Camera body

Abstract

To provide a camera body capable of improving the effect of shake correction.SOLUTION: The camera body 2 includes a first communicator 240a that transmits and receives information to and from the camera accessory 3 and a second communicator 240b that receives information from the camera accessory 3, the first communicator 240a transmits, to the camera accessory 3, information indicating a share ratio of shake correction when shake is corrected by the camera accessory 3 and the camera body 2, and the second communicator 240b receives, from the camera accessory 3, information on a position of the lens. The instruction to start communication by the second communication unit 240b is communicated by the first communication unit 240a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a camera body. [Background technology]

[0002] Interchangeable lenses equipped with image stabilization devices are known (see Patent Document 1). However, when an interchangeable lens equipped with an image stabilization device is attached to a camera body equipped with an image stabilization device, cooperation between the image stabilization devices of the interchangeable lens and the camera body becomes an issue. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-38461 Summary of the Invention

[0004] The camera body of the first aspect of the present invention is a camera body that has a lens and can be fitted with a camera accessory that forms a subject image, and is equipped with a first communication unit that sends and receives information to the camera accessory, and a second communication unit that receives information from the camera accessory, wherein the first communication unit sends information to the camera accessory indicating the proportion of shake correction that is shared when shake is corrected between the camera accessory and the camera body, the second communication unit receives information from the camera accessory regarding the position of the lens, and an instruction to start communication for the second communication unit is communicated via the first communication unit. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 2 is a block diagram illustrating a configuration of a main part of the camera system. [Figure 2] 10 is a timing chart illustrating command data communication and hotline communication. [Figure 3] 10 is a diagram illustrating the timing of a RDY signal, a CLK signal, a DATAB signal, and a DATAL signal. [Figure 4] 10 is a diagram illustrating the timing of an HCLK signal and an HDATA signal. [Figure 5] 10 is a diagram illustrating information included in second data 92. FIG. [Figure 6] 10 is a diagram illustrating calculation of the drive amount of the shake correction lens 361b by the lens side control unit 330. FIG. [Figure 7] 10 is a diagram illustrating the operation of a second determination unit 336. FIG. [Figure 8] FIG. 10 is a diagram showing the relationship between the total shake state, the cutoff frequency fcω, and the first correction factor Gω1 for angular shake. [Figure 9] FIG. 10 is a diagram showing the relationship between still image / video image stabilization, shutter speed, and second correction factor. [Figure 10] FIG. 10 is a diagram showing the relationship between still image / video image stabilization, stabilization mode, and cutoff frequency fc_inteω. [Figure 11] FIG. 10 is a diagram showing the relationship between the total shake state, the cutoff frequency fcα, and the first correction factor Gα1 for translational shake. [Figure 12] FIG. 10 is a diagram showing the relationship between still image / video image stabilization, stabilization mode, and cutoff frequency fc_inteα. [Figure 13] 10 is a timing chart showing the state of shake correction when shooting a moving image. [Figure 14] 10 is a timing chart showing the state of shake correction when capturing a still image. DETAILED DESCRIPTION OF THE INVENTION

[0006] Hereinafter, an embodiment of the invention will be described with reference to the drawings. Fig. 1 is a block diagram illustrating the essential configuration of a camera system 1. In this embodiment, camera system 1 has an interchangeable lens 3 detachably attached to a camera body 2. In Fig. 1, the optical axis O of the interchangeable lens 3 and the X-axis and Y-axis directions in a plane intersecting with the optical axis O are indicated by lines.

[0007] <Camera body> The camera body 2 has a body side control unit 230, a body side communication unit 240, a power supply unit 250, an image sensor 260, a sensor driving unit 265, a signal processing unit 270, an operation member 280, a vibration sensor 290, and a display unit 285. The body side control unit 230 is connected to the body side communication unit 240, the power supply unit 250, the image sensor 260, the sensor driving unit 265, the signal processing unit 270, the operation member 280, and the vibration sensor 290.

[0008] The body side communication unit 240 performs predetermined communication with the lens side communication unit 340 of the interchangeable lens 3. The body side communication unit 240 transmits signals to the body side control unit 230. The body side communication unit 240 includes a first body side communication unit 240a and a second body side communication unit 240b. The first body side communication unit 240a performs command data communication with the interchangeable lens 3, which will be described later, and the second body side communication unit 240b performs hotline communication with the interchangeable lens 3, which will be described later.

[0009] The body-side first communication unit 240a is connected to the body-side first control unit 230a, which will be described later, and information sent and received between the camera body 2 and the interchangeable lens 3 via command and data communication is output or input by the body-side first control unit 230a. The body-side second communication unit 240b is connected to the body-side first control unit 230a and the body-side second control unit 230b, which will be described later, and information sent from the interchangeable lens 3 to the camera body 2 via hotline communication is sent to the body-side first control unit 230a and the body-side second control unit 230b.

[0010] The power supply unit 250 converts the voltage of a battery (not shown) into a voltage used by each part of the camera system 1, and supplies it to each part of the camera body 2 and the interchangeable lens 3. The power supply unit 250 can switch the power supply on and off for each power supply destination according to instructions from the body-side control unit 230.

[0011] The image sensor 260 is a solid-state image sensor such as a CMOS image sensor or a CCD image sensor. The image sensor 260 captures a subject image on an image sensor surface 260S in response to a control signal from the body-side control unit 230 and outputs a signal. The image sensor 260 is capable of capturing both video and still images. Video capture not only includes recording video, but also capturing so-called through images for continuously displaying the imaging state on the display unit 285. The signal output from the image sensor 260 is used to generate image data for a live view image and image data for still image capture by the signal processing unit 270. The image sensor 260 is connected to the signal processing unit 270 and the body side control unit 230.

[0012] The signal processing unit 270 generates image data by performing predetermined image processing on the signal output from the image sensor 260. The generated image data is recorded in a predetermined file format on a storage medium (not shown), or is used to display an image on the display unit 285. The signal processing unit 270 is connected to the body side control unit 230, the image sensor 260, and the display unit 285.

[0013] Shake sensor 290 detects shake of camera body 2 due to camera shake or the like. Shake sensor 290 includes an angular velocity sensor 290a and an acceleration sensor 290b. Shake sensor 290 detects angular shake and translational shake by separating them into an X-axis component and a Y-axis component.

[0014] The angular velocity sensor 290a detects the angular velocity generated by the rotational movement of the camera body 2. The angular velocity sensor 290a detects rotation around an axis parallel to the X-axis and an axis parallel to the Y-axis, for example, and outputs a detection signal of a shake angular velocity ω1 about the X-axis direction and a detection signal of a shake angular velocity ω2 about the Y-axis direction to the body-side control unit 230.

[0015] Additionally, acceleration sensor 290b detects acceleration generated by translational motion of camera body 2. Acceleration sensor 290b detects acceleration in the directions of axes parallel to the X-axis and Y-axis, for example, and outputs a detection signal of shake acceleration α1 in the X-axis direction and a detection signal of shake acceleration α2 in the Y-axis direction to body-side control unit 230, respectively. The angular velocity sensor 290a and the acceleration sensor 290b can each output a detection signal periodically at a period shorter than the period of hotline communication.

[0016] The body side control unit 230 is composed of a microcomputer and its peripheral circuits, etc. The body side control unit 230 includes a memory unit 235. The body side control unit 230 controls the recording and reading of data in the memory unit 235. The memory unit 235 stores control programs and the like to be executed by the body side control unit 230. The body side control unit 230 executes the control programs stored in the memory unit 235 to control each unit within the camera body 2.

[0017] The body-side control unit 230 includes a body-side first control unit 230a and a body-side second control unit 230b. The body-side first control unit 230a mainly controls the entire camera body 2, while the body-side second control unit 230b is connected to the sensor drive unit 265 and mainly controls the shake correction operation, which moves the image sensor 260 in a direction intersecting the optical axis. Since the body-side second control unit 230b mainly controls the shake correction operation, it can quickly perform control related to shake correction. The body-side first control unit 230a sends instructions related to shake correction, such as starting shake correction and the correction rate (described later), to the body-side second control unit 230b. Necessary data and instructions are sent and received between the body-side first control unit 230a and the body-side second control unit 230b as appropriate.

[0018] The sensor driving unit 265 includes, for example, an actuator, a driving mechanism, and a position detection unit. The sensor driving unit 265 moves the image sensor 260 in a direction intersecting the optical axis O based on instructions output from the body side control unit 230. By moving the image sensor 260 in a direction intersecting the optical axis O, blurring of the subject image (image shake) on the imaging surface 260S of the image sensor 260 is suppressed. The sensor driving unit 265 detects the position of the image sensor 260 in the direction intersecting the optical axis O using a position detection unit such as a Hall element.

[0019] An operation member 280 including a release button, operation switches, etc. is provided on the exterior surface of the camera body 2. The user operates the operation member 280 to give instructions for shooting, setting shooting conditions, etc. The user can also use the operation member 280 to turn the shake correction function on or off, to specify which vibration reduction mode to set (sports mode, normal mode, or lens side priority mode), and to set shake correction.

[0020] The sports mode is a mode suitable for image stabilization under conditions such as chasing a fast-moving subject, frequently changing the composition, and using a fast shutter speed, by reducing the range of motion and the image stabilization angle compared to the normal mode. The normal mode increases the range of motion by matching it with the mechanical range of motion, thereby enhancing the effect of image stabilization. The lens side priority mode is a mode in which, when the vibration isolation modes of the camera body 2 and the interchangeable lens 3 do not match, the vibration isolation mode of the camera body 2 is set to the vibration isolation mode set in the interchangeable lens 3.

[0021] In this embodiment, as will be described later, at least some of the shake correction settings can also be set using the indicator 375 of the interchangeable lens 3, so there are cases where the shake correction settings do not match between the camera body 2 and the interchangeable lens 3. If the shake correction settings do not match between the camera body 2 and the interchangeable lens 3, the shake correction effect of the interchangeable lens 3 and the shake correction effect of the camera body 2 will not match, and live view images and the like may appear unnatural.

[0022] In this embodiment, operations performed by the operating member 280 are sent to the body-side first control unit 230a, and instructions from the instruction unit 375 are sent to the body-side first control unit 230a via command data communication or hotline communication. Therefore, the body-side first control unit 230a can recognize the shake correction settings of the camera body 2 and the interchangeable lens 3, and the body-side first control unit 230a can send instructions related to the shake correction settings to the interchangeable lens 3 via command data communication, thereby matching the shake correction settings of the camera body 2 and the interchangeable lens 3. The operation member 280 sends an operation signal to the body side control unit 230 in response to an operation by the user.

[0023] The display unit 285 is configured with, for example, a liquid crystal display panel. The display unit 285 displays an image based on image data processed by the signal processing unit 270, an operation menu screen, etc., in response to instructions from the body-side control unit 230. Furthermore, by operating the display unit 285 as a touch panel, shooting conditions may be set instead of the operation member 280.

[0024] <Interchangeable lenses> The interchangeable lens 3 has a lens side control unit (calculation unit) 330, a lens side communication unit 340, a lens side memory unit 350, an imaging optical system 360, a lens driving unit 370, an instruction unit 375, and a shake sensor 390. The lens side control unit 330 is connected to the lens side communication unit 340, the lens side memory unit 350, the lens driving unit 370, the instruction unit 375, and the shake sensor 390.

[0025] The lens-side control unit 330 is composed of a microcomputer and its peripheral circuits, etc. The lens-side control unit 330 executes a control program stored in the lens-side storage unit 350, and controls each part of the interchangeable lens 3, such as autofocus control and shake correction control. The shake correction control performed by the lens-side control unit 330 will be described later.

[0026] The lens-side storage unit 350 is configured with a non-volatile storage medium. The lens-side storage unit 350 has data recording and reading controlled by the lens-side control unit 330. In addition to storing control programs and the like executed by the lens-side control unit 330, the lens-side storage unit 350 also stores data indicating the optical characteristics of the imaging optical system 360, cutoff frequencies (fcω, fcα, fc_inteω, fc_inteα, described below) according to the shake correction settings, and first correction factors (Gω1, Gα1, described below).

[0027] The imaging optical system 360 has multiple lenses and a diaphragm member, and forms a subject image on an image formation plane (imaging plane 260S). At least a part of the imaging optical system 360 is configured as a movable member so that its position within the interchangeable lens 3 can be moved. The imaging optical system 360 includes, for example, a focusing lens 361a as a moving member and a vibration correction lens 361b as a moving member.

[0028] Lens driving unit 370 moves the movable member and includes lens driving units 370a and 370b. Each lens driving unit 370 includes an actuator, a driving mechanism, and a unit for detecting the position of the movable member. Lens-side control unit 330 periodically generates position information of the movable member based on signals from the position detection unit and actuator of lens driving unit 370.

[0029] Furthermore, the lens side control unit 330 periodically recognizes the movement state, such as whether the movable member is being driven to move, the direction of movement of the movable member, and whether the movable member is stopped, based on signals from the position detection unit and actuator of the lens drive unit 370. The period for creating the position information of the movable member and the period for recognizing the movement state of the movable member can be shorter than the period for hotline communication.

[0030] The focusing lens 361a is configured to be movable forward and backward in the direction of the optical axis O by the lens driving unit 370a. The focal position of the imaging optical system 360 is adjusted by moving the focusing lens 361a. Drive instructions such as the direction, amount, and speed of movement of the focusing lens 361a may be issued by the body-side control unit 230, or may be issued by the lens-side control unit 330 in consideration of instructions from the body-side control unit 230. The position of the focusing lens 361a in the direction of the optical axis O is detectable by an encoder or the like of the lens driving unit 370a.

[0031] The shake correction lens 361b is configured to be movable forward and backward by the lens drive unit 370b in a direction intersecting the optical axis O. Movement of the shake correction lens 361b reduces shaking (image shake) of the subject image on the imaging surface 260S of the image sensor 260. Drive instructions for the movement direction, amount of movement, movement speed, etc. of the shake correction lens 361b may be issued from the lens-side control unit 330 based on a detection signal from the shake sensor 390, or may be issued from the lens-side control unit 330 in consideration of the detection signal from the shake sensor 390 and instructions from the body-side control unit 230.

[0032] The position of the shake correction lens 361b can be detected by a Hall element or the like of the lens driver 370b. As position information of the shake correction lens 361b, the lens driver 370b detects, for example, the position of the optical axis O' of the shake correction lens 361b in a plane intersecting with the optical axis O. In other words, it detects the coordinate values ​​in the X-axis direction and the Y-axis direction of the optical axis O' of the shake correction lens 361b, which has the optical axis O as its origin position. Therefore, the position information of the shake correction lens 361b can be expressed by the positions of the optical axis O' in the X-axis direction and the Y-axis direction, or can be expressed by the amount of movement of the optical axis O' in the X-axis direction (the difference in coordinate values) and the amount of movement in the Y-axis direction.

[0033] The instruction unit 375 is provided, for example, on the outer barrel of the interchangeable lens 3. By operating the instruction unit 375, the user can set the shake correction function of the interchangeable lens 3 to ON or OFF, or set the vibration reduction mode of the interchangeable lens 3 to sports mode or normal mode, etc. An operation signal corresponding to the user's operation is sent from the instruction unit 375 to the lens-side control unit 330.

[0034] The shake sensor 390 detects shake of the interchangeable lens 3 due to camera shake or the like. The shake sensor 390 is equivalent to the shake sensor 309 of the camera body 2. The shake sensor 390 outputs detection signals from an angular velocity sensor 390a and an acceleration sensor 390b to the lens side control unit 330. The angular velocity sensor 390a and the acceleration sensor 390b can each output detection signals periodically at a cycle shorter than the cycle of hotline communication.

[0035] The lens side communication unit 340 performs predetermined communication with the body side communication unit 240. The lens side communication unit 340 includes a first lens side communication unit 340a and a second lens side communication unit 340b. The first lens side communication unit 340a performs command data communication with the camera body 2, which will be described later, and the second lens side communication unit 340b performs hotline communication with the camera body 2, which will be described later.

[0036] The first lens-side communication unit 340a is connected to the lens-side control unit 330, and information sent from the interchangeable lens 3 to the camera body 2 by command and data communication is created by the lens-side control unit 330. The second lens-side communication unit 340b is also connected to the lens-side control unit 330, and information sent from the interchangeable lens 3 to the camera body 2 by hotline communication is created by the lens-side control unit 330, the second lens-side communication unit 340b, etc.

[0037] The arrows between the lens side communication unit 340 and the body side communication unit 240 in FIG. 1 indicate the flow of signals. The lens side first communication unit 340a outputs a signal (hereinafter referred to as a RDY signal) indicating whether or not the interchangeable lens 3 is capable of command and data communication, and a data signal (hereinafter referred to as a DATAL signal), to the body side first communication unit 240a. The body side first communication unit 240a outputs a clock signal (hereinafter referred to as a CLK signal) and a data signal (hereinafter referred to as a DATAB signal) for command and data communication, to the lens side first communication unit 340a.

[0038] The second lens side communication section 340b outputs a clock signal (hereinafter referred to as HCLK signal) and a data signal (hereinafter referred to as HDATA signal) for hotline communication to the second body side communication section 240b. Hotline communication is one-way data communication from the interchangeable lens 3 to the camera body 2, while command data communication is two-way data communication between the interchangeable lens 3 and the camera body 2.

[0039] <Communication details> The camera system 1 has two independent communication systems for command data communication and hotline communication, and therefore each type of communication can be carried out in parallel. In other words, the camera body 2 and the interchangeable lens 3 can start and end hotline communication while performing command data communication, and can also perform command data communication while performing hotline communication. Therefore, even during command data communication, the interchangeable lens 3 can continuously send data via hotline communication to the camera body 2. For example, even if the time required for command data communication increases due to an increase in the amount of data, hotline communication can be performed at the required timing.

[0040] Furthermore, even while the camera body 2 is receiving data via hotline communication, it can send various instructions and requests to the interchangeable lens 3 via command data communication at any time, and can receive data from the interchangeable lens 3 at any time.

[0041] FIG. 2 is a timing chart illustrating command data communication and hotline communication. After issuing an instruction to start hotline communication via command data communication, the camera body 2 periodically receives data from the interchangeable lens 3 via hotline communication, for example, from time t1 onwards. The camera body 2 also transmits and receives data via command data communication with the interchangeable lens 3. In more detail, between times t2 and t3 and between times t9 and t10, the camera body 2 issues transmission instructions to the interchangeable lens 3 and receives various data, between times t5 and t6 and between times t12 and t13, it transmits various data to the interchangeable lens 3, and between times t4, t7, t8, and t11 it transmits instructions to the interchangeable lens 3 relating to movement control of movable members, such as an instruction to start shake correction, an instruction to drive the aperture, and an instruction to drive the focus, respectively.

[0042] In this embodiment, command data communication involves sending and receiving a wide variety of data and frequently issuing instructions to the interchangeable lens 3. Furthermore, depending on the type of data, the time required for sending and receiving can be long, and the time required for sending and receiving various types of data from time t2 to t3, from time t5 to t6, from time t9 to t10, and from time t12 to t13 is longer than the time required for sending instructions at times t4, t7, t8, and t11.

[0043] For example, in response to an instruction from the camera body 2 sent by command data communication, the interchangeable lens 3 transmits data indicating information about the interchangeable lens 3 (focal length, shooting distance, aperture value, optical characteristics of the imaging optical system 360, etc.) to the camera body 2. The interchangeable lens 3 also receives data indicating information about the camera body 2 (frame rate, camera body 2 settings, etc.) transmitted from the camera body 2.

[0044] Command data communication takes a long time to send and receive, and is sent and received frequently, making it difficult to continuously communicate data in short cycles. In contrast, hotline communication uses a communication terminal different from the communication terminal used for command and data communication, so data communication can be carried out continuously in short cycles from the interchangeable lens 3 to the camera body 2. For example, hotline communication can be carried out for any desired period from the end of the startup process of the camera body 2 until the shutdown process, including during exposure. The instructions to start and end hotline communication are transmitted from the camera body 2 to the interchangeable lens 3 by command data communication, but this is not the only option.

[0045] <Command data communication explanation> Next, command data communication will be described with reference to Fig. 3. Fig. 3 illustrates the timing of the RDY signal, CLK signal, DATAB signal, and DATAL signal. In one command data communication, one command packet 402 is sent from the camera body 2 to the interchangeable lens 3, and then one data packet 406, 407 is sent and received between the camera body 2 and the interchangeable lens 3, respectively.

[0046] The first lens side communication unit 340a sets the potential of the RDY signal to L level when command data communication starts (t21). When the RDY signal is L level, the first body side communication unit 240a starts outputting a CLK signal 401. The frequency of the CLK signal 401 is, for example, 8 MHz. The first body side communication unit 240a outputs a DATAB signal including a command packet 402 of a predetermined length in synchronization with the clock signal 401. The command packet 402 is indicated by switching between H level and L level. The first body side communication unit 240a outputs the CLK signal 401 for a period corresponding to the data length of the command packet 402, and then stops outputting the CLK signal (t22).

[0047] The command packet 402 includes, for example, synchronization data, data for identifying which command data communication it is, data indicating an instruction from the camera body 2, data indicating the data length of the subsequent data packet 406, data for checking communication errors, etc. The instructions included in the command packet 402 include, for example, an instruction from the camera body 2 to the interchangeable lens 3 to drive a movable member, an instruction from the camera body 2 to the interchangeable lens 3 to send data, etc.

[0048] The interchangeable lens 3 can determine whether or not a communication error has occurred by checking whether or not a value calculated from the received command packet 402 matches the data for communication error check included in the command packet 402 . When reception of the command packet 402 is complete, the first lens side communication section 340a sets the RDY signal to H level, and the lens side control section 330 starts the first control process 404 based on the command packet 402 (t22).

[0049] When the first control process 404 by the lens side control unit 330 is completed, the first lens side communication unit 340a can set the RDY signal to L level (t23). When the input RDY signal goes to L level, the first body side communication unit 240a outputs a CLK signal 405.

[0050] The body side first communication unit 240a outputs a DATAB signal including a data packet 406 in synchronization with the CLK signal 405. Furthermore, the lens side first communication unit 340a outputs a DATAL signal including a data packet 407 of a predetermined length in synchronization with the CLK signal 405. The data packets 406, 407 are indicated by switching between H level and L level. After outputting the CLK signal 405 for a period equivalent to the data length of the data packet 406, the body side first communication unit 240a then stops outputting the CLK signal (t24).

[0051] The data packets 406 and 407 are variable-length data having the number of pieces of data indicated by the command packet 402. The data packets 406 and 407 include synchronization data, data indicating information about the camera body 2, data indicating information about the interchangeable lens 3, and data for communication error checks.

[0052] The data packet 406 sent from the camera body 2 to the interchangeable lens 3 includes data indicating the amount of drive of the moving member, data for conveying settings and operating conditions within the camera body 2, and the like. The data packet 407 sent from the interchangeable lens 3 to the camera body 2 includes data indicating the model name information of the interchangeable lens 3, data indicating the shake correction control in the interchangeable lens 3, data regarding the optical characteristics of the imaging optical system 360, and the like.

[0053] The receiving device (interchangeable lens 3 or camera body 2) can determine whether a communication error has occurred by checking whether the value calculated from the received data packets 406, 407 matches the data for communication error check contained in the data packets 406, 407.

[0054] When the transmission and reception of the data packets 406, 407 is completed, the first lens side communication unit 340a sets the RDY signal to H level, and the lens side control unit 330 starts the second control process 408 based on the data packets 406, 407 (t24).

[0055] (Explanation of the first and second control processes) Next, an example of the first control process 404 and the second control process 408 for command data communication will be described. For example, suppose the command packet 402 includes an instruction to drive the focusing lens 361a. As a first control process 404, the lens side control unit 330 generates a data packet 407 indicating that the instruction to drive the focusing lens 361a has been received.

[0056] Next, as second control processing 408, the lens side control unit 330 issues an instruction to the lens driving unit 370a to move the focusing lens 361a by the amount of movement indicated by the data packet 406. This causes the focusing lens 361a to start moving in the direction of the optical axis O. When the lens side control unit 330 issues an instruction to move the focusing lens 361a to the lens driving unit 370a, the lens side first communication unit 340a sets the RDY signal to L level, determining that the second control processing 408 has been completed (t25).

[0057] Also, for example, suppose the command packet 402 includes an instruction to start hotline communication. As a first control process 404, the lens-side control unit 330 generates a data packet 407 indicating that the instruction to start hotline communication has been received. Next, as a second control process 408, the lens-side control unit 330 causes the second lens-side communication unit 340b to start hotline communication. Once hotline communication has started, the first lens-side communication unit 340a sets the RDY signal to L level, indicating that the second control process 408 has been completed (t25).

[0058] Also, for example, assume that the command packet 402 includes a drive instruction for shake correction. As a first control process 404, the lens side control unit 330 generates a data packet 407 indicating that a drive instruction for the shake correction lens 361b has been received.

[0059] Next, as second control processing 408, the lens-side control unit 330 issues an instruction to the lens driver 370b to move the shake correction lens 361b based on the correction rate and shake correction control instruction indicated by the data packet 406 and the output of the shake sensor 390. This causes the shake correction lens 361b to start moving in a direction intersecting with the optical axis O. When the lens-side control unit 330 issues an instruction to the lens driver 370b to move the shake correction lens 361b, the lens-side first communication unit 340a sets the RDY signal to L level, determining that the second control processing 408 has been completed (t25).

[0060] <Hotline communication explanation> Next, hotline communication will be explained using Fig. 4. Fig. 4 illustrates the timing of the HCLK signal and HDATA signal. In one hotline communication, one HDATA signal 503 is transmitted from the interchangeable lens 3 to the camera body 2 in synchronization with one HCLK signal 502.

[0061] In camera system 1 according to this embodiment, prior to transmitting and receiving an instruction to start hotline communication, matters relating to hotline communication are determined in advance between interchangeable lens 3 and camera body 2. Matters relating to hotline communication include, for example, the data length (number of bytes) of the HDATA signal transmitted in one hotline communication, the data to be included in the HDATA signal and its order, the clock frequency and period of the HCLK signal (Tinterval in FIG. 4), and the communication time per period (Ttransmit in FIG. 4). In this embodiment, the frequency of the HCLK signal is 2.5 MHz, the data length of one hotline communication is longer than the command packet 402, the cycle of one hotline communication is 1 millisecond, and the communication time in one cycle is less than 75% of the transmission interval, but this is not limited to these.

[0062] Note that one hotline communication refers to data transmission carried out in one cycle of hotline communication, and is different from the period from the hotline communication start instruction to the hotline communication end instruction by command data communication from the camera body 2.

[0063] First, the operation of the second lens-side communication unit 340b in hotline communication will be described. When an instruction to start hotline communication is received by command data communication before time t31, the second lens-side communication unit 340b starts outputting an HCLK signal to the camera body 2 (t31). The HCLK signal is output periodically from the interchangeable lens 3, and is shown in Fig. 4 as HCLK signals 502, 502', ...

[0064] The second lens-side communication unit 340b outputs an HDATA signal in synchronization with the HCLK signal. The HDATA signal is indicated by switching between H level and L level. One HDATA signal has a predetermined data length, and in FIG. 4 is represented as N bytes, each of which contains 8 bits D0 to D7. One HDATA signal may include unused bit areas and unused byte areas to ensure a fixed length. Predetermined initial values ​​are input to the unused bit areas and unused byte areas. The HDATA signals are output periodically from the interchangeable lens 3 in synchronization with the HCLK signals 502, 502', ..., and are represented in FIG. 4 as HDATA signals 503, 503', ....

[0065] When the second lens side communication unit 340b completes transmission of the HDATA signal (t32), it stops outputting the HCLK signal until time t34, when it starts transmitting the next HDATA signal. The period from time t31 to t32 is considered one hotline communication, and the period from time t31 to t34 is considered one cycle of hotline communication. The second lens side communication unit 340b starts the second hotline communication from time t34. The second lens side communication section 340b continues the hotline communication periodically until an instruction to end the hotline communication is sent from the camera body 2 by command data communication.

[0066] The second lens side communication unit 340b transmits HDATA signals 503, 503', ... to the second body side communication unit 240b via a built-in serial communication unit. The second lens side communication unit 340b efficiently transfers data stored in a data area of ​​memory (not shown) as HDATA signals, for example, using a DMA (Direct Memory Access) function. The DMA function is a function that automatically accesses data in memory without CPU intervention.

[0067] Next, the operation of the body-side second communication unit 240b during hotline communication will be described. In this embodiment, the body-side second communication unit 240b waits in a receivable state when the initialization process at power-on is completed or when it determines that a command to start hotline communication will be sent via command data communication.

[0068] When the interchangeable lens 3 starts transmitting an HDATA signal and the body-side second communication unit 240b completes reception of a predetermined length of data (t32) within a predetermined time Terror0 from the start time t31 (time t33), the body-side second communication unit 240b determines that communication was successful and confirms the received data. The predetermined time Terror0 is a time that allows for some leeway in the communication time Ttransmit in one cycle, and may be 80% of one cycle, for example. After receiving one HDATA signal, the body-side second communication unit 240b remains in a wait state in which it is ready to receive, and begins receiving the next HDATA signal when one cycle has elapsed since time t31 (t34).

[0069] If the body side second communication unit 240b does not complete reception of a specified length of data within a specified time Terror0 after the lens side communication unit 340 starts transmitting the HDATA signal, the body side second communication unit 240b discards the received data, assuming that communication was not successful (a communication error). In hotline communication, it is preferable that the communication time (Ttransmit) in one cycle does not exceed 75% so that communication error processing can be performed between each cycle (between time t33 and t34), but this is not a limitation.

[0070] <Hotline Data> In one hotline communication, one piece of hotline data 90 is sent from the interchangeable lens 3 to the camera body 2. The hotline data 90 can include at least two types of information for each moving member: position information of the moving member and information different from the position information of the moving member. In this embodiment, the hotline data 90 includes first data 91 including position information of the focusing lens 361a and information that can be used to calculate the drive amount of the focusing lens 361a, and second data 92 including position information of the shake correction lens 361b and information that can be used to calculate the drive amount of the shake correction lens 361b. The information included in the first data 91 and the information included in the second data may be the same, or some of the information may be different. Furthermore, the camera body 2 may or may not use the information transmitted via hotline communication to calculate the drive amount of the movable members.

[0071] The information different from the position information of the movable member is information that can be used to calculate the drive amount of the movable member, and can be set for each movable member. For example, it includes at least one of the reliability of the position information, the movement state of the movable member, and the operation state of an operation member such as the indicator 375. The above information and conditions are expressed in the form of a numerical value or an identifier by the lens-side control unit 330, the second lens-side communication unit 340b, etc., and are included in the hotline data 90.

[0072] The position information indicating the position of the movable member indicates, when the movable member is a focusing lens 361a, the relative or absolute position of the focusing lens 361a in the direction of the optical axis O, and is, for example, the number of pulses of the actuator of the lens driving unit 370a or the detection value detected by the lens driving unit 370a. When the movable member is a shake correction lens 361b, the position information indicating the position of the movable member indicates the relative or absolute position of the shake correction lens 361b in a plane intersecting with the optical axis O, and is, for example, the coordinate value or movement amount of the optical axis O' of the shake correction lens 361b in the plane intersecting with the optical axis O.

[0073] The reliability of the location information is expressed by an identifier indicating whether the location information is valid or invalid, a numerical value indicating the reliability of the location information, or the like.

[0074] The movement state of the moving member is expressed by an identifier indicating whether the moving member is moving or not, an identifier indicating whether the moving member is in a state where it can move or not, an identifier indicating whether the moving member has stopped being driven or not, an identifier indicating whether the moving member has started being driven or not, an identifier indicating the movement direction of the moving member, etc.

[0075] The operation state of the operation member such as the indicator 375 is represented by an identifier indicating the vibration isolation mode indicated by the indicator 375, an identifier indicating the presence or absence of the indicator 375, or the like.

[0076] (Explanation of second data 92) FIG. 5 is a diagram illustrating information included in the second data 92. As shown in FIG. The second data 92 includes, for example, at least one of data 92h, 92i relating to the position of the shake correction lens 361b, data 92a to 92d relating to the shake state based on the detection signal from the shake sensor 390, data 92e, 92f relating to the shake correction amount or the reliability of the calculated shake amount, data 92g relating to the movement state of the shake correction lens 361b, and data 92q indicating an instruction by the instruction unit 375.

[0077] The data 92a to 92d relate to the shake state based on the detection signal from the shake sensor 390, and include an identifier selected by the lens side control unit 330 or the shake sensor 390 based on the detection signal from the shake sensor 390. The lens-side control unit 330 determines the shake state from the detection signal of the shake sensor 390. In this embodiment, the shake state is determined to be a state in which the composition is being changed, a state in which the composition is stable, a state in which the camera is fixed to a tripod, etc. The lens-side control unit 330 selects an identifier indicating whether the composition is being changed, an identifier indicating whether the composition is stable, or an identifier indicating whether the camera is fixed to a tripod, and includes each identifier in hotline data 90 before transmitting it to the camera body 2. For example, based on the angular shake detection signal in the X-axis direction output from the angular velocity sensor 390a, the lens side control unit 330 selects an identifier indicating whether or not the composition is being changed, an identifier indicating whether or not the composition is stable, and an identifier indicating whether or not the camera is fixed to the tripod, and sets these as data 92a. The data 92b differs from the data 92a in that the above determination is made in the Y-axis direction. The data 92c differs from the data 92a in that the above determination is made for translational shake. The data 92d differs from the data 92a in that the above determination is made for translational shake in the Y-axis direction. The body side control unit 230 can know the results of determining the shake state of the interchangeable lens 3 from the data 92a to 92d, and can match the shake state between the interchangeable lens 3 and the camera body 2.

[0078] The data 92g is related to the movement state of the shake correction lens 361b and includes an identifier selected by the lens side control unit 330. In this embodiment, shake control states include still image shake correction in progress, video shake correction in progress, and shake not being corrected. Shake not being corrected in progress refers to a state in which the lens driving unit 370b is not driven and shake correction is not being performed.

[0079] Still image stabilization in progress refers to a state in which shake correction appropriate for capturing a still image is being performed based on a still image stabilization start instruction and shutter speed sent from the camera body 2 by command data communication. "Video stabilization in progress" refers to a state in which shake correction appropriate for capturing video or live view images is being performed based on a video stabilization start instruction sent from the camera body 2 via command data communication. In this embodiment, the settings are such that the effect of shake correction is stronger during video shake correction than during still image shake correction during high-speed shooting. The body side control unit 230 can know the movement state of the shake correction lens 361b from the data 92g.

[0080] The data 92h and 92i relate to the position of the vibration correction lens 361b and are expressed as a numerical value indicating the position of the vibration correction lens 361b or a numerical value indicating the amount of movement of the vibration correction lens 361b. Data 92h indicates the current position of the optical axis O' of the shake correction lens 361b in the X-axis direction. In this embodiment, data 92h indicates coordinate values ​​in the X-axis direction detected within the interchangeable lens 3 converted into coordinate values ​​(image plane equivalent values) on the imaging plane 260S of the image sensor 260. The image plane equivalent values ​​are calculated by multiplying the coordinate values ​​of the shake correction lens 361b detected in the interchangeable lens 3 by a vibration reduction coefficient. The vibration reduction coefficient indicates the amount of movement of the image plane on the imaging plane 260S per unit movement amount of the shake correction lens 361b, and is a value that varies depending on the focal length and shooting distance of the imaging optical system 360, and is stored in the lens-side storage unit 350 or the like.

[0081] The lens-side control unit 330 reads from the lens-side storage unit 350 the image stabilization coefficient corresponding to the focal length and shooting distance when the coordinate values ​​of the shake correction lens 361b are detected, and calculates an image plane equivalent value. Calculating the image plane equivalent value in the interchangeable lens 3 has the advantage of eliminating the need to transmit the image stabilization coefficient corresponding to the focal length and shooting distance to the camera body 2, but it is also possible to transmit the value before image plane conversion via hotline communication.

[0082] The data 92i differs from the data 92h in that the above determination is made in the Y-axis direction. The data 92e and 92f include an identifier selected by the lens side control unit 330 based on the reliability of the data 92h to 92o, which relates to the reliability of the position information of the shake correction lens 361b and the reliability of the calculated shake amount and shake correction amount. In this embodiment, the data 92e and 92f indicate whether or not the data 92h to 92o are each valid, but this is not a limitation. The body side control unit 230 can know the reliability of the data 92h to 92o from the data 92e and 92f.

[0083] The data 92q indicates an instruction given by the instruction unit 375, and includes, for example, whether the instruction unit 375 is instructing a sports mode or a normal mode, or an identifier indicating the presence or absence of the instruction unit 375. In the case of an interchangeable lens 3 that does not have an instruction unit 375, the lens side control unit 330 includes, in the data 92q, an identifier indicating that the instruction unit 375 is not present.

[0084] <Explanation of image stabilization> Camera system 1 according to this embodiment is configured to be capable of performing lens-side shake correction by driving shake correction lens 361b with lens driving unit 370b, and body-side shake correction by driving image sensor 260 with sensor driving unit 265. Therefore, for example, lens-side shake correction and body-side shake correction can be used in conjunction with each other to improve the shake correction effect.

[0085] With lens-side and body-side shake correction, control can be changed as appropriate depending on the shake correction settings and the state of the shake. For example, the movable range of the shake correction lens 361b or the image sensor 260 (hereinafter referred to as the movable part) and the frequency band of the shake to be corrected can be changed depending on the state of shake. In the tripod-fixed state, a shake detection signal in a frequency band of around 10 Hz that is likely to occur when the camera is fixed to a tripod may be extracted and corrected. In the composition change state, the frequency band may be limited to a specific range or the movable range may be narrowed so as not to correct shake of the interchangeable lens 3 that is intended by the user due to a change in composition. In the composition stable state, the frequency band range may be wider than in the composition change state, and the movable range may be increased by matching it with the mechanical movable range, for example.

[0086] The frequency band of shake to be corrected and the movable range of the movable part can also be changed depending on the vibration reduction mode, shutter speed, etc. When the vibration reduction mode is the sports mode, the movable range can be narrowed to accommodate shooting at a faster shutter speed than in the normal mode. When the vibration reduction mode is the normal mode, the movable range can be made wider than in the sports mode to enhance the effect of vibration reduction.

[0087] Furthermore, the shake correction control may be changed between when capturing a still image and when capturing a moving image. When shooting video, the frequency band may be widened or the range of motion may be increased so that even large shakes can be corrected. When shooting still images, the frequency band range may be narrowed compared to when shooting video, thereby improving accuracy by removing noise, etc. In this embodiment, by sending one of two types of instructions, a still image stabilization start instruction or a video stabilization start instruction, from the camera body 2 to the interchangeable lens 3 via command data communication, it is possible for the interchangeable lens 3 to perform shake correction control appropriate for still images or videos.

[0088] The video stabilization start instruction includes a second correction rate (Gω2, Gα2) that indicates the share of shake correction in the interchangeable lens 3 (see FIG. 9). The second correction rate (Gω2, Gα2) indicates the shake correction rate of the interchangeable lens 3 when the interchangeable lens 3 and the camera body 2 work together to correct shake. The second correction rate (Gω2, Gα2) indicates the shake correction rate of the camera body 2, and the lens-side control unit 330 may calculate the shake correction rate of the interchangeable lens 3 so that when combined with the shake correction rate of the camera body 2, it amounts to 100%. The second correction rate (Gω2, Gα2) can be set separately for angular shake and translational shake. The second correction rate is the sum of the second correction rate Gω2 for angular shake correction and the second correction rate Gα2 for translational shake correction. The still image stabilization start instruction also includes a second correction factor that corresponds to the shutter speed. If the second correction factor changes due to a change in shutter speed, the second correction factor is changed and the still image stabilization start instruction is sent again from the camera body 2 to the interchangeable lens 3. The shutter speed corresponds to the accumulation time of the photoelectric conversion unit of the image sensor 260 or, if a mechanical shutter mechanism is provided, the drive speed of the shutter mechanism, and may be either an electrical shutter speed or a mechanical shutter speed. In this embodiment, the second correction factor corresponding to the shutter speed is sent from the camera body 2 to the interchangeable lens 3 via command data communication along with the instruction to start still image stabilization. However, it is also possible to store the second correction factor corresponding to the shutter speed in the interchangeable lens 3, and send information related to the shutter speed from the camera body 2 via command data communication. The camera body 2 may change the second correction rate depending on the shake correction settings (shake compensation mode and shake state). When the second correction rate changes, the camera body 2 again sends to the interchangeable lens 3 a video shake compensation start instruction or a still image shake compensation start instruction with the second correction rate changed.

[0089] <Calculating the target position for shake correction> 6, the calculation of the drive amount of the shake correction lens 361b by the lens side control unit 330 will be described. In this embodiment, the drive amount is the drive amount to the target position of the shake correction lens 361b required to correct shake, and is also called the total shake amount. Furthermore, the target position of the shake correction lens 361b is calculated as the drive amount. Similar to the lens-side control unit 330, the second body-side control unit 230b in the camera body 2 calculates the target position of the image sensor 260 as the amount of drive for shake correction.

[0090] The lens side control unit 330 calculates a target position LC1 for correcting angular velocity shake around the X axis based on the detection signal of the angular velocity sensor 390a, and a target position LC2 for correcting acceleration shake in the X axis direction based on the detection signal of the acceleration sensor 390b, and calculates a target position LC for correcting shake in the X axis direction of the shake correction lens 361b.

[0091] Although the above explanation only concerns the X axis, the lens side control unit 330 similarly calculates a target position LC1' for correcting angular velocity shake and a target position LC2' for correcting translational shake for the Y axis based on the detection signals of the angular velocity sensor 390a and the acceleration sensor 390b, and calculates a target position LC' for correcting shake in the Y axis direction. Because the operations for the X axis and Y axis are similar, only the X axis will be described below.

[0092] The lens side control unit 330 includes a filter unit 331, a first change unit 332, a second change unit 333, an integration unit 334, a first determination unit 335, a second determination unit 336, and a third determination unit 337. The shake angular velocity ω1 detected by the angular velocity sensor 390a is input to the filter unit 331. The filter unit 331 cuts out frequencies equal to or lower than a predetermined cutoff frequency fcω from the shake angular velocity ω1, and outputs the shake angular velocity ω2 to the first change unit 332. The first change unit 332 multiplies the shake angular velocity ω2 by a predetermined first angular shake compensation rate Gω1 and outputs the shake angular velocity ω3 to the second change unit 333. The second change unit 333 multiplies the shake angular velocity ω3 by a predetermined second angular shake compensation rate Gω2 and outputs the shake angular velocity ω4 to the integration unit 334. The integration unit 334 integrates the shake angular velocity ω4 and outputs a target position LC1 of the shake compensation lens 361b for correcting the angular shake.

[0093] The first determination unit 335 receives the detection signal (shake angular velocity ω1) output from the angular velocity sensor 390a and determines the lens-side shake state related to the angular shake occurring in the interchangeable lens 3. In this embodiment, the shake state may be at least one of the following: whether or not the interchangeable lens 3 is in a composition change state, whether or not the interchangeable lens 3 is in a composition stabilized state, and whether or not the interchangeable lens 3 is in a tripod-fixed state. The composition change state is a state in which the user is changing the composition by swinging the interchangeable lens 3 horizontally or vertically. The composition stabilized state is a state in which the user has fixed the position of the interchangeable lens 3 and the composition is stabilized. The tripod-fixed state is a state in which the interchangeable lens 3 or the camera body 2 is fixed to a tripod.

[0094] The lens-side vibration state determined by the first determination unit 335 is input to the second determination unit 336. In addition, the lens-side vibration state determined by the first determination unit 335 is transmitted to the camera body 2 by hotline communication, which will be described later.

[0095] Here, the body-side second control unit 230b determines the body-side shake state related to angular shake occurring in the camera body 2 based on the detection signal of the angular velocity sensor 290a. The body-side second control unit 230b determines the shake state as a lens-side priority state in addition to a composition changing state, a composition stable state, and a tripod fixed state, similar to those of the lens-side control unit 330. The lens-side priority state is a state in which, due to user settings or the like, the determination of the interchangeable lens 3 is given priority when the determinations of the interchangeable lens 3 and the camera body 2 regarding the shake state do not match.

[0096] The body side shake state determined by the body side second control unit 230b is transmitted to the lens side control unit 330 by command data communication, which will be described later, and input to the second determination unit 336. Therefore, the lens side shake state and the body side shake state are input to the second determination unit 336. The second determination unit 336 determines the total shake state for angular shake based on the lens side shake state and the body side shake state.

[0097] As shown in FIG. 7, the second determination unit 336 determines the lens side shake state as a total shake state when the body side shake state is a lens side priority state, and determines the body side shake state as a total shake state when the body side determination result is other than a lens side priority state.

[0098] The second determination unit 336 stores the relationship between the total shake state for angular shake, the threshold value, and the coefficient (FIG. 8), and outputs the cutoff frequency fcω corresponding to the total shake state for angular shake to the filter unit 331, and outputs the first correction factor Gω1 to the first change unit.

[0099] The second change section 333 receives as input the second correction factor Gω2 determined by the body side first control section 230a and transmitted by command data communication.

[0100] In this embodiment, the second correction factor of the camera body 2 and the second correction factor of the interchangeable lens 3 are set so that the sum of them is 1. As shown in FIG. 9, the body-side first control unit 230a stores the relationship between still image / video stabilization, shutter speed, and second correction factor. In this embodiment, the second correction factor in the X-axis direction and the second correction factor in the Y-axis direction are the same, but this is not limited to this. Furthermore, the second correction factor Gω2 for angular shake and the second correction factor Gα2 for translational shake are also the same, but this is not limited to this. In this embodiment, when the shutter speed is fast, the interchangeable lens 3 performs shake correction suitable for high-speed shooting, and when the shutter speed is not fast, the interchangeable lens 3 and the camera body 2 work together to perform shake correction, thereby increasing the effect of shake correction.

[0101] Therefore, when using still image stabilization and the shutter speed is faster than, for example, 1 / 60 second, the second correction factor of the interchangeable lens 3 is set to 1 and the second correction factor of the camera body 2 is set to 0. Also, when using video stabilization or still image stabilization and the shutter speed is slower than, for example, 1 / 60 second, the second correction factor of the interchangeable lens 3 is set to 0.5 and the second correction factor of the camera body 2 is set to 0.5. The second correction factor can be changed as appropriate, and if the camera body 2 does not have a shake correction function, the second correction factor of the interchangeable lens 3 is set to 1 and the second correction factor of the camera body 2 is set to 0.

[0102] Furthermore, if the interchangeable lens 3 has a rotational shake compensation function but not a translational shake compensation function, the second correction rate for rotational shake is set as described above, and for translational shake, the second correction rate for the interchangeable lens 3 is set to 0, and the second correction rate for the camera body 2 is set to 1. The second correction rate may also be adjusted depending on the accuracy of the shake compensation functions of the camera body 2 and the interchangeable lens 3. Although the second correction rate is transmitted from the camera body 2 to the interchangeable lens 3 in command data communication instructing the start of image stabilization, it is also possible to provide correction rate change command data communication and transmit the rate each time it is changed after image stabilization has started.

[0103] The third determination unit 337 receives instructions regarding shake correction sent by command data communication from the body-side first control unit 230a. The instructions regarding shake correction sent from the camera body 2 include whether the shake correction control is video shake correction or still image shake correction, and whether the shake correction mode is sports mode, normal mode, or lens-side priority mode. The third determination unit 337 also receives an input from the instruction unit 375 of the shake correction mode set by the user.

[0104] The third determination unit 337 stores the relationship between shake correction instructions (still image / video shake reduction, shake reduction mode) and thresholds (frequency band, cutoff frequency fc_inteω) shown in Figure 10, and outputs the corresponding cutoff frequency fc_inteω to the integrating unit 334. In this embodiment, the cutoff frequency fc_inteω in sports mode is set to be higher than the cutoff frequency fc_inteω in normal mode, but this is not limited to this. The integrating unit 334 integrates based on the shake angular velocity ω4 and the cutoff frequency fc_inteω, and calculates a target position LC1 for angular shake.

[0105] The lens side control unit 330 calculates the translational shake target position LC2 required to correct the translational shake, in the same way as calculating the angular shake target position LC1 required to correct the shake angular velocity, and calculates the final target position LC by adding and subtracting LC1 and LC2.

[0106] Here, the following describes the differences between the calculation of the translational shake target position LC2 and the calculation of the rotational shake target position LC1 by the lens side control unit 330. Note that although the components 331 to 337 that calculate the rotational shake target position LC1 and the components 331 to 337 that calculate the translational shake target position LC2 are described as being the same, this is not necessarily the case.

[0107] The shake acceleration α1 detected by the acceleration sensor 390b is input to the filter unit 331. The filter unit 331 cuts off frequencies equal to or lower than a predetermined cutoff frequency fcα and outputs the shake acceleration α2 to the first change unit 332. The first change unit 332 multiplies the shake acceleration α2 by a predetermined first correction factor Gα1 for translational shake and outputs the shake acceleration α3 to the second change unit 333. The second change unit 333 multiplies the shake acceleration α3 by a predetermined second translational shake correction factor Gα2 and outputs the shake acceleration α4 to the integration unit 334. The integration unit 334 integrates twice based on the shake acceleration α4 and the cutoff frequency fc_inteα and outputs the target position LC2 for correcting the translational shake of the shake correction lens 361b.

[0108] The second determination unit 336 stores the relationship between the total shake state, cutoff frequency fcα, and first correction factor Gα1 for translational shake (FIG. 11), and outputs the cutoff frequency fcα corresponding to the total shake state to the filter unit 331 and outputs the first correction factor Gα1 to the first change unit 332.

[0109] The second change section 333 receives as input the second correction factor Gα2 for translational shake that has been determined by the body side first control section 230a and transmitted by command data communication. 12, and outputs the corresponding cutoff frequency fc_inteα to the integrating unit 334. In this embodiment, the cutoff frequency fc_inteα at the translational shake target position LC2 is set to be greater than the cutoff frequency fc_inteω at the rotational shake target position LC1, but this is not limited to the above.

[0110] Next, the calculation of the target position BC1 of the image sensor 260 for correcting rotational shake and the target position BC2 of the image sensor 260 for correcting acceleration shake by the body-side second control unit 230b will be described in terms of differences from the calculation of the target positions LC1, LC2 by the lens-side control unit 330. Note that, although the explanation will be given using the components 331 to 337 as the components for calculating the target positions BC1, BC2, these components may be different from the components of the lens-side control unit 330.

[0111] Furthermore, in this embodiment, the body side second control unit 230b includes a filter unit 331, a first change unit 332, a second change unit 333, and an integration unit 334, and the body side first control unit 230a includes a first judgment unit 335, a second judgment unit 336, and a third judgment unit 337, and transmits the judgment results to the body side second control unit 230b, but this can be modified as appropriate.

[0112] The body side second control unit 230b outputs target positions BC1 and BC2 based on the shake angular velocity ω1, shake acceleration α1, cutoff frequencies fcω, fcα, first correction factors Gω1, Gα1, body side second correction factors Gω2, Gα2, and cutoff frequencies fc_inteω, fc_inteα detected by the shake velocity sensors 290a, 290b. The same applies to the X-axis and Y-axis.

[0113] The first determination unit 335 of the body-side first control unit 230a determines the body-side shake state for each of rotational shake and angular velocity shake, based on the output of the shake sensor 290. Furthermore, the second determination unit 336 of the body-side first control unit 230a determines the total shake state based on the body-side shake state and the lens-side shake state transmitted by hotline communication from the interchangeable lens 3, and determines the cutoff frequencies fcω, fcα, and the first correction factors Gω1, Gα1. The determination method is the same as that of the lens-side control unit 330.

[0114] Furthermore, the third determination unit 337 of the body-side first control unit 230a determines the cutoff frequencies fc_inteω and fc_inteα based on information as to whether video or still image shooting is in progress recognized by the body-side first control unit 230a, the body-side image stabilization mode, and the lens-side image stabilization mode transmitted by hotline communication from the interchangeable lens 3. The determination method is the same as that of the lens-side control unit 330.

[0115] In this embodiment, the variables and thresholds (first correction rate, cutoff frequency) used to calculate the target positions LC and BC are the same for the camera body 2 and the interchangeable lens 3. This makes it possible to suppress any sense of incongruity in the shake correction effect that occurs when the first correction rate or cutoff frequency does not match between the camera body 2 and the interchangeable lens 3. Note that the coefficients and thresholds may differ to the extent that no sense of incongruity in the shake correction effect occurs between the camera body 2 and the interchangeable lens 3.

[0116] Furthermore, with regard to the second correction rate, the sum of the lens-side second correction rate (the interchangeable lens 3's share of shake correction) and the body-side second correction rate (the camera body 2's share of shake correction) is set to 1 (or 100%). Therefore, by having the shake correction in the interchangeable lens 3 and the shake correction in the camera body 2 work together, it is possible to improve the effectiveness of shake correction without excessively performing shake correction or suppressing it too much.

[0117] Although the second determination unit 336 is provided in both the lens-side control unit 330 and the second body-side control unit 230b, the total shake state may be transmitted by command data communication from the camera body 2 to the interchangeable lens 3. In that case, it is possible to omit transmission of the lens-side shake state from the first determination unit 335 to the second determination unit 336 in the lens-side control unit 330, and the second determination unit 336 does not need to store or refer to the correspondence in Figure 7.

[0118] 8 and 11 are provided with the second determination unit 336, but the cutoff frequency and first correction rate may be transmitted by command data communication from the camera body 2 to the interchangeable lens 3. In that case, there is no need for the lens-side control unit 330 to transmit the lens-side shake state from the first determination unit 335 to the second determination unit 336, and the second determination unit 336 may also be omitted.

[0119] Similarly, although the third determination unit 337 is provided in both the lens-side control unit 330 and the body-side second control unit 230b to determine the cutoff frequency of the integrator 334 in Figures 10 and 12, the cutoff frequency may be transmitted and received between the camera body 2 and the interchangeable lens 3. In this case, it is possible to omit the determination of the cutoff frequency in either the lens-side control unit 330 or the body-side second control unit 230b.

[0120] The lens-side control unit 330 may further read the image-plane equivalent coefficient at the time the detection signal is output, and calculate an image-plane equivalent value of the target position LC based on the total amount of shake and the image-plane equivalent coefficient. In this case, the lens-side control unit 330 calculates the image-plane equivalent value without considering the drive range (mechanical movable range and controlled movable range) of the shake correction lens 361b. Here, the mechanical movable range refers to the movable range based on the holding mechanism of the shake correction lens 361b, and the controlled movable range refers to the movable range limited by the user's settings and shooting conditions.

[0121] The lens side control unit 330 also calculates the target position of the shake correction lens 361b in the X-axis direction and the Y-axis direction, taking into account the mechanical range of movement and the controlled range of movement. The movement amount may be calculated as the difference (difference in coordinate values) between the target position and the current position in the X-axis direction and the Y-axis direction.

[0122] The lens side control unit 330, which has calculated the movement amount or target position of the shake correction lens 361b, outputs a drive signal to the lens drive unit 370b to drive the shake correction lens 361b. Upon receiving the drive signal, the lens drive unit 370b moves the shake correction lens 361b in the X-axis and Y-axis directions that intersect with the optical axis O.

[0123] Furthermore, lens driving unit 370b periodically detects the positions of shake correction lens 361b in the X-axis direction and Y-axis direction, and outputs this as the current position to lens side control unit 330. Lens side control unit 330 may use the values ​​output from lens driving unit 370b as data 92h, 92i as is, or may use values ​​that have been calculated using image plane conversion or the like as data 92h, 92i.

[0124] The body-side second control unit 230b creates a drive signal based on at least one of the position information of the shake correction lens 361b received via hotline communication, instructions from the body-side first control unit 230a, and the detection signal output from the shake sensor 290, and outputs the drive signal to the sensor drive unit 265. Upon receiving the drive signal, the sensor drive unit 265 moves the image sensor 260 in the X-axis and Y-axis directions that intersect with the optical axis O.

[0125] An example of the vibration reduction operation will be described below with reference to FIGS. <Anti-shake operation during video recording> FIG. 13 is a timing chart showing the state of shake correction when shooting video. While there are actually timing charts for two axes, the X-axis and the Y-axis, the operation for only one axis is shown here because the X-axis and Y-axis are nearly identical. Also, FIGS. 13 and 14 illustrate angular shake, and translational shake is omitted because it is similar. Also, in FIGS. 13 and 14, it is assumed that the lens-side priority state is selected as the body-side shake state. It is also assumed that there is no change in the shake correction mode, so it is omitted.

[0126] At time t1, the body side first control unit 230a recognizes that a start switch such as a main switch has been turned on. At time t2, the body-side first control unit 230a instructs the lens-side control unit 330 to start shake detection via command data communication, and also instructs the body-side second control unit 230b to start shake detection. In accordance with this instruction, the shake sensors 290, 390 start detecting shake, and output detection signals from time t3. The body-side second control unit 230b and lens-side control unit 330 determine the shake state based on the detection signal, and determine the determination results as a lens-side shake state and a body-side shake state, respectively.

[0127] It is assumed that the body-side first control unit 230a has instructed the start of hotline communication by command data communication before time t4. The lens-side control unit 330 has been periodically outputting hotline data 90 since before time t4, and in Figure 13, hotline communication is taking place at times t4, t4', and other times.

[0128] The body-side first control unit 230a recognizes the lens-side shake state from data 92a to 92d of the hotline data 90. At approximately the same time, the body-side first control unit 230a also acquires at least the body-side shake state from the body-side second control unit 230b. At time t4, both the interchangeable lens 3 and the camera body 2 are determined to be in a stable composition state (indicated by the black circles in FIG. 13).

[0129] At time t5, the body-side first control unit 230a instructs the lens-side control unit 330 to start video stabilization and also instructs the body-side second control unit 230b to start video stabilization via command data communication. The video stabilization start instruction via command data communication includes the body-side stabilization mode, the body-side shake state, and the second correction rate.

[0130] Here, hotline communication starts at time t5, and the body-side first control unit 230a recognizes the lens-side image stabilization mode from hotline communication data 92q sent at time t4. Taking into account the lens-side image stabilization mode and the body-side image stabilization mode set using the operation member 280 or the like, the body-side first control unit 230a sends the body-side image stabilization mode to the lens-side control unit 330 via command data communication at time t5.

[0131] Furthermore, at time t4, the body-side first control unit 230a recognizes from data 92a of the hotline data 90 that the lens-side shake state for angular shake is in a composition stable state (indicated by a black circle in FIG. 13). Because the lens-side shake state is in a composition stable state and the body-side shake state is in a lens-side priority state, the body-side first control unit 230a transmits to the lens-side control unit 330, via command data communication at time t5, that the total shake state for angular shake is in a composition stable state. Here, at time t4, the body-side shake state for angular shake based on the detection signal of the shake sensor 290 is also in a composition stable state. Therefore, even at time t4, the shake states of the camera body 2 and the interchangeable lens 3 can be made to match.

[0132] In addition, the body-side first control unit 230a determines the second correction factor Gω2 based on the settings at time t5 and Figure 9, and transmits the lens-side second correction factor Gω2 to the lens-side control unit 330 in command data communication at time t5, and at the same time transmits the body-side second correction factor Gω2 to the body-side second control unit 230b.

[0133] Upon receiving the video stabilization start instruction at time t5, the lens side control unit 330 or the second body side control unit 230b calculates the target position of the movable unit, and from time t6, the lens drive unit 370b or the sensor drive unit 265 drives the movable unit to start shake correction. In the example of Figure 13, before time t5, the drive of the movable unit is stopped and it is in a state of falling in the direction of gravity. Upon receiving the instruction at time t5, the movable unit is temporarily driven to the center of movement, and shake correction is performed from time t6 onwards.

[0134] In this way, the body-side first control unit 230a periodically acquires the hotline data 90, and is therefore able to recognize changes in the lens-side vibration reduction mode or the lens-side shake state from the hotline data 90. When the body-side first control unit 230a recognizes from the hotline data 90 that the lens-side vibration reduction mode or the lens-side shake state has changed, it performs command data communication as necessary, so as to synchronize the shake correction control of the camera body 2 and the interchangeable lens 3.

[0135] The command data communication at time t5' will be described. 13, suppose that the user operates the interchangeable lens 3 to change the composition. The first determination unit 335 of the lens-side control unit 330 then determines that the lens-side vibration state is in the composition-changing state. Then, in hotline communication (time t4') that takes place after time t7, hotline data 90 is transmitted that includes data 92a indicating that the lens-side vibration state is in the composition-changing state. Meanwhile, the detection result of the vibration sensor 290 of the camera body 2 continues to indicate that the composition is stable.

[0136] 13, the lens-side priority state has been selected as the body-side shake state, so the body-side first control unit 230a transmits in command data communication at time t5' that the total shake state is the lens-side priority state, and at the same time transmits the lens-side shake state (composition changing state) to the body-side second control unit 230b. When the lens-side control unit 330 receives in command data communication at time t5' that the total shake state is the lens-side priority state, the second determination unit 336 determines that the total shake state is the composition changing state, and starts shake correction in the composition changing state at time t5'. Furthermore, the body-side second control unit 230b also receives that the total shake state is the composition changing state, and starts shake correction in the composition changing state at time t5'.

[0137] In this way, the lens-side shake state can be transmitted from the interchangeable lens 3 through periodic hotline communication at times t4 and t4', and therefore the camera body 2 does not need to perform command data communication including an instruction to transmit the lens-side shake state from the interchangeable lens 3 to the camera body 2. Furthermore, when performing command data communication including an instruction to transmit the lens-side shake state from the interchangeable lens 3 to the camera body 2, it is necessary to perform command data communication periodically, and if this period is longer than that of hotline communication, there is a problem that the time during which the lens-side shake state and the body-side shake state do not match will become longer.

[0138] Furthermore, if command data communication including an instruction to transmit the lens-side vibration state from the interchangeable lens 3 to the camera body 2 is attempted to be performed at a fast cycle, there is a problem that other command data communication cannot be performed during that time. However, according to this embodiment, the vibration state and the like are transmitted via hotline communication that is independent of command data communication, which has the advantage of eliminating the above-mentioned problem.

[0139] <Anti-shake operation when taking still images> Figure 14 is a timing chart showing the state of shake correction when taking a still image, and includes the through image exposure before and after the release operation that commands still image shooting. Also, although there are actually two axes, the X axis and the Y axis, the X axis and the Y axis are similar, so only the operation of one axis is shown.

[0140] After time t1, the above-mentioned hotline communication is performed periodically. At time t2, the above-mentioned video stabilization start instruction is sent by command data communication from the camera body 2 to the interchangeable lens 3. In Figure 14, the lens side priority state is selected for the body side shake state.

[0141] At time t2, the user operates the interchangeable lens 3 to change the composition, and a shake state in which the composition is being changed is detected by both the interchangeable lens 3 and the camera body 2. Therefore, in video stabilization from time t2 onwards, the composition is being changed state is selected as the total shake state.

[0142] At time t3, when the user stops the composition change operation of the interchangeable lens 3, data 92a indicating a stable composition state as a lens-side vibration state is transmitted in the next hotline communication (time t4).

[0143] On the other hand, at time t4, the detection result of vibration sensor 290 continues to detect a composition change state, which does not match the detection result of vibration sensor 390. Also, it is assumed that the user performs an operation to capture a still image at time t5.

[0144] At time t5, the body side first control unit 230a recognizes that the release switch has been turned on by the operation member 280. At time t6, the body side first control unit 230a operates the image sensor 260 to stop creating a through image.

[0145] At time t7, the body-side first control unit 230a instructs the lens-side control unit 330 to start still image stabilization by command data communication, and also instructs the body-side second control unit 230b to start still image stabilization. Between time t7 and time t9, shake correction control suitable for still image shooting is performed.

[0146] The still image stabilization start instruction at time t7 can include the body side stabilization mode, the body side angular shake state (lens side priority state), and the second correction rate, just like the video stabilization start instruction. The body side first control unit 230a determines that the total shake state is a stable composition state because the data 92a from the hotline communication (time t4) immediately before time t7 indicates that the lens side shake state is a stable composition state and that the body side shake state is a lens side priority state.

[0147] Therefore, at time t7, the still image stabilization start instruction to the interchangeable lens 3 includes the lens side priority state, and the still image stabilization start instruction to the body side second control unit 230b includes the composition stable state as the total shake state.

[0148] In addition, the body side first control unit 230a determines the second correction factor Gω2 based on the settings at time t7 and Figure 9, and transmits the lens side second correction factor Gω2 to the lens side control unit 330 and the body side second correction factor Gω2 to the body side second control unit 230b in command data communication at time t7. In response to this instruction, the lens-side control unit 330 operates the lens driving unit 370b to drive the shake correction lens 361b, thereby starting shake correction suitable for still images. The same is true for the second body-side control unit 230b.

[0149] The body side first control unit 230a starts still image exposure by the image sensor 260 at time t8, ends still image exposure at time t9, and resumes live image exposure at time t12. When exposure is complete, the body-side first control unit 230a instructs the lens-side control unit 330 to start video stabilization via command data communication, thereby restarting video stabilization (time t10). The body-side first control unit 230a also instructs the body-side second control unit 230b to start video stabilization, just like the interchangeable lens 3.

[0150] When exposure ends, the lens side control unit 330 resumes hotline communication at time t11. Note that hotline communication may also be continued between time t8 and time t11.

[0151] At time t13, the user performs a composition change operation, and a composition changing state is detected from the detection result of the shake sensor 390 of the interchangeable lens 3. Meanwhile, a composition stable state is detected from the detection result of the shake sensor 290 of the camera body 2. In FIG. 14, the lens side priority state is set as the body side shake state, so at time t14 the body side first control unit 230a transmits to the interchangeable lens 3 via command data communication that it is in the lens side priority state, and also transmits the lens side shake state (composition changing state) received via hotline communication to the body side second control unit 230b as the total shake state. From time t14, the lens side control unit 330 and the body side second control unit 230b perform shake correction control with the total shake state set to the composition changing state.

[0152] As described above, even if the lens-side vibration state and the body-side vibration state do not match, the lens-side vibration state can be transmitted to the camera body 2 via hotline communication, thereby shortening the time during which the vibration states of the camera body 2 and the interchangeable lens 3 do not match.

[0153] According to the above-described embodiment, the following effects can be obtained. Since the shake correction sharing ratio between the interchangeable lens 3 and the camera body 2 is transmitted and received, the shake correction of the interchangeable lens 3 and the camera body 2 can be coordinated in the camera system 1 to improve the shake correction effect. Furthermore, since the sharing ratio between the interchangeable lens 3 and the camera body 2 can be set, it is possible to prevent the interchangeable lens 3 or the camera body 2 from over-performing or over-suppressing shake correction. Furthermore, since the correction rate can be set by the body-side control unit 230, shake correction can be performed according to shooting conditions such as whether still image or video is being shot and the shutter speed. Furthermore, the sharing ratio can be set separately for rotational shake and translational shake, so that the camera body 2 and the interchangeable lens 3 can cooperate even if the interchangeable lens 3 has a rotational shake correction function but not a translational shake correction function. Furthermore, since the sharing ratio is transmitted via command data communication, the timing of transmission from the camera body 2 can be determined, and hotline communication can also be performed in parallel. Furthermore, since the body-side first control unit 230a transmits the body-side share ratio to the body-side second control unit 230b and transmits the lens-side share ratio to the lens-side control unit 330, the body-side second control unit 230b and the lens-side control unit 330 can easily perform control based on their respective share ratios.

[0154] The camera body 2 transmits to the interchangeable lens 3 body-side information based on information used to calculate the target position of the movable part from the detection signal of the shake sensor 309, so the information used to calculate the target position can be consistent between the camera body 2 and the interchangeable lens 3. Information used to calculate the target position includes information related to the threshold value of the frequency band for correcting shake, such as the cutoff frequency, and information related to the strength of the shake correction effect, such as the first correction rate.

[0155] Here, if the information used to calculate the target position is the same between the camera body 2 and the interchangeable lens 3, for example, the shake state detection results can be matched, and the shake correction frequency band or the movable range of the shake correction movable part can be changed to improve the shake correction effect. Furthermore, because the shake state is transmitted from the interchangeable lens 3 to the camera body 2 via hotline communication, the time during which the shake state does not match between the interchangeable lens 3 and the camera body 2 can be shortened. If the shake state were not transmitted via hotline communication but instead transmitted from the interchangeable lens 3 to the camera body 2 via command data communication only, the time it takes for the camera body 2 to recognize the detection result of the shake state on the lens side would be delayed, increasing the time during which the detection results between the interchangeable lens 3 and the camera body 2 differ, resulting in a poor user experience (uncomfortable feeling) regarding the viewfinder image and through-the-lens image during shake correction. However, in this embodiment, the time during which the detection results differ between the interchangeable lens 3 and the camera body 2 can be shortened.

[0156] The lens side second communication unit 340b can also periodically transmit hotline data 90 at a shorter period than the period for receiving instructions from the camera body 2 via command data communication, and can instantly transmit information used for shake correction control regardless of the timing or duration of command data communication. In addition, the vibration sensor 390 can periodically output a detection signal at a cycle shorter than that of hotline communication, which eliminates the need to consider the difference between the timing of output of the hotline data 90 and the timing of output of the detection signal from the vibration sensor 390, thereby improving the immediacy of the hotline data 90.

[0157] The interchangeable lens 3 can also transmit the reliability of the numerical values ​​included in the hotline data 90 (validity of the position information, validity of the lens side shake state, etc.), so that the numerical values ​​and their reliability can be associated with each other in a single hotline communication and transmitted to the camera body 2, allowing the camera body 2 to take action according to the reliability.

[0158] The interchangeable lens 3 periodically transmits fixed-length hotline data 90 to the camera body 2, and therefore, unlike when variable-length data is transmitted, transmission can be repeated at regular intervals.

[0159] The present invention is not limited to the above-described contents, and other embodiments conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention.

[0160] (Variation 1) In the above description, an example has been described in which the DMA function is used in hotline communication. Instead of using the DMA function, the hotline data 90 may be generated through software intervention. In Modification 1, the HDATA signal is transmitted by the second lens-side communication unit 340b, and the hotline data 90 is generated by the lens-side control unit 330. With this configuration, hotline communication and the generation of hotline data 90 can be performed in parallel without using the DMA function. However, the generation of hotline data 90 is performed within a period not exceeding one cycle of hotline communication.

[0161] (Variation 2) In the above explanation, an example has been described in which the body side control unit 230 is divided into the first body side control unit 230a and the second body side control unit 230b, but it is also possible to configure it as a single body side control unit 230 without dividing it into the first body side control unit 230a and the second body side control unit 230b. In this case, the body side control unit 230 only needs to directly control the sensor drive unit 265, and the communication line via the second body side communication unit 240b only needs to be connected to one body side control unit 230.

[0162] 4 shows an example in which the data transfer direction of clock-synchronized communication using only two signal lines, the HCLK signal line and the HDATA signal line, is unidirectional, from the interchangeable lens 3 to the camera body 2, but it is also possible to add one more signal line to enable bidirectional data transfer. Alternatively, it is also possible to configure the HDATA signal line to be switchable between input and output, thereby enabling bidirectional data communication.

[0163] Hotline communication is not limited to clock synchronous communication, and UART (start-stop synchronous communication) may also be used. Furthermore, in addition to the clock signal line and data signal line, a handshake signal line or a CS (chip select) signal line may be added so that the lens side control unit 330, the first body side control unit 230a, and the second body side control unit 230b can synchronize their communication start timing.

[0164] (Variation 3) The camera body 2 may be configured to omit the sensor driving unit 265 that drives the image sensor 260 in a direction intersecting the optical axis O, and perform shake correction by moving the position of the image through image processing performed by the signal processing unit 270. Alternatively, the camera body 2 may perform shake correction by the sensor driving unit 265 and shake correction by the signal processing unit 270 together.

[0165] (Variation 4) The interchangeable lens 3 and the camera body 2 may be configured to share shake correction depending on the shake component. For example, the interchangeable lens 3 may share angular shake about the X-axis and Y-axis and translational shake about the X-axis and Y-axis, and the camera body 2 may share shake about the optical axis O (roll component).

[0166] (Variation 5) Although the lens-side shake state and lens-side stabilization mode are transmitted to the camera body 2 via hotline communication, they may also be transmitted via command data communication. In this case, the format used for transmission via hotline data communication may differ from the format used for transmission via command data communication. [Explanation of symbols]

[0167] 1: camera system, 2: camera body, 3: interchangeable lens, 230: body side control unit, 230a: first body side control unit, 230b: second body side control unit, 235: memory unit, 240: body side communication unit, 240a: first body side communication unit, 240b: second body side communication unit, 250: power supply unit, 260: image sensor, 260S: image pickup surface, 265: sensor drive unit, 270: signal processing unit, 280: operation member, 285: display unit, 290: sensor, 290a: angular velocity sensor, 290b: acceleration sensor, 309: sensor, 330: lens side control unit, 331: filter unit, 332: first change unit, 333: second change unit, 334: integration unit, 335: first Determination unit, 336: second determination unit, 337: third determination unit, 340: lens side communication unit, 340a: lens side first communication unit, 340b: lens side second communication unit, 350: lens side memory unit, 360: imaging optical system, 361a: focusing lens, 361b: correction lens, 370: lens driving unit, 370a: lens driving unit, 370b: lens driving unit, 375: instruction unit, 390: sensor, 390a: angular velocity sensor, 390b: acceleration sensor, 401: clock signal, 402: command packet, 404: first control processing, 405: signal, 406: data packet, 407: data packet, 408: second control processing, 502: signal, 503: signal

Claims

[Claim 1] A camera body to which a camera accessory having a lens and forming a subject image can be attached, a first communication unit that transmits and receives information to and from the camera accessory; a second communication unit for receiving information from the camera accessory; Equipped with the first communication unit transmits, to the camera accessory, information indicating a ratio of shake correction performed by the camera accessory and the camera body when shake correction is performed by the camera accessory, the second communication unit receives information about the position of the lens from the camera accessory; The instruction to start communication from the second communication unit is transmitted to the camera body via the first communication unit.

Images