction means for instructing the focus detection means to detect the in-focus position;
Photographing instruction means for instructing execution of photographing of the subject by causing the light flux transmitted through the photographing lens to enter an imaging element;
Control means for controlling focus bracket shooting for shooting the subject while changing the in-focus position;
A method of controlling an imaging apparatus including:
The control means includes
The focus position of the focus adjustment lens and the detection timing of the focus position continuously detected by the focus detection means within a period instructed to detect the focus position by the focus position detection instruction means. Generating prediction information for predicting the in-focus position at the time of exposure to the imaging device after the shooting instruction is given by the shooting instruction means based on
Triggered by the shooting instruction from the shooting instruction means, the focus adjustment lens is driven to the in-focus position based on the prediction information every time the focus bracket shooting is performed, and shooting is performed.
And a method of controlling the imaging apparatus. The control means is based on a change tendency of the focus position and the detection timing of the focus adjustment lens detected during a period in which detection of the focus position is instructed by the focus position detection instruction means. Generation of the first prediction information for predicting a change in the in-focus position due to movement of a subject, and generation of the second prediction information for predicting a change in the in-focus position due to blurring in the optical axis direction of the photographing lens Switching,
The method for controlling an imaging apparatus according to claim 9. A method for controlling an imaging apparatus, wherein preparation for shooting is performed by half-pressing a release button, and exposure is performed by fully pressing the release button.
A first step of generating prediction information of the in-focus position based on a plurality of in-focus positions and a distance measurement timing based on a distance measurement result during a half-press period of the release button;
A second step of performing continuous shooting by repeating a plurality of exposures while changing a focus position of the focus adjustment lens based on the prediction information and an execution time of the exposure when the release button is fully pressed; ,
A method for controlling an imaging apparatus including: In the first step,
Determining whether the change in the in-focus position during the half-press period of the release button is due to movement of the subject or vibration displacement in the optical axis direction of the imaging device;
When the change in the focus position is caused by the movement of the subject, a prediction straight line that approximates the locus of the predicted focus position in the two-dimensional coordinate space of the focus position and the time axis is generated as the prediction information. And
When the change in the focus position is caused by vibration displacement in the optical axis direction of the imaging apparatus, the predicted focus position is traced in the two-dimensional coordinate space of the focus position and the time axis as the prediction information. Generate a prediction curve that approximates a sine or cosine wave,
The method of controlling an imaging apparatus according to claim 11. In the second step,
When the difference between the in-focus position determined based on the prediction information and the actual in-focus position becomes large, the continuous shooting is stopped.
The method for controlling an imaging apparatus according to claim 12.