JP2019079068A - Imaging apparatus, lens barrel, camera system, and electronic device - Google Patents

Abstract

To provide an imaging apparatus which can control driving of a focus adjustment lens properly.SOLUTION: An imaging apparatus includes: an imaging element which captures a subject image formed by an optical system with a focus lens, and output signals; a communication unit which includes the optical system and communicates a lens barrel where a moving range of the focus lens can be set; a display unit which displays whether the subject image formed by the optical system is in focus on an imaging surface of the imaging element; and a control unit which receives the moving range of the focus lens through the communication unit, and transmits, when the position of the focus lens by which the subject image is in focus on the imaging surface exceeds the moving range, a control signal to the lens barrel to move the focus lens up to an end of the moving range, to cause the display unit to display out-of-focus information.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging device, a lens barrel, a camera system, and an electronic device.

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

Unexamined-Japanese-Patent No. 2006-126330

  However, in the prior art, in the camera body, the lens driving amount required to drive the focusing lens to the in-focus position is calculated, and in the lens barrel, the focusing lens is driven based on the lens driving amount. Since it is repeatedly judged whether or not the focusing lens has exceeded the focusable range, the processing load on the lens barrel becomes large, and depending on the timing of the above judgment, the focusing lens 32 In some cases, the camera is driven to the in-focus position which exceeds the in-focus possible range, and the in-focus determination is performed at the in-focus position which exceeds the in-focus possible range.

  The present invention solves the above-mentioned subject by the following solution means.

[1] An imaging device according to the present invention includes an imaging element that captures an object image formed by an optical system having a focus lens and outputs a signal, and the optical system, and sets a range in which the focus lens can move A communication unit for communicating with a possible lens barrel, a display unit for displaying whether or not the subject image by the optical system is focused on the imaging surface of the imaging device, and the focus lens via the communication unit Control of moving the focus lens to the end of the movable range when the information of the movable range of the lens is received and the position of the focus lens where the subject image is focused on the imaging surface exceeds the movable range And a control unit that transmits a signal to the lens barrel and causes the display unit to perform an out-of-focus display.
[2] The image pickup apparatus according to the present invention is provided with an image pickup element which picks up an object image formed by an optical system having a focus lens and outputs a signal, and the optical system, and sets a range where the focus lens can move. A communication unit for communicating with a possible lens barrel, a display unit for displaying whether or not the subject image by the optical system is focused on the imaging surface of the imaging device, and the signal output from the imaging device A detection unit for detecting information on the position of the focus lens at which the subject image is focused on the imaging surface, and information on the movable range of the focus lens via the communication unit, The position of the focus lens focused on the imaging surface of the subject calculated by the position of the focus lens on which the object image is focused on the imaging surface exceeds the movable range If, it transmits a control signal for moving the focus lens to the end of the range the movable to the lens barrel, and a control unit for causing the display is defocused on the display unit.
[3] In the invention relating to the imaging device, the detection unit is output by a focus detection pixel provided in the imaging element as information on the position of the focus lens at which the subject image is focused on the imaging surface. It is possible to detect a defocus amount which is a deviation between the position of the subject image and the imaging plane calculated based on a signal.
[4] In the invention relating to the imaging device, the control unit acquires the position of the focus lens acquired via the communication unit, and the acquired position of the focus lens and the defocus amount The position of the focus lens at which the subject image is focused on the imaging surface can be calculated.
[5] In the invention relating to the imaging device, the control unit can receive information on the movable range of the focus lens after transmitting a control signal for moving the focus lens.
[6] In the invention according to the above imaging apparatus, the communication unit repeatedly performs communication, and the control unit transmits the position of the focus lens and the information of the movable range of the focus lens via the communication unit. It can be acquired repeatedly.
[7] The invention according to a lens barrel attached to the imaging device, the optical system, a setting unit that sets a range in which the focus lens can move, a communication unit that communicates with the imaging device, and the setting unit And a lens control unit that performs control to transmit information indicating a range in which the focus lens set in can move to the imaging device.
[8] A camera system according to the present invention includes the imaging device and the lens barrel.
[9] An electronic device according to the present invention includes an optical system having a focus lens, an imaging device for capturing an object image formed by the optical system and outputting a signal, and a setting unit for setting a range in which the focus lens can move. A display unit for displaying whether or not the subject image by the optical system is focused on the imaging surface of the imaging element; and the imaging of the subject image based on the signal output from the imaging element When the movement target position of the focus lens exceeds the movable range, the focus lens is moved to the end of the movable range, and the display is performed. And a control unit that causes the unit to perform an out-of-focus display.
[10] A lens barrel attachable to a camera according to the present invention includes an optical system having a focus lens, a setting unit for setting a range in which the focus lens can move, and a terminal for communicating with the camera. Control for periodically transmitting to the camera via the terminal, a mechanism for attaching the camera to the camera, a drive unit for driving the focus lens, and a range in which the focus lens set in the setting unit can move And a control unit that

  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 a diagram showing an example of the focusable range of the focus lens. FIG. 3 is a diagram for explaining an example of transmission and reception of information between the lens barrel and the camera body. FIG. 4 is a front view showing an imaging surface of the imaging device shown in FIG. FIG. 5 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging the portion V of FIG. 6A is an enlarged front view of one of the imaging pixels 221, FIG. 6B is an enlarged front view of one of the focus detection pixels 222a, and FIG. 6 (D) is a cross-sectional view showing one of the imaging pixels 221 in an enlarged manner, and FIG. 6 (E) is one of the focus detection pixels 222a. 6F is a cross-sectional view showing one of the focus detection pixels 222b in an enlarged manner. 7 is a cross-sectional view taken along the line VII-VII in FIG. FIG. 8 is a diagram for explaining an example of a focus detection method using a contrast detection method. FIG. 9 is a flowchart showing the operation of the camera according to the present embodiment. FIG. 10 is a flowchart showing lens drive control processing based on the focus detection result by the phase difference detection method in step S112. FIG. 11 is a diagram showing an example of a scan drive range. FIG. 12 is a flowchart showing lens drive control processing based on the focus detection result by the contrast detection method in step S113. FIG. 13 is a flowchart showing focus limit change processing in step S117. FIG. 14 is a diagram showing another example of the scan drive range.

  Hereinafter, embodiments of the present invention will be described based on the drawings.

  FIG. 1 is a main part configuration diagram showing a digital camera 1 according to an embodiment of the present invention. The digital camera 1 (hereinafter simply referred to as the camera 1) of the present embodiment is composed of a camera body 2 and a lens barrel 3, and the camera body 2 and the lens barrel 3 are detachably coupled by a mount unit 4 There is.

  The lens barrel 3 is an interchangeable lens that is detachable from the camera body 2. As shown in FIG. 1, the lens barrel 3 incorporates a photographing optical system including lenses 31, 32, 33 and a diaphragm 34.

  The lens 32 is a focus lens, and can move in the direction of the optical axis L1 to adjust the focal length of the imaging optical system. The focus lens 32 is provided so as to be movable 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 calculated based on this information. The drive position is driven by being sent from the camera control unit 21 via the lens control unit 37.

  The aperture 34 is configured to adjust the aperture diameter centered on the optical axis L1 in order to limit the light amount of the light flux passing through the imaging optical system and reaching the imaging device 22 and to adjust the blur amount. Adjustment of the aperture diameter by the aperture stop 34 is performed, for example, by transmitting 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 the manual operation by the operation unit 28 provided in the camera body 2. The aperture diameter of the diaphragm 34 is detected by a diaphragm aperture sensor (not shown), and the lens controller 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 focusable range is a range that is determined to be in focus when the in-focus position is detected within the focusable range. In the present embodiment, the lens barrel 3 is provided with the focus limit switch 38 for setting the focusable range, and the photographer operates the focus limit switch 38 to select the focus limit mode. The focusable range can be selected.

FIG. 2 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. 2A, “FULL mode” in which the range from the infinite far-end soft limit SL _IP to the near-end soft limit SL _NP is set as the focusable range Rf 1, as shown in FIG. As shown in FIG. 2 (C), as shown in FIG. 2 (C), the “near-side limit mode” in which the range from the infinite distance end soft limit SL _IP to the near side soft limit SL _NS is set as the focusable range Rf2 as shown, the range of infinity from the far side soft limit SL _iS to the closest end soft limit SL _NP, set as an in-focus range Rf3 of "infinite side limit mode", to select three focus limit mode Can.

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

For example, when the "FULL mode" shown in FIG. 2A is set by the focus limit switch 38, the lens control unit 37 sets the limit of the focusable range Rf1 in the "FULL mode" as the focus limit information. The position (end), the far end soft limit SL _IP and the near end soft limit SL _NP , are transmitted to the camera body 2.

Further, when the “near-side limit mode” shown in FIG. 2B is set by the focus limit switch 38, the lens control unit 37 can perform focusing in the “near-side limit mode” as focus limit information. The far-end soft limit SL _IP and the near-side soft limit SL _NS which are limit positions of the range Rf 2 are transmitted to the camera body 2.

Similarly, when the “infinite distance side limit mode” shown in FIG. 2C is set by the focus limit switch 38, the lens control unit 37 sets the in-focus possible range Rf3 in the “infinite distance side limit mode”. The infinite-side soft limit SL _IS and the near-end soft limit SL _NP , which are the limit positions of, are transmitted to the camera body 2 as focus limit information.

In FIG. 2A, the infinite distance design value DV _IP is on the infinity side of the lens positions which ensure that the lens barrel 3 is focused on the object in the "FULL mode". This is the limit position, and in consideration of the design error of the lens barrel 3, the infinite far end soft limit SL _IP is provided on the infinity side of the infinite far end design value DV _IP , and this infinite far end soft limit SL _IP It is designed to enable detection of the in-focus position. Similarly, the closest end design value DV _NP is a limit position on the closest side of the lens positions that ensures that the lens barrel 3 is focused on the subject in design, and the design error of the lens barrel 3 Considering this, the near end soft limit SL _NP is provided on the near side of the near end design value DV _NP, and it is designed to be able to detect the in-focus position up to the near end soft limit SL _NP . .

Further, in FIG. 2B, the close design value _DVNS is the closest side of the lens positions that ensure that the lens barrel 3 is focused on the object in the “close limit mode”. of a limit position, taking into account the design errors of the lens barrel 3, than the close side design value DV _NS to the closest side soft limit SL _NS of the near side is designed so as to allow detection of the focusing position ing. Similarly, in FIG. 2C, the infinity design value DV _IS is a lens position that ensures that the lens barrel 3 is focused on the subject in the “infinity limit mode”. infinite is the limit position of the distance side, taking into account the design errors of the lens barrel 3, indefinitely until infinity side soft limit SL _iS infinity side than the far side design value DV _iS, the detection of the focusing position It is designed to be possible.

  Further, as shown in FIG. 3, in addition to the focus limit information, information of the focus lens position is periodically transmitted from the lens barrel 3 to the camera body 2. Then, in the camera body 2, the lens drive amount of the focus lens 32 is calculated based on the focus limit information and the position information of the focus lens 32, and the calculated lens drive amount is transmitted to the lens barrel 3. FIG. 3 is a view for explaining an example of transmission and reception of information between the lens barrel 3 and the camera body 2.

  On the other hand, in the camera body 2, an imaging element 22 for receiving the light flux L1 from the imaging optical system is provided on a planned focal plane of the imaging optical system, and a shutter 23 is provided on the front surface thereof. The imaging device 22 is configured of a device such as a CCD or a CMOS, converts the received light signal into an electric signal, and sends it to the camera control unit 21. The photographed 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 (provided in the operation unit 28) When the full depression (not shown) is performed, the photographed image information is recorded in the camera memory 24 which is a recording medium. The camera memory 24 can use any of a removable card type memory and a built-in type memory.

  The camera body 2 is provided with an observation optical system for observing an 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 same, and an eyepiece lens 27. The liquid crystal drive circuit 25 reads the photographed image information picked up by the image pickup device 22 and sent to the camera control unit 21, and drives the electronic viewfinder 26 based on this. Thus, the user can observe the current captured image through the eyepiece 27. A liquid crystal display may be provided on the back surface of the camera body 2 or the like instead of or in addition to the above observation optical system according to the optical axis L2, and a photographed image may be displayed on the liquid crystal display.

  A camera control unit 21 is provided in the camera body 2. The camera control unit 21 is electrically connected to the lens control unit 37 by the electrical 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 diameter. In addition, as described above, the camera control unit 21 reads out the pixel output from the imaging device 22 and generates image information by performing predetermined information processing on the read out pixel output as necessary, and the generated image information Are 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 such as correction of image information from the image pickup device 22 and detection of a focusing state of the lens barrel 3, an aperture adjusting state, and the like.

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

  The operation unit 28 is an input switch for a photographer such as a shutter release button to set various operation modes of the camera 1, and can switch between an auto focus mode and a manual focus mode. The 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 which is turned on when the button is half pressed, and a second switch SW2 which is turned on when the button is fully pressed.

  Next, the image sensor 22 according to the present embodiment will be described.

  FIG. 4 is a front view showing the imaging surface of the imaging element 22, and FIG. 5 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging a portion V of FIG.

  As shown in FIG. 5, in the imaging device 22 of the present embodiment, a plurality of imaging pixels 221 are two-dimensionally arranged on a plane of an imaging surface, and a green pixel G having a color filter transmitting a green wavelength region And a red pixel R having a color filter transmitting the red wavelength region and a blue pixel B having a color filter transmitting the blue wavelength region are what is called a Bayer arrangement. That is, two green pixels are arranged on one diagonal line in adjacent four pixel groups 223 (a dense square lattice array), and one red pixel and one blue pixel are arranged on the other diagonal line. The imaging element 22 is configured by repeatedly arranging the pixel group 223 two-dimensionally on the imaging surface of the imaging element 22 in units of the pixel group 223 in which the Bayer arrangement is performed.

  The arrangement of the unit pixel groups 223 may be, for example, a close hexagonal lattice arrangement, as well as the close square lattice shown in the drawing. Further, the configuration and arrangement of the color filter are not limited to this, and an arrangement of complementary color filters (green: G, yellow: Ye, magenta: Mg, cyan: Cy) can also be adopted.

  FIG. 6A is an enlarged front view showing one of the imaging pixels 221, and FIG. 6D is a cross-sectional view. One imaging pixel 221 includes a microlens 2211, a photoelectric conversion unit 2212, and a color filter (not shown), and as shown in the cross-sectional view of FIG. 6D, on the surface of the semiconductor circuit substrate 2213 of the imaging element 22. The photoelectric conversion portion 2212 is fabricated, and the micro lens 2211 is formed on the surface thereof. The photoelectric conversion unit 2212 is shaped so as to receive the imaging light flux passing through the exit pupil (for example, F1.0) of the imaging optical system by the microlens 2211 and receives the imaging light flux.

  In addition, focus detection pixel arrays 22a, 22b, and 22c in which focus detection pixels 222a and 222b are arranged instead of the imaging pixels 221 described above at the center of the imaging surface of the imaging element 22 and at three positions symmetrical with respect to the center. Is provided. Then, as shown in FIG. 5, in one focus detection pixel row, a plurality of focus detection pixels 222a and 222b are arranged adjacent to each other and alternately arranged in one horizontal row (22a, 22c, 22c). There is. In the present embodiment, the focus detection pixels 222a and 222b are densely arranged without providing a gap at the positions of the green pixel G and the blue pixel B of the imaging pixel 221 in Bayer arrangement.

  The positions of the focus detection pixel arrays 22a to 22c shown in FIG. 4 are not limited to the illustrated positions, but may be one or two, or may be disposed at four or more positions. it can. Further, at the time of actual focus detection, the photographer manually selects the desired focus detection pixel row as the focus detection area from the plurality of arranged focus detection pixel rows 22a to 22c by manually operating the operation unit 28. It can also be done.

  FIG. 6B is an enlarged front view showing one of the focus detection pixels 222a, and FIG. 6E is a cross-sectional view of the focus detection pixel 222a. 6C is an enlarged front view showing one of the focus detection pixels 222b, and FIG. 6F is a cross-sectional view of the focus detection pixel 222b. The focus detection pixel 222a includes a micro lens 2221a and a semicircular photoelectric conversion unit 2222a as shown in FIG. 6B, and as shown in the cross sectional view of FIG. The photoelectric conversion portion 2222a is formed on the surface of the semiconductor circuit substrate 2213, and the micro lens 2221a is formed on the surface. Further, as shown in FIG. 6C, the focus detection pixel 222b includes a micro lens 2221b and a photoelectric conversion unit 2222b, and as shown in the cross sectional view of FIG. The photoelectric conversion portion 2222b is formed on the surface of the circuit board 2213, and the micro lens 2221b is formed on the surface. Then, as shown in FIG. 5, these focus detection pixels 222a and 222b are arranged adjacent to each other and alternately in a horizontal row, to form 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 have shapes that receive light beams passing through a predetermined area (for example, F2.8) of the exit pupil of the photographing optical system by the micro lenses 2221a and 2221b. Be done. Further, no color filter is provided in the focus detection pixels 222a and 222b, and the spectral characteristics thereof are obtained by integrating the spectral characteristics of the photodiode performing photoelectric conversion and the spectral characteristics of the infrared cut filter (not shown). ing. However, one of the same color filters as the imaging pixel 221, for example, a green filter may be provided.

  The photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b shown in FIGS. 6B and 6C have a semicircular shape, but the shape of the photoelectric conversion units 2222a and 2222b is not limited thereto. And other shapes, for example, an oval shape, a rectangular shape, and a polygonal shape.

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

  FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 5 and is disposed in the vicinity of the photographing optical axis L1 and the focus detection pixels 222a-1, 222b-1, 222a-2, 222b-2 adjacent to each other are It shows that light beams AB1-1, AB2-1, AB1-2, and AB2-2 emitted from the focusing pupils 351 and 352 of the exit pupil 350 are respectively received. Although FIG. 7 illustrates only one of the plurality of focus detection pixels 222a and 222b located in the vicinity of the photographing optical axis L1, the other focus detection pixels other than the focus detection pixels shown in FIG. 7 are shown. Similarly, the light beams emitted from the pair of distance measuring pupils 351 and 352 are also received.

  Here, the exit pupil 350 is an image set at the position of the distance D in front of the microlenses 2221 a and 2221 b of the focus detection pixels 222 a and 222 b disposed on the planned focal plane of the imaging optical system. The distance D is a value uniquely determined according to the curvature of the micro lens, the refractive index, the distance between the micro lens and the photoelectric conversion part, and the like, and this distance D is referred to as a distance measurement pupil distance. Further, the ranging pupils 351 and 352 refer to images of the photoelectric conversion units 2222a and 2222b respectively projected by the micro lenses 2221a and 2221b of the focus detection pixels 222a and 222b.

  In FIG. 7, the arrangement direction of the focus detection pixels 222 a-1, 222 b-1, 222 a-2 and 222 b-2 coincides with the arrangement direction of the pair of distance measurement pupils 351 and 352.

  Further, as shown in FIG. 7, the micro lenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 of the focus detection pixels 222a-1, 222b-1, 222a-2, 222b-2 are optical systems. It is arranged near the planned focal plane. The shape of each of the photoelectric conversion units 2222a-1, 2222b-1, 2222a-2, 2222b-2 disposed behind the microlenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 is The light is projected onto the exit pupil 350 separated by the distance measurement distance D from the lenses 2221a-1 and 2221b-1, and 2221a-2 and 2221b-2, and the projected shapes form distance measurement pupils 351 and 352.

  That is, on the exit pupil 350 located at the distance measurement distance D, the microlenses and photoelectric conversion units in each focus detection pixel are matched so that the projection shapes (distance measurement pupils 351, 352) of the photoelectric conversion units of each focus detection pixel match. The relative positional relationship of is determined, whereby the projection direction of the photoelectric conversion unit at each focus detection pixel is determined.

  As shown in FIG. 7, the photoelectric conversion unit 2222a-1 of the focus detection pixel 222a-1 is formed on the microlens 2221a-1 by the light beam AB1-1 which passes through the distance measurement pupil 351 and is directed to the microlens 2221a-1. Output a signal corresponding to the intensity of the image being Similarly, the photoelectric conversion unit 2222a-2 of the focus detection pixel 222a-2 passes through the distance measurement pupil 351, and the intensity of the image formed on the microlens 2221a-2 by the light beam AB1-2 directed to the microlens 2221a-2. Output a signal corresponding to

  In addition, the photoelectric conversion unit 2222b-1 of the focus detection pixel 222b-1 passes through the distance measurement pupil 352, and the intensity of the image formed on the microlens 2221b-1 by the light beam AB2-1 directed to 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 distance measurement pupil 352, and the intensity of the image formed on the microlens 2221b-2 by the light beam AB2-2 directed to the microlens 2221b-2. Output a signal corresponding to

  Then, a plurality of the two types of focus detection pixels 222a and 222b described above are linearly arranged as shown in FIG. 5, and the output of the photoelectric conversion units 2222a and 2222b of each focus detection pixel 222a By combining the output groups corresponding to each of the focus detection pupils 352 and the focus detection pupil 352, the intensities of a pair of images formed on the focus detection pixel array by the focus detection light beams passing through the focus detection pupil 351 and the focus detection pupil 352, respectively. Data on the distribution is obtained. Then, image shift detection calculation processing such as correlation calculation processing or phase difference detection processing is performed on the intensity distribution data to detect an image shift amount by a so-called phase difference detection method.

  Then, a conversion operation according to the distance between the center of gravity of the pair of distance measuring pupils is performed on the obtained image shift amount to obtain the current focal plane with respect to the planned focal plane (the focal point corresponding to the position of the microlens array on the planned focal plane). The deviation of the focal plane in the detection area can be determined.

  The calculation of the image shift amount, the calculation of the defocus amount, and the focusing drive according to the phase difference detection method are executed by the camera control unit 21.

  Further, the camera control unit 21 reads the output of the imaging pixel 221 of the imaging element 22, and calculates the focus evaluation value based on the read pixel output. The focus evaluation value can be obtained, for example, by extracting the high frequency component of the image output from the imaging pixel 221 of the imaging device 22 using a high frequency transmission filter. It can also be determined 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) to obtain a focus evaluation value at each position, and the focus evaluation value is maximum. The focus detection by the contrast detection method is performed to obtain the position of the focus lens 32 as the in-focus position. It should be noted that, for example, when the focus evaluation value is calculated while driving the focus lens 32, the in-focus position is further lowered twice after the focus evaluation value rises twice. It can obtain | require by performing calculations, such as an interpolation method, using the focus evaluation value of.

  Here, FIG. 8 is a diagram for explaining an example of the focus detection method by the contrast detection method. In the example shown in FIG. 8, the focus lens 32 is located at P0 shown in FIG. 8. First, the focus lens 32 is driven from P0 to a predetermined search start position (position P1 in FIG. 8). Initial driving is performed. Then, while the focus lens 32 is driven from the infinite distance side to the near side from the search start position (position P1 in FIG. 8), the search is performed to obtain the focus evaluation value by the contrast detection method at predetermined intervals. Driving is performed. Then, when the focus lens 32 is moved to the position P2 shown in FIG. 8, the peak position of the focus evaluation value (the position P3 in FIG. 8) is detected as the in-focus position, and the detected in-focus position Focusing drive for driving the focus lens 32 is performed up to (position P3 in FIG. 8).

  Next, an operation example of the camera 1 according to the present embodiment will be described. FIG. 9 is a flowchart showing the operation of the camera 1 according to the present embodiment.

  First, in step S101, the camera control unit 21 acquires focus limit information. In the present embodiment, 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 a predetermined interval. The focus limit information corresponding to the currently set focus limit mode is acquired from the lens control unit 37.

For example, as shown in FIG. 2A, when the “FULL mode” is set by the focus limit switch 38, the lens control unit 37 sets the focusable range in the “FULL mode” as the focus limit information. An infinite far-end soft limit SL _IP and a near-end soft limit SL _NP , which are limit positions (ends) of Rf 1, are periodically transmitted to the camera body 2. Thus, the camera control unit 21 acquires information on the infinite end soft limit SL _IP and the near end soft limit SL _NP as focus limit information.

Similarly, as illustrated in FIG. 2B, when the “near-side limit mode” is set by the focus limit switch 38, the camera control unit 21 can set the in-focus possible range in the “near-side limit mode”. Information on the infinity far-end soft limit SL _IP and the near-side soft limit SL _NS which are the limit position of Rf 2 is acquired as focus limit information, and as shown in FIG. When the infinity side limit mode is set, the infinity side soft limit SL _IS and the near end soft limit SL _NP which are the limit positions of the focusable range Rf3 in the “infinity side limit mode” are set. , As focus limit information.

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

  In step S102, as shown in FIGS. 2A to 2C, calculation of the focusable range of the focus lens 32 is performed by the camera control unit 21 based on the focus limit information acquired in step S101. .

For example, as shown in FIG. 2A, the camera control unit 21 is set to the “FULL mode”, and the infinity far end soft limit SL _IP and the near end soft limit SL _NP are acquired as the focus limit information. If it is, the range from the infinite end soft limit SL _IP to the near end soft limit SL _NP is calculated as the focusable range Rf1.

Similarly, as shown in FIG. 2 (B), the camera control unit 21 is set to the “near-side limit mode”, and the far-end soft limit SL _IP and the near-side soft limit SL _NS are used as focus limit information. Is acquired, the range from the infinity end soft limit SL _IP to the near-side soft limit SL _NS is calculated as the focusable range Rf2. Further, as shown in FIG. 2C, the camera control unit 21 is set to the “infinite distance side limit mode”, and as the focus limit information, the infinite distance side soft limit SL _IS and the near end soft limit SL If _{the NP} is acquired, a range of infinity from the far side soft limit _{SL iS} to the closest end soft limit _{SL NP,} calculated as an in-focus range Rf3.

Depending on the type of the lens barrel 3, the focus limit function may not be obtained, and the focus limit information may not be obtained from the lens barrel 3. In such a case, as shown in FIG. 2A, the camera control unit 21 calculates the range Rf1 from the infinite end soft limit SL _IP to the near end soft limit SL _NP as the focusable range. be able to.

  In step S103, the camera control unit 21 starts the process of calculating the defocus amount according to the phase difference detection method. In the present embodiment, the process of calculating the defocus amount 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 a pair of images from each of the focus detection pixels 222a and 222b that constitute the three focus detection pixel arrays 22a to 22c of the imaging device 22. Then, the camera control unit 21 executes image shift detection calculation processing (correlation calculation processing) based on the read pair of image data, and images at focus detection positions corresponding to the three focus detection pixel arrays 22a to 22c. The shift amount is calculated, and the image shift amount is converted into the defocus amount. Also, the camera control unit 21 evaluates the reliability of the calculated defocus amount. The evaluation of the reliability of the defocus amount is performed, for example, on the basis of the matching degree or the contrast of the pair of image data. Moreover, the calculation process of the defocus amount by such a phase difference detection system is repeatedly performed at a predetermined interval.

  In step S104, the process of calculating the focus evaluation value by the camera control unit 21 is started. In the present embodiment, the calculation process of the focus evaluation value is performed by reading out the pixel output of the imaging pixel 221 of the imaging device 22, extracting the high frequency component of the read pixel output using a high frequency transmission filter, and integrating it. To 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 manual operation of the user or by the subject recognition mode or the like. May be read out. The calculation process of the focus evaluation value is repeatedly performed at predetermined intervals.

  In step S105, the camera control unit 21 determines whether the shutter release button provided on the operation unit 28 has been half-pressed (the first switch SW1 is turned on). If the first switch SW1 is turned on, the process proceeds to step S106. On the other hand, when the first switch SW1 is not turned on, step S105 is repeated until the first switch SW1 is turned on. That is, until the first switch SW1 is turned on, the process of calculating the defocus amount by the phase difference detection method and the process of calculating the focus evaluation value are repeatedly executed.

  In step S106, the camera control unit 21 determines whether the defocus amount has been calculated by the phase difference detection method. If the defocus amount can be calculated, it is determined that distance measurement is possible, and the process proceeds to step S112. On the other hand, when the defocus amount can not be calculated, it is determined that the distance measurement can not be performed, and the process proceeds to step S107. In the present embodiment, even when the defocus amount can be calculated, the defocus amount can not be calculated even if the reliability of the calculated defocus amount is low, and the process proceeds to step S107. I will proceed.

  If it is determined in step S106 that the defocus amount has been calculated and it is determined that distance measurement is possible, the process proceeds to step S112, 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. 10 is a flowchart showing the lens drive control process of step S112. In the following, the lens drive control process of step S112 will be described with reference to FIG.

First, in step S201, the camera control unit 21 determines whether the in-focusable range is limited. For example, in step S101, when information on an infinite far-end soft limit SL _IP and a near-end soft limit SL _NP is acquired as focus limit information, the camera control unit 21 determines the infinity far-end soft limit SL _IP and the near end. Based on the information of the soft limit SL _NP , as shown in FIG. 2A, 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, in step S101, when the information on the infinity far-end soft limit SL _IP and the near-side soft limit SL _NS is acquired as the focus limit information, the camera control unit 21 determines the infinity far-end soft limit SL _IP and the near-side soft limit Based on the information of _SLNS , it is determined that the “close side restriction mode” is set, and it can be determined that the focusable range Rf2 is restricted. Similarly, in step S101, when information on the infinity side soft limit _SLIS and the near end soft limit SL _NP is acquired as the focus limit information, the camera control unit 21 determines the infinity side soft limit _SLIS and the near position soft limit. Based on the information of the end soft limit SL _NP , it is determined that the "infinite distance limit mode" is set, and it can be determined that the focusable range Rf3 is limited.

If it is determined in step S201 that the focusable range is limited, the process proceeds to step S202. In step S202, the camera control unit 21 determines whether 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 will be. Specifically, the camera control unit 21 calculates the lens drive amount (unit: number of pulses) to the drive target position based on the defocus amount calculated by the phase difference detection method and the current focus lens position. Do. The camera control unit 21 then adjusts the drive target position based on the calculated lens drive amount of the focus lens 32 (unit: number of pulses) and the focusable range (unit: number of pulses) calculated in step S102. It is determined whether the in-focus range is exceeded. For example, in the example shown in FIG. 2 (B), when the drive target position based on the defocus amount, the lens position of the near side than the near side soft limit SL _NS, the camera control unit 21, drive target position Can be determined as exceeding the focusable range Rf2. Then, if it is determined that the drive target position based on the defocus amount exceeds the focusable range, the process proceeds to step S203, while it is determined that the drive target position based on the defocus amount is within the focusable range. If it has been, the process proceeds to step S206.

  In step S203, since it is determined that the drive target position based on the defocus amount exceeds the focusable range, the camera control unit 21 moves the focus lens 32 to the limit position (end) of the focusable range. Calculation of the lens driving amount necessary for driving is performed. Specifically, the camera control unit 21 is required to drive the focus lens 32 to the limit position of the focusable range close to the drive target position based on the current position of the focus lens 32 and the focusable range. Calculate the amount of lens drive.

For example, in the example shown in FIG. 2 (B), when the drive target position based on the defocus amount, a lens position of the near side than the near side soft limit SL _NS, the camera control unit 21, drive target position a limit position of the focus adjustable range Rf2 close to, calculates the lens driving amount necessary to drive the focus lens 32 on the near side soft limit SL _NS. Further, in the example shown in FIG. 2 (C), drive target position based on the defocus amount, when a lens position of the infinity side than the infinity side soft limit SL _IS, the camera control unit 21, the driving a limit position of the focus adjustable range Rf3 close to the target position, calculates the lens driving amount necessary to drive the focus lens 32 to the infinity side software limit SL _iS.

Then, in step S204, processing for driving the focus lens 32 to the limit position of the focusable range is performed by the camera control unit 21 based on the lens driving amount calculated in step S203. Specifically, the camera control unit 21 sends the lens driving amount calculated in step S203 to the focus lens driving motor 36 via the lens control unit 37. Then, the focus lens drive motor 36 drives the focus lens 32 to the limit position of the focusable range based on the received lens drive amount. Thus, for example, in the example shown in FIG. 2 (B), drive target position based on the defocus amount, even if than near side soft limit SL _NS is a lens position of the near side, the focus lens 32 is close side software It will be moved to the limit SL _NS . Further, in the example shown in FIG. 2 (C), drive target position based on the defocus amount, the infinity side software limit SL even if a lens position of the infinity side than _IS, the focus lens 32 is an infinite Togawa soft It will be moved to the limit SL _IS .

  In the subsequent step S205, since the focus lens 32 can not be driven to the drive target position (the in-focus position) based on the defocus amount, it is displayed that the subject is out of focus. The out-of-focus indication is performed, for example, by the electronic viewfinder 26.

  On the other hand, if it is determined in step S201 that the focusable range is not limited, or if it is determined that the drive target position based on the defocus amount is within the focusable range in step S202. , And proceeds to step S206. In step S206, 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 following step S207, based on the calculated lens drive amount. Thus, the focus lens 32 is driven to the drive target position (in-focus position). Thereafter, in step 208, the in-focus indication is performed.

  As described above, drive control processing of the focus lens 32 is performed based on the defocus amount calculated by the phase difference detection method. When driving the focus lens 32 based on the defocus amount calculated by the phase difference detection method, the focus lens 32 is driven within the focusable ranges Rf1 to Rf3 shown in FIGS. 2A to 2C. Thus, drive control of the focus lens 32 is performed. That is, when the drive target position based on the defocus amount exceeds the focusable range Rf1 to Rf3, the lens drive amount necessary for driving to the limit position of the focusable range is calculated in the camera body 2 In the lens barrel 3, the focus lens 32 is driven to the limit position of 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 beyond the focusable range Rf1 to Rf3 to effectively prevent an in-focus display from being performed at the lens position beyond the focusable range. it can. Then, after the lens drive control process shown in FIG. 10 is completed, the process proceeds to step S117 shown in FIG.

  If it is determined in step S106 shown in FIG. 9 that the defocus amount can not be calculated by the phase difference detection method, the process proceeds to step S107. In step S107, the camera control unit 21 calculates a scan drive range which is a drivable range of the focus lens 32 in the scan operation, and in the following step S108, scan drive is performed in the scan drive range calculated in step S107. The scan operation to be performed is started.

  In the scan operation, while the focus lens drive motor 36 drives the focus lens 32 at a predetermined drive speed (scan drive), the camera control unit 21 calculates the defocus amount by the phase difference detection method, and the focus evaluation value Is calculated simultaneously at a predetermined interval, whereby the detection of the in-focus position by the phase difference detection method and the detection of the in-focus position by the contrast detection method are simultaneously performed at the 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 perform focusing. The lens 32 is scan driven along the optical axis L1. The scan drive of the focus lens 32 may be performed from the infinity end to the close end, or may be performed from the close end to the infinity end.

  Then, while driving the focus lens 32, 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 sensor 22 at predetermined intervals. According to the phase difference detection method, the defocus amount is calculated, and the pixel output is read from the imaging pixel 221 of the imaging 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 the focus evaluation value at different focus lens positions.

  Further, in the present embodiment, calculation of a scan drive range is performed in step S107 in order to perform scan drive. FIG. 11 is a diagram showing an example of a scan drive range. As shown in FIGS. 11A to 11C, scan drive ranges Rs1 to Rs3 include focusable ranges Rf1 to Rf3 shown in FIGS. 2A to 2C, and focusable range Rf1. It is calculated as a range wider than Rf3.

Here, as described above, while the focus lens 32 is driven, the scan operation simultaneously performs the calculation of the defocus amount by the phase difference detection method and the calculation of the focus evaluation value by the contrast detection method at predetermined intervals. It is an operation. Then, in order to detect the peak position (focus position) of the focus evaluation value by the contrast detection method, as shown in FIG. 8, the focus lens 32 is driven to a position (P2 in FIG. 8) beyond the peak position. It is necessary to calculate the focus evaluation value. Therefore, for example, by contrast detection method, in order to detect the peak position of the focus evaluation value (focus position) in an infinite far soft limit SL _IP is infinity than the focus lens 32 infinitely far soft limit SL _IP It is necessary to drive to the side to calculate the focus evaluation value. Similarly, for example, in the scanning operation, in order to detect the peak position (focus position) of the focus evaluation value at the near end soft limit SL _NP by the contrast detection method, the focus lens 32 is used as the near end soft limit SL. _The focus evaluation value needs to be calculated by driving the lens closer to the _NP side.

Therefore, the camera control unit 21, when performing the scanning operation, when the focus limit mode is "FULL mode", as shown in FIG. 11 (A), infinity than infinite far soft limit SL _IP A range from the lens position on the side to the lens position on the near side of the near end soft limit SL _NP is calculated as a scan drive range Rs1. For example, in the present embodiment, when the focus evaluation value rises twice and then descends two more times, these focus evaluation values are used to calculate the peak of the focus evaluation value. The unit 21 calculates a focus evaluation value of 2 on the near side of the near-end soft limit SL _NP from a lens position capable of calculating two focus evaluation values on the infinity side of the infinite-end soft limit SL _IP. The range up to the lens position that can be calculated can be calculated as the scan drive range Rs1 in the scan operation.

Further, the camera control unit 21, when performing the scanning operation, when the focus limit mode is "close side limit mode", as shown in FIG. 11 (B), than infinite far soft limit SL _IP from the lens position of the infinity side, the range to the lens position of the near side than the near side soft limit SL _NS, calculated as a scan driving range Rs2. Similarly, when the focus limit mode is the “infinity side limit mode”, as shown in FIG. 11C, the camera control unit 21 sets the lens at the infinity side with respect to the infinity side soft limit SL _{IS as} shown in FIG. A range from the position to the lens position closer to the near end soft limit SL _NP is calculated as a scan drive range Rs3 in the scan operation.

  Then, in step S108, a scan operation for performing scan drive is performed in the scan drive ranges Rs1 to Rs3 shown in FIGS. 11 (A) to 11 (C). 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. 11A to 11C as the drivable range of the focus lens 32. Even when the in-focus position exists at the limit position of the in-focus possible range shown in FIGS. 2A to 2C, such an in-focus position can be detected by the contrast detection method.

  Then, in step S109, as a result of performing the scan operation, the camera control unit 21 determines whether the defocus amount has been calculated by the phase difference detection method. If the defocus amount can be calculated, it is determined that distance measurement is possible, and the process proceeds to step S112. On the other hand, if the defocus amount can not be calculated, it is determined that the distance measurement is not possible, and the process proceeds to step S110. . In step S109, as in step S106 described above, even if the defocus amount can be calculated, the defocus amount can not be calculated if the reliability of the calculated defocus amount is low. It treats as a thing and supposes that it progresses to step S110.

  In step S110, as a result of performing the scanning operation, the camera control unit 21 determines whether the in-focus position can be detected by the contrast detection method. If the in-focus position can be detected by the contrast detection method, the process proceeds to step S113. If the in-focus position can not be detected, the process proceeds to step S111.

  In step S111, the camera control unit 21 determines whether scan drive has been performed for the entire scan drive range calculated in step S107. If scan drive is not performed for the entire scan drive range, the process returns to step S109, and steps S109 to S111 are repeated to perform a scan operation, that is, a phase difference detection method while causing the focus lens 32 to scan drive. The operation of simultaneously executing the calculation of the defocus amount by the above and the detection of the in-focus position by the contrast detection method at a predetermined interval is continued. On the other hand, if execution of the scan operation has been completed for the entire scan drive range, the process proceeds to step S114.

  Then, as a result of executing the scan operation, if it is determined in step S109 that the defocus amount has been calculated by the phase difference detection method, the scan operation is stopped, the process proceeds to step S112, and similarly to the above, Drive control of the focus lens 32 is performed based on the result of the phase difference detection method.

  That is, when the focusable range is limited and the drive target position according to the defocus amount exceeds the focusable range (step S201 = Yes, S202 = Yes), the focus lens 32 is selected. The lens drive amount for driving to the limit position of the focusable range is calculated (step S203), and the focus lens 32 is driven to the limit position of the focusable range based on the calculated lens drive amount (step S204) , And out-of-focus display (step S208). On the other hand, when the drive target position according to the defocus amount is within the focusable range (step S 202 = No), or when the focusable range is not limited (step S 201 = No), defocusing is performed. The lens drive amount according to the amount is calculated (step S206), the focus lens 32 is driven based on the lens drive amount according to the defocus amount (step S207), and focusing display is performed (step S208).

  If it is determined in step S110 that the in-focus position has been detected by the contrast detection method as a result of performing the scan operation, the scan operation is stopped, and the process proceeds to step S113 to obtain focus detection results by the contrast detection method. Driving control of the focus lens 32 based on the above is performed. Here, FIG. 12 is a flowchart showing lens drive control processing based on the focus detection result by the contrast detection method.

  As shown in FIG. 12, first, in step S301, as in step S201, it is determined whether the in-focusable range is limited. If the in-focusable range is restricted, the process proceeds to step S302. If the in-focusable range is not restricted, the process proceeds to step S306.

In step S302, it is determined whether the in-focus position detected by the contrast detection method exceeds the in-focusable range. For example, in the scanning operation, as shown in FIG. 2 (B), when the "near side limit mode" is set, the focus evaluation by driving the focus lens 32 to the near side than the near side soft limit SL _NS result of calculating the value, the peak position of the focus evaluation value (focus position) is, if it is detected in the near side than the near side soft limit SL _NS, the camera control unit 21, detected by the contrast detection method It is determined that the in-focus position is a position beyond the focusable range Rf2, and the process proceeds to step S303. Further, in the scan operation, as shown in FIG. 2C, when the “infinite distance side limit mode” is set, the focus lens 32 is driven to the infinite distance side beyond the infinite distance soft limit SL _IS. result of calculating the focus evaluation value each, when the peak position of the focus evaluation value (focus position) is detected in the infinity side of the infinity side soft limit SL _iS, the camera control unit 21, a contrast detection method It is determined that the in-focus position detected by the position exceeds the in-focusable range Rf3 and the process proceeds to step S303.

  In steps S303 to S305, the camera control unit 21 calculates the lens driving amount necessary to drive the focus lens 32 to the limit position of the in-focusable range close to the in-focus position detected by the contrast detection method. After the focus lens 32 is driven to the limit position of the in-focusable range based on the calculated lens drive amount (step S304), out-of-focus display is performed (step S305).

Thus, for example, in the example shown in FIG. 2 (B), focus calculated by the contrast detection method position, even if than near side soft limit SL _NS is a lens position of the near side, the focus lens 32 is closest It will be moved to the side soft limit SL _NS . Further, in the example shown in FIG. 2C, even when the in-focus position calculated by the contrast detection method is a lens position on the infinity side of the software limit Sl _IS on the infinity side, the focusing lens 32 is at infinity. It will be moved to the side soft limit SL _IS .

  On the other hand, if it is determined in step S301 that the in-focusable range is not restricted, or if it is determined in step S302 that the in-focus position detected by the contrast detection method is within the in-focusable range. In step S306, the process proceeds to step S306. In step S306, the camera control unit 21 calculates the lens driving amount up to the in-focus position detected by the contrast detection method. Then, in step S307, the camera control unit 21 calculates the lens calculated in step S306. A process of driving the focus lens 32 to the in-focus position is performed based on the drive amount. Thereafter, in step S308, the in-focus display is performed.

  As described above, drive control of the focus lens 32 is performed based on the in-focus position detected by the contrast detection. As described above, in the in-focus drive in which the focus lens 32 is driven to the in-focus position detected by the contrast detection method, the focus lens 32 is driven within the in-focusable range shown in FIGS. The 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-focusable range, the lens drive amount necessary for driving the focus lens 32 to the in-focus range limit position in the camera body 2 is The focus lens 32 is driven in the lens barrel 3 based on the 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 beyond the focusable range and that the focus display is performed at the position beyond the focusable range. Then, after the lens drive control process shown in FIG. 12 is completed, the process proceeds to step S117 shown in FIG.

  When it is determined in step S111 that the execution of the scan operation is completed for the entire scan drive range, the process proceeds to step S114. In step S114, as a result of performing the scan operation, focus detection can not be performed by any of the phase difference detection method and the contrast detection method. Therefore, the scan operation end processing is performed, and the process proceeds to step S115.

  In step S115, the camera control unit 21 moves the focus lens 32 to the limit position of the focusable range close to the current focus lens position. Then, in step S116, the in-focus state is displayed because the in-focus position can not be detected.

  Further, in the present embodiment, after the focus adjustment based on the focus detection result is performed, the process proceeds to step S117, and the focus limit changing process is performed in step S117. FIG. 13 is a flowchart showing the focus limit changing process of step S117.

  As shown in FIG. 13, first, in step S401, the camera control unit 21 reacquires focus limit information. Then, in step S402, the camera control unit 21 recalculates the focusable range on the basis of the focus limit information acquired in step S401.

  In step S403, the camera control unit 21 compares the in-focusable range newly calculated in step S402 with the immediately preceding in-focusable range to determine whether the in-focusable range has been changed. If the focusable range has been changed, the process proceeds to step S404. If the focusable range has not been changed, the focus limit change process shown in FIG. 13 is ended.

  In step S404, the camera control unit 21 determines whether the drive target position of the focus lens 32 is within the focusable range after change calculated in step S402. 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. In such a case, when the focus limit mode is changed, the drive target position based on the defocus amount may be outside the focusable range after the change calculated in step S402. If the drive target position of the focus lens 32 is inside the newly calculated focusable range, the process proceeds to step S405. On the other hand, if the drive target position of the focus lens 32 is outside the focusable range In step S406, the process proceeds to step S406. If the drive target position of the focus lens 32 is not calculated, the process proceeds to step S405.

  In step S405, the inside of the focusable range after the change of the focus lens 32 is performed by the camera control unit 21 based on the focusable range after the change calculated in step S402 and the current position of the focus lens 32. A determination is made as to whether it is located at For example, when the focusable range is changed by the photographer via the focus limit switch 38, the focus lens 32 may be positioned outside the focusable range after the change. 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 positioned outside the focusable range, the process proceeds to step S406. On the other hand, when the focus lens 32 is positioned inside the focusable range, FIG. End the focus limit change process shown.

  In step S406, the camera control unit 21 calculates the lens driving amount necessary to drive the focus lens 32 to the limit position of the in-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 S402 and the current position of the focus lens 32. The lens drive amount necessary to drive to the limit position of the range is calculated.

  Then, in step S407, based on the lens drive amount calculated in step S406, the camera control unit 21 drives the focus lens 32 to the limit position of the focusable range. Specifically, the camera control unit 21 sends the lens driving amount calculated in step S406 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 of the focusable range based on the lens drive amount calculated by the camera control unit 21.

Thus, for example, in the "near side limit mode" shown in FIG. 2 (B), when the focus lens 32 is positioned on the infinity side than the infinity side software limit SL _IS, focus limit mode is "close The "side limit mode" is changed to "infinity side limit mode", and the focusable range is changed from the focusable range Rf2 shown in FIG. 2 (B) to the focusable range Rf3 shown in FIG. 2 (C) In this case, the focus lens 32 is moved to the infinity side soft limit S- _IS, which is the limit position of the in-focus possible range of 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 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, if the defocus amount can be calculated by the phase difference detection method, it is determined whether or not the drive target position according to the defocus amount is inside the focusable range, and the drive according to the defocus amount When the target position exceeds the focusable range, the lens drive amount necessary for moving the focus lens 32 to the limit position of the focusable range is calculated in the camera body 2. Then, in the lens barrel 3, the following effects can be achieved by driving the focus lens 32 to the limit position of the focusable range based on the lens drive amount calculated by the camera body 2.

  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 calculated. 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 in-focusable range, and when the focus lens 32 has reached the limit position in the in-focus range, the driving of the focus lens 32 is performed. Was stopped. Therefore, conventionally, in the lens barrel 3, the processing load for determining whether or not the focus lens 32 has exceeded the focusable range increases, and depending on the timing of determination, the focusable range is exceeded. The focus lens 32 may be stopped at a position beyond the focusable range, and an in-focus display may be performed.

  On the other hand, in the present embodiment, when the drive target position based on the defocus amount exceeds the focusable range, in the camera body 2, the focus lens 32 is driven to the limit position of the focusable 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 since the drive of the focus lens 32 is appropriately limited within the focusable range, It is possible to effectively prevent the in-focus display from being performed at the lens position beyond the focusable range.

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

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

  Furthermore, in the present embodiment, the scan drive range when performing the scan operation is calculated in a range including the focusable range and wider than the focusable range, and the scan operation is performed in the calculated scan drive range. Do. Thus, in the present embodiment, even when the peak position (focus position) of the focus evaluation value is present at the limit position of the focusable range, it is possible to appropriately detect the focus position. That is, conventionally, when performing focus detection using a contrast detection method such as scan driving, it is repeatedly determined whether or not the focus lens 32 has reached the limit position of the focusable range, and the focus lens 32 can be focused. When the limit position in the range is reached, since the drive of the focus lens 32 is stopped, the peak position (focus position) of the focus evaluation value is in focus when it is at the limit position of the focusable range. There is a problem that the position can not be detected. On the other hand, in the present embodiment, even when the peak position (focus position) of the focus evaluation value is present 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 properly detect the in-focus position.

  Further, in the present embodiment, by transmitting 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. It is possible to determine in the camera body 2 whether or not the subject can be focused. Therefore, in the present embodiment, the determination of the in-focus indication and the out-of-focus indication can be appropriately performed in the camera body 2, and the in-focus indication is displayed when the in-focus position exists outside the in-focusable range. It can be effectively prevented.

  Furthermore, in the present embodiment, when the focusable range is changed by the photographer via the focus limit switch 38, the drive target position of the focus lens 32 is outside the focusable range after the change, or When the focus lens 32 is located outside the focusable range after the change, the focus lens 32 is moved to the limit position of the focusable range after the change, and the out-of-focus display is performed. Thereby, when the focusable range is changed, the focus lens 32 remains positioned outside the focusable range after the change, or the focus indication is displayed outside the focusable range after the change. It can be effectively prevented.

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

For example, in the above-described embodiment, when the “FULL mode” is set in the scan operation, as shown in FIG. 11A, from the lens position on the infinity side beyond the infinity end soft limit SL _IP The configuration to set the range up to the lens position on the nearer side than the closest end soft limit SL _NP is set as the scan drive range Rs1. However, the present invention is not limited to this configuration. For example, as shown in FIG. Alternatively, the range from the infinite end soft limit SL _IP to the near end soft limit SL _NP may be set as the scan drive range Rs1. FIG. 14 is a diagram showing another example of the scan drive range.

Similarly, when the “near-side limit mode” is set in the scan operation, as shown in FIG. 11 (B), the near-end side from the lens position on the infinity side of the infinite-end soft limit SL _IP Although the configuration to calculate the range up to the lens position closer to the soft limit SL _NS as the scan drive range Rs2 has been illustrated, the present invention is not limited to this configuration. For example, as shown in FIG. The range from the end soft limit SL _IP to the lens position closer to the near side soft limit SL _NS may be calculated as the scan drive range Rs2. Further, when the "infinite side limit mode" is set in the scan operation, as shown in FIG. 14 (C), the lens position of the infinity side than the infinity side software limit SL _IS, close The range up to the end soft limit SL _NP may be calculated as the scan drive range Rs3.

  In the embodiment described above, servo drive (step S112) for driving the focus lens 32 based on the defocus amount calculated by the phase difference detection method, scan drive (steps S108 to S111) in the scan operation, and contrast The drive control of the focus lens 32 in the focus drive (step S113) for driving the focus lens 32 based on the focus position detected by the detection method has been described as an example, but in addition to this configuration, for example, As shown in FIG. 8, in search drive for calculating the focus evaluation value while driving the focus lens 32, and in initial drive for driving the focus lens 32 to a predetermined search start position, as shown in FIG. Scan drive shown in 11 (A) to (C) Within it may be configured to restrict the drive of the focus lens 32.

  Also, for example, when shooting a moving subject, when the focus state of the optical system changes due to the movement of the subject, the focus lens 32 is driven according to the change of the focus state according to the above-described embodiment. The drive control of the lens 32 may be performed.

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

Reference Signs List 1 digital camera 2 camera body 21 camera control unit 22 imaging device 3 lens barrel 32 focus lens 36 focus lens driving motor 37 lens control unit

Claims (10)

An image pickup element which picks up an object image formed by an optical system having a focus lens and outputs a signal;
A communication unit that includes the optical system and communicates with a lens barrel that can set a range in which the focus lens can move;
A display unit for displaying whether or not the subject image by the optical system is in focus on the imaging surface of the imaging device;
Information on the movable range of the focus lens is received via the communication unit, and the end of the movable range is reached when the position of the focus lens for focusing the object image on the imaging surface exceeds the movable range. A control unit that transmits, to the lens barrel, a control signal for moving the focus lens to the unit, and causes the display unit to perform an out-of-focus display;
An imaging device having An image pickup element which picks up an object image formed by an optical system having a focus lens and outputs a signal;
A communication unit that includes the optical system and communicates with a lens barrel that can set a range in which the focus lens can move;
A display unit for displaying whether or not the subject image by the optical system is in focus on the imaging surface of the imaging device;
A detection unit that detects information related to the position of the focus lens at which the subject image is focused on the imaging surface, based on the signal output from the imaging element;
Information on the movable range of the focusing lens is received via the communication unit, and the focusing is performed on the imaging surface of the subject calculated based on the position of the focusing lens at which the subject image is focused on the imaging surface When the position of the lens exceeds the movable range, a control signal for moving the focus lens to the end of the movable range is transmitted to the lens barrel to cause the display section to perform an out-of-focus display. A control unit,
An imaging device having The imaging apparatus according to claim 2,
The detection unit calculates, based on a signal output from a focus detection pixel provided in the imaging device, information on the position of the focus lens at which the subject image is focused on the imaging surface. An imaging apparatus that detects a defocus amount that is a shift between a position and the imaging surface. The imaging apparatus according to claim 3,
The control unit acquires the position of the focus lens acquired via the communication unit, and the object image is focused on the imaging surface by the acquired position of the focus lens and the defocus amount. An imaging device that calculates the position of the focus lens. The imaging apparatus according to any one of claims 1 to 4, wherein
The image pickup apparatus, wherein the control unit receives information of the movable range of the focus lens after transmitting a control signal for moving the focus lens. The imaging apparatus according to any one of claims 1 to 5, wherein
The communication unit repeatedly performs communication,
The imaging device repeatedly acquires the position of the focus lens and the information of the movable range of the focus lens through the communication unit. A lens barrel attached to the imaging device according to any one of claims 1 to 6,
The optical system,
A setting unit configured to set a range in which the focus lens can move;
A communication unit that communicates with the imaging device;
A lens control unit that performs control of transmitting to the image pickup apparatus information indicating a movable range of the focus lens set by the setting unit;
Lens barrel with.   The camera system which has an imaging device as described in any one of Claims 1-6, and the said lens barrel. An optical system having a focus lens,
An imaging element that captures an object image formed by the optical system and outputs a signal;
A setting unit configured to set a range in which the focus lens can move;
A display unit for displaying whether or not the subject image by the optical system is in focus on the imaging surface of the imaging device;
A detection unit that detects the position of the focus lens at which the subject image is focused on the imaging surface based on the signal output from the imaging element;
A control unit that moves the focus lens to an end of the movable range when the movement target position of the focus lens exceeds the movable range, and causes the display unit to perform an out-of-focus display;
Electronic equipment having. A lens barrel that can be attached to a camera
An optical system having a focus lens, and a setting unit configured to allow a user of the camera to set a range in which the focus lens can move.
An attachment mechanism to a camera having a terminal in communication with the camera;
A drive unit for driving the focus lens;
A control unit configured to control periodic transmission of information on a range in which the focus lens can be moved, which is set by the setting unit, to the camera via the terminal;
Lens barrel with.

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