JP2023080152A - Lens barrel and camera body - Google Patents

Abstract

To provide a lens barrel capable of appropriately controlling the drive of a focus adjustment lens.SOLUTION: A lens barrel attachable to/detachable from a camera body having an imaging section includes: a focus lens 32; a drive section for moving the focus lens 32 in an optical axis direction; and a control section for controlling the drive section on the basis of a first mode for limiting a range where the focus lens 32 can move within a first range and a second mode that does not limit the range where the focus lens can move; and a receiving section for receiving information on focus from the camera body. When the receiving section receives the information on the focus in the first mode, the drive section moves the focus lens 32 to a target position of the focus if the target position is in the first range and the drive section moves the focus lens in the direction of the first range if the target position is not in the first range.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens barrel and a camera body.

Conventionally, in a lens barrel capable of setting a plurality of focusable ranges, there has been known a technique of limiting driving of a focusing lens based on the set focusable ranges (see, for example, Patent Document 1). .

JP 2006-126330 A

However, in the prior art, in the camera body, the lens driving amount required to drive the focusing lens to the in-focus position is calculated, and in the lens barrel, the focusing lens is driven based on the lens driving amount. Since it is configured to repeatedly determine whether or not the focus adjustment lens exceeds the focusable range, the processing load on the lens barrel increases, and depending on the timing of the above determination, the focus lens may In some cases, the focus position is driven beyond the focusable range, and the focus determination is performed at the focus position beyond the focusable range.

The present invention solves the above problems by the following solutions.

[1] A lens barrel according to the present invention is a lens barrel attachable to and detachable from a camera body having an imaging section, comprising: a focus lens; a driving section for moving the focus lens in an optical axis direction; a first mode that limits the movable range of the focus lens to a first range and a second mode that does not limit the movable range of the focus lens; a receiving unit that receives information from the camera body, and when the receiving unit receives the information regarding the focus in the state of the first mode, if the target position of the focus is within the first range, the driving unit moves the focus lens to the target position, and when the target position is not in the first range, the drive unit moves the focus lens in the direction of the first range.
[2] In the lens barrel according to the present invention, when the receiving unit receives the focus information in the first mode, the driving unit performs , to move the focus lens in the direction of the first range.
[3] In the above lens barrel, the first range may be narrower than the entire movable range of the focus lens.
[4] The lens barrel of the invention further includes a storage unit that stores a plurality of predetermined ranges within the drivable range of the focus lens as the first ranges.
[5] In the above lens barrel, the storage section may be configured to store information on the first range set by the user.
[6] In the above lens barrel, the control section may be configured to perform control based on any one of the first ranges stored in the storage section.
[7] In the above lens barrel, the receiving section may be configured to periodically receive the drive amount based on the position information of the focus lens from the camera body at regular intervals.
[8] In the above lens barrel, the receiving section further includes a transmitting section for transmitting information regarding the first mode or the second mode to the camera body.
[9] In the above lens barrel, if the target position received by the receiver in the first mode is outside the first range, the transmitter warns the camera body or It can be configured to transmit focus indication information.
[10] The camera body according to the present invention is detachable from the lens barrel.
[11] A detachable camera body according to the present invention includes a detachable lens barrel capable of switching between a first mode in which the movable range of the focus lens is limited to the first range and a second mode in which the movable range is not limited. A body, comprising: an operation unit for a user to perform a focus operation; and a receiving unit for receiving information about the first mode or the second mode from the lens barrel. When the operation unit is operated and the target position of the focus lens is within the first range, an instruction to move the focus lens to the target position is transmitted to the lens barrel, and the target position is the first range. If it is not within the range, an instruction to move the focus lens in the direction of the first range is sent to the lens barrel.
[12] A detachable camera body according to the present invention includes a detachable lens barrel capable of switching between a first mode in which the movable range of the focus lens is limited to the first range and a second mode in which the movable range is not limited. a body, comprising: an operation unit for a user to perform a focus operation; and a receiving unit for receiving information about the first mode or the second mode from the lens barrel. When the mode is switched, if the position of the focus lens is within the first range, information for moving the focus lens is not transmitted to the lens barrel, and if the position of the focus lens is not within the first range. sends information to the lens barrel to move the focus lens in the direction of the first range.

According to the present invention, it is possible to appropriately control the driving of the focusing lens.

FIG. 1 is a block diagram showing a camera according to this embodiment. FIG. 2 is an external view of the lens barrel 3 according to this embodiment. FIG. 3 is a diagram showing an example of the focusable range of the focus lens. FIG. 4 is a diagram for explaining an example of information transfer between the lens barrel and the camera body. 5 is a front view showing an imaging surface of the imaging device shown in FIG. 1. FIG. FIG. 6 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging the VI section of FIG. 7A is an enlarged front view showing one of the imaging pixels 221, FIG. 7B is an enlarged front view showing one of the focus detection pixels 222a, and FIG. FIG. 7D is an enlarged cross-sectional view of one of the imaging pixels 221, and FIG. 7E is one of the focus detection pixels 222a. FIG. 7F is an enlarged cross-sectional view showing one of the focus detection pixels 222b. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 6. FIG. FIG. 9 is a diagram for explaining an example of a focus detection method using a contrast detection method. FIG. 10 is a flowchart showing communication processing between the lens barrel and the camera body. FIG. 11 is a flow chart showing the operation of the camera of this embodiment. FIG. 12 is a flowchart showing lens drive control processing based on the focus detection result by the phase difference detection method in step S213. FIG. 13 is a diagram showing an example of the scan drive range. FIG. 14 is a flowchart showing lens drive control processing based on the focus detection result by the contrast detection method in step S214. FIG. 15 is a flowchart showing focus limit change processing in step S218. FIG. 16 is a diagram showing another example of the scan drive range. FIG. 17 is a diagram showing another example of an external view of the lens barrel 3. As shown in FIG.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a main part showing a digital camera 1 according to an embodiment of the invention. A digital camera 1 (hereinafter simply referred to as camera 1) of this embodiment comprises a camera body 2 and a lens barrel 3. The camera body 2 and lens barrel 3 are detachably connected by a mount portion 4. there is

A lens barrel 3 is an interchangeable lens that can be attached to and detached from the camera body 2 . As shown in FIG. 1, the lens barrel 3 incorporates a photographing optical system including lenses 31, 32, 33 and a diaphragm .

The lens 32 is a focus lens, and can adjust the focal length of the imaging optical system by moving in the direction of the optical axis L1. The focus lens 32 is provided movably along the optical axis L<b>1 of the lens barrel 3 , and its position is adjusted by a focus lens drive motor 36 while its position is detected by an encoder 35 .

Information on the current position of the focus lens 32 detected by the encoder 35 is sent to the camera control section 21, which will be described later, via the lens control section 37, and the focus lens drive motor 36 controls the position of the focus lens 32 calculated based on this information. drive position is sent from the camera control unit 21 via the lens control unit 37 to drive.

The diaphragm 34 is configured so that the aperture diameter around the optical axis L1 can be adjusted in order to limit the amount of light that passes through the photographing optical system and reach the imaging device 22 and to adjust the amount of blurring. Adjustment of the aperture diameter by the diaphragm 34 is performed by sending an appropriate aperture diameter calculated in the automatic exposure mode, for example, from the camera controller 21 via the lens controller 37 . Further, the set aperture diameter is input from the camera control section 21 to the lens control section 37 by manual operation using the operation section 28 provided in the camera body 2 . The aperture diameter of the aperture 34 is detected by an aperture aperture sensor (not shown), and the lens controller 37 recognizes the current aperture diameter.

Further, the lens barrel 3 according to this embodiment can limit the focusable range of the focus lens 32 . The focusable range is a range in which focus is determined when an in-focus position is detected within the focusable range. In this embodiment, as shown in FIGS. 1 and 2, the lens barrel 3 is provided with a focus limit switch 38 for setting a focusable range, and the user operates the focus limit switch 38 to By selecting the focus limit mode, the focusable range can be selected. Note that FIG. 2 is an external view of the lens barrel 3 according to this embodiment.

FIG. 3 is a diagram showing an example of a focusable range that can be set in this embodiment. In this embodiment, as shown in FIG. 3(A), the range from the soft limit SL _IP at the infinity end to the soft limit SL _NP at the close end is set as the focusable range Rf1; 3(B), the range from the infinite end soft limit SL _IP to the closest side soft limit SL _NS is set as a focusable range Rf2; As shown, the range from the infinity side soft limit SL _IS to the near end soft limit SL _NP is set as the focusable range Rf3. can be done. In this embodiment, the "FULL mode" is set by setting the focus limit switch 38 to "FULL" shown in FIG. is set, and by matching with the "limit 2" shown in FIG. 2, the "infinity side limit mode" is set.

When one of the focus limit modes is selected by the user, focus limit information corresponding to the selected focus limit mode is transmitted from the lens barrel 3 to the camera body 2 as shown in FIG. be. The focus limit information is stored in the ROM of the lens control section 37 for each focus limit mode.

For example, when the focus limit switch 38 sets the "FULL mode" shown in FIG. Infinity end soft limit SL _IP and closest end soft limit SL _NP , which are positions (ends), and corresponding infinite far end design value DV _IP and closest end design value DV _NP are transmitted to the camera body 2. do.

When the focus limit switch 38 sets the "closest side limit mode" shown in FIG. The infinite far end soft limit SL _IP and the closest side soft limit SL _NS , which are the limit positions of the range Rf2, and the corresponding infinite far end design value DV _IP and the closest side designed value DV _NS are transmitted to the camera body 2. .

Similarly, when the focus limit switch 38 sets the "infinite distance limit mode" shown in FIG. The infinity side soft limit SL _IS and the closest end soft limit SL _NP , which are the limit positions of the focusable range Rf3, and the corresponding infinity side design value DV _IS and the closest end design value DV _NP are set to the camera body. 2.

In the present embodiment, the lens barrel 3 sets the closest side soft limit SL _NS , the closest side design value DV _NS , the infinity side soft limit SL _IS , or the infinity side design value DV _IS for each zoom lens position. The lens control unit 37 also stores, as focus limit information, information indicating whether or not the focusable range can be limited in the lens barrel 3 and information on the focus limit mode selected by the user. It can be transmitted from the lens barrel 3 to the camera body 2 .

Further, in the present embodiment, for example, information indicating whether or not the focusable range can be limited in the lens barrel 3, such as the focusable ranges Rf2 and Rf3; The focus limit mode selected by the user, such as "infinity side limit mode", is stored as focus limit information in the ROM of the lens control unit 37, and the lens control unit 37 sets the close side soft limit SL _NS , the closest side design value DV _NS , the infinity side soft limit SL _IS , or the infinity side design value DV _IS , information indicating whether or not the focusable range can be limited, and the user-selected Information on the focus limit mode is transmitted from the lens barrel 3 to the camera body 2 as focus limit information.

In FIG. 3A, the infinity end design value DV _IP is the infinity side of the lens positions at which the lens barrel 3 guarantees that the subject is in focus by design in the "FULL mode". In consideration of the design error of the lens barrel 3, the infinity end soft limit SL _IP is provided on the infinity side of the infinity end design value DV _IP , and the limit is set up to this infinity end soft limit SL _IP . It is designed to enable detection of the focus position. Similarly, the closest end design value DV _NP is a limit position on the closest side of the lens positions at which the lens barrel 3 is guaranteed to be focused on the subject by design, and the design error of the lens barrel 3 is Considering this, the closest end soft limit SL _NP is provided on the close side of the closest end design value DV _NP , and the design is made so that the in-focus position can be detected up to this closest end soft limit SL _NP . .

Further, in FIG. 3B, the closest side design value DV _NS is the closest side of the lens positions at which the lens barrel 3 guarantees that the object is in focus in the "closest side limited mode". In consideration of the design error of the lens barrel 3, it is designed so that the in-focus position can be detected up to the closest side soft limit SL _NS , which is closer to the closest side than the closest side design value DV _NS . ing. Similarly, in FIG. 3C, the design value DV _IS on the infinity side is set at In consideration of the design error of the lens barrel 3, it is possible to detect the in-focus position from the infinity side design value DV _IS to the infinity side soft limit SL _IS . designed to be possible.

Further, as shown in FIG. 4, in addition to focus limit information, focus lens position information is also periodically transmitted from the lens barrel 3 to the camera body 2 . Then, in the camera body 2 , the lens drive amount of the focus lens 32 is calculated based on the focus limit information and the position information of the focus lens 32 , and the calculated lens drive amount is transmitted to the lens barrel 3 . 4A and 4B are diagrams for explaining an example of exchange of information between the lens barrel 3 and the camera body 2. FIG.

On the other hand, in the camera body 2, an imaging device 22 for receiving the light flux L1 from the photographic optical system is provided on the predetermined focal plane of the photographic optical system, and a shutter 23 is provided in front of it. The imaging element 22 is composed of a device such as a CCD or CMOS, converts the received optical signal into an electrical signal, and sends the electrical signal to the camera control section 21 . The captured image information transmitted to the camera control unit 21 is sequentially transmitted to the liquid crystal drive circuit 25 and displayed in the electronic viewfinder (EVF) 26 of the observation optical system, and the release button ( (not shown) is fully pressed, the captured image information is recorded in the camera memory 24, which is a recording medium. Note that the camera memory 24 can be either a detachable card-type memory or a built-in memory.

The camera body 2 is provided with an observation optical system for observing an image captured by the imaging device 22 . The observation optical system of this embodiment includes an electronic viewfinder (EVF) 26 made up of a liquid crystal display element, a liquid crystal drive circuit 25 for driving the same, and an eyepiece lens 27 . The liquid crystal drive circuit 25 reads captured image information captured by the image sensor 22 and sent to the camera control section 21, and drives the electronic viewfinder 26 based on this. This allows the user to observe the currently captured image through the eyepiece lens 27 . Instead of or in addition to the observation optical system using the optical axis L2, a liquid crystal display may be provided on the rear surface of the camera body 2 or the like, and the captured image may be displayed on this liquid crystal display.

A camera control unit 21 is provided in the camera body 2 . The camera control section 21 is electrically connected to the lens control section 37 by an electrical signal contact section 41 provided in the mount section 4 , receives lens information from the lens control section 37 , and sends lens driving information to the lens control section 37 . Sends information such as amount and aperture diameter. In addition, the camera control unit 21 reads pixel outputs from the image sensor 22 as described above, and generates image information by performing predetermined information processing on the read pixel outputs as necessary, and generates image information. is output to the liquid crystal drive circuit 25 of the electronic viewfinder 26 and the memory 24 . Further, the camera control unit 21 controls the entire camera 1 by detecting correction of image information from the imaging device 22, focus adjustment state of the lens barrel 3, aperture adjustment state, and the like.

In addition to the above, the camera control unit 21 detects the focus state of the optical system by the phase detection method and detects the focus state of the optical system by the contrast detection method based on the pixel data read from the image sensor 22. . A specific focus state detection method will be described later.

The operation unit 28 is an input switch such as a shutter release button for the user to set various operation modes of the camera 1, and can switch between an autofocus mode and a manual focus mode. Various modes set by the operation section 28 are sent to the camera control section 21, and the operation of the camera 1 as a whole is controlled by the camera control section 21. FIG. The shutter release button also includes a first switch SW1 that is turned ON when the button is half-pressed, and a second switch SW2 that is turned ON when the button is fully pressed.

Next, the imaging device 22 according to this embodiment will be described.

5 is a front view showing the imaging surface of the image sensor 22, and FIG. 6 is a front view schematically showing the arrangement of focus detection pixels 222a and 222b by enlarging the VI portion of FIG.

As shown in FIG. 6, the imaging element 22 of the present embodiment has a plurality of imaging pixels 221 arranged two-dimensionally on the plane of the imaging surface, and green pixels G having color filters that transmit green wavelength regions. , a so-called Bayer arrangement of a red pixel R having a color filter transmitting a red wavelength region and a blue pixel B having a color filter transmitting a blue wavelength region. That is, in four adjacent pixel groups 223 (close-packed square lattice arrangement), two green pixels are arranged on one diagonal line, and one red pixel and one blue pixel are arranged on the other diagonal line. The image pickup device 22 is configured by repeatedly arranging the pixel groups 223 in a two-dimensional manner on the image pickup surface of the image pickup device 22 with the Bayer-arranged pixel groups 223 as a unit.

The arrangement of the unit pixel group 223 may be, for example, a hexagonal lattice arrangement other than the illustrated close-packed square lattice. Also, the configuration and arrangement of the color filters are not limited to this, and an arrangement of complementary color filters (green: G, yellow: Ye, magenta: Mg, cyan: Cy) can be employed.

FIG. 7A is a front view showing an enlarged one of the imaging pixels 221, and FIG. 7D is a cross-sectional view. One imaging pixel 221 is composed of a microlens 2211, a photoelectric conversion unit 2212, and a color filter (not shown). A photoelectric conversion portion 2212 is built in, and a microlens 2211 is formed on its surface. The photoelectric conversion unit 2212 is shaped to receive the imaging light flux passing through the exit pupil (for example, F1.0) of the imaging optical system through the microlens 2211, and receives the imaging light flux.

Focus detection pixel arrays 22a, 22b, and 22c in which focus detection pixels 222a and 222b are arranged in place of the image pickup pixel 221 described above are arranged at the center of the image pickup surface of the image sensor 22 and at three positions symmetrical from the center. is provided. As shown in FIG. 6, one focus detection pixel row is constructed by arranging a plurality of focus detection pixels 222a and 222b alternately adjacent to each other in a horizontal row (22a, 22c, 22c). there is In this embodiment, the focus detection pixels 222a and 222b are densely arranged without gaps between the green pixels G and blue pixels B of the imaging pixels 221 arranged in Bayer array.

The positions of the focus detection pixel arrays 22a to 22c shown in FIG. 5 are not limited to the positions shown in the figure, and may be arranged at one or two positions, or at four or more positions. can. In actual focus detection, the user can manually operate the operation unit 28 to select a desired focus detection pixel row as a focus detection area from among the plurality of arranged focus detection pixel rows 22a to 22c. can also

FIG. 7B is an enlarged front view showing one of the focus detection pixels 222a, and FIG. 7E is a cross-sectional view of the focus detection pixel 222a. Also, FIG. 7C is a front view showing an enlarged one of the focus detection pixels 222b, and FIG. 7F is a cross-sectional view of the focus detection pixel 222b. The focus detection pixel 222a is composed of a microlens 2221a and a semicircular photoelectric conversion unit 2222a, as shown in FIG. 7B. A photoelectric conversion portion 2222a is formed on the surface of a semiconductor circuit board 2213, and a microlens 2221a is formed on the surface. 7C, the focus detection pixel 222b is composed of a microlens 2221b and a photoelectric conversion unit 2222b. As shown in the cross-sectional view of FIG. A photoelectric conversion portion 2222b is formed on the surface of a circuit board 2213, and a microlens 2221b is formed on the surface. As shown in FIG. 6, these focus detection pixels 222a and 222b are arranged adjacent to each other alternately in a horizontal row to form the focus detection pixel rows 22a to 22c shown in FIG.

Note that the photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b are shaped so as to receive light beams passing through a predetermined area (for example, F2.8) of the exit pupil of the imaging optical system by the microlenses 2221a and 2221b. be done. The focus detection pixels 222a and 222b are not provided with color filters, and their spectral characteristics are the sum of the spectral characteristics of the photodiodes that perform photoelectric conversion and the spectral characteristics of an infrared cut filter (not shown). ing. However, it can also be configured to include one of the same color filters as the imaging pixel 221, for example, a green filter.

Further, although the photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b shown in FIGS. 7B and 7C are semicircular, the shape of the photoelectric conversion units 2222a and 2222b is not limited to this. , other shapes such as elliptical, rectangular, and polygonal.

Here, a so-called phase difference detection method for detecting the focus state of the photographing optical system based on the pixel outputs of the focus detection pixels 222a and 222b described above will be described.

FIG. 8 is a cross-sectional view along line VIII-VIII in FIG. 6, in which focus detection pixels 222a-1, 222b-1, 222a-2, and 222b-2 adjacent to each other are arranged near the imaging optical axis L1. Light beams AB1-1, AB2-1, AB1-2, and AB2-2 emitted from ranging pupils 351 and 352 of exit pupil 350 are received, respectively. Although FIG. 8 illustrates only the focus detection pixels 222a and 222b located near the imaging optical axis L1 among the plurality of focus detection pixels 222a and 222b, other focus detection pixels other than the focus detection pixels shown in FIG. are also configured to receive light beams emitted from a pair of distance measuring pupils 351 and 352, respectively.

Here, the exit pupil 350 is an image set at a distance D in front of the microlenses 2221a and 2221b of the focus detection pixels 222a and 222b arranged on the intended focal plane of the imaging optical system. The distance D is a value that is uniquely determined according to the curvature and refractive index of the microlens, the distance between the microlens and the photoelectric conversion unit, etc. This distance D is referred to as the ranging pupil distance. Also, the ranging pupils 351 and 352 refer to images of the photoelectric conversion units 2222a and 2222b projected by the microlenses 2221a and 2221b of the focus detection pixels 222a and 222b, respectively.

In FIG. 8, the direction in which the focus detection pixels 222a-1, 222b-1, 222a-2, and 222b-2 are arranged matches the direction in which the pair of distance measuring pupils 351 and 352 are arranged.

Also, as shown in FIG. 8, the microlenses 2221a-1, 2221b-1, 2221a-2, and 2221b-2 of the focus detection pixels 222a-1, 222b-1, 222a-2, and 222b-2 are It is placed near the intended focal plane. The photoelectric conversion units 2222a-1, 2222b-1, 2222a-2, and 2222b-2 arranged behind the microlenses 2221a-1, 2221b-1, 2221a-2, and 2221b-2 have different shapes. It is projected onto the exit pupil 350 which is separated from the lenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 by the range-finding distance D, and the projected shape forms range-finding pupils 351, 352. FIG.

That is, on the exit pupil 350 at the ranging distance D, the microlenses and the photoelectric conversion sections of the focus detection pixels are arranged so that the projection shapes (ranging pupils 351 and 352) of the photoelectric conversion sections of the focus detection pixels match. are determined, and thereby the projection direction of the photoelectric conversion unit in each focus detection pixel is determined.

As shown in FIG. 8, the photoelectric conversion unit 2222a-1 of the focus detection pixel 222a-1 is formed on the microlens 2221a-1 by the light beam AB1-1 passing through the range finding pupil 351 and directed to the microlens 2221a-1. It outputs a signal corresponding to the intensity of the image received. Similarly, the photoelectric conversion unit 2222a-2 of the focus detection pixel 222a-2 passes through the distance measurement pupil 351, and the intensity of the image formed on the microlens 2221a-2 by the light flux AB1-2 directed toward the microlens 2221a-2 is Outputs a signal corresponding to

Further, the photoelectric conversion unit 2222b-1 of the focus detection pixel 222b-1 passes through the distance measuring pupil 352 and the intensity of the image formed on the microlens 2221b-1 by the light beam AB2-1 directed toward the microlens 2221b-1 is Output the corresponding signal. Similarly, the photoelectric conversion unit 2222b-2 of the focus detection pixel 222b-2 passes through the distance measuring pupil 352, and the intensity of the image formed on the microlens 2221b-2 by the light flux AB2-2 directed toward the microlens 2221b-2 is Outputs a signal corresponding to

A plurality of the two types of focus detection pixels 222a and 222b described above are linearly arranged as shown in FIG. and the focus detection pupil 352, the intensity of a pair of images formed on the focus detection pixel array by the focus detection light beams passing through the focus detection pupil 351 and the focus detection pupil 352 respectively. Data on the distribution are obtained. Then, image shift detection calculation processing such as correlation calculation processing or phase difference detection processing is performed on the intensity distribution data to detect an image shift amount by a so-called phase difference detection method.

Then, by applying a conversion operation to the obtained image shift amount according to the distance between the centers of gravity of the pair of distance measuring pupils, the current focal plane with respect to the planned focal plane (the focal point corresponding to the position of the microlens array on the planned focal plane) focal plane in the detection area), that is, the amount of defocus can be obtained.

Note that the camera control unit 21 executes the calculation of the image shift amount, the calculation of the defocus amount, and the focusing drive by these phase difference detection methods.

In addition, the camera control unit 21 reads the output of the image pickup pixel 221 of the image sensor 22, and calculates the focus evaluation value based on the read pixel output. This focus evaluation value can be obtained, for example, by extracting the high frequency components of the image output from the imaging pixels 221 of the imaging device 22 using a high frequency transmission filter. It can also be obtained by extracting high-frequency components using two high-frequency transmission filters having different cutoff frequencies.

Then, the camera control unit 21 sends a control signal to the lens control unit 37 to drive the focus lens 32 at a predetermined sampling interval (distance), obtains the focus evaluation value at each position, and obtains the focus evaluation value at the maximum. Focus detection is performed by the contrast detection method, in which the position of the focus lens 32 at which is obtained is obtained as the in-focus position. Note that, for example, when the focus evaluation value is calculated while driving the focus lens 32, the focus evaluation value increases twice and then decreases twice. can be obtained by performing a calculation such as an interpolation method using the focus evaluation value of .

Here, FIG. 9 is a diagram for explaining an example of the focus detection method by the contrast detection method. In the example shown in FIG. 9, the focus lens 32 is positioned at P0 shown in FIG. 9. First, the focus lens 32 is driven from P0 to a predetermined search start position (position P1 in FIG. 9). Initial drive is performed. Then, while the focus lens 32 is driven from the search start position (position P1 in FIG. 9) from the infinity side to the close-up side, the focus evaluation value is acquired by the contrast detection method at predetermined intervals. driving takes place. Then, when the focus lens 32 is moved to the position P2 shown in FIG. 9, the peak position of the focus evaluation value (the position P3 in FIG. 9) is detected as the in-focus position, and the detected in-focus position Focusing drive for driving the focus lens 32 is performed until (the position of P3 in FIG. 9).

Next, an operation example of the camera 1 according to this embodiment will be described. FIG. 10 is a flowchart showing communication processing between the lens barrel 3 and the camera body 2, and FIG. 11 shows the camera control performed after communication between the lens barrel 3 and the camera body 2 is started by the communication processing shown in FIG. 1 is a flowchart showing the operation of No. 1; Note that the operations shown in FIGS. 10 and 11 are started when the power of the camera body 2 is turned on.

First, communication processing between the lens barrel 3 and the camera body 2 will be described. As shown in FIG. 10, in step S101, the camera control unit 21 determines whether the lens barrel 3 is attached to the camera body 2 or not. For example, when the camera control section 21 becomes energized with the lens control section 37 via the electrical signal contact section 41 provided in the mount section 4, the lens barrel 3 is attached to the camera body 2. can be determined. If it is determined that the lens barrel 3 is attached to the camera body 2, the process proceeds to step S102, and if it is determined that the lens barrel 3 is not attached to the camera body 2, step Wait in S101.

In step S<b>102 , power is supplied from the camera body 2 to the lens barrel 3 by the camera control unit 21 . This enables communication between the lens barrel 3 and the camera body 2 .

The following step S103 is processing on the lens barrel 3 side. In step S<b>103 , initial communication processing is performed by the lens control unit 37 to transmit information specific to the lens barrel 3 from the lens barrel 3 to the camera body 2 . Specifically, the lens control unit 37 transmits information indicating the type of the lens barrel 3 and information indicating whether the lens barrel 3 has a range limit function to the camera body 2 .

In step S104, communication setting processing is performed by the camera control unit 21 and the lens control unit 37 as preparations for starting regular communication in step S105, which will be described later. In this embodiment, the communication between the lens barrel 3 and the camera body 2 includes regular communication in which predetermined information is collectively transmitted periodically at regular intervals, and non-periodic transmission of the minimum necessary information. In step S104, settings are made for performing steady communication.

Then, in step S105, steady communication is started by the camera control unit 21 and the lens control unit 37. FIG. As a result, for example, the lens control unit 37 can transmit lens information including focus limit information and focus lens position information to the camera body 2 through regular communication. In this embodiment, in step S106, lens information including focus limit information is periodically transmitted to the camera body 2 at regular intervals by regular communication until the power of the camera body 2 is turned off.

Next, operation of the camera 1 will be described with reference to FIG. In the process shown in FIG. 11, drive control of the focus lens 32 is performed based on the focus limit information transmitted from the lens barrel 3 to the camera body 2 by regular communication as shown in FIG.

Specifically, first, in step S201, it is determined whether or not regular communication has started between the lens barrel 3 and the camera body 2 by the communication processing shown in FIG. If steady communication has not started between the lens barrel 3 and the camera body 2, the process waits in step S201 until the steady communication starts, and steady communication between the lens barrel 3 and the camera body 2 is started. If communication has started, the process proceeds to step S202.

In step S202, the camera control unit 21 acquires focus limit information. In this embodiment, the focus limit information corresponding to the focus limit mode set in the lens barrel 3 is periodically transmitted from the lens control unit 37 to the camera control unit 21 by regular communication at predetermined intervals. The camera control section 21 can acquire focus limit information corresponding to the currently set focus limit mode from the lens control section 37 .

For example, as shown in FIG. 3A, when the "FULL mode" is set by the focus limit switch 38, the lens control unit 37 sets the focus limit information to the focusable range in the "FULL mode". Information including the infinite far end soft limit SL _IP and the close end soft limit SL _NP , which are the limit positions (ends) of Rf1, are periodically transmitted to the camera body 2 . Thereby, the camera control unit 21 can acquire focus limit information including the infinite far end soft limit SL _IP and the close end soft limit SL _NP .

Similarly, as shown in FIG. 3B, when the focus limit switch 38 is set to the "closest side limit mode", the camera control unit 21 controls the focusable range in the "closest side limit mode". Information including the infinity end soft limit SL _IP and the close-up side soft limit SL _NS , which are the limit positions of Rf2, is acquired as focus limit information, and as shown in FIG. When the "infinity side limit mode" is set, the infinity side soft limit SL _IS and the closest end soft limit SL _NP , which are the limit positions of the focusable range Rf3 in the "infinity side limit mode" can be acquired as focus limit information.

Note that even when the focus limit mode is the same, depending on the type of the lens barrel 3, the focusable ranges Rf1 to Rf3 of the focus lens 32 may differ from each other. Therefore, the camera control unit 21 acquires focus limit information unique to the lens barrel 3 from the lens barrel 3 .

In step S203, the camera control unit 21 calculates the focusable range of the focus lens 32 based on the focus limit information acquired in step S202, as shown in FIGS. .

For example, as shown in FIG. 3A, the camera control unit 21 is set to "FULL mode", and acquires the infinity end soft limit SL _IP and the close end soft limit SL _NP as the focus limit information. If so, the range from the infinite far end soft limit SL _IP to the closest end soft limit SL _NP is calculated as the focusable range Rf1.

Similarly, as shown in FIG. 3B, the camera control unit 21 is set to the "closest side limit mode", and as focus limit information, infinity end soft limit SL _IP and close side soft limit SL _NS is obtained, the range from the infinity end soft limit SL _IP to the closest side soft limit SL _NS is calculated as the focusable range Rf2. In addition, as shown in FIG. 3C, the camera control unit 21 is set to the "infinity side limit mode", and as focus limit information, the infinity side soft limit SL _IS and the close end soft limit SL When _NP is acquired, the range from the infinity side soft limit SL _IS to the closest end soft limit SL _NP is calculated as the focusable range Rf3.

Depending on the type of the lens barrel 3 , there are cases where the focus limit information cannot be acquired from the lens barrel 3 because it does not have a focus limit function. In such a case, as shown in FIG. 3A, the camera control unit 21 calculates a range Rf1 from the soft limit SL _IP at the infinity end to the soft limit SL _NP at the closest end as the focusable range. be able to.

In step S204, the camera control unit 21 starts defocus amount calculation processing by the phase difference detection method. In this embodiment, the process of calculating the defocus amount by the phase difference detection method is performed as follows. First, the camera control unit 21 reads a pair of image data corresponding to a pair of images from each of the focus detection pixels 222a and 222b forming the three focus detection pixel arrays 22a to 22c of the image sensor 22. FIG. Then, the camera control unit 21 executes image shift detection arithmetic processing (correlation arithmetic processing) based on the read pair of image data, and images at the focus detection positions corresponding to the three focus detection pixel rows 22a to 22c. A shift amount is calculated, and the image shift amount is converted into a defocus amount. The camera control unit 21 also evaluates the reliability of the calculated defocus amount. Note that the evaluation of the reliability of the defocus amount is performed based on, for example, the matching degree and contrast between a pair of image data. Further, the process of calculating the defocus amount by such a phase difference detection method is repeatedly executed at predetermined intervals.

In step S205, calculation processing of the focus evaluation value by the camera control unit 21 is started. In the present embodiment, the process of calculating the focus evaluation value reads the pixel output of the image pickup pixel 221 of the image sensor 22, extracts the high frequency component of the read pixel output using a high frequency transmission filter, and integrates it. done. When a specific focus detection position is selected by a user's manual operation or in an object recognition mode, the calculation of the focus evaluation value is based on only the pixel output of the imaging pixels 221 corresponding to the selected focus detection position. may be read out. Note that the focus evaluation value calculation process is repeatedly executed at predetermined intervals.

In step S206, the camera control unit 21 determines whether or not the shutter release button provided in the operation unit 28 has been half-pressed (first switch SW1 turned on). If the first switch SW1 is turned on, the process proceeds to step S207. On the other hand, if the first switch SW1 is not turned on, step S206 is repeated until the first switch SW1 is turned on. That is, until the first switch SW1 is turned on, the defocus amount calculation process and the focus evaluation value calculation process by the phase difference detection method are repeatedly executed.

In step S207, the camera control unit 21 determines whether or not the defocus amount has been calculated by the phase difference detection method. If the defocus amount can be calculated, it is determined that distance measurement is possible, and the process proceeds to step S213. On the other hand, if the defocus amount could not be calculated, it is determined that distance measurement is impossible, and the process proceeds to step S208. Note that in this embodiment, even if the defocus amount can be calculated, even if the calculated defocus amount is unreliable, it is treated as if the defocus amount could not be calculated, and the process proceeds to step S208. I will proceed.

If it is determined in step S207 that the defocus amount has been calculated, and if it is determined that distance measurement is possible, the process proceeds to step S213, and the focus lens 32 is driven based on the defocus amount calculated by the phase difference detection method. A lens drive control process is performed to allow the lens to move. Here, FIG. 12 is a flow chart showing the lens driving control process in step S213. The lens drive control process in step S213 will be described below with reference to FIG.

First, in step S301, the camera control unit 21 determines whether or not the focusable range is restricted. For example, in step S202, when the information of the infinity end soft limit SL _IP and the closest end soft limit SL _NP is acquired as the focus limit information, the camera control unit 21 acquires the infinity end soft limit SL _IP and the closest end soft limit SL NP. Based on the information of the soft limit SL _NP , as shown in FIG. 3A, it can be determined that the "FULL mode" is set and the focusable range Rf1 is not limited.

On the other hand, in step S202, when the information of the infinity end soft limit SL _IP and the closest side soft limit SL _NS is acquired as the focus limit information, the camera control unit 21 sets the infinity end soft limit SL _IP and the closest side soft limit Based on the SL _NS information, it can be determined that the "closest side limit mode" is set, and thereby the focusable range Rf2 is limited. Similarly, in step S202, when information on the infinity side soft limit SL _IS and the near end soft limit SL _NP is acquired as the focus limit information, the camera control unit 21 controls the infinity side soft limit SL IS and the near end soft limit SL _IS . Based on the information of the edge soft limit SL _NP , it can be determined that the "infinite distance limit mode" is set, and thereby the focusable range Rf3 is limited.

If it is determined in step S301 that the focusable range is restricted, the process proceeds to step S302. In step S302, the camera control unit 21 determines whether or not the drive target position of the focus lens 32 based on the defocus amount calculated by the phase difference detection method exceeds the focusable range of the focus lens 32. will be

Specifically, the camera control unit 21 first determines the lens position at which the subject is in focus based on the defocus amount calculated by the phase difference detection method and the current focus lens position. number). Further, when the subject is a moving body, the camera control unit 21 calculates the drive target position based on the subject position, taking into consideration the movement of the subject. In the present embodiment, the camera control unit 21 can calculate the drive target position by, for example, the number of pulses required to drive the focus lens 32 from the lens position corresponding to the infinity end to the drive target position. can. Then, the camera control unit 21 calculates a lens drive amount (unit: number of pulses) for moving the focus lens 32 to the drive target position based on the drive target position.

Then, the camera control unit 21 determines the drive target position based on the calculated lens drive amount (unit: number of pulses) of the focus lens 32 and the focusable range (unit: number of pulses) calculated in step S203. It is determined whether or not the focusable range is exceeded. For example, in the example shown in FIG. 3B, when the drive target position based on the defocus amount is the lens position closer to the near side than the close-up side soft limit SL _NS , the camera control unit 21 sets the drive target position exceeds the focusable range Rf2. If it is determined that the drive target position based on the defocus amount exceeds the focusable range, the process proceeds to step S303, and it is determined that the drive target position based on the defocus amount is within the focusable range. If so, the process proceeds to step S306.

In step S303, it is determined that the drive target position based on the defocus amount exceeds the focusable range. A lens drive amount required for driving is calculated. Specifically, the camera control unit 21 drives the focus lens 32 to the limit position of the focusable range close to the drive target position based on the current position of the focus lens 32 and the focusable range. A lens drive amount is calculated.

For example, in the example shown in FIG. 3B, when the drive target position based on the defocus amount is a lens position closer to the close side than the close-up side soft limit SL _NS , the camera control unit 21 sets the drive target position A lens drive amount required to drive the focus lens 32 to the closest side soft limit SL _NS , which is the limit position of the focusable range Rf2 closer to the camera, is calculated. Further, in the example shown in FIG. 3C, when the drive target position based on the defocus amount is a lens position on the infinity side of the infinity side soft limit SL _IS , the camera control unit 21 A lens drive amount required to drive the focus lens 32 to the infinity side soft limit SL _IS , which is the limit position of the focusable range Rf3 near the target position, is calculated.

Then, in step S304, the camera control unit 21 performs processing for driving the focus lens 32 to the limit position of the focusable range based on the lens driving amount calculated in step S303. Specifically, the camera control unit 21 sends the lens drive amount calculated in step S303 to the focus lens drive motor 36 via the lens control unit 37 by non-periodic communication. Then, the focus lens drive motor 36 drives the focus lens 32 to the limit position of the focusable range based on the received lens drive amount. As a result, for example, in the example shown in FIG. 3B, even if the drive target position based on the defocus amount is a lens position closer to the near side than the near side soft limit SL _NS , the focus lens 32 is set to the near side soft limit. It will be moved to limit SL _NS . Further, in the example shown in FIG. 3C, even when the target drive position based on the defocus amount is a lens position on the infinity side of the infinity side soft limit SL _IS , the focus lens 32 is set to the infinity side soft limit. It will be moved to limit SL _IS .

In subsequent step S305, since the focus lens 32 could not be driven to the drive target position (in-focus position) based on the defocus amount, a message indicating that the focus is out of focus is displayed. Out-of-focus display is provided by the electronic viewfinder 26, for example.

On the other hand, if it is determined in step S301 that the focusable range is not restricted, or if it is determined in step S302 that the drive target position based on the defocus amount is within the focusable range , the process proceeds to step S306. In step S306, the camera control unit 21 calculates the lens drive amount of the focus lens 32 based on the defocus amount calculated by the phase difference detection method. Then, the focus lens 32 is driven to the drive target position (focus position). Thereafter, in step 208, an in-focus indication is provided.

As described above, the drive control processing of the focus lens 32 is performed based on the defocus amount calculated by the phase difference detection method. When the focus lens 32 is driven based on the defocus amount calculated by the phase difference detection method, the focus lens 32 is driven within the focusable ranges Rf1 to Rf3 shown in FIGS. Drive control of the focus lens 32 is performed as described above. That is, when the drive target position based on the defocus amount exceeds the focusable range Rf1 to Rf3, in the camera body 2, the lens drive amount necessary for driving to the limit position of the focusable range is calculated. In the lens barrel 3, the focus lens 32 is driven to the limit position of the focusable range based on the lens driving amount calculated by the camera body 2. As a result, it is possible to effectively prevent the focus lens 32 from being driven to a lens position beyond the focusable range Rf1 to Rf3 and in-focus indication being performed at a lens position beyond the focusable range. can. After the lens driving control process shown in FIG. 12 is completed, the process proceeds to step S218 shown in FIG.

Further, when it is determined in step S207 shown in FIG. 11 that the defocus amount cannot be calculated by the phase difference detection method, the process proceeds to step S208. In step S208, the camera control unit 21 calculates the scan driving range, which is the drivable range of the focus lens 32 in the scanning operation. The scanning operation to be performed is started.

The scanning operation is performed by the camera control unit 21 while the focus lens drive motor 36 drives the focus lens 32 at a predetermined drive speed (scan drive), while the camera control unit 21 calculates the defocus amount by the phase difference detection method and calculates the focus evaluation value. is calculated simultaneously at predetermined intervals, and thereby detection of the focus position by the phase difference detection method and detection of the focus position by the contrast detection method are simultaneously performed at predetermined intervals.

Specifically, the camera control unit 21 sends a scan drive start command to the lens control unit 37, and the lens control unit 37 drives the focus lens drive motor 36 based on the command from the camera control unit 21 to focus. The lens 32 is driven to scan along the optical axis L1. The scanning drive of the focus lens 32 may be performed from the infinity end to the closest end, or may be performed from the closest end to the infinity end.

Then, while driving the focus lens 32, the camera control unit 21 reads a pair of image data corresponding to the pair of images from the focus detection pixels 222a and 222b of the image sensor 22 at predetermined intervals. A defocus amount is calculated by a phase difference detection method, and pixel outputs are read out from the imaging pixels 221 of the imaging device 22 at predetermined intervals while driving the focus lens 32. Based on this, a focus evaluation value is calculated. By obtaining focus evaluation values at different focus lens positions, the in-focus position is detected by the contrast detection method.

Further, in this embodiment, in order to perform scan drive, the scan drive range is calculated in step S208. FIG. 13 is a diagram showing an example of the scan drive range. As shown in FIGS. 13A to 13C, scan drive ranges Rs1 to Rs3 include focusable ranges Rf1 to Rf3 shown in FIGS. 3A to 3C, and focusable range Rf1 It is calculated as a range wider than ~Rf3.

Here, as described above, the scanning operation simultaneously performs the calculation of the defocus amount by the phase difference detection method and the calculation of the focus evaluation value by the contrast detection method at predetermined intervals while driving the focus lens 32. It is action. In order to detect the peak position (in-focus position) of the focus evaluation value by the contrast detection method, as shown in FIG. 9, the focus lens 32 is driven to a position beyond the peak position (P2 in FIG. 9). It is necessary to calculate the focus evaluation value. Therefore, for example, in order to detect the peak position (in-focus position) of the focus evaluation value with the soft limit SL _IP at the infinity end by the contrast detection method, the focus lens 32 must be set at infinity rather than at the soft limit SL _IP at the infinity end. It is necessary to calculate the focus evaluation value by driving to the side. Similarly, for example, in the scanning operation, in order to detect the peak position (in-focus position) of the focus evaluation value at the closest end soft limit SL _NP by the contrast detection method, the focus lens 32 is set to the closest end soft limit SL It is necessary to calculate the focus evaluation value by driving to the close-up side of _{the NP} .

Therefore, when performing a scanning operation, the camera control unit 21, when the focus limit mode is the "FULL mode", as shown in _FIG . A scan drive range Rs1 is calculated as a range from the lens position on the side to the lens position on the close side of the close-up end soft limit SL _NP . For example, in the present embodiment, when the focus evaluation value rises twice and then drops two more times, these focus evaluation values are used to calculate the peak of the focus evaluation value. The unit 21 calculates two focus evaluation values on the close side of the closest end soft limit SL _NP from a lens position where two focus evaluation values can be calculated on the infinity side of the infinity end soft limit SL _IP . The range up to the lens position that can be calculated can be calculated as the scan drive range Rs1 in the scan operation.

Further, when performing a scan operation, if the focus limit mode is the "close-up side limit mode", the camera control unit 21 sets the focus limit to the infinite far end soft limit SL _IP as shown in FIG. 13B. The range from the lens position on the infinity side to the lens position on the close side of the close side soft limit SL _NS is calculated as the scan driving range Rs2. Similarly, when the focus limit mode is the "infinite side limit mode", the camera control unit 21, as shown in _FIG . The range from the position to the lens position on the closest side of the closest end soft limit SL _NP is calculated as the scan drive range Rs3 in the scan operation.

Then, in step S209, a scan operation is performed in the scan drive range Rs1 to Rs3 shown in FIGS. 13A to 13C. As described above, in the scan drive in the scan operation, the drive of the focus lens 32 is controlled with the scan drive range Rs1 to Rs3 shown in FIGS. Even if the focus position exists at the limit position of the focusable range shown in FIGS. 3A to 3C, such a focus position can be detected by the contrast detection method.

Then, in step S210, the camera control unit 21 determines whether or not the defocus amount can be calculated by the phase difference detection method as a result of the scanning operation. If the defocus amount can be calculated, it is determined that the distance can be measured, and the process proceeds to step S213. . Note that in step S210, even if the defocus amount could be calculated in the same manner as in step S207 described above, the defocus amount could not be calculated if the calculated defocus amount was unreliable. It is treated as a thing, and the process proceeds to step S211.

In step S211, the camera control unit 21 determines whether or not the in-focus position can be detected by the contrast detection method as a result of the scanning operation. If the focus position can be detected by the contrast detection method, the process proceeds to step S214, and if the focus position cannot be detected, the process proceeds to step S212.

In step S212, the camera control unit 21 determines whether or not the scan drive has been executed for the entire scan drive range calculated in step S208. If scan drive is not performed for the entire scan drive range, the process returns to step S210, and by repeating steps S210 to S212, the scan operation, that is, the phase difference detection method is performed while the focus lens 32 is scan-driven. Calculation of the defocus amount by , and detection of the focus position by the contrast detection method are performed simultaneously at predetermined intervals. On the other hand, if execution of the scan operation has been completed for the entire scan drive range, the process proceeds to step S215.

Then, as a result of executing the scanning operation, if it is determined in step S210 that the defocus amount has been calculated by the phase difference detection method, the scanning operation is stopped, the process proceeds to step S213, and in the same manner as described above, Drive control of the focus lens 32 is performed based on the result of the phase difference detection method.

That is, when the focusable range is limited and the drive target position corresponding to the defocus amount exceeds the focusable range (step S301=Yes, S302=Yes), the focus lens 32 is moved. A lens drive amount for driving to the limit position of the focusable range is calculated (step S303), and based on the calculated lens drive amount, the focus lens 32 is driven to the limit position of the focusable range (step S304). , out-of-focus display is performed (step S308). On the other hand, if the drive target position according to the defocus amount is within the focusable range (step S302=No), or if the focusable range is not limited (step S301=No), the defocus A lens driving amount corresponding to the defocus amount is calculated (step S306), the focus lens 32 is driven based on the lens driving amount corresponding to the defocus amount (step S307), and an in-focus display is performed (step S308).

If it is determined in step S211 that the in-focus position has been detected by the contrast detection method as a result of executing the scanning operation, the scanning operation is stopped, and the process proceeds to step S214. The drive control of the focus lens 32 based on this is performed. Here, FIG. 14 is a flow chart showing lens driving control processing based on the result of focus detection by the contrast detection method.

As shown in FIG. 14, first, in step S401, similarly to step S301, it is determined whether or not the focusable range is restricted. If the focusable range is limited, the process proceeds to step S402, and if the focusable range is not limited, the process proceeds to step S406.

In step S402, it is determined whether or not the focus position detected by the contrast detection method exceeds the focusable range. For example, in the scanning operation, as shown in FIG. 3B, when the "closest side limit mode" is set, the focus evaluation is performed by driving the focus lens 32 to the close side beyond the close side soft limit SL _NS . As a result of calculating the value, if the peak position (in-focus position) of the focus evaluation value is detected on the close-up side of the close-up side soft limit SL _NS , the camera control unit 21 determines that the peak position (in-focus position) is detected by the contrast detection method. It is determined that the in-focus position is beyond the focusable range Rf2, and the process proceeds to step S403. Also, in the scanning operation, as shown in FIG. 3C, when the "infinite side limit mode" is set, the focus lens 32 is driven to the infinity side of the infinity side soft limit SL _IS . As a result of calculating the focus evaluation value, if the peak position (in-focus position) of the focus evaluation value is detected on the infinity side of the infinity side soft limit SL _IS , the camera control unit 21 selects the contrast detection method. It is determined that the focus position detected by is beyond the focusable range Rf3, and the process proceeds to step S403.

Then, in steps S403 to S405, the camera control unit 21 calculates the lens drive amount required to drive the focus lens 32 from the focus position detected by the contrast detection method to the limit position of the focusable range close to the focus position. is performed (step S403), and after the focus lens 32 is driven to the limit position of the focusable range based on the calculated lens driving amount (step S404), out-of-focus display is performed (step S405).

As a result, for example, in the example shown in FIG. 3B, even if the in-focus position calculated by the contrast detection method is a lens position closer to the near side than the near side soft limit SL _NS , the focus lens 32 side soft limit SL _NS . In the example shown in FIG. 3C, even if the in-focus position calculated by the contrast detection method is a lens position on the infinity side of the infinity side soft limit SL _IS , the focus lens 32 side soft limit SL _IS .

On the other hand, if it is determined in step S401 that the focusable range is not restricted, or if it is determined in step S402 that the in-focus position detected by the contrast detection method is within the focusable range. , the process proceeds to step S406. In step S406, the camera control unit 21 calculates the lens drive amount up to the in-focus position detected by the contrast detection method. A process of driving the focus lens 32 to the in-focus position is performed based on the drive amount. After that, in step S408, an in-focus display is performed.

As described above, drive control of the focus lens 32 is performed based on the in-focus position detected by contrast detection. As described above, in the focus drive for driving the focus lens 32 to the focus position detected by the contrast detection method, the focus lens 32 is driven within the focusable range shown in FIGS. , drive control of the focus lens 32 is performed. That is, when the focus position detected by the contrast detection method exceeds the focusable range, the lens driving amount required to drive the focus lens 32 to the limit position of the focusable range in the camera body 2 is The focus lens 32 is driven in the lens barrel 3 based on the lens drive amount calculated in the camera body 2 . As a result, it is possible to effectively prevent the focus lens 32 from being driven to a position beyond the focusable range and from displaying the focus at a position beyond the focusable range. After the lens driving control process shown in FIG. 14 is completed, the process proceeds to step S218 shown in FIG.

Further, when it is determined in step S212 that the execution of the scanning operation has been completed for the entire scanning driving range, the process proceeds to step S215. In step S215, as a result of the scanning operation, focus detection cannot be performed by either the phase difference detection method or the contrast detection method.

In step S216, the camera control unit 21 performs a process of moving the focus lens 32 from the current focus lens position to the limit position of the close focusable range. Then, in step S217, since the in-focus position could not be detected, an in-focus display is performed.

Further, in this embodiment, after focus adjustment is performed based on the focus detection result, the process proceeds to step S218, and focus limit change processing is performed in step S218. FIG. 15 is a flow chart showing focus limit change processing in step S218.

As shown in FIG. 15, first, in step S501, the camera control unit 21 reacquires the focus limit information. Then, in step S502, the camera control unit 21 recalculates the focusable range based on the focus limit information acquired in step S501.

In step S503, the camera control unit 21 compares the focusable range newly calculated in step S502 with the previous focusable range, and determines whether or not the focusable range has been changed. If the focusable range has been changed, the process proceeds to step S504, and if the focusable range has not been changed, the focus limit change processing shown in FIG. 15 ends.

In step S504, the camera control unit 21 determines whether or not the drive target position of the focus lens 32 is within the focusable range after the change calculated in step S502. For example, even after driving the focus lens 32 to the in-focus position, the focus lens 32 can be driven based on the newly calculated defocus amount by repeatedly calculating the defocus amount using the phase difference detection method. can be done. In such a case, when the focus limit mode is changed, the drive target position based on the defocus amount may be outside the focusable range after the change calculated in step S502. If the drive target position of the focus lens 32 is inside the newly calculated focusable range, the process proceeds to step S505. , the process proceeds to step S506. If the drive target position of the focus lens 32 has not been calculated, the process proceeds to step S505.

In step S505, the camera control unit 21 moves the focus lens 32 inside the changed focusable range based on the changed focusable range calculated in step S502 and the current position of the focus lens 32. A determination is made as to whether or not the . For example, when the user changes the focusable range via the focus limit switch 38, the focus lens 32 may be positioned outside the changed focusable range. In such a case, the camera control section 21 can determine that the focus lens 32 is positioned outside the focusable range. If the focus lens 32 is positioned outside the focusable range, the process proceeds to step S506. end the focus limit change processing shown.

In step S506, the camera control unit 21 calculates the lens drive amount required to drive the focus lens 32 to the limit position of the focusable range. Specifically, the camera control unit 21 adjusts the focus lens 32 based on the focusable range calculated in step S<b>502 and the current position of the focus lens 32 so that the focus lens 32 can be focused closer to the current position of the focus lens 32 . A lens drive amount required to drive to the limit position of the range is calculated.

Then, in step S507, the camera control unit 21 performs processing for driving the focus lens 32 to the limit position of the focusable range based on the lens driving amount calculated in step S506. Specifically, the camera controller 21 sends the lens drive amount calculated in step S506 to the focus lens drive motor 36 via the lens controller 37 . Then, the lens drive motor 36 drives the focus lens 32 to the limit position of the focusable range based on the lens drive amount calculated by the camera control section 21 .

As a result, for example, in the "close range limit mode" shown in FIG _. side limit mode" to "infinity side limit mode", and the focusable range is changed from the focusable range Rf2 shown in FIG. 3(B) to the focusable range Rf3 shown in FIG. 3(C). In this case, the focus lens 32 is moved to the infinity side soft limit SL _IS , which is the limit position of the focusable range in the "infinity side limited mode", and the out-of-focus display is performed.

As described above, the operation of the camera 1 according to this embodiment is performed.

As described above, in this embodiment, the focus limit information is transmitted from the lens barrel 3 to the camera body 2 before the focus state of the optical system is detected. Therefore, the following effects can be obtained. For example, based on the focus limit information transmitted from the lens barrel 3, as shown in FIG. 2B, when it is determined that the focus lens 32 is positioned near the close side soft limit SL _NS , step S207 is performed. If the defocus amount cannot be detected in , it can be determined that the in-focus position does not exist on the close-up side soft limit SL _NS side. can be made Thereby, the time required for the scanning operation can be shortened.

Conventionally, since the camera body 2 cannot acquire focus limit information, the camera body 2 waits until the camera body 2 receives a signal from the lens barrel 3 indicating that the focus lens 32 has reached the limit position. 2 needed to transmit a drive signal for driving the focus lens 32 . In particular, since the drive signal is transmitted with the motor drive power for driving the focus lens 32, the power consumption of the camera 1 may increase accordingly. On the other hand, in the present embodiment, the camera body 2 can acquire the focus limit information in advance before transmitting the drive signal for the focus lens 32. Therefore, even if the focus lens 32 exceeds the limit position, In spite of this, it is possible to effectively prevent the drive signal from being transmitted and the motor drive power from being wasted.

Furthermore, in the present embodiment, since the focus limit information is transmitted from the lens barrel 3 to the camera body 2, the camera body 2, for example, determines whether or not the in-focus position is within the focusable range. When it is determined that the in-focus position is not within the in-focus range, a warning or out-of-focus display can be given in advance. Further, for example, when the user performs focus adjustment in the manual focus mode, if the user attempts to drive the focus lens 32 beyond the focusable range, the focus lens 32 is driven beyond the focusable range. It is also possible to present information to the user to the effect that it is not possible. Furthermore, the camera body 2 can display an illustration representing the focusable range selected by the user on the electronic viewfinder 26 or the liquid crystal display.

Further, in the present embodiment, by transmitting focus limit information from the lens barrel 3 to the camera body 2, the camera body 2 determines whether or not the drive target position of the focus lens 32 exceeds the focusable range. It is possible to determine whether or not the camera body 2 can focus on the subject. Therefore, in the present embodiment, the camera body 2 can appropriately determine whether the in-focus display or the out-of-focus display is performed. It is possible to effectively prevent being caught.

Furthermore, in the present embodiment, the focus limit information is acquired from the lens barrel 3 in the camera body 2, and the focusable range is calculated based on the acquired focus limit information. Then, when the defocus amount can be calculated by the phase difference detection method, it is determined whether or not the drive target position according to the defocus amount is inside the focusable range, and the drive is performed according to the defocus amount. If the target position exceeds the focusable range, the camera body 2 calculates the lens drive amount required to move the focus lens 32 to the limit position of the focusable range. By driving the focus lens 32 to the limit position of the focusable range in the lens barrel 3 based on the lens driving amount calculated by the camera body 2, the following effects can be obtained.

That is, conventionally, when the defocus amount can be calculated by the phase difference detection method in the camera body 2, the lens drive amount is calculated based on the drive target position according to the defocus amount, and the calculated lens drive amount is calculated. was sent to the lens barrel 3. In the lens barrel 3, it is repeatedly determined whether or not the focus lens 32 has reached the focusable range, and when the focus lens 32 reaches the limit position of the focusable range, the focus lens 32 is driven. had stopped. For this reason, conventionally, in the lens barrel 3, the processing load for determining whether or not the focus lens 32 has exceeded the focusable range increases. In some cases, the focus lens 32 stops at a position beyond the focusable range, and an in-focus display is performed.

On the other hand, in the present embodiment, when the drive target position based on the defocus amount exceeds the focusable range, the camera body 2 is configured to drive the focus lens 32 to the limit position of the focusable range. A lens drive amount is calculated, and the focus lens 32 is driven in the lens barrel 3 based on the lens drive amount. This eliminates the need to repeatedly determine whether or not the focus lens 32 in the lens barrel 3 exceeds the focusable range. It is possible to effectively prevent in-focus display from being performed at a lens position beyond the focusable range.

Similarly, in the present embodiment, when the focus lens 32 is driven to the in-focus position detected by the contrast detection method, if the drive target position (focus position) of the focus lens 32 exceeds the focusable range, In the camera body 2, the lens drive amount required to drive the focus lens 32 to the limit position of the focusable range is calculated, and in the lens barrel 3, the focus lens 32 is driven based on the lens drive amount. This eliminates the need to repeatedly determine whether or not the focus lens 32 has exceeded the focusable range in the lens barrel 3 even when focus detection is performed by the contrast detection method. can be effectively prevented from exceeding.

In particular, in the present embodiment, servo drive for driving the focus lens 32 based on the defocus amount calculated by the phase difference detection method, and focus drive for driving the focus lens 32 to the in-focus position detected by the contrast detection method. , by limiting the drive of the focus lens 32 within the focusable range, the focus determination is performed and the focus display is performed at the lens position beyond the focusable range. can be effectively prevented.

Furthermore, in the present embodiment, the scan drive range for performing the scan operation is calculated as a range that includes the focusable range and is wider than the focusable range, and the scan operation is performed in the calculated scan drive range. do. As a result, in the present embodiment, even when the peak position of the focus evaluation value (in-focus position) exists at the limit position of the focusable range, it is possible to appropriately detect the in-focus position. That is, conventionally, when focus detection is performed by a contrast detection method such as scan driving, it is repeatedly determined whether or not the focus lens 32 has reached the limit position of the focusable range. Since the drive of the focus lens 32 is stopped when the limit position of the range is reached, when the peak position of the focus evaluation value (in-focus position) exists at the limit position of the focusable range, the in-focus There was a problem that the position could not be detected. In contrast, in the present embodiment, even when the peak position of the focus evaluation value (in-focus position) exists at the limit position of the focusable range, the focus evaluation value is calculated beyond the limit position of the focusable range. is performed, it is possible to appropriately detect the in-focus position.

Further, in the present embodiment, when the focusable range is changed by the user via the focus limit switch 38, the drive target position of the focus lens 32 is outside the changed focusable range, or When the focus lens 32 is positioned outside the changed focusable range, the focus lens 32 is moved to the limit position of the changed focusable range, and out-of-focus display is performed. As a result, when the focusable range is changed, the focus lens 32 remains positioned outside the changed focusable range, and the in-focus display is not displayed outside the changed focusable range. You can effectively prevent it from happening. In particular, in this embodiment, since information on the focus limit mode selected by the user is also transmitted from the lens barrel 3 to the camera body 2 as focus limit information, the focus limit mode can be switched by the user and focusing is possible. When the range is changed, the focus lens 32 can be quickly moved to the limit position of the focusable range after the change.

It should be noted that the embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

For example, in the above-described embodiment, when the "FULL mode" is set in the scanning operation, as shown in _FIG . , the range up to the lens position on the closest side of the closest end soft limit SL _NP is set as the scan drive range Rs1, but the configuration is not limited to this configuration. Alternatively, the range from the infinite far end soft limit SL _IP to the close end soft limit SL _NP may be set as the scan drive range Rs1. Note that FIG. 16 is a diagram showing another example of the scan drive range.

Similarly, when the "closest side limit mode" is set in the scanning operation, as shown in _FIG . Although the configuration in which the range from the soft limit SL _NS to the lens position on the closest side is calculated as the scan drive range Rs2 has been exemplified, the configuration is not limited to this configuration. A configuration may be adopted in which the range from the end soft limit SL _IP to the lens position on the near side of the close side soft limit SL _NS is calculated as the scan drive range Rs2. Also, when the "infinity side limit mode" is set in the scanning operation, as shown in _FIG . A configuration may be employed in which the range up to the end soft limit SL _NP is calculated as the scan driving range Rs3.

Further, in the above-described embodiment, the servo drive (step S213) for driving the focus lens 32 based on the defocus amount calculated by the phase difference detection method, the scan drive in the scan operation (steps S209 to S212), and the contrast The drive control of the focus lens 32 in the focus drive (step S214) for driving the focus lens 32 based on the focus position detected by the detection method has been described as an example. 9, in the search drive for calculating the focus evaluation value while driving the focus lens 32 and the initial drive for driving the focus lens 32 to a predetermined search start position, similar to the scan drive in the scan operation, 13(A) to 13(C) may be configured to limit the drive of the focus lens 32 within the scan drive range.

Further, for example, when the focus state of the optical system changes due to the movement of the subject, such as when photographing a moving subject, and when the focus lens 32 is driven in accordance with the change in the focus state, the focus lens according to the above-described embodiment can be used. A configuration in which drive control of the lens 32 is performed may be employed.

Furthermore, in the above-described embodiment, the three modes of "FULL mode", "closest side limited mode", and "infinity side limited mode" can be set. , Rf3 can be respectively set, but the configuration is not limited to this configuration, and for example, a configuration in which a range desired by the user can be set as the focusable range may be employed.

For example, as shown in FIG. 17, the camera lens barrel 3a is provided with a focus limit switch 38' and a preset memory switch 39, and the user sets the focus limit switch 38' to "preset", and the user selects the desired position. By pressing the preset storage switch 39 at the limit position (end) on the infinity side and the limit position (end) on the close-up side of the focusable range, the lens barrel 3 can be focused as desired by the user. A possible range (preset range) can be stored, and thereafter, when the user sets the focus limit switch 38' to "preset", the focusable range can be limited to the preset range set by the user.

Note that the camera 1 of the above-described embodiment is not particularly limited, and the present invention may be applied to other optical equipment such as a digital video camera, a lens-integrated digital camera, and a camera for mobile phones.

DESCRIPTION OF SYMBOLS 1... Digital camera 2... Camera body 21... Camera control part 22... Imaging element 3... Lens barrel 32... Focus lens 36... Focus lens drive motor 37... Lens control part

Claims (12)

A lens barrel attachable to and detachable from a camera body having an imaging unit,
focus lens and
a driving unit that moves the focus lens in the optical axis direction;
a control unit that controls the driving unit based on a first mode that limits the movable range of the focus lens to a first range and a second mode that does not limit the movable range of the focus lens;
a receiving unit that receives information about focus from the camera body,
When the receiving unit receives the information about the focus in the first mode, if the target position of the focus is within the first range, the driving unit moves the focus lens to the target position, A lens barrel in which, when the target position is not within the first range, the driving section moves the focus lens in the direction of the first range. When the receiving unit receives the focus information in the first mode, the driving unit moves the focus lens in the direction of the first range if the position of the focus lens is not within the first range. 2. The lens barrel according to claim 1, which is movable. 3. The lens barrel according to claim 1, wherein said first range is a range narrower than the entire movable range of said focus lens. 4. The lens barrel according to any one of claims 1 to 3, further comprising a storage unit that stores a plurality of predetermined ranges within the drivable range of the focus lens as the first ranges. 5. The lens barrel according to claim 4, wherein the storage unit stores information about the first range set by a user. The lens barrel according to claim 4 or 5, wherein the control section performs control based on any one of the first ranges stored by the storage section. 7. The lens barrel according to any one of claims 1 to 6, wherein the receiving section periodically receives the driving amount based on the positional information of the focus lens from the camera body at regular intervals. 8. The lens barrel according to any one of claims 1 to 7, wherein the receiving section further includes a transmitting section that transmits information regarding the first mode or the second mode to the camera body. 9. The transmitting unit according to claim 8, wherein when the target position received by the receiving unit in the state of the first mode is outside the first range, the transmitting unit transmits information of warning or out-of-focus display to the camera body. lens barrel. A camera body detachable from the lens barrel according to any one of claims 1 to 9. A camera body having a detachable lens barrel capable of switching between a first mode in which a movable range of a focus lens is limited to a first range and a second mode in which the range is not limited,
an operation unit for the user to operate the focus;
a receiver that receives information about the first mode or the second mode from the lens barrel;
When the operation unit is operated in the state of the first mode, if the target position of the focus lens is within the first range, an instruction to move the focus lens to the target position is transmitted to the lens barrel. and a camera body for transmitting an instruction to move the focus lens in the direction of the first range to the lens barrel when the target position is not within the first range. A camera body having a detachable lens barrel capable of switching between a first mode in which a movable range of a focus lens is limited to a first range and a second mode in which the range is not limited,
an operation unit for the user to operate the focus;
a receiver that receives information about the first mode or the second mode from the lens barrel;
When the second mode is switched to the first mode, if the position of the focus lens is in the first range, information for moving the focus lens is not transmitted to the lens barrel, and the position of the focus lens is changed. is not within the first range, the camera body transmits information to the lens barrel to move the focus lens in the direction of the first range.

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