JP2021165853A - Lens barrel - Google Patents

Abstract

To provide a lens barrel capable of properly controlling drive of a focus adjustment lens.SOLUTION: A lens barrel which can be attached to/detached from a camera body includes, an imaging part includes a focus lens 32, a driving part for moving the focus lens 32 in an optical axis direction, a control part for controlling the driving part on the basis of a first mode in which a movable range of the focus lens 32 is restricted to a first range and a second mode in which the movable range of the focus lens is not restricted, and a receiving part for receiving information on focusing from the camera body. When the receiving part receives the information on the focusing in the state of the first mode, the driving part moves the focus lens 32 up to a target position, when the target position of the focusing is in the first range and moves the focus lens toward the first range, when the target position is not in the first range.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens barrel.

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

Japanese Unexamined Patent Publication No. 2006-126330

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

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

[1] The lens barrel according to the present invention is a lens barrel that can be attached to and detached from a camera body having an imaging unit, and includes a focus lens, a drive unit that moves the focus lens in the optical axis direction, and the focus lens. The control unit that controls the drive unit based on the first mode that limits the movable range of the focus lens to the first range and the second mode that does not limit the movable range of the focus lens, and information on the focus. A receiving unit that receives from the camera body is provided, and when the receiving unit receives information about the focus in the state of the first mode, if the target position of the focus is in 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 driving unit moves the focus lens in the direction of the first range.
[2] In the lens barrel according to the present invention, when the drive unit receives information about the focus in the state of the first mode, the position of the focus lens is not in the first range. , The focus lens can be configured to move to the first range.
[3] In the invention relating to the lens barrel, the first range can be configured to be narrower than the entire movable range of the focus lens.
[4] In the invention according to the lens barrel, a storage unit for storing a plurality of predetermined ranges within the driveable range of the focus lens as the first range is further provided.
[5] In the invention relating to the lens barrel, the storage unit can be configured to store information in the first range set by the user.
[6] In the invention relating to the lens barrel, the control unit can be configured to control based on any one of the first ranges stored by the storage unit.
[7] In the invention relating to the lens barrel, the receiving unit can be configured to periodically receive a drive amount based on the position information of the focus lens from the camera body at regular intervals.
[8] In the invention relating to the lens barrel, the receiving unit may be further provided with a transmitting unit that transmits information regarding the first mode or the second mode to the camera body.
[9] In the invention relating to the lens barrel, when the target position received by the receiving unit is outside the first range in the state of the first mode, the transmitting unit warns or disagrees with the camera body. It can be configured to transmit the focus display information.
[10] The camera body according to the present invention is removable from the lens barrel.
[11] The detachable camera body according to the present invention is a camera having a detachable lens barrel capable of switching between a first mode that limits the movable range of the focus lens to the first range and a second mode that does not limit the movable range of the focus lens. The body, an operation unit in which the user operates the focus, a reception unit that receives information regarding the first mode or the second mode from the lens barrel, and the operation unit in the state of the first mode. When operated, if the target position of the focus lens is in 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 not in the first range. In this case, an instruction to move the focus lens in the direction of the first range is transmitted to the lens barrel.
[12] The detachable camera body according to the present invention is a camera having a detachable lens barrel capable of switching between a first mode that limits the movable range of the focus lens to the first range and a second mode that does not limit the movable range of the focus lens. The body, an operation unit in which the user performs a focus operation, a reception unit that receives information on the first mode or the second mode from the lens barrel, and the second mode is switched to the first mode. When the position of the focus lens is in the first range, the information for moving the focus lens is not transmitted to the lens barrel, and when the position of the focus lens is not in the first range, the above Information for moving the focus lens to the first range is transmitted to the lens barrel.

According to the present invention, the drive of the focusing lens can be appropriately controlled.

FIG. 1 is a block diagram showing a camera according to the present embodiment. FIG. 2 is an external view of the lens barrel 3 according to the present 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 exchanging information between the lens barrel and the camera body. FIG. 5 is a front view showing an image pickup surface of the image pickup device shown in FIG. FIG. 6 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging the VI portion of FIG. 7 (A) is an enlarged front view showing one of the imaging pixels 221; FIG. 7 (B) is an enlarged front view showing one of the focus detection pixels 222a, and FIG. 7 (C) is an enlarged front view. A front view showing one of the focus detection pixels 222b in an enlarged manner, FIG. 7 (D) is a cross-sectional view showing one of the imaging pixels 221 in an enlarged manner, and FIG. 7 (E) is one of the focus detection pixels 222a. 7 (F) is an enlarged cross-sectional view showing one of the focus detection pixels 222b. FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. FIG. 9 is a diagram for explaining an example of a focus detection method by a contrast detection method. FIG. 10 is a flowchart showing a communication process between the lens barrel and the camera body. FIG. 11 is a flowchart showing the operation of the camera of the present embodiment. FIG. 12 is a flowchart showing a lens drive control process 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 a lens drive control process based on the focus detection result by the contrast detection method in step S214. FIG. 15 is a flowchart showing the focus limit change process 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 the external view of the lens barrel 3.

Hereinafter, embodiments of the present invention will be described 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 present invention. The digital camera 1 of the present embodiment (hereinafter, simply referred to as a camera 1) is composed of a camera body 2 and a lens barrel 3, and the camera body 2 and the lens barrel 3 are detachably connected by a mount portion 4. There is.

The 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 has a built-in photographing optical system including lenses 31, 32, 33, and an aperture 34.

The lens 32 is a focus lens, and the focal length of the photographing optical system can be adjusted by moving in the optical axis L1 direction. The focus lens 32 is movably provided along the optical axis L1 of the lens barrel 3, and its position is adjusted by the focus lens drive motor 36 while its position is detected by the encoder 35.

The current position information of the focus lens 32 detected by the encoder 35 is sent to the camera control unit 21 described later via the lens control unit 37, and the focus lens drive motor 36 calculates the focus lens 32 based on this information. Is driven by being transmitted from the camera control unit 21 via the lens control unit 37.

The aperture 34 is configured so that the aperture diameter centered on the optical axis L1 can be adjusted in order to limit the amount of light of the light flux passing through the photographing optical system and reaching the image pickup element 22 and to adjust the amount of blur. The aperture diameter is adjusted by the aperture 34, for example, by sending an appropriate aperture diameter calculated in the automatic exposure mode from the camera control unit 21 via the lens control unit 37. Further, the set aperture diameter is input from the camera control unit 21 to the lens control unit 37 by a manual operation by the operation unit 28 provided on the camera body 2. The aperture diameter of the aperture 34 is detected by an aperture aperture sensor (not shown), and the lens control unit 37 recognizes the current aperture diameter.

Further, in the lens barrel 3 according to the present embodiment, the focusable range of the focus lens 32 can be limited. The in-focus range is a range in which the focus is determined when the in-focus position is detected within the in-focus range. In the present 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 a user operates the focus limit switch 38 to operate the focus limit switch 38. 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 the present embodiment.

Further, FIG. 3 is a diagram showing an example of a focusable range that can be set in the present embodiment. In the present embodiment, as shown in FIG. 3A, _{the "FULL mode" in which the range from the infinity end soft limit SL IP} to the nearest end soft limit SL _NP is set as the in-focus possible range Rf1 and the figure. As shown in FIG. 3 (B), _{the "closest side limit mode" in which the range from the infinity end soft limit SL IP} to the nearest soft limit SL _NS is set as the focusable range Rf2, and FIG. 3 (C). As shown, select three focus limit modes of "infinity side limit mode" that sets the range from the infinity side soft limit SL _IS to the nearest end soft limit SL _{NP as the focusable range Rf3.} Can be done. In the present embodiment, the "FULL mode" is set by adjusting the focus limit switch 38 to the "FULL" shown in FIG. 2, and the "closest side restriction mode" is set by adjusting the focus limit switch 38 to the "limit 1" shown in FIG. Is set, and by adjusting to the "limit 2" shown in FIG. 2, the "infinity side limit mode" is set.

Then, when any of the focus limit modes is selected by the user, as shown in FIG. 4, the focus limit information corresponding to the selected focus limit mode is transmitted from the lens barrel 3 to the camera body 2. NS. The focus limit information is stored in the ROM provided in the lens control unit 37 for each focus limit mode.

For example, when the "FULL mode" shown in FIG. 3A is set by the focus limit switch 38, the lens control unit 37 uses the focus limit information as the limit of the focusable range Rf1 in the "FULL mode". The infinity end soft limit SL _IP and the nearest end soft limit SL _NP , which are the positions (ends), and the corresponding infinity end design value DV _IP and the nearest end design value DV _NP are transmitted to the camera body 2. do.

Further, when the "closest side limit mode" shown in FIG. 3B is set by the focus limit switch 38, the lens control unit 37 can focus in the "closest side limit mode" as focus limit information. _{The infinity end soft limit SL IP} and the nearest soft limit SL _NS , which are the limit positions of the range Rf2, and the corresponding infinity end design value DV _IP and the nearest side design value DV _NS are transmitted to the camera body 2. ..

Similarly, when the "infinity side limit mode" shown in FIG. 3C is set by the focus limit switch 38, the lens control unit 37 sets the focus limit information in the "infinity side limit mode". _{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 nearest end design value DV _NP are displayed on the camera body. Send to 2.

In the present embodiment, the lens barrel 3 has a close-up side soft limit SL _NS , a close-up side design value DV _NS , an infinity side soft limit SL _IS , or an infinity side design value DV _IS for each zoom lens position. The lens control unit 37 also stores 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 as focus limit information. It can be transmitted from the lens barrel 3 to the camera body 2.

Further, in the present embodiment, information indicating whether or not the in-focus range can be limited in the lens barrel 3, such as the in-focus range Rf2 and Rf3, and the "FULL mode" and "FULL mode" and "FULL mode" The focus limit mode selected by the user, such as "infinite side limit mode", is stored in the ROM of the lens control unit 37 as focus limit information, and the lens control unit 37 uses the nearest soft limit SL _NS. , Nearest design value DV _NS , Infinity side soft limit SL _IS , or Infinity side design value DV _IS , plus information indicating whether the focusable range can be limited and selected by the user. The focus limit mode information is transmitted from the lens barrel 3 to the camera body 2 as focus limit information.

In addition, in FIG. 3A, the infinity end design value DV _IP is on the infinity side of the lens positions that guarantee that the lens barrel 3 is designed to focus on the subject in the “FULL mode”. a limit position, taking into account the design errors of the lens barrel 3, an infinite far soft limit SL _IP provided on the infinite side of the infinity end design value DV _IP, if up to the infinite far soft limit SL _IP It is designed to enable detection of the focal position. Similarly, the closest end design value DV _NP is the limit position on the closest side of the lens positions that guarantee that the lens barrel 3 is in focus on the subject in terms of design, and the design error of the lens barrel 3 is reduced. In consideration, the near-end soft limit SL _NP is provided on the side closer to the nearest-end design value DV _NP, and it is designed so that the focusing position can be detected up to this closest-end soft limit SL _NP. ..

Further, in FIG. 3B, the closest design value DV _NS is the closest side of the lens positions that guarantees that the lens barrel 3 is designed to focus on the subject in the “closest side restriction 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 nearest soft limit SL _{NS , which is closer than the nearest design value DV NS.} ing. Similarly, in FIG. 3 (C), the infinity side design value DV _IS is the "infinity side restriction mode", the lens barrel 3, the design, of the lens position to ensure that focus on the subject This is the limit position on the infinity side, and in consideration of the design error of the lens barrel 3, the in-focus position can be detected up to the _{infinity side soft limit SL IS} on the infinity side from the _{infinity side design value DV IS.} Designed to be possible.

Further, as shown in FIG. 4, information on the focus lens position is periodically transmitted from the lens barrel 3 to the camera body 2 in addition to the focus limit information. 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. Note that FIG. 4 is a diagram for explaining an example of exchanging information between the lens barrel 3 and the camera body 2.

On the other hand, the camera body 2 is provided with an image pickup element 22 that receives the light flux L1 from the photographing optical system on the planned focal plane of the photographing optical system, and a shutter 23 is provided on the front surface thereof. The image sensor 22 is composed of a device such as a CCD or CMOS, converts the received optical signal into an electric signal, and sends it to the camera control unit 21. The captured image information sent to the camera control unit 21 is sequentially sent to the liquid crystal drive circuit 25 and displayed on the electronic viewfinder (EVF) 26 of the observation optical system, and the release button (release button) provided on the operation unit 28. When (not shown) is fully pressed, the captured image information is recorded in the camera memory 24 which is a recording medium. As the camera memory 24, either a detachable card type memory or a built-in type memory can be used.

The camera body 2 is provided with an observation optical system for observing the image captured by the image sensor 22. The observation optical system of the present embodiment includes an electronic viewfinder (EVF) 26 composed of a liquid crystal display element, a liquid crystal drive circuit 25 for driving the electronic viewfinder (EVF) 26, and an eyepiece lens 27. The liquid crystal drive circuit 25 reads the captured image information captured by the image sensor 22 and sent to the camera control unit 21, and drives the electronic viewfinder 26 based on the captured image information. This allows the user to observe the current captured image through the eyepiece 27. In addition to or in addition to the above-mentioned observation optical system by the optical axis L2, a liquid crystal display may be provided on the back surface of the camera body 2 or the like, and a photographed image may be displayed on the liquid crystal display.

The camera body 2 is provided with a camera control unit 21. The camera control unit 21 is electrically connected to the lens control unit 37 by an electric signal contact unit 41 provided in the mount unit 4, receives lens information from the lens control unit 37, and drives the lens to the lens control unit 37. Send information such as the amount and aperture opening diameter. Further, the camera control unit 21 reads the pixel output from the image sensor 22 as described above, and generates image information by performing predetermined information processing on the read pixel output as necessary, and the generated image information. Is output to the liquid crystal drive circuit 25 and the memory 24 of the electronic viewfinder 26. Further, the camera control unit 21 controls the entire camera 1 by correcting the image information from the image sensor 22, detecting the focus adjustment state and the aperture adjustment state of the lens barrel 3, and the like.

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

The operation unit 28 is an input switch for the user such as a shutter release button to set various operation modes of the camera 1, and can switch between the autofocus mode and the manual focus mode. Various modes set by the operation unit 28 are sent to the camera control unit 21, and the operation of the entire camera 1 is controlled by the camera control unit 21. Further, the shutter release button 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 image pickup device 22 according to the present embodiment will be described.

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

In the image pickup device 22 of the present embodiment, as shown in FIG. 6, a plurality of image pickup pixels 221 are arranged two-dimensionally on a plane of an image pickup surface, and a green pixel G having a color filter that transmits a green wavelength region is provided. A red pixel R having a color filter that transmits a red wavelength region and a blue pixel B having a color filter that transmits a blue wavelength region are arranged in a so-called Bayer Arrangement. That is, in the four adjacent pixel groups 223 (dense square grid array), 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 sensor 22 is configured by repeatedly arranging the pixel group 223 on the image pickup surface of the image pickup device 22 in a two-dimensional manner with the Bayer-arranged pixel group 223 as a unit.

The arrangement of the unit pixel group 223 may be, for example, a dense hexagonal lattice arrangement in addition to the dense square lattice shown in the figure. Further, 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 adopted.

FIG. 7A is an enlarged front view showing one of the imaging pixels 221 and FIG. 7D is a cross-sectional view. One image pickup pixel 221 is composed of a microlens 2211, a photoelectric conversion unit 2212, and a color filter (not shown), and is formed on the surface of the semiconductor circuit board 2213 of the image pickup element 22 as shown in the cross-sectional view of FIG. 7 (D). A photoelectric conversion unit 2212 is built in, and a microlens 2211 is formed on the surface thereof. The photoelectric conversion unit 2212 has a shape that receives an imaging light flux passing through an exit pupil (for example, F1.0) of a photographing optical system by a microlens 2211, and receives an imaging light beam.

Further, focus detection pixel rows 22a, 22b, 22c in which focus detection pixels 222a, 222b are arranged in place of the above-mentioned image pickup pixels 221 at the center of the image pickup surface of the image pickup element 22 and at three positions symmetrically positioned from the center. Is provided. Then, as shown in FIG. 6, one focus detection pixel array is composed of a plurality of focus detection pixels 222a and 222b arranged in a horizontal row (22a, 22c, 22c) alternately adjacent to each other. There is. In the present embodiment, the focus detection pixels 222a and 222b are densely arranged without providing a gap between the green pixel G and the blue pixel B of the Bayer-arranged imaging pixels 221.

The positions of the focus detection pixel rows 22a to 22c shown in FIG. 5 are not limited to the positions shown in the drawing, and may be one or two positions, or may be arranged at four or more positions. can. Further, in actual focus detection, the user manually operates the operation unit 28 to select a desired focus detection pixel array as the focus detection area from the plurality of arranged focus detection pixel sequences 22a to 22c. You 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. Further, FIG. 7C is an enlarged front view showing one of the focus detection pixels 222b, and FIG. 7F is a cross-sectional view of the focus detection pixel 222b. As shown in FIG. 7B, the focus detection pixel 222a is composed of a microlens 2221a and a semicircular photoelectric conversion unit 2222a, and as shown in the cross-sectional view of FIG. 7E, the image pickup element 22 A photoelectric conversion unit 2222a is built on the surface of the semiconductor circuit board 2213, and a microlens 2221a is formed on the surface thereof. Further, the focus detection pixel 222b is composed of a microlens 2221b and a photoelectric conversion unit 2222b as shown in FIG. 7C, and is a semiconductor of the image pickup element 22 as shown in the cross-sectional view of FIG. 7F. A photoelectric conversion unit 2222b is built on the surface of the circuit board 2213, and a microlens 2221b is formed on the surface thereof. Then, as shown in FIG. 6, these focus detection pixels 222a and 222b are arranged adjacent to each other in a horizontal row alternately to form the focus detection pixel rows 22a to 22c shown in FIG.

The photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b are shaped so as to receive the light flux passing through a predetermined region (for example, F2.8) of the exit pupil of the photographing optical system by the microlenses 2221a and 2221b. Will be done. Further, the focus detection pixels 222a and 222b are not provided with a color filter, and the spectral characteristics thereof are a combination of the spectral characteristics of the photodiode that performs photoelectric conversion and the spectral characteristics of an infrared cut filter (not shown). ing. However, it may be configured to include one of the same color filters as the image pickup 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. 7 (B) and 7 (C) have a semicircular shape, the shapes of the photoelectric conversion units 2222a and 2222b are not limited to this. , Other shapes, such as elliptical, rectangular, polygonal.

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

FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. It is shown that the light fluxes AB1-1, AB2-1, AB1-2, and AB2-2 emitted from the distance measuring pupils 351 and 352 of the exit pupil 350 are received, respectively. Note that, in FIG. 8, of the plurality of focus detection pixels 222a and 222b, only those located near the photographing optical axis L1 are shown as an example, but other focus detection pixels other than the focus detection pixels shown in FIG. 8 are shown. Similarly, the light beam emitted from the pair of ranging pupils 351 and 352 is also configured to receive light.

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 planned focal plane of the photographing optical system. The distance D is a value uniquely determined according to the curvature and refractive index of the microlens, the distance between the microlens and the photoelectric conversion unit, and the like, and this distance D is referred to as a distance measuring pupil distance. Further, the distance measuring 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 arrangement directions of the focus detection pixels 222a-1,222b-1,222a-2, 222b-2 coincide with the arrangement directions of the pair of ranging pupils 351 and 352.

Further, as shown in FIG. 8, the microlenses 2221a-1,2221b-1,2221a-2, 2221b-2 of the focus detection pixels 222a-1,222b-1,222a-2, 222b-2 are of the optical system. It is located near the planned focal plane. Then, the shapes of the photoelectric conversion units 2222a-1,2222b-1,2222a-2, 2222b-2 arranged behind the microlenses 2221a-1,221b-1,2221a-2, 2221b-2 are microscopic. It is projected onto the exit pupil 350, which is separated by the distance measurement distance D from the lenses 2221a-1,221b-1,2221a-2, 2221b-2, and the projected shape forms the distance measurement pupils 351 and 352.

That is, the microlens and the photoelectric conversion unit in each focus detection pixel match so that the projection shapes (distance measurement pupils 351 and 352) of the photoelectric conversion unit of each focus detection pixel match on the exit pupil 350 at the distance measurement distance D. The relative positional relationship between the two is determined, and the projection direction of the photoelectric conversion unit in each focus detection pixel is determined accordingly.

As shown in FIG. 8, the photoelectric conversion unit 2222a-1 of the focus detection pixel 222a-1 passes through the ranging pupil 351 and is formed on the microlens 2221a-1 by the luminous flux AB1-1 toward the microlens 2221a-1. A signal corresponding to the intensity of the image to be produced is output. Similarly, the photoelectric conversion unit 2222a-2 of the focus detection pixel 222a-2 passes through the ranging pupil 351 and the intensity of the image formed on the microlens 2221a-2 by the luminous flux AB1-2 toward the microlens 2221a-2. Outputs the 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 luminous flux AB2-1 toward the microlens 2221b-1. Output the corresponding signal. Similarly, the photoelectric conversion unit 2222b-2 of the focus detection pixel 222b-2 passes through the ranging pupil 352, and the intensity of the image formed on the microlens 2221b-2 by the luminous flux AB2-2 directed toward the microlens 2221b-2. Outputs the signal corresponding to.

Then, a plurality of the above-mentioned two types of focus detection pixels 222a and 222b are linearly arranged as shown in FIG. 6, and the outputs of the photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b are output to the distance measuring pupil 351. By grouping them into output groups corresponding to each of the distance measuring pupil 352 and the focusing pupil 352, the intensity of the pair of images formed on the focal detection pixel array by the focal detection light flux passing through each of the focusing pupil 351 and the focusing pupil 352. Data on the distribution is obtained. Then, the image shift amount by the so-called phase difference detection method is detected by performing an image shift detection calculation process such as a correlation calculation process or a phase difference detection process on the intensity distribution data.

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

The image shift amount calculation, the defocus amount calculation, and the focusing drive by these phase difference detection methods are executed by the camera control unit 21.

Further, the camera control unit 21 reads out the output of the image pickup pixel 221 of the image pickup element 22, and calculates the focus evaluation value based on the read out pixel output. This focus evaluation value can be obtained, for example, by extracting the high-frequency component of the image output from the image pickup pixel 221 of the image pickup 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 a focus evaluation value at each position, and the focus evaluation value is the maximum. Focus detection by a contrast detection method is performed, in which the position of the focus lens 32 is determined as the in-focus position. It should be noted that this focusing position is determined, for example, when the focus evaluation value is calculated while driving the focus lens 32, and when the focus evaluation value increases twice and then decreases twice. It can be obtained by performing an operation 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 located at P0 shown in FIG. 9, and first, the focus lens 32 is driven from P0 to a predetermined search start position (position of P1 in FIG. 9). The initial drive is performed. Then, the focus lens 32 is driven from the search start position (position P1 in FIG. 9) from the infinity side to the closest side, and the focus evaluation value is acquired by the contrast detection method at predetermined intervals. The drive is done. Then, when the focus lens 32 is moved to the position of P2 shown in FIG. 9, the peak position of the focus evaluation value (the position of P3 in FIG. 9) is detected as the in-focus position, and the detected in-focus position is detected. Focusing drive for driving the focus lens 32 is performed up to (the position of P3 in FIG. 9).

Next, an operation example of the camera 1 according to the present embodiment will be described. FIG. 10 is a flowchart showing a communication process between the lens barrel 3 and the camera body 2, and FIG. 11 is a camera performed after the start of communication between the lens barrel 3 and the camera body 2 by the communication process shown in FIG. It is a flowchart which shows the operation of 1. The operations shown in FIGS. 10 and 11 are started when the power of the camera body 2 is turned on.

First, the communication process 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 or not the lens barrel 3 is attached to the camera body 2. For example, in the camera control unit 21, the lens barrel 3 is attached to the camera body 2 when the lens control unit 37 can be energized via the electric signal contact unit 41 provided in the mount unit 4. Can be judged. If it is determined that the lens barrel 3 is attached to the camera body 2, the process proceeds to step S102, while if it is determined that the lens barrel 3 is not attached to the camera body 2, step S102 is performed. Wait at S101.

In step S102, the camera control unit 21 supplies electric power from the camera body 2 to the lens barrel 3. As a result, communication between the lens barrel 3 and the camera body 2 becomes possible.

Subsequent step S103 is a process on the lens barrel 3 side. In step S103, the lens control unit 37 performs an initial communication process of transmitting information unique 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 such as whether the lens barrel 3 has a range limit function to the camera body 2.

In step S104, the camera control unit 21 and the lens control unit 37 perform communication setting processing, respectively, in preparation for starting steady communication in step S105, which will be described later. In the present embodiment, as communication between the lens barrel 3 and the camera body 2, a steady communication in which predetermined information is collectively transmitted at regular intervals and a minimum necessary information are transmitted irregularly. Non-steady communication is possible, and in step S104, a setting for performing steady communication is made.

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

Next, the operation of the camera 1 will be described with reference to FIG. In the process shown in FIG. 11, as shown in FIG. 10, the 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 steady communication.

Specifically, first, in step S201, it is determined by the communication process shown in FIG. 10 whether or not steady communication has been started between the lens barrel 3 and the camera body 2. If steady-state communication has not been started between the lens barrel 3 and the camera body 2, it waits in step S201 until steady-state communication is started, and is steady between the lens barrel 3 and the camera body 2. When the communication is started, the process proceeds to step S202.

In step S202, the camera control unit 21 acquires the focus limit information. In the present 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 at predetermined intervals by steady communication. The camera control unit 21 can acquire the focus limit information corresponding to the currently set focus limit mode from the lens control unit 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 uses the focus limit information as the focus limit information in the focusable range in the “FULL mode”. Information including the limit position (end) of Rf1 including the infinity end soft limit SL _IP and the nearest end soft limit SL _NP is periodically transmitted to the camera body 2. As a result, the camera control unit 21 can acquire focus limit information including _{the infinity end soft limit SL IP} and the near end soft limit SL _NP.

Similarly, as shown in FIG. 3B, when the focus limit switch 38 sets the "closest side limiting mode", the camera control unit 21 can focus in the "closest side limiting mode". _{Information including the infinity end soft limit SL IP} and the nearest soft limit SL _NS , which are the limit positions of Rf2, is acquired as focus limit information, and as shown in FIG. 3C, the focus limit switch 38 is used. _{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". Information including the above can be acquired as focus limit information.

Even if the focus limit mode is the same, the focusing range Rf1 to Rf3 of the focus lens 32 may be different depending on the type of the lens barrel 3. Therefore, the camera control unit 21 acquires the 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. 3A to 3C. ..

For example, as shown in FIG. 3A, the camera control unit 21 is set to "FULL mode", and the infinity end soft limit SL _IP and the nearest end soft limit SL _NP are acquired as focus limit information. If so, the range from the infinity end soft limit SL _IP to the nearest end soft limit SL _NP is calculated as the in-focus possible range Rf1.

Similarly, as shown in FIG. 3B, the camera control unit 21 is set to the "closest side limit mode", and the infinity end soft limit SL _IP and the near side soft limit SL _{NS are set as focus limit information.} If is acquired, the range from the infinity end soft limit SL _IP to the nearest soft limit SL _NS is calculated as the focusable range Rf2. Further, as shown in FIG. 3C, the camera control unit 21 is set to the "infinity side limit mode", and the infinity side soft limit SL _IS and the nearest end soft limit SL are set as focus limit information. _{When the NP} is acquired, the range from the infinity side soft limit SL _IS to the nearest end soft limit SL _NP is calculated as the focusable range Rf3.

Depending on the type of the lens barrel 3, the focus limit function may not be provided, and the focus limit information may not be acquired from the lens barrel 3. In such a case, as shown in FIG. 3A, the camera control unit 21 _{calculates the range Rf1 from the infinity end soft limit SL IP} to the nearest end soft limit SL _NP as the focusable range. be able to.

In step S204, the camera control unit 21 starts the process of calculating the defocus amount by the phase difference detection method. In the present embodiment, the defocus amount calculation process by the phase difference detection method is performed as follows. That is, first, the camera control unit 21 reads out a pair of image data corresponding to the pair of images from the focus detection pixels 222a and 222b constituting the three focus detection pixel rows 22a to 22c of the image sensor 22. Then, the camera control unit 21 executes an image shift detection calculation process (correlation calculation process) based on the pair of read image data, and images at the focus detection positions corresponding to the three focus detection pixel sequences 22a to 22c. The amount of deviation is calculated, and the amount of image deviation is further converted into the amount of defocus. Further, the camera control unit 21 evaluates the reliability of the calculated defocus amount. The reliability of the defocus amount is evaluated based on, for example, the degree of coincidence and contrast of a pair of image data. Further, the defocus amount calculation process by such a phase difference detection method is repeatedly executed at predetermined intervals.

In step S205, the process of calculating the focus evaluation value by the camera control unit 21 is started. In the present embodiment, the focus evaluation value is calculated by reading out the pixel output of the image pickup pixel 221 of the image pickup element 22, extracting the high frequency component of the read out pixel output using a high frequency transmission filter, and integrating this. Will be done. The focus evaluation value is calculated only by the pixel output of the imaging pixel 221 corresponding to the selected focus detection position when a specific focus detection position is selected by the user's manual operation or by the subject recognition mode or the like. May be configured to read. 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 on the operation unit 28 is half-pressed (the first switch SW1 is 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 can be calculated by the phase difference detection method. If the defocus amount can be calculated, it is determined that the distance can be measured, and the process proceeds to step S213. On the other hand, if the defocus amount cannot be calculated, it is determined that the distance measurement is impossible, and the process proceeds to step S208. In the present 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 in step S208. Let's move on.

If it is determined in step S207 that the defocus amount has been calculated and it is determined that the distance can be measured, 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. Lens drive control processing is performed. Here, FIG. 12 is a flowchart showing the lens drive control process in step S213. In the following, the lens drive control process in step S213 will be described with reference to FIG.

First, in step S301, the camera control unit 21 determines whether or not the in-focus range is limited. For example, in step S202, when the information of the infinity end soft limit SL _IP and the nearest end soft limit SL _NP is acquired as the focus limit information, the camera control unit 21 receives the infinity end soft limit SL IP and the nearest end _{soft limit SL IP.} 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 it can be determined that the focusable range Rf1 is not limited.

On the other hand, when the information of the infinity end soft limit SL _IP and the nearest side soft limit SL _NS is acquired as the focus limit information in step S202, the camera control unit 21 receives the infinity end soft limit SL IP and the nearest side soft limit _{SL IP.} Based on the SL _NS information, it can be determined that the "closest side restriction mode" is set, and thereby it can be determined that the focusable range Rf2 is restricted. Similarly, in step S202, when the information of the infinity side soft limit SL _IS and the nearest end soft limit SL _NP is acquired as the focus limit information, the camera control unit 21 has the infinity side soft limit SL _IS and the closest end. Based on the information of the edge soft limit SL _NP , it can be determined that the "infinity side restriction mode" is set, and thereby it can be determined that the focusable range Rf3 is limited.

If it is determined in step S301 that the focusable range is limited, 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. It is said.

Specifically, the camera control unit 21 first sets the lens position (unit: pulse) in which the subject is in focus based on the defocus amount calculated by the phase difference detection method and the current focus lens position. Calculate as number). Further, when the subject is a moving object, the camera control unit 21 calculates the drive target position based on the subject position, taking into account 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 the 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 matches the drive target position based on the calculated lens drive amount (unit: pulse number) of the focus lens 32 and the focusable range (unit: pulse number) calculated in step S203. Judge whether or not the focal 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 nearest _{soft limit SL NS, the camera control unit 21 moves the drive target position.} Can be determined to exceed 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, while 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, since it is determined that the drive target position based on the defocus amount exceeds the focusable range, the camera control unit 21 sets the focus lens 32 to the limit position (end) of the focusable range. The lens drive amount required for driving is calculated. Specifically, the camera control unit 21 is required to drive the focus lens 32 to a limit position in the focusable range close to the drive target position based on the current position of the focus lens 32 and the focusable range. Calculate the amount of lens drive.

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 nearest _{soft limit SL NS, the camera control unit 21 moves the drive target position.} The lens drive amount required to drive the focus lens 32 to the _{nearest soft limit SL NS} , which is the limit position of the focusable range Rf2 close to the subject, is calculated. Further, in the example shown in FIG. 3C, when the drive target position based on the defocus amount is the lens position on the infinity side of the infinity _{side soft limit SL IS, the camera control unit 21 drives.} The amount of lens drive 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 close to the target position, is calculated.

Then, in step S304, the camera control unit 21 performs a process 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-regular communication. Then, the focus lens drive motor 36 drives the focus lens 32 to the limit position in 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 the lens position closer to the nearest soft limit SL NS} , the focus lens 32 is softened to the nearest side. It will be moved to the limit SL _NS. Further, in the example shown in FIG. 3C, even when the drive target position based on the defocus amount is the lens position on the infinity side of the infinity _{side soft limit SL IS, the focus lens 32 is infinity side soft.} It will be moved to the limit SL _IS.

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

On the other hand, in step S301, when it is determined that the in-focus range is not limited, or in step S302, it is determined that the drive target position based on the defocus amount is within the in-focus range. , 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, and in the subsequent step S307, it is based on the calculated lens drive amount. The focus lens 32 is driven to the drive target position (focusing position). Then, in step 208, the focus display is performed.

As described above, the drive control process 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 in-focus range Rf1 to Rf3 shown in FIGS. 3A to 3C. As described above, the drive control of the focus lens 32 is performed. That is, when the drive target position based on the defocus amount exceeds the in-focus range Rf1 to Rf3, the lens drive amount required to drive the camera body 2 to the limit position in the in-focus range is calculated. In the lens barrel 3, the focus lens 32 is driven to the limit position in the focusable range based on the lens drive amount calculated by the camera body 2. As a result, the focus lens 32 is driven to a lens position that exceeds the in-focus range Rf1 to Rf3, and it is possible to effectively prevent the in-focus display from being performed at the lens position that exceeds the in-focus range. can. Then, after the lens drive control process shown in FIG. 12 is completed, the process proceeds to step S218 shown in FIG.

If 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 drive range, which is the driveable range of the focus lens 32 in the scan operation, and in the following step S209, the scan drive is performed in the scan drive range calculated in step S208. The scanning operation to be performed is started.

The scan operation is the calculation of the defocus amount by the phase difference detection method and the focus evaluation value by the camera control unit 21 while driving the focus lens 32 at a predetermined drive speed (scan drive) by the focus lens drive motor 36. Is calculated at the same time at a predetermined interval, whereby the detection of the focusing position by the phase difference detection method and the detection of the focusing position by the contrast detection method are simultaneously executed at a predetermined interval.

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 scanned driven along the optical axis L1. The scan drive of the focus lens 32 may be performed from the infinity end to the nearest end, or may be performed from the closest end to the infinity end.

Then, the camera control unit 21 reads out a pair of image data corresponding to the pair of images from the focus detection pixels 222a and 222b of the image pickup element 22 at predetermined intervals while driving the focus lens 32, and based on this, the camera control unit 21 reads out a pair of image data corresponding to the pair of images. The defocus amount is calculated by the phase difference detection method, and the pixel output is read out from the image pickup pixel 221 of the image pickup element 22 at predetermined intervals while driving the focus lens 32, and the focus evaluation value is calculated based on this. The focus position is detected by the contrast detection method by calculating and acquiring the focus evaluation values at different focus lens positions.

Further, in the present embodiment, in order to perform the 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, the scan drive ranges Rs1 to Rs3 include the focusable ranges Rf1 to Rf3 shown in FIGS. 3A to 3C, and the focusable range Rf1 It is calculated as a range wider than ~ Rf3.

Here, in the scanning operation, as described above, while driving the focus lens 32, 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 are simultaneously performed at predetermined intervals. It is an operation. Then, in order to detect the peak position (focusing 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 (focus position) of the focus evaluation value with the _{infinity end soft limit SL IP} by the contrast detection method, the focus lens 32 is set to infinity more than the _{infinity end soft limit SL IP.} It is necessary to drive to the side and calculate the focus evaluation value. Similarly, for example, in the scanning operation, in order to detect the peak position (focusing position) of the focus evaluation value _{by the near-end soft limit SL NP by the contrast detection method, the focus lens 32 is moved to the closest-end soft limit SL. It} is necessary to drive to the side closer to the NP and calculate the focus evaluation value.

Therefore, when the camera control unit 21 performs the scanning operation, when the focus limit mode is the "FULL mode", as shown in FIG. 13A, the camera control unit 21 is farther than the _{infinity end soft limit SL IP.} The range from the lens position on the side to the lens position on the closest side to the nearest soft limit SL _NP is calculated as the scan drive range Rs1. For example, in the present embodiment, when the focus evaluation value rises twice and then falls again twice, the peak of the focus evaluation value is calculated using these focus evaluation values, so that the camera control From the lens position where two focus evaluation values can be calculated on the infinity side of the infinity end soft limit SL _{IP , the unit 21 sets the focus evaluation value of 2 on the near end soft limit SL NP.} 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 the camera control unit 21 performs the scanning operation, when the focus limit mode is the "closest side limit mode", as shown in FIG. 13B, the camera control unit 21 is more than the _{infinity end soft limit SL IP.} The range from the lens position on the infinity side to the lens position on the closest side to the nearest soft limit SL _NS is calculated as the scan drive range Rs2. Similarly, when the focus limit mode is the "infinity side limit mode", the camera control unit 21 is a lens on the infinity side of the infinity _{side soft limit SL IS as shown in FIG. 13 (C).} The range from the position to _{the lens position closer to the nearest soft limit SL NP} is calculated as the scan drive range Rs3 in the scan operation.

Then, in step S209, a scan operation for driving the scan is performed in the scan drive ranges 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 by setting the scan drive ranges Rs1 to Rs3 shown in FIGS. 13 (A) to 13 (C) as the driveable range of the focus lens 32. Even when the focusing position exists at the limit position of the focusing possible range shown in FIGS. 3A to 3C, such a focusing 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 performing the scanning operation. 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 cannot be calculated, it is determined that distance measurement is not possible and the process proceeds to step S211. .. In step S210, even if the defocus amount could be calculated 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 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 performing the scanning operation. If the in-focus position can be detected by the contrast detection method, the process proceeds to step S214, while if the in-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. When the scan drive is not performed for the entire scan drive range, the process returns to step S210 and the steps S210 to S212 are repeated to perform a scan operation, that is, a phase difference detection method while driving the focus lens 32 for scan. The operation of simultaneously executing the calculation of the defocus amount by the above method and the detection of the focusing position by the contrast detection method at predetermined intervals is continuously performed. On the other hand, if the execution of the scan operation is completed for the entire scan drive range, the process proceeds to step S215.

Then, as a result of executing the scan operation, if it is determined in step S210 that the defocus amount can be calculated by the phase difference detection method, the scan operation is stopped, the process proceeds to step S213, and the same procedure as described above is performed. 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 according to the defocus amount exceeds the focusable range (step S301 = Yes, S302 = Yes), the focus lens 32 is moved. The lens drive amount for driving to the limit position in the in-focus range is calculated (step S303), and the focus lens 32 is driven to the limit position in the in-focus range based on the calculated lens drive amount (step S304). , Out-of-focus display is performed (step S308). On the other hand, when the drive target position according to the defocus amount is within the focusable range (step S302 = No), or when the focusable range is not limited (step S301 = No), the defocus is achieved. The lens drive amount corresponding to the amount is calculated (step S306), the focus lens 32 is driven based on the lens drive amount according to the defocus amount (step S307), and the in-focus display is performed (step S308).

Further, as a result of executing the scanning operation, if it is determined in step S211 that the focusing position can be detected by the contrast detection method, the scanning operation is stopped, the process proceeds to step S214, and the focus detection result by the contrast detection method is obtained. Based on this, the drive control of the focus lens 32 is performed. Here, FIG. 14 is a flowchart showing a lens drive control process based on the focus detection result by the contrast detection method.

As shown in FIG. 14, first, in step S401, as in step S301, it is determined whether or not the in-focus range is limited. Then, if the in-focus range is limited, the process proceeds to step S402, while if the in-focus range is not limited, the process proceeds to step S406.

In step S402, it is determined whether or not the focusing position detected by the contrast detection method exceeds the focusing possible range. For example, in the scanning operation, as shown in FIG. 3B, when the "closest side restriction mode" is set, the focus lens 32 is driven to the closer side than the _{nearest side soft limit SL NS to evaluate the focus.} As a result of calculating the value, when the peak position (focusing position) of the focus evaluation value _{is detected on the side closer to the nearest soft limit SL NS} , the camera control unit 21 is detected by the contrast detection method. It is determined that the in-focus position exceeds the in-focus possible range Rf2, and the process proceeds to step S403. Further, in the scanning operation, as shown in FIG. 3C, when the "infinity side restriction mode" is set, the focus lens 32 is driven to the infinity side from the _{infinity side soft limit SL IS.} As a result of calculating the focus evaluation value, when the peak position (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 uses a contrast detection method. It is determined that the focusing position detected by the above-mentioned is beyond the focusing possible range Rf3, and the process proceeds to step S403.

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

As a result, for example, in the example shown in FIG. 3B, the focus lens 32 is close even when the _{focusing position calculated by the contrast detection method is the lens position closer to the nearest soft limit SL NS.} It will be moved to the side soft limit SL _NS. Further, in the example shown in FIG. 3C, the focus lens 32 is at infinity even when the _{focusing position calculated by the contrast detection method is the lens position on the infinity side of the infinity side soft limit SL IS.} It will be moved to the side soft limit SL _IS.

On the other hand, in step S401, it is determined that the in-focus range is not limited, or in step S402, it is determined that the in-focus position detected by the contrast detection method is within the in-focus range. 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, and in the following step S407, the camera control unit 21 calculates the lens calculated in step S406. The process of driving the focus lens 32 to the in-focus position is performed based on the driving amount. After that, in step S408, the in-focus display is performed.

As described above, the drive control of the focus lens 32 is performed based on the focusing position detected by the contrast detection. In this way, in the focusing drive in which the focus lens 32 is driven to the focusing position detected by the contrast detection method, the focus lens 32 is driven within the focusing range shown in FIGS. 3A to 3C. , Drive control of the focus lens 32 is performed. That is, when the in-focus position detected by the contrast detection method exceeds the in-focus range, the lens drive amount required to drive the focus lens 32 to the limit position in the in-focus range in the camera body 2 is increased. The focus lens 32 is driven in the lens barrel 3 based on the calculated lens drive 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 position exceeding the in-focus range and displaying the in-focus display at a position exceeding the in-focus range. Then, after the lens drive control process shown in FIG. 14 is completed, the process proceeds to step S218 shown in FIG.

If it is determined in step S212 that the execution of the scan operation has been completed for the entire scan drive range, the process proceeds to step S215. In step S215, as a result of performing the scan operation, the focus could not be detected by either the phase difference detection method or the contrast detection method. Therefore, the end process of the scan operation is performed, and the process proceeds to step S216.

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

Further, in the present embodiment, after the focus adjustment is performed based on the focus detection result, the process proceeds to step S218, and the focus limit change process is performed in step S218. FIG. 15 is a flowchart showing the focus limit change process 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 immediately preceding focusable range, and determines whether or not the focusable range has been changed. If the in-focus range is changed, the process proceeds to step S504. On the other hand, if the in-focus range is not changed, the focus limit change process shown in FIG. 15 is terminated.

In step S504, the camera control unit 21 determines whether or not the drive target position of the focus lens 32 is within the changed focusable range calculated in step S502. For example, even after the focus lens 32 is driven to the in-focus position, the focus lens 32 is driven based on the newly calculated defocus amount by repeatedly calculating the defocus amount by the phase difference detection method. Can be done. In such a case, by changing the focus limit mode, the drive target position based on the defocus amount may be outside the changed focusable range 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, while the drive target position of the focus lens 32 is outside the focusable range. 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 focus lens 32 is inside the changed focusable range based on the changed focusable range and the current position of the focus lens 32 calculated by the camera control unit 21 in step S502. It is determined whether or not it is located in. For example, when the focus limit switch 38 is changed by the user, the focus lens 32 may be located outside the changed focus range. In such a case, the camera control unit 21 can determine that the focus lens 32 is located outside the focusable range. Then, when the focus lens 32 is located outside the focusable range, the process proceeds to step S506, while when the focus lens 32 is located inside the focusable range, FIG. 15 shows. The indicated focus limit change process ends.

In step S506, the camera control unit 21 calculates the amount of lens drive required to drive the focus lens 32 to the limit position in the focusable range. Specifically, the camera control unit 21 can focus the focus lens 32 closer to the current position of the focus lens 32 based on the focusable range calculated in step S502 and the current position of the focus lens 32. Calculate the lens drive amount required to drive to the limit position of the range.

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

As a result, for example, in the "closest side limiting mode" shown in FIG. 3B, when the focus lens 32 is _{located on the infinity side of the infinity side soft limit SL IS} , the focus limit mode is "closest". The "side restriction mode" is changed to the "infinity side restriction mode", and the in-focus range is changed from the in-focus range Rf2 shown in FIG. 3 (B) to the in-focus range Rf3 shown in FIG. 3 (C). _{If so, the focus lens 32 is moved to the infinity side soft limit SL IS,} which is the limit position of the infinity possible range in the "infinity side limit mode", and the out-of-focus display is performed.

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

As described above, in the present embodiment, the focus limit information is transmitted from the lens barrel 3 to the camera body 2 before detecting the focal state of the optical system, so that the following effects can be obtained. For example, when it is determined _{that the focus lens 32 is located near the nearest soft limit SL NS} as shown in FIG. 2B based on the focus limit information transmitted from the lens barrel 3, step S207 If the defocus amount cannot be detected in, it can be determined that the focusing position _{does not exist on the near side soft limit SL NS} side, so that the focus lens 32 is scanned from the near side to the infinity side. Can be made to. As a result, the time required for the scanning operation can be shortened.

Further, conventionally, since the camera body 2 cannot acquire the focus limit information, 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 this drive signal is transmitted by the motor drive power for driving the focus lens 32, the power consumption of the camera 1 may be increased by that amount. 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 of the focus lens 32, so that the focus lens 32 exceeds the limit position. Nevertheless, it is possible to effectively prevent the drive signal from being transmitted and the motor drive power from being wasted.

Further, in the present embodiment, the focus limit information is transmitted from the lens barrel 3 to the camera body 2, so that the camera body 2 determines, for example, whether or not the in-focus position is within the in-focus range. If it is determined that the in-focus position does not exist within the in-focus range, a warning or out-of-focus display can be given in advance. Further, for example, when the user adjusts the focus in the manual focus mode and the user tries 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 that it cannot be done. Further, the camera body 2 can also display an illustration showing a focusable range selected by the user on the electronic viewfinder 26 or the liquid crystal display.

Further, in the present embodiment, by transmitting the focus limit information from the lens barrel 3 to the camera body 2, it is determined whether or not the drive target position of the focus lens 32 exceeds the focusable range in the camera body 2. This makes it possible for the camera body 2 to determine whether or not the subject can be focused. Therefore, in the present embodiment, the camera body 2 can appropriately determine the in-focus display and the out-of-focus display, and when the in-focus position exists outside the in-focus possible range, the in-focus display is performed. It can be effectively prevented from being damaged.

Further, 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 in-focus range, and the drive according to the defocus amount is determined. When the target position exceeds the in-focus range, the camera body 2 calculates the lens drive amount required to move the focus lens 32 to the limit position in the in-focus range. Then, in the lens barrel 3, the focus lens 32 is driven to the limit position in the focusable range based on the lens drive amount calculated by the camera body 2, and 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 transmitted to the lens barrel 3. Then, 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. Was stopped. Therefore, conventionally, in the lens barrel 3, the processing load for determining whether or not the focus lens 32 exceeds the in-focus range is increased, and depending on the timing of the determination, the in-focus range is exceeded. In some cases, the focus lens 32 is stopped and the focus display is performed at a position exceeding the focus possible range.

On the other hand, in the present embodiment, when the drive target position based on the defocus amount exceeds the in-focus range, the camera body 2 drives the focus lens 32 to the limit position in the in-focus range. The lens drive amount is calculated, and the focus lens 32 is driven in the lens barrel 3 based on the lens drive amount. As a result, it is not necessary to repeatedly determine whether or not the focus lens 32 exceeds the focusable range in the lens barrel 3, and the drive of the focus lens 32 is appropriately restricted within the focusable range. It is possible to effectively prevent the in-focus display from being performed at a lens position that exceeds the in-focus possible range.

Similarly, in the present embodiment, when the focus lens 32 is driven to the in-focus position detected by the contrast detection method, when the drive target position (focus position) of the focus lens 32 exceeds the in-focus possible range, In the camera body 2, the lens drive amount required to drive the focus lens 32 to the limit position in the focusable range is calculated, and in the lens barrel 3, the focus lens 32 is driven based on the lens drive amount. As a result, even when the focus is detected by the contrast detection method, it is not necessary to repeatedly determine whether or not the focus lens 32 exceeds the focusable range in the lens barrel 3, and the focus lens 32 has the focusable range. Can be effectively prevented from exceeding.

In particular, in the present embodiment, a servo drive that drives the focus lens 32 based on the defocus amount calculated by the phase difference detection method and a focusing drive that drives the focus lens 32 to the focusing position detected by the contrast detection method. By limiting the drive of the focus lens 32 within the in-focus range, the in-focus determination is performed and the in-focus display is performed at the lens position exceeding the in-focus range. It can be effectively prevented.

Further, in the present embodiment, the scan drive range for performing the scan operation is calculated in a range including the in-focus range and wider than the in-focus range, and the scan operation is executed in the calculated scan drive range. do. Thereby, in the present embodiment, even when the peak position (focusing position) of the focus evaluation value exists at the limit position of the focusing possible range, the focusing position can be appropriately detected. That is, conventionally, in the case of performing focus detection by a contrast detection method such as scan drive, it is repeatedly determined whether or not the focus lens 32 has reached the limit position of the focusable range, and the focus lens 32 can be focused. Since the drive of the focus lens 32 was stopped when the limit position of the range was reached, if the peak position (focusing position) of the focus evaluation value exists at the limit position of the focusable range, the focus is focused. There was a problem that the position could not be detected. On the other hand, in the present embodiment, even when the peak position (focusing position) of the focus evaluation value exists at the limit position of the focusable range, the focus evaluation value is calculated beyond the limit position of the focusable range. Therefore, 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 located outside the changed in-focus range, the focus lens 32 is moved to the limit position of the changed in-focus range to display the out-of-focus display. As a result, when the in-focus range is changed, the focus lens 32 remains located outside the changed in-focus range, and the in-focus display is displayed outside the changed in-focus range. It can be effectively prevented from being done. In particular, in the present embodiment, the focus limit mode information selected by the user is also transmitted from the lens barrel 3 to the camera body 2 as the focus limit information, so that the user can switch the focus limit mode and focus. When the range is changed, the focus lens 32 can be quickly moved to the limit position of the changed focusable range.

It should be noted that the embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above-described embodiment is intended to include all design changes and equivalents belonging to 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. 13 (A), from the lens position on the infinity side of _{the infinity end soft limit SL IP.} Although a configuration in which the range to the lens position closer to the nearest soft limit SL _NP is set as the scan drive range Rs1, the configuration is not limited to this configuration, and is not limited to this configuration, for example, as shown in FIG. 16 (A). In addition, the range from the infinity end soft limit SL _IP to the nearest 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 restriction mode" is set in the scanning operation, as shown in FIG. 13 (B), the closest side from the lens position on the infinity side of _{the infinity end soft limit SL IP.} A configuration in which the range to the lens position closer to the soft limit SL _NS is calculated as the scan drive range Rs2 has been illustrated, but the configuration is not limited to this configuration, and is, for example, infinity as shown in FIG. 16 (B). The range from the edge soft limit SL _IP to the lens position closer to the nearest soft limit SL _NS may be calculated as the scan drive range Rs2. When the "infinity side restriction mode" is set in the scanning operation, as shown in FIG. 16C, the lens position on the infinity side of the infinity _{side soft limit SL IS is closer.} The range up to the edge soft limit SL _NP may be calculated as the scan drive 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 (steps S209 to S212) in the scan operation, and the contrast. The drive control of the focus lens 32 in the focusing drive (step S214) for driving the focus lens 32 based on the focusing position detected by the detection method has been described as an example. In addition to this configuration, for example, FIG. As shown in FIG. 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, the same as the scan drive in the scan operation, FIG. The drive of the focus lens 32 may be restricted within the scan drive range shown in 13 (A) to 13 (C).

Further, when the focus state of the optical system changes due to the movement of the subject, for example, when shooting a moving subject, and when the focus lens 32 is driven in response to the change in the focus state, the focus according to the above-described embodiment. It may be configured to control the drive of the lens 32.

Further, in the above-described embodiment, three modes of "FULL mode", "closest side restriction mode", and "infinity side restriction mode" can be set, and a predetermined focusing range Rf1 and Rf2 can be set. , Rf3 can be set respectively, but the configuration is not limited to this configuration, and for example, a configuration in which a user-desired range can be set as a focusable range may be used.

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

The camera 1 of the above-described embodiment is not particularly limited, and the present invention may be applied to other optical devices such as a digital video camera, a digital camera with an integrated lens, and a camera for a mobile phone.

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

Claims (12)

A lens barrel that can be attached to and detached from the camera body that has an image pickup unit.
Focus lens and
A drive unit that moves the focus lens in the optical axis direction,
A control unit that controls the drive 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 receiver that receives information about focus from the camera body is provided.
When the receiving unit receives the information regarding the focus in the state of the first mode, when the target position of the focus is in the first range, the driving unit moves the focus lens to the target position, and the above-mentioned When the target position is not in the first range, the driving unit is a lens barrel that moves the focus lens in the direction of the first range. When the receiving unit receives the information regarding the focus in the state of the first mode, the driving unit moves the focus lens to the first range when the position of the focus lens is not in the first range. The lens barrel according to claim 1. The lens barrel according to claim 1 or 2, wherein the first range is narrower than the entire movable range of the focus lens. 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 driveable range of the focus lens as the first range. The lens barrel according to claim 4, wherein the storage unit stores information in the first range set by the user. The lens barrel according to claim 4 or 5, wherein the control unit controls based on any one of the first ranges stored by the storage unit. The lens barrel according to any one of claims 1 to 6, wherein the receiving unit periodically receives a drive amount based on the position information of the focus lens from the camera body at regular intervals. The lens barrel according to any one of claims 1 to 7, wherein the receiving unit further includes a transmitting unit that transmits information about the first mode or the second mode to the camera body. The eighth aspect of the present invention, wherein the transmitting unit transmits information of a warning or out-of-focus display to the camera body when the target position received by the receiving unit is outside the first range in the first mode. Lens barrel. A camera body that can be attached to and detached from the lens barrel according to any one of claims 1 to 9. A camera body with a removable lens barrel that can switch between the first mode that limits the movable range of the focus lens to the first range and the second mode that does not limit it.
The operation unit where the user operates the focus, and
When the receiving unit that receives information about the first mode or the second mode from the lens barrel and the operating unit are operated in the state of the first mode, the target position of the focus lens is set to the first range. If there is, an instruction to move the focus lens to the target position is transmitted to the lens barrel, and if the target position is not in the first range, the focus lens is moved in the direction of the first range. A camera body that transmits instructions to the lens barrel. A camera body with a removable lens barrel that can switch between the first mode that limits the movable range of the focus lens to the first range and the second mode that does not limit it.
The operation unit where the user operates the focus, and
A receiver that receives information about the first mode or the second mode from the lens barrel, and
When the second mode is switched to the first mode, when the position of the focus lens is in the first range, the information for moving the focus lens is not transmitted to the lens barrel, and the position of the focus lens is not transmitted. Is not in the first range, the camera body transmits information for moving the focus lens to the first range to the lens barrel.

Images