JP2019091050A - Imaging device and interchangeable lens - Google Patents

Abstract

To provide an imaging device and an interchangeable lens with which it is possible to suppress the drive noise of a focus lens.SOLUTION: Provided is an interchangeable lens 3, comprising: a transmission unit for transmitting a first image surface transfer coefficient determined in correspondence to the position of a focus adjustment optical system 33, a second image surface transfer coefficient with which the amount of image surface transfer to the amount of transfer of the focus adjustment optical system becomes maximum, and a silent speed determined in correspondence to the drive noise of the focus adjustment optical system; a lens control unit 36 for controlling a drive unit at a search speed determined by an imaging device 2; and a reception unit 29 for receiving an enabling signal that is transmitted when it is determined by the imaging device by comparison, with the search speed, of a reference speed calculated using the second image surface transfer coefficient and the silent speed, that searching for the focus evaluation value of a contrast AF at a speed different from the search speed is enabled, the lens control unit performing a search of the focus evaluation value of contrast AF at a speed different from the search speed when the reception unit receives an enabling signal.SELECTED DRAWING: Figure 2

Description

The present invention relates to an imaging device and an interchangeable lens.
With respect to designated countries where incorporation by reference is permitted, the contents described in the application document of Japanese Patent Application No. 2013-040116 filed in Japan on February 28, 2013 are incorporated into the present application by reference. , As part of the description of the present application.

  Conventionally, in order to suppress the drive noise of the focus lens, there is known a technique of limiting the drive of the focus lens by providing an upper limit value to the drive speed of the focus lens (see, for example, Patent Document 1).

JP, 2007-6305, A

  The problem to be solved by the present invention is to provide an imaging device and an interchangeable lens capable of suppressing driving noise of a focus lens.

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

  An imaging apparatus according to the present invention includes a first image plane movement coefficient determined corresponding to the position of the focusing optical system, a second image plane movement coefficient not dependent on the position of the focusing optical system, and the focusing operation. Using a receiving unit that receives a silent velocity determined corresponding to the driving sound of the optical system, a determining unit that determines a searching velocity when searching for a focus evaluation value with contrast AF, and the first image plane movement coefficient Evaluation of the contrast AF at a speed different from the search speed using a control unit that controls the focusing optical system to drive at the search speed, and the second image plane movement coefficient and the silent speed And a determination unit configured to determine whether to permit the search for the value.

  In the invention relating to the above imaging apparatus, the search speed is a speed at which the moving speed of the image plane becomes constant, and the determination unit uses the second image plane moving coefficient and the silent speed to perform the focusing optical The present invention can be configured to permit searching for the focus evaluation value of the contrast AF at the movement speed of the image plane at which the movement speed of the system becomes constant.

  In the invention relating to the image pickup apparatus, the determination unit may search for the focus evaluation value of the contrast AF at a speed slower than the search speed using the second image plane movement coefficient and the silent speed. It can be configured to allow.

In the invention relating to the above imaging device, when the determination unit sets a reference velocity which is a moving velocity of the image plane corresponding to the silent velocity as V0, a coefficient of one or more as Kc, and the search velocity as _Vlns. When V _lns × Kc> V 0, the search for the focus evaluation value of the contrast AF can be permitted at a speed different from the search speed.

In the invention relating to the image pickup apparatus, the determination unit may be configured to search for the focus evaluation value of the contrast AF at a speed different from the search speed when V _lns × Kc ≦ V0.

  In the invention relating to the above imaging apparatus, the determination unit determines the lens position at which the image plane movement coefficient indicating the correspondence between the movement amount of the focusing optical system and the movement amount of the image plane is the second image plane movement coefficient. The moving speed of the image plane when the focusing optical system is driven at the silent speed may be set as the reference speed V0.

  In the invention relating to the imaging device, the determination unit may be configured to increase the value of Kc as the diaphragm value is larger, as the compression ratio of the image is larger, or as the pixel pitch of the imaging device is larger. Can.

  In the invention relating to the above imaging apparatus, the image plane movement coefficient is a coefficient indicating the correspondence between the movement amount of the focusing optical system and the movement amount of the image plane, and the focusing optical system is faster than the silent speed. When driven at a speed, the focusing optical system may be configured such that the driving noise is smaller than when driven at a speed slower than the silent speed.

In the invention relating to the above imaging apparatus, the first image plane movement coefficient and the second image plane movement coefficient are such that the movement amount of the focusing optical system in the optical axis direction is T _L and the movement amount of the image plane is T _I and when a coefficient corresponding to the ratio between T _L and T _I, the second image plane shift factor, when a coefficient corresponding to T _I / T _L is the maximum T _I / T _L is becomes a value, when the image plane shift factor is a coefficient corresponding to T _L / T _I may be T _L / T _I is configured such that a value becomes minimum.

  An interchangeable lens according to a first aspect of the present invention is a drive unit for driving an optical system including a focusing optical system, a first image plane movement coefficient determined corresponding to a position of the focusing optical system, A second image plane movement coefficient which does not depend on the position of the focusing optical system, and a transmitting unit for transmitting a silent speed determined corresponding to the driving sound of the focusing optical system, and a search speed determined by the imaging device A lens control unit for controlling the drive unit, and a receiving unit for receiving a signal for permitting the search for a focus evaluation value of contrast AF at a speed different from the search speed, the lens control section comprising When the receiving unit receives the permission signal, the focus evaluation value of the contrast AF is searched at a speed different from the search speed.

  In the invention relating to the interchangeable lens, the lens control unit receives the signal that the reception unit permits, and the speed of the focusing optical system reaches the speed corresponding to the silent speed. The focus evaluation value of the contrast AF may be searched at a speed different from the speed.

  In the invention relating to the interchangeable lens, the lens control unit searches for a focus evaluation value of contrast AF so that the moving speed of the focusing optical system becomes constant when the reception unit receives the permission signal. It can be configured to do.

  An interchangeable lens according to a second aspect of the present invention is a receiving unit that receives a predetermined signal from a camera body, and the focusing optics more than when the receiving unit receives the predetermined signal when the receiving unit does not receive the predetermined signal. And a control unit that performs control so as to reduce the moving speed of the system.

  An interchangeable lens according to a third aspect of the present invention controls the focusing optical system to have a predetermined image plane moving speed when the moving speed of the focusing optical system is faster than a predetermined speed, and When the moving speed is slower than the predetermined speed, the control unit may control the focusing optical system at a speed different from the predetermined image plane moving speed.

  In the invention relating to the above interchangeable lens, it can be configured to include a receiving unit that receives a predetermined signal from the camera body.

  In the invention relating to the interchangeable lens, the predetermined signal may be configured to be a signal for permitting the focusing optical system to move within a predetermined speed range.

  In the interchangeable lens according to the fourth aspect of the present invention, a transmission unit that transmits an image plane movement coefficient smaller than the image plane movement coefficient at the current position of the focusing optical system, and the movement speed of the image plane become substantially constant. And a control unit configured to control the focusing optical system.

  According to a fifth aspect of the present invention, there is provided an interchangeable lens comprising: a transmitter configured to transmit an image plane movement coefficient smaller than an image plane movement coefficient at a current position of a focusing optical system and information corresponding to a velocity of the focusing optical system. It is characterized by having.

  In the invention relating to the interchangeable lens, the transmission unit may include: an image plane movement coefficient at a current position of the focusing optical system; an image plane movement coefficient smaller than an image plane movement coefficient at a current position of the focusing optical system; It can be configured to transmit an image plane movement coefficient larger than the image plane movement coefficient at the current position of the optical system.

  The interchangeable lens according to the sixth aspect of the present invention transmits, to the camera body, an image plane movement coefficient smaller than the image plane movement coefficient at the current position of the focusing optical system, and information corresponding to the moving speed of the focusing optical system. And a transmitting / receiving unit for receiving a predetermined signal from the camera body, and the focal point so as to have a predetermined image plane moving speed when the moving speed of the focusing optical system is faster than the predetermined speed when the predetermined signal is received. A control unit that performs drive control of an optical system and performs drive control of the focus optical system so that the movement speed of the focus optical system becomes substantially constant when the movement speed of the focus optical system is slower than the predetermined speed; And the like.

  In the invention relating to the interchangeable lens described above, when the control unit receives the predetermined signal, and the moving speed of the focusing optical system is slower than the predetermined speed, the moving speed of the focusing optical system is the camera. The drive control of the focusing optical system may be performed to achieve a speed corresponding to the information transmitted to the body.

  In the invention relating to the interchangeable lens, the image plane movement coefficient smaller than the image plane movement coefficient at the current position of the focusing optical system can be configured to be the minimum value of the image plane movement coefficient.

  In the invention relating to the interchangeable lens, it may be configured to have an imaging optical system including the focusing optical system.

  According to the present invention, the drive noise of the focus lens can be suppressed.

FIG. 1 is a perspective view showing a camera according to the present embodiment. FIG. 2 is a main part configuration diagram showing a camera according to the present embodiment. FIG. 3 is a table showing the relationship between the lens position (focal length) of the zoom lens and the lens position (shooting distance) of the focus lens, and the image plane movement coefficient K. FIG. 4 is a schematic view showing details of the connection parts 202 and 302. As shown in FIG. FIG. 5 is a diagram showing an example of command data communication. FIG. 6 is a diagram illustrating an example of hotline communication. FIG. 7 is a flowchart showing the clip operation according to the present embodiment. FIG. 8 is a diagram for explaining the relationship between the lens driving speed V1b of the focus lens and the silent noise lower limit lens moving speed V0b. FIG. 9 is a flowchart showing the clip operation control process according to the present embodiment. FIG. 10 is a diagram for explaining the relationship between the image plane movement velocity V1a of the focus lens and the silent noise lower limit image plane movement velocity V0a_max. FIG. 11 is a view showing the relationship between the moving speed V1a of the image plane at the time of focus detection and the clipping operation. FIG. 12 is a diagram for explaining the relationship between the lens driving speed V1b of the focus lens and the clipping operation. FIG. 13 is a main configuration diagram showing a camera according to another embodiment.

  FIG. 1 is a perspective view showing a single-lens reflex digital camera 1 according to this embodiment. Moreover, FIG. 2 is a principal part block diagram which shows the camera 1 of this embodiment. The digital camera 1 (hereinafter simply referred to as the camera 1) according to this embodiment includes a camera body 2 and a lens barrel 3, and the camera body 2 and the lens barrel 3 are detachably coupled.

  The lens barrel 3 is an interchangeable lens that is detachable from the camera body 2. As shown in FIG. 2, the lens barrel 3 incorporates a photographing optical system including lenses 31, 32, 33, 34 and a diaphragm 35.

  The lens 33 is a focusing lens, and is movable in the direction of the optical axis L1 to adjust the focal length of the photographing optical system. The focus lens 33 is provided to be movable along the optical axis L1 of the lens barrel 3, 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 the 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 per second, and the drive speed of the focus lens 33 is faster as the number of pulses per unit time is larger. In the present embodiment, the camera control unit 21 of the camera body 2 transmits a drive instruction speed (unit: pulse / second) of the focus lens 33 to the lens barrel 3, and the lens control unit 36 receives the command from the camera body 2. The driving instruction speed (unit: pulse) transmitted from the camera body 2 by outputting a pulse signal corresponding to the transmitted driving instruction speed (unit: pulse / second) to the focus lens driving motor 331 / Sec).

  The lens 32 is a zoom lens, and can move in the direction of the optical axis L1 to adjust the imaging magnification of the imaging optical system. The position of the zoom lens 32 is also adjusted by the zoom lens drive motor 321 while the position thereof is detected by the zoom lens encoder 322 in the same manner as 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 diaphragm 35 is configured to adjust the aperture diameter centered on the optical axis L1 in order to limit the light amount of the light flux passing through the above-mentioned photographing optical system and reaching the image pickup device 22 and to adjust the blur amount. Adjustment of the aperture diameter by the diaphragm 35 is performed, for example, by sending out an appropriate aperture diameter calculated in the automatic exposure mode from the camera control unit 21 via the lens control unit 35. Further, the set aperture diameter is input from the camera control unit 21 to the lens control unit 36 by manual operation by the operation unit 28 provided in the camera body 2. The aperture diameter of the diaphragm 35 is detected by a diaphragm 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 movement coefficient K is a value indicating the correspondence between the drive amount of the focus lens 33 and the movement amount of the image plane, and is, for example, the ratio between the drive amount of the focus lens 33 and the movement amount of the image plane. In the present embodiment, the image plane movement coefficient is obtained, for example, by the following equation (3), and the smaller the image plane movement coefficient K, the larger the movement amount of the image plane accompanying the drive of the focus lens 33.
Image plane movement coefficient K = (driving amount of focus lens 33 / moving amount of image plane) (3)
Further, in the camera 1 of the present embodiment, even if the drive amount of the focus lens 33 is the same, the amount of movement of the image plane is different depending on the lens position of the focus lens 33. Similarly, even if the drive amount of the focus lens 33 is the same, the amount of movement of the image plane is different depending on the lens position of the zoom lens 32. That is, the image plane movement coefficient K changes in accordance with the lens position in the optical axis direction of the focus lens 33 and the lens position in the optical axis direction of the zoom lens 32, and in the present embodiment, the lens control unit 36 stores the image plane movement coefficient K for each lens position of the focus lens 33 and for each lens position of the zoom lens 32.
The image plane movement coefficient K can also be defined as, for example, image plane movement coefficient K = (movement amount of image plane / drive amount of focus lens 33). In this case, as the image plane movement coefficient K increases, the amount of movement of the image plane accompanying the drive of the focus lens 33 increases.

  Here, FIG. 3 shows a table showing the relationship between the lens position (focal length) of the zoom lens 32 and the lens position (shooting distance) of the focus lens 33 and the image plane movement coefficient K. In the table shown in FIG. 3, the drive area of the zoom lens 32 is divided into nine areas “f1” to “f9” in order from the wide end to the tele end, and the drive area of the focus lens 33 is close The image plane movement coefficient K corresponding to each lens position is stored in nine areas of “D1” to “D9” in order from the end toward the infinite end. For example, when the lens position (focal length) of the zoom lens 32 is at "f1" and the lens position (shooting distance) of the focus lens 33 is at "D1", the image plane movement coefficient K is "K11." Although the table shown in FIG. 3 exemplifies a mode in which the drive 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 preferably changes in accordance with the current lens position of the zoom lens 32. In addition, it is preferable that the minimum image plane movement coefficient K _min be a fixed value (fixed value) even if the current lens position of the focus lens 33 changes if the current lens position of the zoom lens 32 does not change. That is, the minimum image plane movement coefficient K _min is a fixed value (constant value) determined according to the lens position (focal length) of the zoom lens 32, and is not dependent on the lens position (shooting distance) of the focus lens 33. Is preferred.

For example, in FIG. 3, the zoom lens 32 “K11”, “K21”, “K31”, “K41”, “K52”, “K62”, “K72”, “K82”, and “K91” shown in gray. Among the image plane movement coefficients K at each lens position (focal length) of the lens, the minimum image plane movement coefficient K _min that indicates the minimum value. That is, when the lens position (focal length) of the zoom lens 32 is "f1", the lens position (shooting distance) of the focus lens 33 among "D1" to "D9" is "D1". “K11”, which is the image plane movement coefficient K, is the minimum image plane movement coefficient K _min which indicates the minimum value. Therefore, “K11”, which is the image plane movement coefficient K when the lens position (shooting distance) of the focus lens 33 is “D1,” has a lens position (shooting distance) of “D1” to “D9”. In the case of the image plane movement coefficient K in the above case, the smallest value is indicated among "K11" to "K19". Similarly, when the lens position (focal length) of the zoom lens 32 is “f2”, the image plane movement coefficient K when the lens position (shooting distance) of the focus lens 33 is “D1” "K21" represents the smallest value among "K21" to "K29" which is the image plane movement coefficient K in the case of "D1" to "D9". That is, "K21" is the minimum image plane movement coefficient K _min . Similarly, even when each lens position (focal length) of the zoom lens 32 is “f3” to “f9”, “K31”, “K41”, “K52”, “K62”, “G31” shown in gray K72 ′ ′, “K82”, and “K91” are respectively 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 preferably changes in accordance with the current lens position of the zoom lens 32. Further, it is preferable that the maximum image plane movement coefficient K _max be a fixed value (fixed value) even if the current lens position of the focus lens 33 changes if the current lens position of the zoom lens 32 does not change. For example, in FIG. 3, the hatched "K19", "K29", "K39", "K49", "K59", "K59", "K69", "K79", "K89", "K99" are zooms. Among the image plane movement coefficients K at each lens position (focal length) of the lens 32, it is the maximum image plane movement coefficient K _max that indicates the largest value.

Thus, as shown in FIG. 3, the lens memory 37 has the image plane movement coefficient K corresponding to the lens position (focal length) of the zoom lens 32 and the lens position (shooting distance) of the focus lens 33, and The image plane movement coefficient for each lens position (focal length) of the zoom lens 32 and the minimum image plane movement coefficient K _min which indicates the minimum value among the image plane movement coefficients K for each of 32 lens positions (focal distance) The maximum image plane movement coefficient K _max indicating the maximum value of K is stored.

  Further, the lens memory 37 stores a silent noise lower limit lens moving speed V0b. For example, when the focus lens 33 is driven at a low speed equal to or lower than a predetermined speed, the drive load of the focus lens drive motor 331 is increased, and a drive sound of a predetermined value or more (for example, a drive sound of 50 decibels or more) is generated. There is a case. The silent lens lower limit lens moving speed V0b can prevent such a driving noise of a predetermined value or more when the focus lens 33 is driven at a speed equal to or higher than the silent lower limit lens moving speed V0b. It is a moving speed.

  On the other hand, the camera body 2 includes a mirror system 220 for guiding a light flux 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 which is rotated by a predetermined angle between the observation position of the subject and the imaging position around the rotation axis 223, and the quick return mirror 221 is pivotally supported by the quick return mirror 221. And a sub mirror 222 that rotates in accordance with the rotation. In FIG. 1, a state where the mirror system 220 is at the observation position of the subject is indicated by a solid line, and a 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 on the optical path of the optical axis L1 in the state of observation of the subject, and rotates so as to retract from the optical path of the optical axis L1 in the state of imaging of the object.

  The quick return mirror 221 is configured by a half mirror, and reflects light flux (optical axes L2 and L3) of a part of the luminous flux (optical axis L1) from the subject by the quick return mirror 221 when the object is at the observation position. Then, the light is guided to the finder 235 and the photometric sensor 237, and a part of the luminous flux (optical axis L4) is transmitted and guided to the sub mirror 222. On the other hand, the sub mirror 222 is 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 from the subject (optical axis L1) is guided to the finder 235, the photometric sensor 237, and the focus detection module 261, and the subject is observed by the photographer. The detection of the focusing state of the focusing lens 33 is performed. Then, when the photographer fully presses the release button, the mirror system 220 pivots to the photographing position, all the light flux from the subject (optical axis L1) is guided to the imaging element 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 disposed on a plane optically equivalent to the imaging device 22, and the pentaprism 233 and the eyepiece 234 are combined. It is possible to observe through. At this time, the transmissive liquid crystal display 232 superimposes and displays a focus detection area mark etc. on the subject image on the focusing screen 231, and relates to shooting of shutter speed, aperture value, number of shots, etc. in an area outside the subject image. Display information Thus, the photographer can observe the subject and the background thereof, shooting related information, and the like through the finder 235 in the shooting preparation state.

  The photometric sensor 237 is formed of a two-dimensional color CCD image sensor or the like, and divides the shooting screen into a plurality of areas to output a photometric signal according to the brightness of each area in order to calculate an exposure value at the time of shooting. A signal detected by the photometric sensor 237 is output to the camera control unit 21 and used for automatic exposure control.

  The imaging element 22 is provided on the optical axis L1 of the light flux from the subject of the camera body 2, and is provided on the planned focal plane of the photographing optical system including the lenses 31, 32, 33, 34, and the shutter 23 is It is provided. The imaging device 22 is a device in which a plurality of photoelectric conversion devices are two-dimensionally arranged, and can be configured from a device such as a two-dimensional CCD image sensor, a MOS sensor, or a CID. The image signal photoelectrically converted by the imaging device 22 is subjected to image processing by the camera control unit 21 and then recorded in the camera memory 24 which is a recording medium. The camera memory 24 can use any of a removable card type memory and a built-in type memory.

  Further, the camera control unit 21 detects the focusing state of the photographing optical system by the contrast detection method based on the pixel data read out from the image sensor 22. For example, the camera control unit 21 reads the output of the image sensor 22 and calculates the focus evaluation value based on the read output. The focus evaluation value can be obtained, for example, by extracting the high frequency component of the output from the imaging device 22 using a high frequency transmission filter. It can also be determined by extracting high frequency components using two high frequency transmission filters having different cutoff frequencies.

  Then, the camera control unit 21 sends a drive signal to the lens control unit 36 to drive the focus lens 33 at a predetermined sampling interval (distance) to obtain a focus evaluation value at each position, and the focus evaluation value is maximum. The focus detection by the contrast detection method is performed to obtain the position of the focus lens 33 as the in-focus position. It should be noted that, for example, when the focus evaluation value is calculated while driving the focus lens 33, the in-focus position is further lowered twice after the focus evaluation value rises twice. It can obtain | require by performing calculations, such as an interpolation method, using the focus evaluation value of.

  In focus detection by the contrast detection method, the sampling interval of the focus evaluation value increases as the drive speed of the focus lens 33 increases, and when the drive speed of the focus lens 33 exceeds a predetermined speed, the sampling interval of the focus evaluation value Becomes too large, and it becomes impossible to properly detect the in-focus position. This is because, when the focus lens 33 is driven from the near end to the infinity end as the sampling interval of the focus evaluation value becomes larger, the object field to be detected can properly detect the focus state even once. This is because the focus state at the position of the subject may not be properly detected without entering the depth. Therefore, the camera control unit 21 drives the focus lens 33 such 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 the search control for driving the focus lens 33 to detect the focus evaluation value, the camera control unit 21 detects the in-focus position appropriately, and the image plane movement speed at the maximum of the image plane movement speed at the sampling interval. The focus lens 33 is driven to achieve the driving speed. The search control includes, for example, web ringing, a proximity search (neighboring scan) for searching only the vicinity of a predetermined position, and an entire region search (whole scanning) for searching the entire drive range of the focus lens 33.

  The camera control unit 21 drives the focus lens 33 at a high speed when starting search control when triggered by a half press of the release switch, and starts search control when triggered by conditions other than a half press of the release switch. The focus lens 33 may be driven at a low speed. By performing control in this manner, it is possible to perform contrast AF at high speed when the release switch is half pressed, and perform contrast AF that is suitable for the appearance of the through image when the release switch is not half pressed. It is.

  Furthermore, the camera control unit 21 may control the focus lens 33 to be driven at high speed in search control in the still image shooting mode and to drive the focus lens 33 at low speed in search control in the moving image shooting mode. By performing control in this manner, it is possible to perform contrast AF at high speed in the still image shooting mode and perform contrast AF in which the appearance of the moving image is suitable in the moving image shooting mode.

  Further, in at least one of the still image shooting mode and the moving image shooting mode, the contrast AF may be performed at high speed in the sport shooting mode, and 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.

  Furthermore, in the present embodiment, focus detection can be performed by a phase difference detection method. Specifically, the focus detection module 261 is a pair in which a plurality of pixels each having a micro lens arranged in the vicinity of a predetermined focal plane of the imaging optical system and a photoelectric conversion element arranged for the micro lens are arranged. Line sensor (not shown). Then, a pair of light beams passing through a pair of different regions of the exit pupil of the focus lens 33 are received by each pixel arranged in the pair of line sensors, whereby a pair of image signals can be acquired. Then, it is possible to perform focus detection according to a phase difference detection method for detecting a focus adjustment state by obtaining a phase shift of a pair of image signals acquired by a pair of line sensors by a well-known correlation operation described later.

  The operation unit 28 is an input switch for setting the various operation modes of the camera 1 such as a shutter 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 Switching of the focus mode, and further, switching of the AF-S mode / AF-F mode can be performed even in the autofocus mode. The various modes set by the operation unit 28 are sent to the camera control unit 21, and the operation of the entire camera 1 is controlled by the camera control unit 21. Further, the shutter release button includes a first switch SW1 which is turned on when the button is half pressed, and a second switch SW2 which is turned on when the button is fully pressed.

  Here, in the AF-S mode, when the focus lens 33 is driven based on the focus detection result when the shutter release button is pressed halfway, the position of the focus lens 33 adjusted once is fixed. In this mode, shooting is performed at the focus lens position. The AF-S mode is a mode suitable for still image shooting, and is usually selected when performing still image shooting. In the AF-F mode, regardless of the operation of the shutter release button, the focus lens 33 is driven based on the focus detection result, and after that, the focus state is repeatedly detected and the focus state changes. In this mode, scan drive of the focus lens 33 is performed. The AF-F mode is a mode suitable for moving image shooting, and is usually selected when moving image shooting is performed.

  Further, in the present embodiment, a switch for switching between the one-shot mode and the continuous mode may be provided as a switch for switching the autofocus mode. 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 selected when the photographer selects the continuous mode. Can be configured to be set to

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

  The camera body 2 is provided with a body side mount portion 201 to which the lens barrel 3 is detachably attached. Further, as shown in FIG. 1, a connection portion 202 projecting to the inner peripheral side of the body side mount portion 201 is provided at a position near the body side mount portion 201 (inner side of the body side mount portion 201). ing. The connection portion 202 is provided with a plurality of electrical contacts.

  On the other hand, the lens barrel 3 is provided with a lens side mount portion 301 which is an interchangeable lens that is attachable to and detachable from the camera body 2 and that is detachably attached to the camera body 2. Further, as shown in FIG. 1, a connection portion 302 projecting to the inner peripheral side of the lens side mount portion 301 is provided at a position near the lens side mount portion 301 (inner side of the lens side mount portion 301). ing. The connection portion 302 is provided with a plurality of electrical contacts.

  When the lens barrel 3 is attached to the camera body 2, the electrical contacts of the connection portion 202 provided on the body side mount portion 201 and the electrical contacts of the connection portion 302 provided on the lens side mount portion 301 are electrically connected. And physically connected. Thereby, 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 become possible through the connection portions 202 and 302.

  FIG. 4 is a schematic view showing the details of the connection portions 202 and 302. As shown in FIG. The connection portion 202 is disposed on the right side of the body side mount portion 201 in FIG. 4 in accordance with an actual mount structure. That is, the connection portion 202 of the present embodiment is disposed at a position (a position on the right side of the body side mount portion 201 in FIG. 4) deeper than the mount surface of the body side mount portion 201. Similarly, the connection portion 302 is disposed on the right side of the lens side mount portion 301 because the connection portion 302 of the present embodiment is disposed at a location where it protrudes from the mount surface of the lens side mount portion 301. It represents. By arranging the connection portion 202 and the connection portion 302 in this manner, the mount surface of the body side mount portion 201 and the mount surface of the lens side mount portion 301 are brought into contact, and the camera body 2 and the lens barrel 3 are made. The connection portion 202 and the connection portion 302 are connected when mounting and coupling, and thereby the electrical contacts provided on both the connection portions 202 and 302 are connected to each other.

  As shown in FIG. 4, in the connection portion 202, twelve electrical contacts BP1 to BP12 are present. Further, in the connection portion 302 on the lens 3 side, 12 electric contacts LP1 to LP12 respectively corresponding to the 12 electric contacts on the camera body 2 side are present.

  The electrical contact BP1 and the electrical contact BP2 are connected to the first power supply circuit 230 in the camera body 2. The first power supply circuit 230 operates the operating voltage to each part in the lens barrel 3 (except for circuits with relatively large power consumption such as the lens drive motors 321 and 331) via the electrical contact BP1 and the electrical contact LP1. Supply. The voltage value supplied by the first power supply circuit 230 via the electrical contact BP1 and the electrical contact LP1 is not particularly limited, and for example, a voltage value of 3 to 4 V (typically in the middle of this voltage width 3 Voltage value in the vicinity of 5 V). In this case, the current value supplied from the camera body side 2 to the lens barrel side 3 is a current value within the range of several tens of mA to several hundreds of mA in the power on state. The electrical contact BP2 and the electrical contact LP2 are ground terminals corresponding to the above-mentioned operating voltage supplied via the electrical contact BP1 and the electrical contact LP1.

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

  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. . Then, the camera side second communication unit 292 and the lens side second communication unit 382 transmit and receive signals with each other using these electrical contacts. The contents of communication performed by the camera side second communication unit 292 and the lens side second communication unit 382 will be described in detail later.

  The electrical contact BP11 and the electrical contact BP12 are connected to the second power supply circuit 240 in the camera body 2. The second power supply circuit 240 supplies an operating voltage to a circuit with relatively large power consumption, such as the lens drive motors 321 and 331, via the electrical contact BP11 and the electrical contact LP11. The voltage value supplied by the second power supply circuit 230 is not particularly limited, but the maximum value of the voltage values supplied by the second power supply circuit 240 is the number of maximum values of the voltage values supplied by the first power supply circuit 230. It can be doubled. Further, 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 the range of several tens of mA to several A when the power is on. In addition, the electrical contact BP12 and the electrical contact LP12 are ground terminals corresponding to the above-mentioned operating voltage supplied via the electrical contact BP11 and the electrical contact LP11.

  The first communication unit 291 and the second communication unit 292 on the camera body 2 side shown in FIG. 4 constitute the camera transmission / reception unit 29 shown in FIG. 1, and the first communication unit on the lens barrel 3 side shown in FIG. The third communication unit 381 and the second communication unit 382 constitute the lens transmission / reception unit 38 illustrated in FIG. 1.

  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 composed of electrical contacts BP3 and LP3, a signal line BDAT composed of electrical contacts BP4 and LP4, a signal line LDAT composed of 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 from the lens side first communication unit 381 to the camera side first 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. 5 is a timing chart showing an example of command data communication. The camera control unit 21 and the first camera-side communication unit 291 first confirm the signal level of the signal line RDY at the start of command data communication (T1). Here, the signal level of the signal line RDY indicates whether the first lens communication unit 381 can communicate or not, and if communication is not possible, the lens control unit 36 and the first lens communication unit 381 determine 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 communicate with the lens barrel 3 or does not execute the next process even when communication is in progress.

  On the other hand, when the signal line RDY is at L (LOW) level, the camera control unit 21 and the first camera side communication unit 291 transmit the clock signal 401 to the first lens side communication unit 291 using the signal line CLK. . Further, the camera control unit 21 and the first camera-side communication unit 291 synchronize the clock signal 401 and use the signal line BDAT to transmit the camera-side command packet signal 402 as control data to the first lens-side communication unit 291. Send to In addition, when the clock signal 401 is output, the lens control unit 36 and the lens first communication unit 381 synchronize with the clock signal 401 and use the signal line LDAT to execute a lens side command packet signal as response data. Send 403

  The lens control unit 36 and the lens-side first 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 403 (T2). Then, the lens control unit 36 starts the first control processing 404 in accordance with the content of the body side command packet signal 402 received by time T2.

  For example, in the case where the received body side command packet signal 402 is content for requesting specific data on the lens barrel 3 side, the lens control unit 36 performs the content of the command packet signal 402 as the first control processing 404. It analyzes and executes processing to generate requested specific data. Furthermore, as the first control processing 404, the lens control unit 36 uses the checksum data included in the command packet signal 402 to simplify whether there is an error in the communication of the command packet signal 402 from the number of data bytes. It also executes communication error check processing to check regularly. The signal of the specific data generated in the first control process 404 is output as the lens side data packet signal 407 to the camera body 2 (T3). In this case, the camera-side data packet signal 406 output from the camera body 2 after the command packet signal 402 is dummy data (including checksum data) that does not make sense for the lens side. . In this case, the lens control unit 36 executes the communication error check process as described above using the checksum data included in the camera-side data packet signal 406 as the second control process 408 (T4).

  Also, for example, when the camera side command packet signal 402 is a drive instruction of the focus lens 33 and the camera side data packet signal 406 is the drive speed and drive amount of the focus lens 33, the lens control unit 36 performs the first operation. As the control processing 404, the content of the command packet signal 402 is analyzed, and a confirmation signal indicating that the content is understood is generated (T2). The confirmation signal generated in the first control process 404 is output to the camera body 2 as a lens side data packet signal 407 (T3). The lens control unit 36 executes analysis of the contents of the camera-side data packet signal 406 as the second control process 408 and executes communication error check processing using the checksum data included in the camera-side data packet signal 406. Do (T4). Then, after completion of the second control process 408, the lens control unit 36 drives the focus lens drive motor 331 based on the received camera side command packet signal 406, 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).

  In addition, when the second control process 408 is completed, the lens control unit 36 notifies the lens first communication unit 291 of the completion of the second control process 408. Thereby, the lens control unit 36 outputs an L level signal to the signal line RDY (T5).

  The communication performed during the above-described time T1 to T5 is one command data communication. As described above, in one command data communication, the camera control unit 21 and the first camera communication unit 291 transmit the camera command packet signal 402 and the camera data packet 406 one by one. As described above, in the present embodiment, the control data transmitted from the camera body 2 to the lens barrel 3 is divided into two and transmitted for convenience of processing. However, the camera side command packet signal 402 and the camera side Two data packet signals 406 constitute one control data.

  Similarly, in one command data communication, one lens-side command packet signal 403 and one lens-side data packet signal 407 are transmitted by the lens control unit 36 and the lens-side first communication unit 381, respectively. As described above, although the response data transmitted from the lens barrel 3 to the camera body 2 is also divided into two, one response data is obtained by combining both the lens side command packet signal 403 and the lens side data packet signal 407. Configure

  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. The lens control unit 36 includes a signal line HREQ composed of electrical contacts BP7 and LP7, a signal line HANS composed of electrical contacts BP8 and LP8, a signal line HCLK composed of electrical contacts BP9 and LP9, and electrical contacts BP10 and LP10. Hot line communication is performed to perform communication at a cycle (for example, an interval of 1 millisecond) shorter than command data communication via the signal line HDAT.

For example, in the present embodiment, 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 hotline communication includes the lens position of the focus lens 33, the lens position of the zoom lens 32, the current position image plane movement coefficient _Kcur , the minimum image plane movement coefficient _Kmin , and the maximum image plane movement coefficient K _max and the quiet lower limit lens movement velocity V 0 b are included. Here, the current position image plane movement coefficient K _cur is an image plane movement coefficient K corresponding to the current position of the zoom lens (focal length) and the current position of the focus lens (shooting distance). In the present embodiment, the lens control unit 36 refers to a 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. A current position image plane movement coefficient _Kcur corresponding to the 32 current lens positions and the current lens position of the focus lens 33 can be obtained. For example, in the example shown in FIG. 3, when the lens position (focal length) of the zoom lens 32 is at “f1” and the lens position (shooting distance) of the focus lens 33 is at “D4”, the lens control unit 36 the hot line communication, transmits a "K14" as the current position image plane shift factor K _cur, the "K11" as the minimum image plane shift factor K _min, the maximum image plane shift factor K _max to "K19" to the camera control unit 21 Do.

  Here, FIG. 6 is a timing chart showing an example of the hotline communication. FIG. 6 (a) is a diagram showing how hotline communication is repeatedly executed at predetermined intervals Tn. Moreover, a mode that the period Tx of one communication of the hotline communication performed repeatedly is expanded is shown in FIG.6 (b). Hereinafter, based on the timing chart of FIG. 6B, a scene in which the lens position of the focus lens 33 is communicated by hotline communication will be described.

  First, the camera control unit 21 and the second camera-side communication unit 292 output an L level signal to the signal line HREQ to start communication by hotline communication (T6). Then, the lens side second communication unit 382 notifies the lens control unit 36 that this signal is input to the electrical contact LP7. In response to the notification, the lens control unit 36 starts executing the generation process 501 for generating lens position data. The generation process 501 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 process 501, the lens control unit 36 and the second lens side communication unit 382 output an L level signal to the signal line HANS (T7). Then, when the signal is input to the electrical contact BP8, the camera control unit 21 and the second camera-side communication unit 292 output the clock signal 502 from the electrical contact BP9 to the signal line HCLK.

  The lens control unit 36 and the lens side second communication unit 382 output the lens position data signal 503 representing the lens position data from the electric contact LP10 to the signal line HDAT in synchronization with the clock signal 502. Then, when the transmission of the lens position data signal 503 is completed, the lens control unit 36 and the second lens side 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 electrical contact BP8, the camera side second communication unit 292 outputs a signal at the H level to the signal line HREQ from the electrical contact LP7 (T9).

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

  Next, the clip operation according to the present embodiment will be described with reference to FIG. In the present embodiment, in the search control of contrast AF, control is performed so that the moving speed of the image plane of the focus lens 33 becomes constant. The clip operation is an operation for suppressing the drive sound of the focus lens 33 in such contrast AF search control, and the speed of the focus lens 33 is slowed down and interferes with noise reduction. Is an operation of clipping so as not to fall below the silent lower limit speed.

  In the present embodiment, as described later, the camera control unit 21 of the camera body 2 uses the predetermined coefficient (Kc) to reduce the silent speed (moving speed is constant) and the focus lens driving speed (moving speed is constant). It is determined whether the clip operation should be performed or not by comparing with.

  When the camera control unit 21 permits the clipping operation, the lens control unit 36 sets the drive speed of the focus lens 33 so that the drive speed V1b of the focus lens 33 described later does not become less than the silent lower limit lens movement speed V0b. The noise is limited by the lower limit lens movement speed V0b. Hereinafter, this will be described in detail with reference to FIG.

  In step S101, the lens control unit 36 acquires the silent noise lower limit lens moving speed V0b. The silent lower limit lens moving speed V 0 b is stored in the lens memory 37, and the lens control unit 36 can obtain the silent lower limit lens moving speed V 0 b from the lens memory 37.

  In step S102, the lens control unit 36 acquires the drive instruction speed of the focus lens 33. In the present embodiment, the commanded data communication transmits the drive instruction speed of the focus lens 33 from the camera control unit 21 to the lens control unit 36, whereby the lens control unit 36 receives the focus lens from the camera control unit 21. 33 drive instruction speeds can be acquired.

  In step S103, the lens control unit 36 compares the silent lower limit lens moving speed V0b acquired in step S101 with the instructed driving speed of the focus lens 33 acquired in step S102. Specifically, the lens control unit 36 determines whether the driving instruction speed (unit: pulse / second) of the focus lens 33 is less than the silent noise lower limit lens moving speed V 0 b (unit: pulse / second), If the drive instruction speed of the lens 33 is less than the silent lower limit lens movement speed, the process proceeds to step S104. If the drive instruction speed of the focus lens 33 is equal to or higher than the silent lower limit lens movement speed V0b, the process proceeds to step S105. move on.

  In step S104, it is determined that the driving instruction speed of the focus lens 33 transmitted from the camera body 2 is less than the silent noise lower limit lens moving speed V0b. In this case, the lens control unit 36 drives the focus lens 33 at the silent noise lower limit lens moving speed V0b in order to suppress the drive noise of the focus lens 33. As described above, the lens control unit 36 limits the lens drive speed V1b of the focus lens 33 to the noise reduction lower limit lens movement speed V0b when the drive instruction speed of the focus lens 33 is less than the silent noise lower limit lens movement speed V0b.

  On the other hand, in step S105, it is determined that the driving instruction speed of the focus lens 33 transmitted from the camera body 2 is equal to or higher than the silent noise lower limit lens moving speed V0b. In this case, since the drive sound of the focus lens 33 having a predetermined value or more is not generated, the lens control unit 36 drives the focus lens 33 at the drive instruction speed of the focus lens 33 transmitted from the camera body 2.

  Here, FIG. 8 is a diagram for explaining the relationship between the lens driving speed V1b of the focus lens 33 and the silent noise lower limit lens moving speed V0b. As described above, the image plane movement coefficient K changes in accordance with the lens position of the focus lens 33. Therefore, as shown in FIG. 8, when the focus lens 33 is driven such that the moving speed of the image plane becomes constant at the time of focus detection, the lens drive speed V1b of the focus lens 33 is the focus It changes according to the lens position of the lens 33. For example, in the example shown in FIG. 8, the image plane movement coefficient K is smaller toward the near side, and the image plane movement coefficient K is greater toward the infinity side. Therefore, in the example shown in FIG. 8, when the focus lens 33 is driven so that the moving speed of the image plane becomes constant, the lens moving speed V1b of the focus lens 33 becomes slower toward the near side, and becomes closer toward the infinity side. Become faster.

As described above, when the focusing lens 33 is driven such that the moving speed of the image plane is constant, if the clipping operation is not performed, as in the example shown in FIG. The driving speed V1b may be less than the quiet lower limit lens moving speed V0b. For example, at the position of the focus lens 33 at which the minimum image plane movement coefficient K _min is obtained (minimum image plane movement coefficient = 100 in FIG. 8), the lens movement speed V1b is less than the silent noise lower limit lens movement speed V0b.

  In particular, when the focal length of the lens barrel 3 is long or the light environment is bright, the lens moving speed V1b of the focusing lens 33 is likely to be less than the silent noise lower limit lens moving speed V0b. In such a case, as shown in FIG. 8, the lens control unit 36 limits the driving speed V1b of the focus lens 33 by the silent lower limit lens moving speed V0b by performing the clipping operation (from the silent lower limit lens moving speed V0b Can also be controlled so as not to be slow (step S104), whereby the drive noise of the focus lens 33 can be suppressed.

  Next, with reference to FIG. 9, a clip operation control process for determining whether to permit or prohibit the clip operation shown in FIG. 7 will be described. FIG. 9 is a flowchart showing the clip operation control process according to the present embodiment. Note that the clip operation control process described below is executed by the camera body 2 when, for example, the AF-F mode or the moving image shooting mode is set.

First, in step S201, the camera control unit 21 acquires lens information. Specifically, the camera control unit 21, the hot line communication, the lens current image plane shift factor K _cur, minimum image plane shift factor K _min, maximum image plane shift factor K _max, and quietness lower lens moving speed V0b Acquired from the cylinder 3.

Then, in step S202, the camera control unit 21 calculates the silent noise lower limit image plane moving speed V0a_max. The quiet lower limit image plane movement speed V0a_max is a movement speed of a constant image plane, and for example, when the focus lens 33 is driven such that the movement speed of the image plane becomes a constant speed, the minimum image plane movement coefficient At the position of the focus lens 33 at which K _min is obtained, the speed at which the speed of the focus lens 33 becomes the silent noise lower limit lens moving speed V0b is obtained. The silent lower limit image plane moving speed V0a_max will be described in detail below.

  FIG. 10 is a diagram for explaining the relationship between the moving speed V1a of the image plane at the time of focus detection and the silent noise lower limit image plane moving speed V0a_max. The moving speed V1a of the image plane at the time of focus detection shown in FIG. 10 is the moving speed of the image plane when the focus lens 33 is driven at the lens driving speed V1b shown in FIG. Since the drive of the focus lens 33 is controlled so that the moving speed of the image plane is constant at this time, as shown in FIG. 10, the moving speed V1a of the image plane at the time of focus detection is constant.

  The image plane movement velocity V0a corresponding to the silent noise lower limit lens movement velocity V0b shown in FIG. 10 is the movement velocity of the image plane when the focus lens 33 is driven at the silent noise lower limit lens movement velocity V0b shown in FIG. . Here, since the silent lower limit lens moving speed V0b is a constant lens moving speed, when the image plane moving coefficient changes according to the position of the focus lens 33 as shown in FIG. 10, the silent lower limit lens moving speed The image plane movement speed V0a corresponding to V0b also changes according to the position of the focus lens 33.

Further, the lower limit image plane movement velocity V0a_max shown in FIG. 10 is the position of the focus lens 33 at which the minimum image plane movement coefficient K _min can be obtained among the movement velocities of the image plane (in the example shown in FIG. At K = 100), the moving speed of the focus lens 33 is the speed at which the silent noise lower limit lens moving speed V0b is reached. That is, the silent image lower limit image plane moving velocity V0a_max is the moving velocity V0a_max of the largest image plane among the image plane moving velocity V0a corresponding to the silent lower limit lens moving velocity V0b.

As described above, in the present embodiment, among the image plane movement speeds corresponding to the silent lens lower limit lens movement speed V0b, which changes according to the lens position of the focus lens 33, the largest image plane movement speed (the image plane movement coefficient is minimum The image plane movement speed at the lens position, which is given by the following equation, is calculated as the silent noise lower limit image plane movement speed V0a_max. For example, in the example shown in FIG. 10, since the minimum image plane movement coefficient K _min is “100”, the image plane movement speed at the lens position of the focus lens 33 where the image plane movement coefficient is “100” It is calculated as the surface movement speed V0a_max.

Specifically, the lens control unit 36, as shown in the following formula (4), quiet lower lens moving speed V0b (unit: pulse / s) minimum image plane shift factor and K _min (unit: pulse / mm) and Based on the above, the silent noise lower limit image plane moving speed V0a_max (unit: mm / second) is calculated.
Quiet lower limit image plane moving speed V0a_max = Silent lower limit lens moving speed V0b / minimum image plane moving coefficient K _min (4)

As described above, in this embodiment, by calculating the silent lower limit image plane moving speed V0a_max using the minimum image plane movement coefficient K _min , the silent noise lower limit can be generated at the timing when focus detection by AF-F or moving image shooting is started. The image plane movement velocity V0a_max can be calculated. For example, in the example shown in FIG. 10, at the timing t1 when focus detection by AF-F or moving image shooting is started, the image plane movement speed at the lens position of the focus lens 33 where the image plane movement coefficient K becomes "100" The lower limit image plane movement speed V0a_max can be calculated.

Next, in step S203, the camera control unit 21 compares the image plane movement velocity V1a for focus detection acquired in step S201 with the silent noise lower limit image plane movement velocity V0a_max calculated in step S202. Specifically, the camera control unit 21 determines that the image plane movement speed V1a (unit: mm / second) for the focus detection and the silent noise lower limit image plane movement speed V0a_max (unit: mm / second) are expressed by the following formula (5) To determine if
(Image plane movement speed V1a × Kc for focus detection)> Quiet lower limit image plane movement speed V0a_max ... (5)
In the above equation (5), the coefficient Kc is a value of 1 or more (Kc ≧ 1), the details of which will be described later.

  In the case where the above equation (5) is satisfied, the process proceeds to step S204, and the clip operation shown in FIG. 7 is permitted by the lens control unit 36. That is, as shown in FIG. 8, the drive speed V1b of the focus lens 33 is limited to the silent lens lower limit lens movement speed V0b in order to suppress the drive noise of the focus lens 33 (the drive speed V1b of the focus lens 33 is the silent noise lower limit) Search control is performed so as not to be lower than the lens movement speed V0 b).

  On the other hand, if the above equation (5) is not satisfied, the process proceeds to step S205, and the clipping operation shown in FIG. 7 is prohibited. That is, focusing is performed without limiting the driving speed V1b of the focus lens 33 at the silent lower limit lens moving speed V0b (permitting the driving speed V1b of the focus lens 33 to be lower than the silent lower limit lens moving speed V0b) The focus lens 33 is driven so that the image plane movement speed V1a can be detected appropriately.

  Here, if the driving speed of the focus lens 33 is limited by the silent lens lower limit lens moving speed V0b while permitting the clipping operation if the above equation (5) is not satisfied, the moving speed of the image plane becomes equal. It may be faster than the focal plane movement velocity V1a for focus detection which can appropriately detect the focal position, and an appropriate focusing accuracy may not be obtained. On the other hand, if the above equation (5) is satisfied, the clipping operation is inhibited, and the focus lens 33 is driven such that the moving speed of the image plane becomes the image plane moving speed V1a for focus detection. As shown in FIG. 8, the drive speed V1b of the focus lens 33 may be less than the noise reduction lower limit lens movement speed V0b, and drive sound of a predetermined value or more may be generated.

  As described above, when the image plane movement velocity V1a for focus detection is less than the lower limit silent image plane movement velocity V0a_max, the focus lens 33 is configured to obtain the image plane movement velocity V1a capable of appropriately detecting the in-focus position. To drive the lens at a lens drive speed lower than the quiet lower limit lens movement speed V0b or to drive the focus lens 33 at a lens drive speed higher than the silent lower limit lens movement speed V0b in order to suppress the drive noise of the focus lens 33 It becomes.

  Therefore, in the present embodiment, even when the focus lens 33 is driven at the silent lens lower limit lens moving velocity V0b, the constant KC can be detected as the coefficient Kc in the above equation (5) if the above equation (5) is satisfied. Is stored as one or more values that can be secured. Thereby, as shown in FIG. 10, the lens control unit 36 satisfies the above equation (5) even when the image plane movement speed V1a for focus detection is less than the silent noise lower limit image plane movement speed V0a_max. It is determined that a certain focus detection accuracy can be secured, and priority is given to the suppression of the drive sound of the focus lens 33, and the clip operation for driving the focus lens 33 at a lens drive speed less than the silent noise lower limit lens movement speed V0b is permitted.

  On the other hand, if the image plane movement speed V1a × Kc (where Kc ≧ 1) for focus detection falls below the silent noise lower limit image plane movement speed V0a_max, the clipping operation is permitted and the drive speed of the focus lens 33 is silenced. In the case of limiting by the lower limit lens moving speed V0b, the image plane moving speed for focus detection may be too fast, and the focus detection accuracy may not be ensured. Therefore, when the lens control unit 36 does not satisfy the equation (5), the lens control unit 36 prioritizes the focus detection accuracy and prohibits the clipping operation shown in FIG. 7. As a result, at the time of focus detection, the moving speed of the image plane can be made the image plane moving speed V1a capable of appropriately detecting the in-focus position, and focus detection can be performed with high accuracy.

  When the f-number is large (the aperture opening is small), the depth of field becomes deep, so the sampling interval at which the in-focus position can be appropriately detected becomes wide. As a result, it is possible to increase the image plane movement speed V1a that can appropriately detect the in-focus position. Therefore, when the image plane movement speed V1a capable of appropriately detecting the in-focus position is a fixed value, the lens control unit 36 increases the coefficient Kc of the equation (5) as the aperture value increases. can do.

  Similarly, when the image size is small, such as a live view image (when the compression rate of the image is high or when the thinning rate of pixel data is high), high focus detection accuracy is not required. Kc can be increased. Further, also in the case where the pixel pitch in the imaging device 22 is wide, the coefficient Kc in the above equation (5) can be increased.

  Next, control of the clipping operation will be described in more detail with reference to FIGS. 11 and 12. FIG. 11 is a view showing the relationship between the moving speed V1a of the image plane at the time of focus detection and the clipping operation, and FIG. 12 is for explaining the relationship between the lens driving speed V1b of the focus lens 33 and the clipping operation. Of the

  For example, as described above, in the present embodiment, the search control is started when the release switch is half pressed as a trigger and the search control is started when conditions other than the release switch are half pressed. The moving speed of the image plane in the search control may differ depending on the moving image shooting mode, the sport shooting mode and the landscape shooting mode, or the focal length, shooting distance, aperture value, and the like. FIG. 11 exemplifies the moving speeds V1a_1, V1a_2, and V1a_3 of such three different image planes.

  Specifically, the image plane movement velocity V1a_1 at the time of focus detection shown in FIG. 11 is the largest movement velocity among the movement velocities of the image plane that can appropriately detect the focus state, and satisfies the relationship of the above equation (5). It is the moving speed of the image plane. Further, the image plane movement velocity V1a_2 at the time of focus detection is the movement velocity of the image plane slower than V1a_1, but is the movement velocity of the image plane that satisfies the relationship of the equation (5) at the timing t1. On the other hand, the image plane movement velocity V1a_3 at the time of focus detection is the movement velocity of the image plane which does not satisfy the relationship of the above equation (5).

  Thus, in the example shown in FIG. 11, when the moving speeds of the image plane at the time of focus detection are V1a_1 and V1a_2, the clipping operation shown in FIG. 7 is performed because the relationship of the equation (5) is satisfied at timing t1. Is permitted. On the other hand, when the moving speed of the image plane at the time of focus detection is V1a_3, the relationship shown in the above equation (5) is not satisfied, so the clipping operation shown in FIG. 7 is prohibited.

  This point will be specifically described with reference to FIG. In FIG. 12, V1b_1 is a lens driving speed of the focus lens 33 corresponding to the maximum moving speed V1a_1 of the image plane capable of appropriately detecting the focus state shown in FIG. That is, V1b_1 is the drive speed of the focus lens 33 when the drive of the focus lens 33 is controlled such that the moving speed of the image plane at the time of focus detection becomes V1a_1. Further, V1b_2 is a lens driving speed of the focus lens 33 corresponding to the image plane moving speed V1a_2 satisfying the relationship of the above equation (5) as shown in FIG. 11, and V1b_3 is as shown in FIG. The lens driving speed of the focus lens 33 corresponds to the image plane moving speed V1a_3 not satisfying the relationship of the above expression (5).

  As described above, the image plane movement velocity V1a_1 corresponding to the lens drive velocity V1b_1 of the focus lens 33 satisfies the relationship of the above equation (5), and thus the clipping operation is permitted. However, in the example shown in FIG. 12, the lens driving speed V1b_1 does not become less than the noise reduction lower limit lens moving speed V0b even at the lens position where the minimum image plane movement coefficient (K = 100) is obtained. No action is taken.

  Further, the image plane movement velocity V1a_2 corresponding to the lens drive velocity V1b_2 of the focus lens 33 also satisfies the relationship of the above equation (5) at the timing t1, so the clipping operation is permitted. In the example shown in FIG. 12, when the focus lens 33 is driven at the lens driving speed V1b_2 such that the moving speed of the image plane at the time of focus detection is V1a_2, at the lens position where the image plane moving coefficient K is K1. Since the lens driving speed V1b_1 is less than the silent lower limit lens moving speed V0b, the driving speed V1b_2 of the focus lens 33 is limited by the silent lower limit lens moving speed V0b at a lens position where the image plane moving coefficient K is smaller than K1.

  That is, the moving speed V1a_2 of the image plane is constant until the lens position where the lens driving speed V1b_2 of the focusing lens 33 becomes the silent lower limit lens moving speed V0b, but the lens driving speed V1b_2 of the focusing lens 33 is the silent lower limit lens moving When the velocity is less than V0b, the clipping operation is performed, whereby the moving velocity V1a_2 of the image plane at the time of focus detection is different from the moving velocity (searching velocity) of the image plane up to that point. , Search control of the focus evaluation value will be performed. That is, as shown in FIG. 11, at the lens position where the image plane movement coefficient is smaller than K1, the movement velocity V1a_2 of the image plane at the time of focus detection becomes a velocity different from the constant velocity up to now.

  In addition, since the image plane movement velocity V1a_3 corresponding to the lens drive velocity V1b_3 of the focus lens 33 does not satisfy the relationship of the above equation (5), the clipping operation is prohibited. Therefore, in the example shown in FIG. 12, when the focus lens 33 is driven at the lens driving speed V1b_3 such that the moving speed of the image plane is a constant image plane moving speed V1a_3, the image plane moving coefficient K is K2 At the lens position where the lens drive speed V1b_3 is less than the silent lens lower limit lens movement speed V0b, the clipping operation is not performed at the lens position where the image plane movement coefficient K smaller than K2 is obtained, and the focus state is appropriately detected. For this reason, the driving speed V1b_3 of the focus lens 33 is less than the silent noise lower limit lens moving speed V0b.

  As described above, in the present embodiment, among the image plane movement speeds when the focus lens 33 is driven at the silent lower limit lens movement speed V0b, the largest image plane movement speed is calculated as the silent noise lower limit image plane movement speed V0a_max. The calculated silent noise lower limit image plane moving velocity V0a_max is compared with the moving velocity V1a of the image plane at the time of focus detection. Then, when the movement speed V1a × Kc (where Kc) 1) of the image plane at the time of focus detection is faster than the silent lower limit image plane movement speed V0a_max, the focus lens 33 is driven at the silent lower limit lens movement speed V0b. Even in this case, it is determined that the focus detection accuracy above a certain level can be obtained, and the clip operation shown in FIG. Thus, in the present embodiment, the drive noise of the focus lens 33 can be suppressed while securing the focus detection accuracy.

  On the other hand, when the movement speed V1a × Kc (where Kc ≧ 1) of the image plane at the time of focus detection becomes equal to or less than the quiet lower limit image plane movement speed V0a_max, the drive speed V1b of the focus lens 33 is the quiet lower limit lens movement speed V0b In the case of limitation, it may not be possible to obtain appropriate focus detection accuracy. Therefore, in this embodiment, in such a case, the clipping operation shown in FIG. 7 is prohibited so that the image plane movement speed suitable for focus detection can be obtained. Thereby, in the present embodiment, the in-focus position can be appropriately detected at the time of focus detection.

Further, in the present embodiment, the minimum image plane movement coefficient K _min is stored in advance in the lens memory 37 of the lens barrel 3, and the silent image lower limit image plane movement velocity V0a_max is calculated using this minimum image plane movement coefficient K _min. calculate. Therefore, in the present embodiment, for example, as shown in FIG. 10, the image plane movement speed V1a × Kc for focus detection at the timing of time t1 when focus detection in the moving image shooting or AF-F mode is started. It can be determined whether Kc ≧ 1) exceeds the silent image lower limit image plane moving speed V0a_max, and it can be determined whether or not the clipping operation is to be performed. As described above, in the present embodiment, it is not necessary to repeatedly determine whether or not to perform the clipping operation using the current position image plane movement coefficient K _cur, but using the minimum image plane movement coefficient K _min to capture a moving image or Since it is possible to determine whether or not to perform the clipping operation at the first timing when focus detection in the AF-F mode is started, the processing load on the camera body 2 can be reduced.

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

  For example, although the configuration in which the clip operation control process shown in FIG. 7 is executed in the camera body 2 is exemplified in the embodiment described above, the present invention is not limited to this configuration. For example, the clip operation control process shown in FIG. It may be configured to be executed in the lens barrel 3.

Further, in the embodiment described above, as shown in the above equation (3), a configuration for calculating the image plane movement coefficient K by the image plane movement coefficient K = (the drive amount of the focus lens 33 / the movement amount of the image plane) Although illustrated, it is not limited to this composition, for example, it is good also as composition calculated as shown in the following formula (6).
Image plane movement coefficient K = (movement amount of image plane / drive amount of focus lens 33) (6)
In this case, the lens control unit 36 can calculate the silent noise lower limit image plane moving speed V0a_max as follows. That is, as shown in the following equation (7), the lens control unit 36 moves the image plane movement coefficient K at each lens position (focal length) of the silent lens lower limit lens movement velocity V0b (unit: pulse / second) and The silent noise lower limit image plane movement velocity V0a_max (unit: mm / second) can be calculated based on the maximum image plane movement coefficient K _max (unit: pulse / mm) indicating the maximum value among them.
Quiet lower limit image plane moving speed V0a_max = Silent lower limit lens moving speed V0b / maximum image plane moving coefficient K _max (7)
For example, when a value calculated by "the movement amount of the image plane / the drive amount of the focus lens 33" is adopted as the image plane movement coefficient K, the larger the value (absolute value), the more the predetermined value For example, the amount of movement of the image plane when driven by 1 mm is large. When a value calculated by "the driving amount of the focus lens 33 / the moving amount of the image plane" is adopted as the image plane movement coefficient K, the larger the value (absolute value), the more the predetermined value (for example, 1 mm) of the focus lens. ) The amount of movement of the image plane when driven is small.
Further, as long as the maximum image plane movement coefficient K _max can be transmitted, the invention is not limited to the one in which the image plane movement coefficient K is stored in the lens memory 37. For example, the maximum image plane movement coefficient K _max may be calculated according to the zoom lens position or the like, and the calculated maximum image plane movement coefficient K _max may be transmitted to the camera body 2. Similarly, the minimum image plane movement coefficient K _min may be calculated according to the zoom lens position or the like, and the calculated minimum image plane movement coefficient K _min may be transmitted to the camera body 2.
Further, the image plane movement coefficient K and the maximum image plane movement coefficient K _max stored in the lens memory 37 may be an integer, a value including a decimal point or less, or an index. Also, it may be logarithmic. Further, the image plane movement coefficient K and the maximum image plane movement coefficient K _max may be decimal numbers or binary numbers.
Furthermore, if the maximum image plane movement coefficient K _max is to be transmitted to the camera body 2, the electric contact of the mount portion 401 of the camera body 2 and the electric contact of the mount portion 402 of the lens barrel 3 are connected It is not limited. For example, the maximum image plane movement coefficient K _max may be transmitted from the lens barrel 3 to the camera body 2 using wireless communication.

In addition to the above-described embodiment, when the silent mode for suppressing the drive sound of the focus lens 33 is set, the above-described clip operation and clip operation control process are executed, and the silent mode is not set. Alternatively, the clip operation and the clip operation control process described above may not be performed. In addition, when the silent mode is set, priority is given to suppression of the drive sound of the focus lens 33, and the clip operation shown in FIG. 7 may be always performed without performing the clip operation control process shown in FIG. .
In the above-described embodiment, the image plane movement coefficient K = (the drive amount of the focus lens 33 / the movement amount of the image plane) has been described. However, the present invention is not limited to this. For example, when the image plane movement coefficient K = (the movement amount of the image plane / the drive amount of the focus lens 33), the maximum image plane movement coefficient Kmax is used to perform the clipping operation or the like as in the above embodiment. You can control it.

  Furthermore, in the embodiment described above, as shown in FIG. 1, the configuration in which the present invention is applied to a single-lens reflex digital camera is illustrated, but the present invention is not limited to this configuration. For example, as shown in FIG. May be applied to an interchangeable lens mirrorless camera. In the example shown in FIG. 13, the camera body 2 a sequentially sends the captured image captured by the imaging element 22 to the camera control unit 21, and via the liquid crystal drive circuit 25 to the electronic viewfinder (EVF) 26 of the observation optical system. indicate. In this case, for example, the camera control unit 21 reads the output of the imaging device 22 and calculates the focus evaluation value based on the read output, thereby detecting the focusing state of the photographing optical system by the contrast detection method. be able to. In addition, the present invention may be applied to other optical devices such as a digital video camera, a lens-integrated digital camera, and a camera for a mobile phone.

Reference Signs List 1 digital camera 2 camera body 21 camera control unit 22 imaging device 29 camera transmission / reception unit 291 camera side first communication unit 292 camera side second communication unit 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 side first communication unit 382 ... Lens side second communication unit

Claims (1)

A drive unit for driving an optical system including a focusing optical system;
First and second image plane movement coefficients that change according to the position of the focusing optical system and correspond to the amount of movement of the image plane with respect to the amount of movement of the focusing optical system, and correspond to the position of the focusing optical system A second image plane movement coefficient in which the movement amount of the image plane with respect to the movement amount of the focusing optical system is maximized within the drive range of the focusing optical system; A transmitter configured to transmit a silent velocity determined in accordance with the drive sound of the focusing optical system;
A lens control unit that controls the drive unit at a search speed determined by an imaging device;
When it is permitted to search for a focus evaluation value of contrast AF at a speed different from the search speed by comparing the reference speed calculated using the second image plane movement coefficient and the silent speed with the search speed A receiving unit that receives a permission signal that is transmitted when determined by the imaging device;
The interchangeable lens, wherein the lens control unit searches for a focus evaluation value of the contrast AF at a speed different from the search speed when the reception unit receives the permission signal.

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