JP6627239B2 - Lens barrel and camera body - Google Patents

Description

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

  When the camera control unit sends a scan drive instruction to the lens control unit to perform focus detection, and the lens control unit that has received the scan drive command drives the focus adjustment lens in the optical axis direction in a predetermined manner, the camera control unit 2. Description of the Related Art There is known a technique of detecting a focus state of an optical system by calculating an evaluation value relating to contrast by an optical system (for example, see Patent Document 1).

WO 2009/028181

  An object of the present invention is to provide a camera body capable of suitably detecting a focus state of an optical system, and an interchangeable lens that can be mounted on the camera body.

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

  According to one aspect of the present invention, an interchangeable lens that can be mounted on a camera body, a focusing optical system that changes a focal point of the interchangeable lens by movement, and a receiving unit that receives time-related information from the camera body, A control unit for starting movement of the focusing optical system based on the information.

  According to another aspect of the present invention, there is provided a camera body attachable to an interchangeable lens, wherein transmission of an instruction to start movement of a focus optical system of the interchangeable lens and information on time are transmitted to the interchangeable lens. A camera body is provided that includes a unit and a control unit that completes preparation for detecting a focus before a time determined based on the information after transmitting the instruction.

FIG. 1 is a perspective view showing a camera according to the present embodiment. FIG. 2 is a main part configuration diagram showing the camera according to the present embodiment. FIG. 3 is a diagram illustrating a driving range of the focus lens 33. FIG. 4 is a table showing the relationship between the lens position (focal length) of the zoom lens, the lens position (photographing distance) of the focus lens, and the image plane movement coefficient K according to the first embodiment. FIG. 5 is a diagram illustrating a relationship between the focus lens position and the focus evaluation value and a relationship between the focus lens position and time in the scanning operation according to the present embodiment. FIG. 6 is a diagram illustrating an operation at the start of a scan operation according to the present embodiment. FIG. 7 is a diagram illustrating an operation at the start of a scan operation according to the comparative example. FIG. 8 is a schematic diagram showing details of the connection units 202 and 302. FIG. 9 is a diagram illustrating an example of the command data communication. FIG. 10 is a diagram illustrating an example of the hot line communication. FIG. 11 is a flowchart illustrating an operation example of the present embodiment. FIG. 12 is a main part configuration diagram showing a camera according to another embodiment.

<< 1st Embodiment >>
FIG. 1 is a perspective view showing a single-lens reflex digital camera 1 of the present embodiment. FIG. 2 is a main part configuration diagram showing the camera 1 of the present embodiment. A digital camera 1 (hereinafter, simply referred to as a camera 1) of the present embodiment includes a camera body (camera body) 2 and a lens barrel (interchangeable lens) 3, and the camera body 2, the lens barrel 3, Are detachably connected.

  The lens barrel 3 is an interchangeable lens that can be attached to and detached from the camera body 2. As shown in FIG. 2, the lens barrel 3 has a built-in photographing optical system including lenses 31, 32, 33, and 34 and an aperture.

  The lens 33 is a focus lens, and can adjust the focal length of the photographing optical system by moving in the direction of the optical axis L1. The focus lens 33 is provided so as to be movable along the optical axis L1 of the photographing optical system, and its position is adjusted by the focus lens drive motor 331 while its position is detected by the focus lens encoder 332.

  The focus lens drive motor 331 is, for example, an ultrasonic motor, and drives the focus lens 33 according to an electric signal (pulse) output from the lens control unit 36. Specifically, the drive speed of the focus lens 33 by the focus lens drive motor 331 is expressed in pulses / second, and the drive speed of the focus lens 33 increases as the number of pulses per unit time increases. In this embodiment, the camera controller 21 of the camera body 2 transmits the drive instruction speed (unit: pulse / second) of the focus lens 33 to the lens barrel 3, and the lens controller 36 By outputting a pulse signal corresponding to the transmitted drive instruction speed (unit: pulse / second) to the focus lens drive motor 331, the focus lens 33 is driven by the drive instruction speed transmitted from the camera body 2 (unit: pulse). / Sec).

  The lens 32 is a zoom lens, and can adjust the focal length of the photographing optical system by moving in the direction of the optical axis L1. The position of the zoom lens 32 is adjusted by the zoom lens driving motor 321 while the position of the zoom lens 32 is detected by the zoom lens encoder 322, similarly to the focus lens 33 described above. The position of the zoom lens 32 is adjusted by operating a zoom button provided on the operation unit 28 or by operating a zoom ring (not shown) provided on the camera barrel 3.

  The aperture 35 is configured such that the aperture diameter around the optical axis L1 can be adjusted in order to limit the light amount of the light flux that passes through the imaging optical system and reaches the image sensor 22 and adjust the blur amount. The adjustment of the aperture diameter by the diaphragm 35 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 36. Further, the set aperture diameter is input from the camera control unit 21 to the lens control unit 36 by manual operation of the operation unit 28 provided in the camera body 2. The aperture diameter of the aperture 35 is detected by an aperture sensor (not shown), and the lens controller 36 recognizes the current aperture diameter.

  The lens memory 37 stores an image plane movement coefficient K. The image plane moving coefficient K is a value indicating the correspondence between the driving amount of the focus lens 33 and the moving amount of the image plane, and is, for example, a ratio between the driving amount of the focus lens 33 and the moving amount of the image plane. The details of the image plane movement coefficient K stored in the lens memory 37 will be described later.

  On the other hand, the camera body 2 includes a mirror system 220 for guiding a light beam from a subject to the image sensor 22, the finder 235, the photometric sensor 237, and the focus detection module 261. The mirror system 220 includes a quick return mirror 221 that rotates by a predetermined angle between a subject observation position and an imaging position about a rotation axis 223, and a quick return mirror 221 that is supported by the quick return mirror 221. And a sub-mirror 222 that rotates in accordance with the rotation. In FIG. 1, the state where the mirror system 220 is at the observation position of the subject is indicated by a solid line, and the state where the mirror system 220 is at the imaging position of the subject is indicated by a two-dot chain line.

  The mirror system 220 is inserted into the optical path of the optical axis L1 when the object is at the observation position, and rotates so as to retreat from the optical path of the optical axis L1 when the object is at the imaging position.

  The quick return mirror 221 is formed of a half mirror, and reflects a part of the light flux (optical axis L2, L3) of the light flux (optical axis L1) from the subject at the observation position of the subject with the quick return mirror 221. To the finder 235 and the photometric sensor 237, and transmits a part of the light beam (optical axis L4) to the sub mirror 222. On the other hand, the sub mirror 222 is configured by a total reflection mirror, and guides the light beam (optical axis L4) transmitted through the quick return mirror 221 to the focus detection module 261.

  Therefore, when the mirror system 220 is at the observation position, the light flux (optical axis L1) from the subject is guided to the finder 235, the photometric sensor 237, and the focus detection module 261 so that the photographer observes the subject and calculates the exposure. And the focus adjustment state of the focus lens 33 is detected. Then, when the photographer fully presses the release button, the mirror system 220 rotates to the photographing position, all the light beams (optical axis L1) from the subject are guided to the image pickup device 22, and the photographed image data is stored in the memory 24. .

  The light flux (optical axis L2) from the subject reflected by the quick return mirror 221 forms an image on a focusing screen 231 arranged on a plane optically equivalent to the image sensor 22, and causes the pentaprism 233 and the eyepiece 234 to move. Observable through. At this time, the transmissive liquid crystal display 232 superimposes and displays a focus detection area mark and the like on the subject image on the focusing screen 231, and also displays an area outside the subject image such as a shutter speed, an aperture value, and the number of shots. Display information. Thus, the photographer can observe the subject, its background, photographing-related information, and the like through the viewfinder 235 in the photographing preparation state.

  The photometric sensor 237 is composed of a two-dimensional color CCD image sensor or the like, and divides a photographic screen into a plurality of regions and outputs a photometric signal corresponding to the luminance of each region in order to calculate an exposure value at the time of photographing. The signal detected by the photometric sensor 237 is output to the camera control unit 21 and used for automatic exposure control.

  The image pickup device 22 is provided on the optical axis L1 of the light beam from the subject in the camera body 2 and on a predetermined focal plane of an imaging optical system including the lenses 31, 32, 33, and 34, and a shutter 23 is provided on the front surface thereof. Is provided. The image sensor 22 has a plurality of photoelectric conversion elements arranged two-dimensionally, and can be constituted by a device such as a two-dimensional CCD image sensor, a MOS sensor, or a CID. The image signal photoelectrically converted by the image sensor 22 is subjected to image processing by the camera controller 21 and then stored in the memory 24 as a storage medium. As the memory 24, either a removable card type memory or a built-in type memory can be used.

  The operation unit 28 is an input switch for the photographer to set various operation modes of the camera 1, such as a release button and a moving image shooting start switch, and switches between a still image shooting mode / moving image shooting mode, an auto focus mode / manual focus. The mode can be switched, and the AF-S mode / AF-F mode can be switched even in the autofocus mode. The various modes set by the operation unit 28 are transmitted to the camera control unit 21, and the operation of the entire camera 1 is controlled by the camera control unit 21. The 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.

  Here, in the AF-S mode, when the release button is half-pressed, after the focus lens 33 is driven based on the focus detection result, the position of the focus lens 33 that has been adjusted once is fixed. In this mode, shooting is performed at the focus lens position. Note that the AF-S mode is a mode suitable for still image shooting, and is usually selected when still image shooting is performed. In the AF-F mode, the focus lens 33 is driven based on the focus detection result regardless of whether or not the release button is operated, and thereafter, the focus state is repeatedly detected. In this mode, scan driving (search driving, search driving) of the focus lens 33 is performed. The AF-F mode is a mode suitable for moving image shooting, and is usually selected when shooting a moving image.

  Further, in the present embodiment, a configuration may be employed in which a switch for switching between one-shot mode and continuous mode is provided as a switch for switching between autofocus modes. In this case, the AF-S mode is set when the one-shot mode is selected by the photographer, and the AF-F mode is set when the continuous mode is selected by the photographer. May be set.

  The camera control unit 21 detects the focus adjustment state of the imaging optical system by a contrast detection method (hereinafter, appropriately referred to as “contrast AF”) based on the pixel data read from the image sensor 22. For example, the camera control unit 21 reads the output of the image sensor 22 and calculates a focus evaluation value based on the read output. The focus evaluation value can be obtained, for example, by extracting a high-frequency component of the output from the image sensor 22 using a high-frequency transmission filter. Further, it can also be obtained by extracting a high-frequency component using two high-frequency transmission filters having different cutoff frequencies.

  Then, the camera control unit 21 sends a drive signal to the lens control unit 36 to drive the focus lens 33 at a predetermined sampling interval (distance), obtains a focus evaluation value at each position, and determines that the focus evaluation value is maximum. Then, focus detection is performed by a contrast detection method, in which the position of the focus lens 33 is determined as the focus position. Note that, when the focus evaluation value is calculated while driving the focus lens 33, for example, when the focus evaluation value rises twice, and further falls two times, Can be obtained by performing an operation such as an interpolation method using the focus evaluation value.

  In focus detection by the contrast detection method, the sampling interval of the focus evaluation value increases as the driving speed of the focus lens 33 increases, and when the driving speed of the focus lens 33 exceeds a predetermined speed, the sampling interval of the focus evaluation value increases. Becomes too large, so that the in-focus position cannot be properly detected. This is because the larger the sampling interval of the focus evaluation value, the greater the variation of the focusing position and the lower the focusing accuracy. Therefore, the camera control unit 21 drives the focus lens 33 so that the moving speed of the image plane when the focus lens 33 is driven becomes a speed at which the in-focus position can be appropriately detected. For example, in a scan operation (search operation, search operation) for driving the focus lens 33 to detect a focus evaluation value, the camera control unit 21 moves an image plane at a sampling interval at which a focus position can be appropriately detected. The focus lens 33 is driven such that the maximum image plane driving speed among the speeds is obtained. The scanning operation includes, for example, wobbling, a proximity search for searching only in the vicinity of a predetermined position (near scan), and a full search for searching the entire driving range of the focus lens 33 (full scan).

  When the search control is started by half-pressing the release button (first switch SW1 ON) provided on the operation unit 28 as a trigger, the camera control unit 21 drives the focus lens 33 at a high speed, and When the search control is started using a condition other than the half-press as a trigger, the focus lens 33 may be driven at a low speed. By performing such control, it is possible to perform the contrast AF at a high speed when the release button is half-pressed, and to perform the contrast AF with a favorable appearance of the through image when the release button is not half-pressed. It is. In the through image, for example, the mirror system 220 is rotated so as to retract from the optical path of the optical axis L1, the light flux from the subject is guided to the image sensor 22, and the image data captured by the image sensor 22 is monitored (for example, Displaying the image data captured by the image sensor 22 on a monitor for displaying the image data.

  Further, the camera control unit 21 may control the focus lens 33 to be driven at a high speed in the search control in the still image shooting mode, and the focus lens 33 to be driven at a low speed in the search control in the moving image shooting mode. This is because by performing such control, it is possible to perform contrast AF at high speed in the still image shooting mode, and to perform contrast AF with a favorable appearance of the moving image in the moving image shooting mode.

  In at least one of the still image shooting mode and the moving image shooting mode, focus detection by the contrast detection method may be performed at high speed in the sports shooting mode, and contrast AF may be performed at low speed in the landscape shooting mode. Further, the driving speed of the focus lens 33 in the search control may be changed according to the focal length, the photographing distance, the aperture value, and the like.

  Further, in the present embodiment, it is also possible to perform focus detection by a phase difference detection method. Specifically, the camera main body 2 includes a focus detection module 261. The focus detection module 261 is provided with a microlens arranged near a predetermined focal plane of the imaging optical system, and is arranged with respect to the microlens. It has a pair of line sensors (not shown) in which a plurality of pixels each having a photoelectric conversion element are arranged. Then, a pair of light beams passing through a pair of regions having different exit pupils of the focus lens 33 are received by pixels arranged in a pair of line sensors, so that a pair of image signals can be obtained. Then, a phase difference between a pair of image signals acquired by the pair of line sensors is obtained by a well-known correlation operation, so that focus detection by a phase difference detection method for detecting a focus adjustment state can be performed.

  Next, the driving range of the focus lens 33 will be described with reference to FIG.

  As shown in FIG. 3, the focus lens 33 is configured to be movable in an infinity direction 410 and a close-up direction 420 on an optical axis L1 indicated by a dashed line in the figure. A stopper (not shown) is provided at a mechanical end point (mechanical end point) 430 in the infinity direction 410 and a mechanical end point 440 in the close direction 420 to limit the movement of the focus lens 33. That is, the focus lens 33 is configured to be movable from a mechanical end point 430 in the infinity direction 410 to a mechanical end point 440 in the close direction 420.

  However, the range in which the lens control unit 36 actually drives the focus lens 33 is smaller than the range from the mechanical endpoint 430 to the mechanical endpoint 440 described above. More specifically, the lens control unit 36 moves from the infinite soft limit position 450 provided inside the mechanical end point 430 in the infinity direction 410 to the inside from the mechanical end point 440 in the close direction 420. The focus lens 33 is driven within a range up to the provided soft limit position 460. That is, the lens driving unit 212 drives the focus lens 33 between the close soft limit position 460 corresponding to the close drive position and the infinite soft limit position 450 corresponding to the infinite drive limit position.

  The infinity soft limit position 450 is provided outside the infinity focusing position 470. The infinity in-focus position 470 is the position of the focus lens 33 corresponding to the most infinity-side position at which the imaging optical system including the lenses 31, 32, 33, and 34 and the aperture 35 can focus. The reason why the infinite soft limit position 450 is provided at such a position is that a peak of the focus evaluation value may be present at the infinite focus position 470 when performing focus detection by the contrast detection method. That is, if the infinite focus position 470 is made to coincide with the infinite soft limit position 450, there is a problem that the peak of the focus evaluation value existing at the infinite focus position 470 cannot be recognized as a peak. In order to avoid this, the infinite soft limit position 450 is provided outside the infinite focus position 470. Similarly, the close soft limit position 460 is provided outside the close focus position 480. Here, the close focus position 480 is the position of the focus lens 33 corresponding to the closest position where the imaging optical system including the lenses 31, 32, 33, and 34 and the aperture 35 can focus.

  The closest focusing position 480 can be set based on, for example, aberration of the photographing optical system. For example, even if the focus can be adjusted by driving the focus lens 33 closer to the set closest focus position 480 than the set closest focus position 480, if the imaging optical system aberration is deteriorated, the use range of the lens is reduced. Because it is not appropriate.

  In the present embodiment, the position of the focus lens 33 can be represented, for example, by the number of pulses of a drive signal given to the lens drive motor 321. In this case, the number of pulses is set such that the infinity focus position 470 is the origin (reference). can do. For example, in the example shown in FIG. 3, the infinite soft limit position 450 is a position of “−100 pulse”, the close focus position 480 is a position of “9800 pulse”, and the close soft limit position 460 is a position of “9900 pulse”. . In this case, in order to move the focus lens 33 from the infinite soft limit position 450 to the close soft limit position 460, it is necessary to supply a drive signal for 10,000 pulses to the lens drive motor 321. However, the present embodiment is not particularly limited to such an aspect.

  Next, the image plane movement coefficient K stored in the lens memory 37 of the lens barrel 3 will be described.

The image plane moving coefficient K is a value indicating the correspondence between the driving amount of the focus lens 33 and the moving amount of the image plane, and is, for example, a ratio between the driving amount of the focus lens 33 and the moving amount of the image plane. In the present embodiment, the image plane movement coefficient is obtained, for example, by the following equation (1).
Image plane moving coefficient K = (driving amount of focus lens 33 / moving amount of image plane) (1)

Further, in the camera 1 of the present embodiment, even when the driving amount of the focus lens 33 is the same, the moving amount of the image plane differs depending on the lens position of the focus lens 33. Similarly, even when the driving amount of the focus lens 33 is the same, the moving amount of the image plane varies depending on the lens position of the zoom lens 32, that is, the focal length. That is, the image plane movement coefficient K changes according to the lens position of the focus lens 33 in the optical axis direction, and further, according to the lens position of the zoom lens 32 in the optical axis direction. Reference numeral 36 stores an image plane movement coefficient K for each lens position of the focus lens 33 and each lens position of the zoom lens 32.
Further, the image plane movement coefficient K can be defined, for example, as follows: image plane movement coefficient K = (movement amount of image plane / driving amount of focus lens 33). In this case, as the image plane movement coefficient K increases, the amount of movement of the image plane due to the driving of the focus lens 33 increases.

  FIG. 4 shows a table showing the relationship between the lens position (focal length) of the zoom lens 32 and the lens position (photographing distance) of the focus lens 33, and the image plane movement coefficient K. In the table shown in FIG. 4, the driving area of the zoom lens 32 is divided into nine areas “f1” to “f9” in order from the wide end to the telephoto end, and the driving area of the focus lens 33 is close to the driving area. The image plane movement coefficient K corresponding to each lens position is stored in nine regions “D1” to “D9” in order from the end toward the infinity end. Here, of the lens positions of the focus lens 33, “D1” is a predetermined area corresponding to the close focus position 480 shown in FIG. 3, and for example, a predetermined area near the close focus position 480 shown in FIG. Area. “D9” is a predetermined area corresponding to the infinite focus position 470 shown in FIG. 3, and may be, for example, a predetermined area near the infinite focus position 470 shown in FIG. In the table shown in FIG. 4, for example, when the lens position (focal length) of the zoom lens 32 is “f1” and the lens position (photographing distance) of the focus lens 33 is “D1”, the image plane movement coefficient K becomes “K11”. Although the table shown in FIG. 4 exemplifies a mode in which the driving area of each lens is divided into nine areas, the number is not particularly limited and can be set arbitrarily.

Next, the minimum image plane movement coefficient K _min and the maximum image plane movement coefficient K _max will be described with reference to FIG.
The minimum image plane movement coefficient K _min is a value corresponding to the minimum value of the image plane movement coefficient K. The minimum image plane movement coefficient K _min usually changes according to the current lens position of the zoom lens 32. In addition, the minimum image plane movement coefficient K _min is usually a fixed value (fixed value) even if the current lens position of the focus lens 33 changes unless the current lens position of the zoom lens 32 changes. That is, the minimum image plane movement coefficient K _min is usually a fixed value (constant value) determined according to the lens position (focal length) of the zoom lens 32, and depends on the lens position (photographing distance) of the focus lens 33. Not a value.

Here, in the present embodiment, among the lens positions of the focus lens 33, the image plane movement coefficient K at “D1” is set to the minimum image plane movement coefficient K _min . That is, in the present embodiment, when the focus lens 33 is driven near the closest focus position 480 including the closest focus position 480 shown in FIG. 3, the image plane movement coefficient K is set to the minimum image plane movement coefficient K _min In FIG. 4, “K11”, “K21”, “K31”, “K41”, “K51”, “K61”, “K71”, “K81”, and “K91” shown in gray in FIG. Indicates a minimum image plane movement coefficient K _min indicating the minimum value among the image plane movement coefficients K at each lens position (focal length) of the zoom lens 32.

For example, when the lens position (focal length) of the zoom lens 32 is “f1”, the lens position (photographing distance) of the focus lens 33 is “D1” among “D1” to “D9”. “K11”, which is the image plane movement coefficient K, is the minimum image plane movement coefficient K _min indicating the minimum value. Therefore, “K11”, which is the image plane movement coefficient K when the lens position (photographing distance) of the focus lens 33 is “D1”, indicates that the lens position (photographing distance) of the focus lens 33 is “D1” to “D9”. Is the smallest value among "K11" to "K19" which are the image plane movement coefficients K in the case of. Similarly, when the lens position (focal length) of the zoom lens 32 is “f2”, the image plane movement coefficient K when the lens position (photographing distance) of the focus lens 33 is “D1”. “K21” indicates the smallest value among “K21” to “K29”, which are the image plane movement coefficients K in the case of “D1” to “D9”. That is, “K21” is the minimum image plane movement coefficient K _min . Hereinafter, similarly, even when each lens position (focal length) of the zoom lens 32 is “f3” to “f9”, “K31”, “K41”, “K51”, “K61”, and “K61” shown in gray are displayed. K71 "," K81 "," K91 "is the minimum image plane shift factor _{K min,} respectively.

As described above, in the present embodiment, among the lens positions of the focus lens 33, the image plane movement coefficient K at “D1” is set to the minimum image plane movement coefficient K _min . In particular, in the present embodiment, when the focus lens 33 is driven from the infinity side to the close side, the image is different depending on the configuration of 31, 32, 33, and 34 constituting the lens barrel 3. The plane shift coefficient K tends to be small, and the image plane shift coefficient K tends to be the smallest at the close focus position 480 shown in FIG. Therefore, in the present embodiment, the image plane movement coefficient K at “D1” is set as the minimum image plane movement coefficient K _min . However, depending on the configuration of 31, 32, 33, and 34 constituting the lens barrel 3, the image plane movement coefficient K may be the smallest at the infinite focus position 470 shown in FIG. In this case, the image plane movement coefficient K in “D9” can be set to the minimum image plane movement coefficient K _min .

Similarly, the maximum image plane movement coefficient K _max is a value corresponding to the maximum value of the image plane movement coefficient K. The maximum image plane movement coefficient K _max usually changes according to the current lens position of the zoom lens 32. The maximum image plane movement coefficient K _max is normally a fixed value (fixed value) even if the current lens position of the focus lens 33 changes unless the current lens position of the zoom lens 32 changes.

Here, in the present embodiment, among the lens positions of the focus lens 33, the image plane movement coefficient K at “D9” is set to the maximum image plane movement coefficient K _max . That is, in the present embodiment, when the focus lens 33 is driven in the vicinity of the infinite focus position 470 including the infinite focus position 470 shown in FIG. 3, the image plane movement coefficient K is set to the maximum image plane movement coefficient K _max In FIG. 4, "K19", "K29", "K39", "K49", "K59", "K69", "K79", "K89", “K99” indicates the maximum image plane movement coefficient K _max indicating the maximum value among the image plane movement coefficients K at each lens position (focal length) of the zoom lens 32.

As described above, in the present embodiment, among the lens positions of the focus lens 33, the image plane movement coefficient K at “D9” is set to the maximum image plane movement coefficient K _max . In particular, in the present embodiment, when the focus lens 33 is driven from the closest side to the infinity side, although it depends on the configuration of 31, 32, 33, and 34 constituting the lens barrel 3, the image is not changed. The plane shift coefficient K tends to be large, and the image plane shift coefficient K tends to be the largest at the infinite focus position 470 shown in FIG. Therefore, in the present embodiment, the image plane movement coefficient K at “D9” is set as the maximum image plane movement coefficient K _max . However, depending on the configuration of 31, 32, 33, and 34 constituting the lens barrel 3, the image plane movement coefficient K may be the largest at the closest focusing position 480 shown in FIG. In this case, the image plane movement coefficient K at “D1” can be set to the maximum image plane movement coefficient K _max .

As described above, the lens memory 37 stores the image plane movement coefficient K corresponding to the lens position (focal length) of the zoom lens 32 and the lens position (photographing distance) of the focus lens 33, as shown in FIG. For each lens position (focal length) of 32, a minimum image plane movement coefficient K _min indicating the minimum value of the image plane movement coefficient K, and for each lens position (focal length) of the zoom lens 32, an image plane movement coefficient A maximum image plane movement coefficient K _max indicating the maximum value of K is stored.

The lens memory 37 is smallest in place of the minimum image plane shift factor K _min indicating the value, the minimum image plane shift factor K is a value in the vicinity of the minimum image plane shift factor K _min of the image plane shift factor K _min ′ may be stored in the lens memory 37. For example, when the value of the minimum image plane movement coefficient K _min is a large number such as 52.345, a value 50 near 52.345 can be stored as the minimum image plane movement coefficient K _min ′. it can. When 50 (the minimum image plane movement coefficient K _min ′) is stored in the lens memory 37, the storage capacity of the memory is smaller than when 52.345 (the minimum image plane movement coefficient K _min ′) is stored in the lens memory 37. This is because it is possible to reduce the amount of transmitted data when transmitting the data to the camera body 2.

  Next, a focus detection method using a contrast detection method in the present embodiment will be described in detail. In focus detection by the contrast detection method, a scan drive command (search drive command, search drive command) for focus detection by the contrast detection method is transmitted from the camera control unit 21 of the camera body 2 to the lens control unit 36 of the lens barrel 3. ) Is transmitted, and the lens control unit 36 receives the scan drive command and executes the scan drive of the focus lens 33. In addition, during the scan driving of the focus lens 33, the camera control unit 21 repeatedly reads pixel data from the image sensor 22, and detects the focus adjustment state of the imaging optical system by the contrast detection method based on the read pixel data. Is what you do.

Here, FIG. 5 is a diagram illustrating the relationship between the focus lens position and the focus evaluation value and the relationship between the focus lens position and time in the scanning operation according to the present embodiment. As shown in FIG. 5, definitive from the camera control unit 21 when receiving the scan drive command, when the focus lens 33 is located at the P0, first, at time t _0, the lens position P0, infinity close side Initial driving is performed toward the far side. Then, at time t _1, the lens position P1, the scanning operation of the focus lens 33 from the infinite side to the close side is started. At this time, the camera control unit 21 repeatedly reads the pixel data from the image sensor 22, and repeatedly detects the focus adjustment state of the imaging optical system by the contrast detection method based on the read pixel data.

Then, at time t _2, at the time when the focus lens 33 is moved to the lens position P1, the peak position of the focus evaluation value (focus position) P2 is detected, it stops the scanning operation, focusing Following this by performing the driving, at time t _3, the focus lens 33 is driven to an in-focus position. As described above, focus detection by the contrast detection method is performed. Although FIG. 5 illustrates the case where the scanning operation is performed from the infinity side to the closest side, the same applies to the case where the scanning operation is performed from the closest side to the infinity side.

  Here, the operation at the time of starting the scanning operation in the present embodiment will be described in detail with reference to FIG. FIG. 6 is a diagram illustrating an operation at the start of a scan operation according to the present embodiment.

  First, the operation of the camera body 2 will be described. As shown in FIG. 6, before the photographer performs an AF start operation such as half-pressing operation of a release button provided on the operation unit 28 (turning on a first switch SW1) and turning on an AF start switch, a camera control unit. Reference numeral 21 controls a through image. The control for the through image is control by the camera control unit 21 for displaying the through image on a monitor (not shown), and is, for example, imaging control by the image sensor 22 for displaying the through image.

  When the AF start operation is performed, the camera control unit 21 calculates a time required for changing to the control for the contrast AF, and sets the time as a reference time Tα. Then, the camera control unit 21 transmits a scan driving command to the lens control unit 36 together with information on the calculated reference time Tα. The control for contrast AF is control for the camera control unit 21 to detect a focus evaluation value, and is, for example, imaging control for detecting the focus evaluation value by the image sensor 22.

  The reference time Tα is an elapsed time (at least one of the information of the reference time Tα and the scan driving command is transmitted from the camera control unit 21 after transmitting at least one of the information of the reference time Tα and the scan driving command to the lens control unit 36). (Elapsed time from the reception of the control unit 36) or the lens control unit 36 after the camera control unit 21 transmits at least one of the information of the reference time Tα and the scan drive command to the lens control unit 36. May be a time during which the camera control unit 21 prohibits the scan driving by the camera control unit 21. Alternatively, the camera control unit 21 transmits at least one of the information of the reference time Tα and the scan drive command to the lens control unit 36, and then performs the contrast AF It may be a time required to change to the control, or change to the control for contrast AF after the AF start operation is performed. May be required, or may be a time required to change from control for a through image (such as imaging control) to control for contrast AF (such as imaging control), It may be a time from when the camera control unit 21 transmits at least one of the information of the reference time Tα and the scan drive command to the lens control unit 36 to when the preparation by the camera control unit 21 for detecting the focus evaluation value is completed. However, even if the time is shorter than the time from when the camera control unit 21 transmits at least one of the information of the reference time Tα and the scan drive command to the lens control unit 36 until the focus is detected by the camera control unit 21. Good.

  Note that the reference time Tα may be a time required for the above-described change, or a margin (for giving a time margin for the control) to the time required for the above-described change in order to secure control stability. Time).

The information of the reference time Tα may be included in the scan drive command, may be transmitted separately from the scan drive command in association with the scan drive command, or may be transmitted in association with the scan drive command. It may be transmitted separately.
After transmitting the scan drive command to the lens control unit 36, the camera control unit 21 starts a process of changing the control for the through image to the control for the contrast AF. After the process of changing to the control for contrast AF is completed, the imaging element 22 repeatedly performs imaging in imaging control (imaging control for contrast AF) for detecting a focus evaluation value.

  The processing for changing the control for the through image to the control for the contrast AF includes, for example, the processing for changing the exposure sensitivity of the image sensor 22 from the control for the through image to the control for the contrast AF, and the processing for changing the control for the through image from the control for the contrast AF. Processing for changing the exposure time of the image sensor 22 to control for image processing, processing for changing the aperture diameter of the aperture 35 from control for a through image to control for contrast AF, imaging from control for a through image to control for contrast AF This is a process including at least one of a process of changing the frame rate of the element 22 and a process of changing the imaging output level correction control from the control for the through image to the control for the contrast AF.

Next, the operation of the lens barrel 3 will be described. As shown in FIG. 6, when the lens control unit 36 receives a scan drive command from the camera control unit 21 together with the reference time Tα, the lens control unit 36 initially drives the focus lens 33 from the closest side to the infinity side, and then performs the focus lens After the scan drive command is received, the scan drive of the focus lens 33 is started from the infinity side to the close side after a lapse of the reference time Tα after the scan drive command is received.
The camera control unit 21 may start the scan drive at the same time as the reference time Tα has elapsed, or may start the scan drive after a predetermined time has elapsed after the reference time Tα has elapsed.
Further, for example, the lens control unit 36 may receive a scan driving command and the moving speed together with the reference time Tα from the camera control unit 21. In this case, the lens control unit 36 performs initial driving at a speed different from the moving speed received with the scan driving command (for example, the maximum speed of the lens barrel 3), and performs scan driving at the moving speed received with the scan driving command. May go. The moving speed received together with the scan driving command may be the moving speed of the focus lens 33 or the moving speed of the image of the photographing optical system.

  As described above, in the present embodiment, the scan driving of the focus lens 33 is started after the elapse of the reference time Tα, so that the focus control of the photographing optical system by the contrast detection method by the camera control unit 21 during the scan driving of the focus lens 33. The state can be appropriately detected.

As a comparative example, for example, the lens control unit 36 is designed to drive the focus lens 33 as fast as possible, and cannot know the timing at which the camera control unit 21 changes to control for contrast AF. In this case (when the reference time Tα cannot be received from the camera control unit 21), as shown in FIG. 7, before the camera control unit 21 switches to the control for contrast AF, the scan driving of the focus lens 33 is performed by the lens control unit. 36.
Then, in this case, as shown in FIG. 7, after the start of the scan drive, the control for the contrast AF by the camera control unit 21 is performed after the standby for a predetermined time T _los (after the initial drive of the focus lens 33 is completed) until time to change completion to) it has passed, by the camera control unit 21, since the detection of the focusing state of the photographing optical system based on the contrast detection method is not performed, for a period of time T _los, focus The detection result of the adjustment state is lost (the focus evaluation value is skipped). Therefore, in such a case, the camera control unit 21 may not appropriately detect the focus adjustment state of the imaging optical system by the contrast detection method. In particular, in this case, it is necessary to perform the scanning operation again over a wide range including a portion where the detection result of the focus adjustment state is missing (a portion scanned within the time T _los ). It becomes. Such a problem becomes conspicuous when a lens having a relatively high lens drive speed or a lens having a relatively short drive control time is used, such as when a stepping motor is used as a drive source.

  On the other hand, according to the present embodiment, such a problem can be effectively solved by using the reference time Tα which is a time required for changing to the control for the contrast AF. . Although FIG. 6 illustrates a case where the scanning operation is performed from the infinity side to the close side, the same applies to a case where the scanning operation is performed from the close side to the infinity side.

  When the scan drive of the focus lens 33 is started after the lapse of the reference time Tα, the scan drive of the focus lens 33 may be started after the lapse of the reference time Tα. A method of adjusting the time until the start may be adopted, a method of adjusting the driving speed of the initial drive may be adopted, or a method of adjusting the standby time after the initial drive may be adopted. Is also good. Further, a combination of these may be used.

  In the above example, the scan drive of the focus lens 33 is started after the lapse of the reference time Tα. However, the scan drive start timing of the focus lens 33 is determined based on the reference time Tα. For example, the timing may be a predetermined time after the elapse of the reference time Tα (for example, the time when one frame of imaging by the image sensor 22 has elapsed after the elapse of the reference time Tα, or the reference time). The scan driving may be started at a point in time after the lapse of the time Tα, for example, when two frames of the image pickup by the image pickup element 22 have elapsed). Alternatively, a timing that is a predetermined time before the reference time Tα elapses (for example, a time one frame before the imaging by the image sensor 22 before the reference time Tα elapses, or a timing before the reference time Tα elapses) Alternatively, the scan drive may be started at a point in time two frames before the image pickup by the image pickup device 22). The scan drive may be started at a timing that is a predetermined time before the reference time Tα has elapsed, for example, when the camera control unit 21 of the camera body 2 calculates the reference time Tα. A case where a margin is provided for Tα (for example, the margin can be shorter than one frame, longer than one frame, or longer than two frames) can be exemplified.

Further, depending on the type of the lens barrel 3 and the length of the reference time Tα, even when the focus lens 33 is driven as fast as possible, the scan drive of the focus lens 33 is started only after the reference time Tα has elapsed. In some cases, when the above control is performed, the lens control unit 36 determines in advance that the scan driving of the focus lens 33 can be started (the time required until the lens control unit 36 starts the scan drive). The possible start time T _pos is compared with the reference time Tα, and the control is made different based on the comparison result. The drive start possible time T _pos is, for example, the preparation for starting the scan drive after the lens control unit 36 receives at least one of the information on the reference time Tα and the scan drive command from the camera control unit 21 (for example, a predetermined time after the initial drive). The time until the waiting of the time is completed may be the time until the completion.

  In the present embodiment, the time until the preparation for starting the scan driving is completed is the time until the standby for a predetermined time after the initial driving is completed, but the time is not limited to this. For example, when performing contrast AF without performing initial drive before scan drive, the time until preparation for starting scan drive is completed is the time for preparing drive instructions to the focus lens drive motor 331 and the like. It may be.

Specifically, when “driving start possible time T _pos ≦ reference time Tα”, the scan drive start timing of the focus lens 33 is determined based on the reference time Tα. On the other hand, when “driving start possible time T _pos > reference time Tα”, the scan drive start timing of the focus lens 33 is determined based on the driving start possible time T _pos regardless of the reference time Tα. In order to control the drive of the focus lens 33 as fast as possible, it is desirable to make the scan start timing as early as possible. For example, by reducing the accuracy of the stop control of the focus lens 33 and the precision of the backlash control, Alternatively, a method of making the drive control of the focus lens 33 as fast as possible may be adopted. The drive start possible time T _pos may be stored in the lens memory 37, for example.

  Further, in the present embodiment, when transmitting the scan driving command from the camera control unit 21 to the lens control unit 36 together with the reference time Tα, the command is transmitted by command data communication described later.

  Next, a data communication method between the camera body 2 and the lens barrel 3 will be described.

  The camera body 2 is provided with a body-side mount 201 to which the lens barrel 3 is detachably attached. As shown in FIG. 1, a connection portion 202 protruding from the inner surface of the body-side mount portion 201 is provided near the body-side mount portion 201 (on the inner surface side of the body-side mount portion 201). . The connection part 202 is provided with a plurality of electrical contacts.

  On the other hand, the lens barrel 3 is an interchangeable lens that can be attached to and detached from the camera body 2, and the lens barrel 3 is provided with a lens-side mount unit 301 that is detachably attached to the camera body 2. As shown in FIG. 1, a connection portion 302 protruding toward the inner surface of the lens-side mount portion 301 is provided near the lens-side mount portion 301 (on the inner surface side of the lens-side mount portion 301). . The connection portion 302 is provided with a plurality of electrical contacts.

  When the lens barrel 3 is mounted on the camera body 2, the electrical contacts of the connecting portion 202 provided on the body side mounting portion 201 and the electrical contacts of the connecting portion 302 provided on the lens side mounting portion 301 are connected. Connected electrically and physically. This enables power supply from the camera body 2 to the lens barrel 3 and data communication between the camera body 2 and the lens barrel 3 via the connection units 202 and 302.

  FIG. 8 is a schematic diagram showing details of the connection units 202 and 302. In FIG. 8, the connection portion 202 is disposed on the right side of the body-side mount portion 201 in accordance with an actual mount structure. That is, the connection portion 202 of the present embodiment is disposed at a position deeper than the mounting surface of the body-side mount portion 201 (a position on the right side of the body-side mount portion 201 in FIG. 8). Similarly, the reason why the connection portion 302 is disposed on the right side of the lens side mount portion 301 is that the connection portion 302 of the present embodiment is disposed at a position protruding from the mount surface of the lens side mount portion 301. Represents. By arranging the connection part 202 and the connection part 302 in this manner, the mounting surface of the body-side mounting part 201 and the mounting surface of the lens-side mounting part 301 are brought into contact, and the camera body 2 and the lens barrel 3 Are connected to each other, the connection portion 202 and the connection portion 302 are connected to each other, whereby the electrical contacts provided on both of the connection portions 202 and 302 are connected to each other.

  As shown in FIG. 8, twelve electrical contacts BP <b> 1 to BP <b> 12 exist in the connection part 202. The connection portion 302 on the lens 3 side has 12 electrical contacts LP1 to LP12 corresponding to the 12 electrical contacts on the camera body 2 side, respectively.

  The electric contacts BP1 and BP2 are connected to a first power supply circuit 230 in the camera body 2. The first power supply circuit 230 supplies an operating voltage to each unit in the lens barrel 3 (except for circuits such as the lens drive motors 321 and 331 which consume relatively large power) via the electrical contacts BP1 and LP1. Supply. The voltage value supplied by the first power supply circuit 230 via the electric contact BP1 and the electric contact LP1 is not particularly limited, and is, for example, a voltage value of 3 to 4 V (typically, 3 0.5V). In this case, the current value supplied from the camera body side 2 to the lens barrel side 3 is a current value within a range of about several tens mA to several hundred mA in the power-on state. The electric contacts BP2 and LP2 are ground terminals corresponding to the operating voltage supplied via the electric contacts BP1 and LP1.

  The electrical contacts BP3 to BP6 are connected to the camera-side first communication unit 291. The electrical contacts LP3 to LP6 are connected to the lens-side first communication unit 381 corresponding to the electrical contacts BP3 to BP6. . The camera-side first communication unit 291 and the lens-side first communication unit 381 transmit and receive signals to and from each other using these electrical contacts. The contents of the communication performed by the camera-side first communication unit 291 and the lens-side first communication unit 381 will be described later in detail.

  The electrical contacts BP7 to BP10 are connected to the camera-side second communication unit 292, and the electrical contacts LP7 to LP10 are connected to the lens-side second communication unit 382 corresponding to the electrical contacts BP7 to BP10. . The camera-side second communication unit 292 and the lens-side second communication unit 382 transmit and receive signals to and from each other by using these electrical contacts. The details of the communication performed by the camera-side second communication unit 292 and the lens-side second communication unit 382 will be described later in detail.

  The electrical contacts BP11 and BP12 are connected to a second power supply circuit 240 in the camera body 2. The second power supply circuit 240 supplies an operating voltage to circuits such as the lens drive motors 321 and 331 that consume relatively large power through the electrical contacts BP11 and LP11. Although the voltage value supplied by the second power supply circuit 230 is not particularly limited, the maximum value of the voltage value supplied by the second power supply circuit 240 is the number of maximum values of the voltage value supplied by the first power supply circuit 230. It can be about twice. In this case, the current value supplied from the second power supply circuit 240 to the lens barrel 3 side is a current value within a range of about several tens mA to several A in the power-on state. The electrical contacts BP12 and LP12 are ground terminals corresponding to the operating voltage supplied via the electrical contacts BP11 and LP11.

  The first communication unit 291 and the second communication unit 292 on the camera body 2 side shown in FIG. 8 constitute the camera transmission / reception unit 29 shown in FIG. 2, and the first communication unit on the lens barrel 3 side shown in FIG. The lens communication unit 381 and the second communication unit 382 constitute the lens transmission / reception unit 38 illustrated in FIG.

  Next, communication between the camera-side first communication unit 291 and the lens-side first communication unit 381 (hereinafter, referred to as command data communication) will be described. The lens control unit 36 includes a signal line CLK including electrical contacts BP3 and LP3, a signal line BDAT including electrical contacts BP4 and LP4, a signal line LDAT including electrical contacts BP5 and LP5, and an electrical contact. Transmission of control data from the camera-side first communication unit 291 to the lens-side first communication unit 381 via the signal line RDY composed of BP6 and LP6, and transmission of control data from the lens-side first communication unit 381 to the camera-side first communication unit 381. Command data communication is performed in parallel with transmission of response data to the communication unit 291 at a predetermined cycle (for example, at intervals of 16 milliseconds).

  FIG. 9 is a timing chart illustrating an example of the command data communication. At the start of the command data communication (T1), the camera control unit 21 and the camera-side first communication unit 291 first confirm the signal level of the signal line RDY. Here, the signal level of the signal line RDY indicates whether communication is possible with the lens-side first communication unit 381. When communication is not possible, the lens control unit 36 and the lens-side first communication unit 381 transmit H (High). A level signal is output. When the signal line RDY is at the H level, the camera-side first communication unit 291 does not perform communication with the lens barrel 3 or does not execute the following processing even during communication.

  On the other hand, when the signal line RDY is at the L (LOW) level, the camera control unit 21 and the camera-side first communication unit 291 transmit the clock signal 501 to the lens-side first communication unit 291 using the signal line CLK. . Further, in synchronization with the clock signal 501, the camera control unit 21 and the camera-side first communication unit 291 transmit the camera-side command packet signal 502, which is control data, using the signal line BDAT to the lens-side first communication unit 291. Send to When the clock signal 501 is output, the lens control unit 36 and the first lens-side communication unit 381 synchronize with the clock signal 501 and use the signal line LDAT to output the lens-side command packet signal as response data. 503 is transmitted.

  The lens control unit 36 and the first lens-side communication unit 291 change the signal level of the signal line RDY from the L level to the H level in response to the completion of the transmission of the lens-side command packet signal 503 (T2). Then, the lens control unit 36 starts the first control process 504 according to the content of the body-side command packet signal 502 received until time T2.

  For example, when the received body-side command packet signal 502 has a content requesting specific data on the lens barrel 3 side, the lens control unit 36 performs a first control process 504 on the content of the command packet signal 502. Along with the analysis, a process for generating the requested specific data is executed. Further, as the first control process 504, the lens control unit 36 uses the checksum data included in the command packet signal 502 to determine whether there is an error in the communication of the command packet signal 502 based on the number of data bytes. It also executes a communication error check process to check for errors. The specific data signal generated in the first control processing 504 is output to the camera body 2 as a lens-side data packet signal 507 (T3). In this case, the camera-side data packet signal 506 output from the camera body 2 after the command packet signal 502 is dummy data (including checksum data) that has no particular meaning on the lens side. . In this case, the lens control unit 36 executes the above-described communication error check processing using the checksum data included in the camera-side data packet signal 506 as the second control processing 508 (T4).

  For example, when the camera-side command packet signal 502 is a drive instruction for the focus lens 33 and the camera-side data packet signal 506 is the drive speed and drive amount of the focus lens 33, the lens control unit 36 As the control process 504, the content of the command packet signal 502 is analyzed, and a confirmation signal indicating that the content is understood is generated (T2). The confirmation signal generated in the first control processing 504 is output to the camera body 2 as a lens-side data packet signal 507 (T3). In addition, the lens control unit 36 performs the analysis of the content of the camera-side data packet signal 506 as a second control process 508, and executes the communication error check process using the checksum data included in the camera-side data packet signal 506. (T4). After the completion of the second control process 508, the lens control unit 36 drives the focus lens drive motor 331 based on the received camera-side command packet signal 506, that is, the drive speed and drive amount of the focus lens 33. Then, the focus lens 33 is driven at the received drive speed by the received drive amount (T5).

  When the second control process 508 is completed, the lens control unit 36 notifies the lens-side first communication unit 291 of the completion of the second control process 508. Thereby, the lens control unit 36 outputs an L-level signal to the signal line RDY (T5).

  The communication performed between the times T1 to T5 is one command data communication. As described above, in one command data communication, one camera-side command packet signal 502 and one camera-side data packet signal 506 are transmitted by the camera control unit 21 and the camera-side first communication unit 291 respectively. As described above, in the present embodiment, the control data transmitted from the camera body 2 to the lens barrel 3 is divided and transmitted for convenience of processing. The data packet signal 506 constitutes one control data by combining two data packet signals.

  Similarly, in one command data communication, one lens-side command packet signal 503 and one lens-side data packet signal 507 are transmitted by the lens control unit 36 and the lens-side first communication unit 381, respectively. As described above, the response data transmitted from the lens barrel 3 to the camera body 2 is also divided into two, but both the lens-side command packet signal 503 and the lens-side data packet signal 507 constitute one response data. Is composed.

  Next, communication between the camera-side second communication unit 292 and the lens-side second communication unit 382 (hereinafter, referred to as hotline communication) will be described. Referring back to FIG. 8, the lens control unit 36 includes a signal line HREQ including the electrical contacts BP7 and LP7, a signal line HANS including the electrical contacts BP8 and LP8, a signal line HCLK including the electrical contacts BP9 and LP9, Via a signal line HDAT composed of the electrical contacts BP10 and LP10, hot-line communication for performing communication at a shorter cycle (for example, at intervals of 1 millisecond) than command data communication is performed.

For example, in the present embodiment, the lens information of the lens barrel 3 is transmitted from the lens barrel 3 to the camera body 2 by hot line communication. The lens information transmitted by the hot line communication includes a lens position of the focus lens 33, a lens position of the zoom lens 32, a current position image plane movement coefficient K _cur , a minimum image plane movement coefficient K _min , and a maximum image plane movement. The coefficient K _max is included. Here, the current position image plane movement coefficient K _cur is an image plane movement coefficient K corresponding to the current lens position (focal length) of the zoom lens 32 and the current lens position (photographing distance) of the focus lens 33. In the present embodiment, the lens control unit 36 refers to the table indicating the relationship between the lens position (the zoom lens position and the focus lens position) and the image plane movement coefficient K, which is stored in the lens memory 37. The current position image plane movement coefficient _Kcur corresponding to the current lens position of 32 and the current lens position of the focus lens 33 can be obtained. For example, in the example illustrated in FIG. 4, when the lens position (focal length) of the zoom lens 32 is “f1” and the lens position (photographing distance) of the focus lens 33 is “D4”, the lens control unit 36 By hotline communication, “K14” is transmitted to the camera control unit 21 as the current position image plane movement coefficient K _cur , “K11” as the minimum image plane movement coefficient K _min , and “K19” as the maximum image plane movement coefficient K _max. I do.

  Here, FIG. 10 is a timing chart showing an example of the hot line communication. FIG. 10A is a diagram illustrating a state where the hot line communication is repeatedly executed at a predetermined cycle Tn. FIG. 10B shows a state in which the period Tx of one communication among the hot line communication that is repeatedly executed is enlarged. Hereinafter, a case where the lens position of the focus lens 33 is communicated by hotline communication will be described based on the timing chart of FIG.

  First, the camera control unit 21 and the camera-side second communication unit 292 output an L-level signal to the signal line HREQ to start communication by hot line communication (T6). Then, the lens-side second communication unit 382 notifies the lens control unit 36 that this signal has been input to the electrical contact LP7. In response to this notification, the lens control unit 36 starts executing the generation processing 601 for generating lens position data. The generation process 601 is a process in which the lens control unit 36 causes the focus lens encoder 332 to detect the position of the focus lens 33, and generates lens position data representing the detection result.

  When the lens control unit 36 completes the generation processing 601, the lens control unit 36 and the lens-side second communication unit 382 output an L-level signal to the signal line HANS (T7). Then, when this signal is input to the electrical contact BP8, the camera control unit 21 and the camera-side second communication unit 292 output a clock signal 602 from the electrical contact BP9 to the signal line HCLK.

  The lens control unit 36 and the lens-side second communication unit 382 output a lens position data signal 603 indicating lens position data from the electrical contact LP10 to the signal line HDAT in synchronization with the clock signal 602. When the transmission of the lens position data signal 603 is completed, the lens control unit 36 and the lens-side second communication unit 382 output an H-level signal from the electrical contact LP8 to the signal line HANS (T8). Then, when this signal is input to the electric contact BP8, the camera-side second communication unit 292 outputs an H-level signal from the electric contact LP7 to the signal line HREQ (T9).

  The command data communication and the hot line communication can be executed simultaneously or in parallel.

  Next, an operation example of the camera 1 according to the present embodiment will be described with reference to FIG. FIG. 11 is a flowchart illustrating the operation of the camera 1 according to the present embodiment. The following operation is started when the power of the camera 1 is turned on.

  First, in step S101, the camera body 2 performs communication for identifying the lens barrel 3. This is because the communicable communication format differs depending on the type of the lens barrel. Then, the process proceeds to step S102, and in step S102, the camera control unit 21 determines whether the lens barrel 3 is a lens corresponding to a predetermined first type communication format. As a result, if it is determined that the lens is compatible with the first type of communication format, the process proceeds to step S103. On the other hand, when the camera control unit 21 determines that the lens barrel 3 is a lens that does not support the first communication type, the process proceeds to step S113. Further, when the camera control unit 21 determines that the lens barrel 3 is a lens corresponding to a second type communication format different from the first type communication format, the process may proceed to step S113. Further, when the camera control unit 21 determines that the lens barrel 3 is a lens corresponding to the first type and the second type of communication format, the process may proceed to step S103.

For example, the lens barrel 3 that satisfies the drive startable time T _pos > the reference time Tα is a lens whose lens barrel 3 does not support the first type of communication format (a lens corresponding to the second type of communication format). Is preferred.
On the other hand, the lens barrel 3 that satisfies the drive startable time T _pos ≦ the reference time Tα is preferably a lens corresponding to the first type of communication format. However, the lens barrel 3 that satisfies the drive startable time T _pos > the reference time Tα may be included in a lens corresponding to the first type of communication format.

Further, the lens barrel 3 whose product release date is later than a predetermined date is a lens corresponding to the first type of communication format, and the lens barrel 3 whose product release date is earlier than the predetermined date is the first type. (A lens corresponding to the second type of communication format) may be used. This is because there is a possibility that the drive start possible time T _pos of the lens barrel 3 may be shortened as the technology advances.
For the lens barrel 3 (lens corresponding to the first type of communication format) whose product release date is after a predetermined date, the lens type identification number is set to a value within a predetermined range, and the product release date is set to a predetermined value. For lens barrels 3 (lenses not corresponding to the first type of communication format (lenses corresponding to the second type of communication format)) prior to the date, the lens type identification number is set to a value outside the predetermined range. May be set. This is because it is possible to easily determine whether or not the lens is compatible with the first type of communication format based on the lens type identification number (see step S102).

  Next, in step S103, it is determined whether or not the photographer has turned on the live view shooting on / off switch provided in the operation unit 28. When the live view shooting is turned on, the mirror system 220 is turned on. Is the photographing position of the subject, and the luminous flux from the subject is guided to the image sensor 22.

In step S104, hot line communication between the camera body 2 and the lens barrel 3 is started. In the hotline communication, as described above, when the lens control unit 36 receives the L-level signal (request signal) output to the signal line HREQ by the camera control unit 21 and the camera-side second communication unit 292, The lens information is transmitted to the camera control unit 21, and such transmission of the lens information is repeatedly performed. The lens information includes, for example, each of the lens position of the focus lens 33, the lens position of the zoom lens 32, the current position image plane movement coefficient K _cur , the minimum image plane movement coefficient K _min , and the maximum image plane movement coefficient K _max . Information is included. The hotline communication is repeatedly performed after step S104. Hot line communication is repeatedly performed, for example, until the power switch is turned off. At this time, regarding the current position image plane movement coefficient K _cur , the minimum image plane movement coefficient K _min , and the maximum image plane movement coefficient K _max , the current position image plane movement coefficient K _cur , the minimum image plane movement coefficient K _min , and the maximum It is preferable to transmit in the order of the image plane movement coefficient K _max .

When transmitting the lens information to the camera control unit 21, the lens control unit 36 uses a table (see FIG. 4) indicating the relationship between each lens position and the image plane movement coefficient K stored in the camera memory 37. For reference, the current position image plane movement coefficient K _cur corresponding to the current lens position of the zoom lens 32 and the current lens position of the focus lens 33, and the maximum image plane movement corresponding to the current lens position of the zoom lens 32 A coefficient K _max and a minimum image plane movement coefficient K _min are acquired, and the acquired current position image plane movement coefficient K _cur , maximum image plane movement coefficient K _max, and minimum image plane movement coefficient K _min are transmitted to the camera control unit 21. I do.

  In step S105, the camera control unit 21 determines whether the photographer has performed an AF start operation such as a half-press operation (on of the first switch SW1) of a release button provided on the operation unit 28, When these operations are performed, the process proceeds to step S106 (the case where the half-press operation is performed will be described in detail below).

Next, in step S106, the camera control unit 21 performs a process of determining the scan drive speed V, which is the drive speed of the focus lens 33 in the scan operation, based on the minimum image plane movement coefficient K _min acquired in step S104. Is In this operation example, when performing the scan operation, the camera control unit 21 calculates the focus evaluation value by the contrast detection method while driving the focus lens 33 at the scan drive speed V determined in step S106. It is performed simultaneously at predetermined intervals, whereby the in-focus position is detected by the contrast detection method at predetermined intervals.

  Further, in this scanning operation, when detecting the focus position by the contrast detection method, the camera control unit 21 calculates the focus evaluation value at a predetermined sampling interval while driving the focus lens 33 to scan, A lens position at which the calculated focus evaluation value reaches a peak is detected as a focus position. Specifically, the camera controller 21 scans the focus lens 33 to move the image plane by the optical system in the optical axis direction, thereby calculating a focus evaluation value on a different image plane, and The lens position at which the evaluation value reaches a peak is detected as a focus position. However, on the other hand, if the moving speed of the image plane is too high, the interval between the image planes for calculating the focus evaluation value becomes too large, and the focus position may not be properly detected. . In particular, since the image plane movement coefficient K indicating the moving amount of the image plane with respect to the driving amount of the focus lens 33 changes according to the lens position of the focus lens 33 in the optical axis direction, the focus lens 33 is moved at a constant speed. Even when the focus lens 33 is driven, the moving speed of the image plane becomes too fast depending on the lens position of the focus lens 33. Therefore, the distance between the image planes for calculating the focus evaluation value becomes too large, and the focus position is changed. In some cases, detection cannot be performed properly.

Therefore, in the present embodiment, the camera control unit 21 calculates the scan drive speed V when performing the scan drive of the focus lens 33 based on the minimum image plane movement coefficient K _min acquired in step S104. The camera control unit 21 uses the minimum image plane movement coefficient K _min to perform a scan so as to have a drive speed capable of appropriately detecting a focus position by a contrast detection method and to have a maximum drive speed. The driving speed V is calculated.

  Next, in step S107, the camera control unit 21 calculates a reference time Tα which is a time required for changing to the control for contrast AF. The reference time Tα is, for example, a process for changing the exposure sensitivity of the image sensor 22, a process for changing the exposure time of the image sensor 22, a process for changing the aperture diameter of the diaphragm 35, and a process for changing the frame rate of the image sensor 22. It is preferable that the calculation be performed based on a time required for a process including at least one of a process of performing the process and a process of changing the imaging output level correction control, and a margin time.

  Next, in step S108, the camera control unit 21 calculates a scan drive command (scan drive start instruction) in step S108 and the scan drive speed V determined in step S107 in order to perform focus detection by the contrast detection method. This is transmitted to the lens control unit 36 together with the reference time Tα. Note that the scan drive command (the drive speed instruction during scan drive or the drive position instruction) to the lens control unit 36 may be given at the drive speed of the focus lens 33 or at the image plane movement speed. Alternatively, it may be given at the target drive position or the like.

In step S109, the lens control unit 36 performs a process of starting scan drive based on the scan drive command, the scan drive speed V, and the reference time Tα transmitted from the camera control unit 21. Specifically, first, the lens control unit 36 compares the drive start possible time T _pos stored in the lens memory 37, which is the time during which the scan drive of the focus lens 33 can be started, with the reference time Tα. Do. If “driving startable time T _pos ≦ reference time Tα” is satisfied, initial drive of the focus lens 33 is performed so that scan driving of the focus lens 33 can be started after the lapse of the reference time Tα, and a predetermined standby time is set. After a certain time, the scan drive of the focus lens 33 is started (see FIG. 6). In this case, the drive speed of the focus lens 33 is the scan drive speed V transmitted from the camera control unit 21. On the other hand, in the case of “driving start possible time T _pos > reference time Tα”, regardless of the reference time Tα, after the lapse of the driving start possible time T _pos (after driving the focus lens 33 as fast as possible) ), Start the scan drive. Also in this case, the drive speed of the focus lens 33 is the scan drive speed V transmitted from the camera control unit 21.

  In step S109, a process of changing the control by the camera control unit 21 from the control for the through image to the control for the contrast AF is executed in parallel with the process of starting the scan drive.

  Then, the pixel output is read out from the image pickup pixel of the image pickup device 22 at predetermined intervals by the camera control unit 21 while driving the focus lens 33 at the scan drive speed V, and the focus evaluation value Is calculated, thereby obtaining focus evaluation values at different focus lens positions, thereby detecting a focus position by a contrast detection method.

  Next, proceeding to step S110, the camera controller 21 determines whether or not the peak value of the focus evaluation value has been detected (whether or not the in-focus position has been detected). If the peak value of the focus evaluation value cannot be detected, the process stays at step S110, and the operation of step S110 is repeated until the peak value of the focus evaluation value can be detected or the focus lens 33 is driven to a predetermined drive end. Do. On the other hand, when the peak value of the focus evaluation value has been detected, the process proceeds to step S111.

  When the peak value of the focus evaluation value has been detected, the process proceeds to step S111. In step S111, the camera control unit 21 sends a command to the lens control unit 36 to perform focusing driving to a position corresponding to the peak value of the focus evaluation value. Send. The lens control unit 36 controls the driving of the focus lens 33 according to the received command.

  Next, proceeding to step S112, in step S112, the camera control unit 21 determines that the focus lens 33 has reached the position corresponding to the peak value of the focus evaluation value, and the photographer fully presses the release button (the first button). When the 2 switch SW2 is turned on), a still image shooting control is performed. After the photographing control ends, the process returns to step S104.

On the other hand, if it is determined in step S102 that the lens barrel 3 is a lens that does not support the predetermined first type communication format, the process proceeds to step S113, and the processes of steps S113 to S121 are performed. In steps S113 to S121, the camera control unit 21 does not calculate the reference time Tα (there is no step corresponding to step S107), and when starting the scan drive, control based on the reference time Tα is performed. Except for the absence (step S118), the same processing as steps S103 to S112 described above is executed.
In step S118 of the present embodiment, the lens control unit 36 scans based on the scan drive command transmitted from the camera control unit 21, the scan drive speed V, and the drive _startable time T _pos stored in the lens memory 37. Processing for starting driving is performed. Specifically, first, the lens control unit 36 reads a drive start enable time T _pos stored in the lens memory 37, after a drive start enable time T _pos (as far as possible the driving of the focus lens 33 rapidly After that, the scan drive is started.

  As described above, in the present embodiment, when the lens barrel 3 is a lens corresponding to the first type of communication format, the lens control unit 36 sets the start timing of the scan drive of the focus lens 33 to the reference time Tα (contrast AF). (The time required to change to the control for the contrast AF), it is possible to realize a suitable scan drive based on the time required to change to the control for the contrast AF.

  In the present embodiment, when the lens barrel 3 is a lens corresponding to the first type of communication format, the lens control unit 36 determines the start timing of the scan drive of the focus lens 33 based on the reference time Tα. By starting the scan drive by the lens control unit 36 before the camera control unit 21 is changed to the control for the contrast AF, the risk of skipping the focus evaluation value can be reduced.

  In the present embodiment, when the lens barrel 3 is a lens corresponding to the first type of communication format, the lens controller 36 determines the start timing of the scan drive of the focus lens 33 based on the reference time Tα. During the scan drive of the focus lens 33, the camera control unit 21 can appropriately detect the focus adjustment state of the imaging optical system by the contrast detection method.

Further, in the present embodiment, when the lens barrel 3 is a lens that does not support the first type of communication format (when it is a lens that supports the second type of communication format), the lens control unit 36 controls the focus lens. since determined based on the start timing of the scan driver 33 to drive startable time T _pos (after a drive start enable time T _pos because scan driving is started), the camera control unit 21 is the control for the contrast AF By starting the scan drive by the lens control unit 36 before the change, the possibility of skipping the focus evaluation value can be reduced. This is because the lens barrel 3 that does not support the first type of communication format satisfies the drive startable time T _pos > the reference time Tα.

<< 2nd Embodiment >>
A second embodiment will be described. In the second embodiment, the camera 1 shown in FIG. 1 has a configuration similar to that of the above-described first embodiment except that the camera 1 operates as described below. In the second embodiment, in step S107 of the flowchart shown in FIG. 11 described above, the frame rate is determined before the AF start operation (see step S105) is determined to be performed and after the AF start operation is determined to be performed. The camera control unit 21 determines whether or not there is a change in the frame rate, and sets the time T1 or the time T2 as the reference time Tα according to the determination result as to whether or not there is a change in the frame rate.

  For example, before determining that the AF start operation has been performed, the frame rate for the through image (the frame rate when acquiring the through image) of the image sensor 22 is set, and it is determined that the AF start operation has been performed. After that, when the image sensor 22 is changed to a frame rate for contrast AF (a frame rate for acquiring a focus evaluation value in contrast AF) different from the frame rate for the through image, the camera control unit 21 sets the frame rate to It is determined that there is a change. At this time, the camera control unit 21 sets the time T1 as the reference time Tα.

  On the other hand, when the frame rate for the through image before it is determined that the AF start operation has been performed is the same as the frame rate for the contrast AF after it is determined that the AF start operation has been performed, the camera control unit 21 Determines that there is no change in the frame rate, and sets time T2 as the reference time Tα. The time T2 is shorter than the time T1 by the time Ta required for switching the frame rate.

  The reference time Tα is a time required for the process of changing the exposure sensitivity of the image sensor 22, a time required for the process of changing the exposure time of the image sensor 22, and a process of changing the aperture diameter of the diaphragm 35. May be determined based on at least one of the times required for the frame rate and a result of determining whether or not the frame rate has been changed.

  For example, the frame rate before the start operation is determined to be 60 (fps), the frame rate after the AF start operation is determined to be 120 (fps), and the exposure sensitivity of the image sensor 22 is changed. If the processing, the processing for changing the exposure time of the image sensor 22, the processing for changing the aperture diameter of the diaphragm 35, and the processing for switching the frame rate require three frames, the reference time Tα = 1/60 × 3 = 0.05 s.

  When the difference between the frame rate before determining that the AF start operation has been performed and the frame rate after determining that the AF start operation has been performed is a value equal to or smaller than a predetermined threshold, the camera control unit 21 It may be determined that there is no change in the rate. Even when the camera control unit 21 does not perform control for changing the frame rate, the frame rate before the AF start operation is determined to have been performed according to the load condition of the camera control unit 21 and the AF start operation This is because the frame rate after the determination is made may slightly change.

  In the above-described second embodiment, when there is no change in the frame rate before determining that the AF start operation has been performed and after the determination that the AF start operation has been performed, there is a case where the frame rate has changed. Since the reference time Tα is shorter than the reference time by the time Ta, the scan driving of the focus lens 33 can be started earlier by that amount and the speed of the contrast AF can be increased.

<< 3rd Embodiment >>
A third embodiment will be described. In the third embodiment, the camera 1 shown in FIG. 1 has a configuration similar to that of the above-described first embodiment except that the camera 1 operates as described below. In the third embodiment, in the above-described step S107 (see FIG. 11), the imaging output level correction control (AGC) of the imaging output level correction control (AGC) is performed before determining that the AF activation operation has been performed and after determining that the AF activation operation has been performed. The camera control unit 21 determines whether or not there is a change, and sets the time T11 or the time T12 as the reference time Tα according to the determination result of whether or not there is a change in the imaging output level correction control (AGC). I do. Note that the imaging output level correction control (AGC) is for automatically controlling, for example, the gain of an image signal photoelectrically converted by the imaging element 22.

  For example, in the present embodiment, before determining that the AF start operation has been performed, the camera control unit 21 performs multi-pattern photometry (display of a screen for performing photometry) in order to appropriately display a through image on a monitor (not shown). It is possible to set the image pickup output level correction control (AGC) according to the result of (photometry control for performing exposure that balances a bright part and a dark part). Further, after it is determined that the AF start operation has been performed, the camera control unit 21 can set the imaging output level correction control (AGC) according to the result of the multi-pattern photometry, and can appropriately perform the contrast AF. Change to the imaging output level correction control (AGC) according to the result of the spot metering (to obtain the focus evaluation value appropriately) (light metering control for properly exposing the area to be focused on the screen). You can also.

  Before determining that the AF start operation has been performed, the imaging output level correction control (AGC) according to the result of the multi-pattern photometry is set, and after determining that the AF start operation has been performed, the spot metering result is displayed. When changing to the corresponding imaging output level correction control (AGC), the camera control unit 21 determines that the imaging output level correction control (AGC) is changed. At this time, the camera control unit 21 sets the time T11 as the reference time Tα.

  On the other hand, the imaging output level correction control before determining that the AF start operation has been performed (the imaging output level correction control according to the result of the multi-pattern photometry), and the imaging output level after determining that the AF start operation has been performed. When the correction control is the same, the camera control unit 21 determines that there is no change in the imaging output level correction control, and sets a time T12 as the reference time Tα. The time T12 is a time shorter than the time T11 by the time Tb required to switch the imaging output level correction control.

For example, the camera control unit 21 changes the imaging output level correction control when the difference between the multi-pattern photometry result after the AF start operation is determined to be performed and the spot photometry result is within a predetermined threshold. Alternatively, it may be determined that there is no change in the imaging output level correction control.
The camera control unit 21 sets the imaging output level correction control stronger than a predetermined level before determining that the AF start operation has been performed and after determining that the AF start operation has been performed. When the imaging output level correction control weaker than the predetermined level is set, it may be determined that the imaging output level correction control is changed.

  Further, in the above-described embodiment, the imaging output level correction control according to the result of the multi-pattern photometry is set before the AF start operation is determined to be performed, and the multi-pattern is determined after the AF start operation is determined to be performed. Although the description has been made using the example in which the control is changed to the imaging output level correction control according to the result of the photometry or the spot photometry, the invention is not limited thereto. For example, at least one of before the AF start operation is determined to be performed and after at least one of the AF start operations is determined to be performed, the multi-pattern metering, the center-weighted metering (the brightness at the center of the screen is adjusted to the appropriate exposure). Control, spot metering, highlight-weighted metering (light metering control that focuses on the brightest area in the screen), and the like.

  The reference time Tα is a time required for the process of changing the exposure sensitivity of the image sensor 22, a time required for the process of changing the exposure time of the image sensor 22, and a process of changing the aperture diameter of the diaphragm 35. May be determined based on at least one of the required time, the determination result of the presence or absence of a change in the frame rate, and whether or not the imaging output level correction control has been changed.

  In the third embodiment described above, when there is no change in the imaging output level correction control between before the determination that the AF startup operation has been performed and after the determination that the AF startup operation has been performed, the imaging output level correction is performed. Since the reference time Tα is shorter by the time Tb than in the case where the control is changed, the scan drive of the focus lens 33 can be started earlier by that amount, and the speed of the contrast AF can be increased.

<< 4th Embodiment >>
A fourth embodiment will be described. In the fourth embodiment, the camera 1 shown in FIG. 1 has the same configuration as that of the above-described first embodiment except that the camera 1 operates as described below. In the fourth embodiment, in step S107 (see FIG. 11) described above, the camera control unit 21 determines whether or not control for storing a moving image has been performed before determining that the AF start operation has been performed. The camera control unit 21 sets the reference time Tα using the result.

  The camera control unit 21 controls the image signal photoelectrically converted by the imaging device 22 to be stored in the memory 24 as a moving image (control to store a moving image), and the image signal photoelectrically converted by the imaging device 22 as a still image. The control to store the image signal in the memory 24 and the control to display the image signal photoelectrically converted by the image sensor 22 as a through image on a monitor are possible.

If the imaging output level correction control is changed while the camera control unit 21 is controlling to store a moving image, the exposure of the stored moving image becomes unnatural, which is not preferable in many cases. For this reason, the camera control unit 21 does not change the imaging output level correction control after determining that the AF activation operation has been performed when the control for storing a moving image is It is determined that there is not, and the time T22 is set as the reference time Tα. Further, even when the control to store the moving image is not performed, the camera control unit 21 sets the time T22 as the reference time Tα if the imaging output level correction control is not changed after determining that the AF start operation has been performed. Set.
On the other hand, when the camera control unit 21 does not perform the control for storing the moving image and changes the imaging output level correction control after determining that the AF start operation has been performed, the camera control unit 21 sets the time as the reference time Tα. T21 is set. The time T21 is a time longer than the time T22 by the time Tc required for switching the imaging output level correction control.

  In the above-described fourth embodiment, if control to store a moving image is performed before determining that the AF start operation has been performed, the imaging output level correction control is changed after determining that the AF start operation has been performed. Since the reference time Tα is shortened by the time Tc as compared with the case of performing the scan, the scan drive of the focus lens 33 can be started earlier by that amount, and the speed of the contrast AF can be increased.

  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 embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention. Further, the above-described embodiments can be used in appropriate combinations.

  In the above-described embodiment, the example in which the scan drive of the focus lens 33 is started from the infinity side to the close side after the elapse of the reference time Tα has been described, but the present invention is not limited to this. For example, the scan drive of the focus lens 33 may be started from the closest side to the infinity side after the lapse of the reference time Tα, or the focus lens 33 may be wobbled after the lapse of the reference time Tα (to calculate the focus evaluation value). (The operation of causing the focus lens 33 to vibrate with a very small amplitude).

  In the above-described embodiment, the example in which the scan driving of the focus lens 33 is started after the elapse of the reference time Tα has been described, but the present invention is not limited to this. For example, control may be performed such that the focus lens 33 is within a predetermined range when the reference time Tα has elapsed. If the focus lens 33 is within the predetermined range when the reference time Tα has elapsed, the lack of the detection result of the focus adjustment state due to the start of the scan drive before the camera control unit 21 switches to the control for the contrast AF. This is because the influence can be reduced. The predetermined range is preferably, for example, equal to or smaller than the interval between image planes for calculating the focus evaluation value.

  In the above-described embodiment, the contrast AF that waits for a predetermined time after the completion of the initial drive before the scan drive has been described in detail, but the present invention is not limited to this. For example, after the initial drive is completed before the scan drive, the scan drive may be started without waiting for a predetermined time.

  In the above-described embodiment, the contrast AF for performing the initial drive before the scan drive has been described in detail, but the present invention is not limited to this. For example, the contrast AF may be performed without performing the initial drive before the scan drive.

  In the above-described embodiment, when the lens barrel 3 is a lens corresponding to the first type of communication format, the scan drive is not started before the reference time Tα elapses, and the scan drive is performed after the reference time Tα elapses. Has been described in detail, but the present invention is not limited to this. For example, the wobbling may not be started before the reference time Tα has elapsed, but may be started after the reference time Tα has elapsed.

  Further, the camera 1 of the above-described embodiment is not particularly limited, and may be applied to, for example, an interchangeable lens type mirrorless camera 1a as shown in FIG. In the example illustrated in FIG. 12, the camera body 2 a sequentially sends the captured images captured by the imaging element 22 to the camera control unit 21, and sends the captured images to the electronic viewfinder (EVF) 26 of the observation optical system via the liquid crystal drive circuit 25. indicate. In this case, for example, the camera control unit 21 reads out the output of the image sensor 22 and calculates the focus evaluation value based on the read out output, thereby detecting the focus adjustment state of the imaging optical system by the contrast detection method. be able to. Further, 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.

DESCRIPTION OF SYMBOLS 1 ... Digital camera 2 ... Camera main body 21 ... Camera control part 22 ... Image sensor 29 ... Camera transmission / reception part 291 ... Camera side first communication part 292 ... Camera side second communication part 3: Lens barrel 32 ... Zoom lens lens 321 ... Zoom lens drive motor 33 Focus lens 331 Focus lens drive motor 36 Lens control unit 37 Lens memory 38 Lens transmission / reception unit 381 Lens first communication unit 382 Lens second communication unit

Claims (9)

An interchangeable lens that can be attached to the camera body,
A focus optical system that changes the focus of the interchangeable lens by moving,
A receiving unit that receives time-related information from the camera body,
A control unit that starts moving the focus optical system based on the information,
The control unit moves the focus optical system in a first direction after the reception unit receives the information, and moves the focus optical system in a second direction opposite to the first direction based on the information. Interchangeable lens to let. The interchangeable lens according to claim 1,
The interchangeable lens, wherein the control unit starts moving the focus optical system after a lapse of time determined based on the information. An interchangeable lens according to claim 1 or 2,
The interchangeable lens, wherein the information is information on a time from when the information is transmitted by the camera body. An interchangeable lens according to claim 3,
The interchangeable lens, wherein the information is time-related information that is shorter than the time from when the information is transmitted by the camera body to when the focus is detected by the camera body. The interchangeable lens according to claim 4,
The interchangeable lens, wherein the information is information relating to a time from when the information is transmitted by the camera body to when the camera body can detect a focus evaluation value. An interchangeable lens according to any one of claims 1 to 5, wherein
An interchangeable lens for starting the movement of the focusing optical system based on the information before a focus evaluation value is detected by the camera body. An interchangeable lens according to claim 1 or claim 2,
The receiving unit receives an instruction to move the focus optical system before a focus evaluation value is detected by the camera body,
The interchangeable lens, wherein after the receiving unit receives the instruction, the control unit starts the movement of the focusing optical system based on the information. The interchangeable lens according to claim 7,
The control unit moves the focus optical system in a first direction after the receiving unit receives the instruction, and moves the focus optical system in a second direction opposite to the first direction based on the information. Interchangeable lens to let. An interchangeable lens according to claim 8,
The receiving unit receives a moving speed of the focusing optical system from the camera body,
The control unit, when moving the focus optical system in the first direction, moves the focus optical system at a speed different from the moving speed received by the receiving unit, and moves the focus optical system in the second direction. An interchangeable lens that moves the focusing optical system at the moving speed received by the receiving unit when moving the focusing optical system.

Images