Camera body, camera accessories, camera system and communication methods

Abstract

This invention provides a camera body, a camera accessory, a camera system, and a communication method. The camera body has a shake-correcting lens and is capable of mounting a camera accessory that forms an image of a subject. The camera body includes: a first communication unit for transmitting and receiving information with the camera accessory; and a second communication unit for receiving information from the camera accessory. The first communication unit sends an instruction to the camera accessory indicating the start of communication by the second communication unit. The second communication unit receives from the camera accessory first information related to the position of the shake-correcting lens and second information indicating shake of the camera accessory.

Description

[0001] This application is a divisional application of the invention patent application filed on July 12, 2019, with international application number PCT / JP2019 / 027747, national application number 201980047953.4, and entitled "Camera Accessory and Information Transmission Method". Technical Field

[0002] This invention relates to camera accessories and information transmission methods. Background Technology

[0003] There is a known technology that sends information indicating the state of an interchangeable lens to the camera body (see Patent Document 1). However, if the information sent is inappropriate, the performance of shake correction is reduced.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-105402 Summary of the Invention

[0007] According to a first aspect of the present invention, a camera accessory is detachable from a camera body, comprising: a correction optical system movable in a direction intersecting an optical axis; and a first communication unit that transmits first information relating to the position of the correction optical system and second information relating to the shake of the camera accessory to the camera body.

[0008] According to a second aspect of the present invention, an information transmission method is a method for transmitting information between a camera accessory that can be attached to or detached relative to a camera body and the camera body, wherein the method includes: transmitting first information related to the position of a correction optical system and second information related to the shaking of the camera accessory between the camera body and the camera accessory, wherein the correction optical system is movable in a direction intersecting the optical axis. Attached Figure Description

[0009] Figure 1 It is a block diagram illustrating the main structural components of a camera system.

[0010] Figure 2 This is a timing diagram illustrating command data communication and hotline communication.

[0011] Figure 3 This is a diagram illustrating command data communication.

[0012] Figure 4 This is a diagram illustrating hotline communication.

[0013] Figure 5 This is a diagram illustrating the information contained in the hotline data.

[0014] Figure 6 This is an example of an image representing image stabilization. Detailed Implementation

[0015] The following description, with reference to the accompanying drawings, illustrates the methods for carrying out the invention.

[0016] Figure 1 This is a block diagram illustrating the main structural components of camera system 1. In this embodiment, camera system 1 has an interchangeable lens 3 detachably mounted on the camera body 2. Figure 1 In the diagram, the optical axis O of the interchangeable lens 3 and the X-axis and Y-axis directions in the plane intersecting the optical axis O are represented by lines.

[0017] <Camera Body>

[0018] The camera body 2 includes a body-side control unit 230, a body-side communication unit 240, a power supply unit 250, an imaging element 260, a sensor drive unit 265, a signal processing unit 270, an operation member 280, a shake 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 imaging element 260, the sensor drive unit 265, the signal processing unit 270, the operation member 280, and the shake sensor 290.

[0019] The imaging element 260 is, for example, a solid-state imaging element such as a CMOS image sensor or a CCD image sensor. The imaging element 260 captures an image of the subject on the imaging surface 260S and outputs a signal based on a control signal from the camera-side control unit 230. The imaging element 260 is capable of both video recording and still image recording. Video recording, in addition to recording video, also includes recording so-called live-action images for continuous display on the display unit 285.

[0020] The signal output from the imaging element 260 is used by the signal processing unit 270 to generate image data for real-world image generation and image data for still image photography. The imaging element 260 is connected to the signal processing unit 270 and the body-side control unit 230.

[0021] The signal processing unit 270 performs prescribed image processing on the signal output from the imaging element 260 to generate image data. The generated image data is recorded in a prescribed file format on a storage medium (not shown) or used for image display by the display unit 285. The signal processing unit 270 is connected to the body-side control unit 230, the imaging element 260, and the display unit 285.

[0022] The fuselage-side communication unit 240 and the lens-side communication unit 340 of the interchangeable lens 3 conduct predetermined communication. The fuselage-side communication unit 240 sends signals to the fuselage-side control unit 230. The fuselage-side communication unit 240 includes a fuselage-side first communication unit 240a and a fuselage-side second communication unit 240b. The fuselage-side first communication unit 240a conducts command data communication with the interchangeable lens 3 as described later, and the fuselage-side second communication unit 240b conducts hotline communication with the interchangeable lens 3 as described later.

[0023] The first communication unit 240a on the camera body side is connected to the first control unit 230a on the camera body side (described later). Information transmitted and received between the camera body 2 and the interchangeable lens 3 via command data communication is output or input by the first control unit 230a on the camera body side. The second communication unit 240b on the camera body side is connected to the first control unit 230a on the camera body side and the second control unit 230b on the camera body side (described later). Information sent from the interchangeable lens 3 to the camera body 2 via hot-wire communication is sent to the first control unit 230a and the second control unit 230b on the camera body side.

[0024] The power supply unit 250 converts the voltage of a battery (not shown) into the voltage used in various parts of the camera system 1 and supplies it to various parts 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 the instructions of the body-side control unit 230.

[0025] The shake sensor 290 detects camera body shake 2 caused by factors such as hand tremors. The shake sensor 290 includes an angular velocity sensor 290a and an accelerometer 290b. The shake sensor 290 detects angular shake and translational shake by separating them into X-axis and Y-axis components.

[0026] Angular velocity sensor 290a detects the angular velocity generated by the rotational motion of the camera body 2. For example, angular velocity sensor 290a detects rotation about axes parallel to the X-axis, axes parallel to the Y-axis, etc., and outputs the detection signals to the camera body-side control unit 230 respectively.

[0027] In addition, the accelerometer 290b detects the acceleration generated by the translational motion of the camera body 2. For example, the accelerometer 290b detects acceleration in the direction of the axis parallel to the X-axis and the axis parallel to the Y-axis, and outputs the detection signals to the body-side control unit 230 respectively.

[0028] The angular velocity sensor 290a and the acceleration sensor 290b are capable of periodically outputting detection signals with a period shorter than that of hot-wire communication.

[0029] The camera body-side control unit 230 comprises a microcomputer and its peripheral circuitry. The camera body-side control unit 230 includes a storage unit 235. The storage unit 235 records and retrieves control data controlled by the camera body-side control unit 230. The storage unit 235 stores control programs executed by the camera body-side control unit 230. The camera body-side control unit 230 executes the control programs stored in the storage unit 235 to control various components within the camera body 2.

[0030] The camera body-side control unit 230 includes a first camera body-side control unit 230a and a second camera body-side control unit 230b. The first camera body-side control unit 230a primarily controls the overall camera body 2, while the second camera body-side control unit 230b, connected to the sensor drive unit 265, primarily controls the shake correction operation that moves the imaging element 260 in a direction intersecting the optical axis. Because the second camera body-side control unit 230b primarily controls the shake correction operation, it can quickly perform shake correction-related controls. The first camera body-side control unit 230a instructs the second camera body-side control unit 230b to start and stop shake correction. The first camera body-side control unit 230a and the second camera body-side control unit 230b appropriately transmit and receive necessary data and instructions.

[0031] The sensor drive unit 265 includes, for example, an actuator, a drive mechanism, and a position detection unit. Based on an instruction output from the camera body-side control unit 230, the sensor drive unit 265 moves the imaging element 260 in a direction intersecting the optical axis O. By moving the imaging element 260 in this direction, image jitter (shaking) on ​​the imaging surface 260S of the imaging element 260 can be suppressed. The sensor drive unit 265 uses a position detection unit such as a Hall element to detect the position of the imaging element 260 in the direction intersecting the optical axis O.

[0032] Operating components 280, including release buttons and operation switches, are mounted on the outer surface of the camera body 2. Operating components 280 send operation signals corresponding to user input to the body-side control unit 230. Users can use the operating components 280 to give shooting instructions, set shooting conditions, etc. Additionally, users can use the operating components 280 to indicate whether image stabilization is on or off, or to specify whether to set the stabilization mode to sports mode or normal mode. Sports mode is a mode that reduces the range of motion, suitable for shake correction under conditions such as tracking fast-moving subjects, frequently changing composition, or increasing shutter speed. In normal mode, the range of motion is increased by matching the mechanical range of motion, which improves the effectiveness of shake correction.

[0033] The display unit 285 is, for example, composed of a liquid crystal display panel. Based on instructions from the control unit 230 on the camera body side, the display unit 285 displays images, operation menus, etc., based on image data processed by the signal processing unit 270. Alternatively, the display unit 285 can be operated via a touch panel to replace the operation member 280 for setting shooting conditions, etc.

[0034] Interchangeable lens

[0035] The interchangeable lens 3 includes a lens-side control unit 330, a lens-side communication unit 340, a lens-side storage unit 350, a shooting optical system 360, a lens drive unit 370, an indicator 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 storage unit 350, the lens drive unit 370, the indicator unit 375, and the shake sensor 390.

[0036] The lens-side control unit 330 consists of a microcomputer and its peripheral circuits. The lens-side control unit 330 executes the control program stored in the lens-side storage unit 350 to perform automatic focus adjustment control, shake correction control, and other controls on various parts of the interchangeable lens 3. The shake correction control performed by the lens-side control unit 330 will be described later.

[0037] The lens-side storage unit 350 is composed of a non-volatile storage medium. The lens-side storage unit 350 is controlled by the lens-side control unit 330 to record and retrieve data. In addition to storing the control program executed by the lens-side control unit 330, the lens-side storage unit 350 also stores the image stabilization coefficient of the shooting optical system 360, the cutoff frequency corresponding to the image stabilization mode and shake state, and the coefficient.

[0038] The imaging optical system 360 has multiple lenses and aperture components, which image the subject onto the imaging plane (image plane 260S). At least a portion of the imaging optical system 360 serves as a movable component, configured to be movable within the interchangeable lens 3.

[0039] The imaging optical system 360 includes, for example, a focusing lens 361a as a moving component and a shake correction lens 361b as a moving component.

[0040] The lens drive unit 370 moves the moving member and includes lens drive units 370a and 370b. Each lens drive unit 370 includes an actuator, a drive mechanism, and a position detection unit for the moving member. The lens-side control unit 330 periodically generates position information of the moving member based on signals from the position detection unit and the actuator of the lens drive unit 370. Furthermore, based on signals from the position detection unit and the actuator of the lens drive unit 370, the lens-side control unit 330 periodically identifies whether the moving member is being driven, the direction of movement of the moving member, and whether the moving member is in a stationary or other moving state. The period for generating the position information of the moving member and the period for identifying the movement state of the moving member can be shorter than the period of hot-wire communication.

[0041] The focusing lens 361a is configured to move forward and backward along the optical axis O via the lens drive unit 370a. The focus position of the imaging optical system 360 is adjusted by moving the focusing lens 361a. The drive indicators for the moving direction, amount of movement, and speed of the focusing lens 361a can be indicated by the body-side control unit 230, or, considering the indication from the body-side control unit 230, by the lens-side control unit 330. The position of the focusing lens 361a along the optical axis O can be detected by the encoder or the like in the lens drive unit 370a.

[0042] The image correction lens 361b is configured to move forward and backward in a direction intersecting the optical axis O via the lens drive unit 370b. Movement of the image correction lens 361b suppresses image shake (shaking) of the subject image on the imaging surface 260S of the imaging element 260. The direction, amount, and speed of movement of the image correction lens 361b are indicated by the lens-side control unit 330 based on the detection signal from the image correction sensor 390. The position of the image correction lens 361b is configured to be detectable by a Hall element or similar component of the lens drive unit 370b. As position information of the image correction lens 361b, the lens drive unit 370b detects, for example, the position of the optical axis O' of the image correction lens 361b within the plane intersecting the optical axis O. That is, it detects the X-axis coordinate value and Y-axis coordinate value of the optical axis O' of the image correction lens 361b with the optical axis O as the origin. Therefore, the position information of the jitter correction lens 361b can be represented by the position of the optical axis O' in the X-axis direction and the position in the Y-axis direction, or by the amount of movement (the difference in coordinate values) of the optical axis O' in the X-axis direction and the amount of movement in the Y-axis direction.

[0043] The indicator unit 375 is, for example, provided on the outer barrel of the interchangeable lens 3. By operating the indicator unit 375, the user can set the image stabilization settings in the interchangeable lens 3, such as indicating whether the image stabilization function in the interchangeable lens 3 is turned on or off, and setting the image stabilization mode in the interchangeable lens 3 to sports mode or normal mode. The operation signal corresponding to the user's operation is sent from the indicator unit 375 to the lens-side control unit 330.

[0044] The shake sensor 390 detects shake in the interchangeable lens 3 caused by hand tremors, etc. The shake sensor 390 is identical to the shake sensor 290 in the camera body 2. The shake sensor 390 includes an angular velocity sensor 390a and an acceleration sensor 390b, and outputs detection signals to the lens-side control unit 330 respectively. The angular velocity sensor 390a and the acceleration sensor 390b can periodically output detection signals with a period shorter than that of hot-wire communication.

[0045] The lens-side communication unit 340 and the camera body-side communication unit 240 perform prescribed communication. The lens-side communication unit 340 includes a lens-side first communication unit 340a and a lens-side second communication unit 340b. The lens-side first communication unit 340a performs command data communication with the camera body 2 as described later, and the lens-side second communication unit 340b performs hotline communication with the camera body 2 as described later.

[0046] The lens-side first communication unit 340a is connected to the lens-side control unit 330. Information transmitted from the interchangeable lens 3 to the camera body 2 via command data communication is generated by the lens-side control unit 330. The lens-side second communication unit 340b is also connected to the lens-side control unit 330. Information transmitted from the interchangeable lens 3 to the camera body 2 via hot-wire communication is generated by the lens-side control unit 330, the lens-side second communication unit 340b, etc.

[0047] Figure 1 The arrow between the lens-side communication unit 340 and the fuselage-side communication unit 240 indicates the flow of signals.

[0048] The lens-side first communication unit 340a outputs a signal (hereinafter referred to as the RDY signal) and a data signal (hereinafter referred to as the DATAL signal) indicating whether the interchangeable lens 3 can perform command data communication to the body-side first communication unit 240a. The body-side first communication unit 240a outputs a clock signal (hereinafter referred to as the CLK signal) and a data signal (hereinafter referred to as the DATAB signal) for command data communication to the lens-side first communication unit 340a.

[0049] The lens-side second communication unit 340b outputs a hot-wire communication clock signal (hereinafter referred to as HCLK signal) and a data signal (hereinafter referred to as HDATA signal) to the body-side second communication unit 240b.

[0050] Hotline communication is a one-way data communication from the interchangeable lens 3 to the camera body 2, while command data communication is a two-way data communication between the interchangeable lens 3 and the camera body 2.

[0051] <Details of the communication>

[0052] Camera system 1 has two independent communication systems based on command data communication and hot-wire communication, thus enabling parallel communication. That is, while the camera body 2 and interchangeable lens 3 are engaged in command data communication, they can both initiate and terminate hot-wire communication. Furthermore, command data communication can also be performed while hot-wire communication is in progress. Therefore, even while in command data communication, the interchangeable lens 3 can continuously send data to the camera body 2 via hot-wire communication. For example, even if the time required for command data communication increases due to a larger data volume, hot-wire communication can be performed at necessary timed intervals.

[0053] Furthermore, even while the camera body 2 is receiving data via hot-wire communication, it can send various instructions and requests to the interchangeable lens 3 at any time via command data communication, and can receive data from the interchangeable lens 3 at any time.

[0054] Figure 2 This is a timing diagram illustrating command data communication and hot-wire communication. After the camera body 2 indicates the start of hot-wire communication via command data communication, for example after time t1, it periodically receives data from the interchangeable lens 3 via hot-wire communication.

[0055] In addition, the camera body 2 sends and receives data with the interchangeable lens 3 via command data communication. Specifically, during times t2 to t3 and t9 to t10, the camera body 2 sends instructions to the interchangeable lens 3 and receives various data. During times t5 to t6 and t12 to t13, it sends various data to the interchangeable lens 3. During the intervals of t4, t7, t8, and t11, it sends instructions related to the movement control of the moving components, such as the shake detection start instruction, the animation stabilization start instruction, the still image stabilization start instruction, and the focus drive instruction, from the shake sensor 390 to the interchangeable lens 3.

[0056] In this embodiment, the types of data transmitted and received in the command data communication are numerous, and the frequency of instructions to the interchangeable lens 3 is also high. Furthermore, depending on the type of data, the time required for transmission and reception increases. The time for transmitting and receiving various data at times t2 to t3, t5 to t6, t9 to t10, and t12 to t13 is longer than the time for sending instructions at times t4, t7, t8, and t11.

[0057] The interchangeable lens 3, for example, sends data representing information about the interchangeable lens 3 (focal length, shooting distance, aperture value, optical characteristics of the shooting optical system 360, etc.) to the camera body 2 according to instructions sent from the camera body 2 via command data communication. The interchangeable lens 3 also receives data representing information about the camera body 2 (frame rate, camera body 2 settings, etc.) sent from the camera body 2.

[0058] Command data communication is difficult to sustain in short cycles because it takes a long time to send and receive data once, and the frequency of sending and receiving is also high.

[0059] In contrast, hot-wire communication uses a different communication terminal than that used for command data communication, thus enabling continuous data communication from the interchangeable lens 3 to the camera body 2 in short cycles. For example, hot-wire communication can be performed for the desired period, starting from the end of the camera body 2's startup process and including the exposure process until the cutoff process.

[0060] The start and end instructions for hotline communication are sent from the camera body 2 to the interchangeable lens 3 via command data communication, but are not limited to this.

[0061] <Command Data Communication Description>

[0062] Next, use Figure 3 The command data communication is explained. Figure 3 The timing of the RDY, CLK, DATAB, and DATAL signals is shown in the example.

[0063] In a command data communication, after a command packet 402 is sent from the camera body 2 to the interchangeable lens 3, a data packet 406 and a data packet 407 are exchanged between the camera body 2 and the interchangeable lens 3.

[0064] At the start of command data communication (t21), the lens-side first communication unit 340a sets the potential of the RDY signal to L level. When the RDY signal is at L level, the fuselage-side first communication unit 240a begins outputting the CLK signal 401. The frequency of the CLK signal 401 is, for example, 8MHz. The fuselage-side first communication unit 240a outputs a DATAB signal containing a command packet 402 of a predetermined length synchronously with the clock signal 401. The command packet 402 is represented by switching between H level and L level. After outputting the CLK signal 401 for a period of time equivalent to the data length of the command packet 402, the fuselage-side first communication unit 240a ends the output of the CLK signal (t22).

[0065] Command packet 402 may include, for example, synchronization data, data for identifying which command data communication is being communicated, data indicating an instruction from camera body 2, data indicating the data length of subsequent data packets 406, and data for communication error checking. The instructions included in command packet 402 may include, for example, drive instructions from camera body 2 to the moving component of interchangeable lens 3, and data transmission instructions from camera body 2 to interchangeable lens 3.

[0066] The interchangeable lens 3 can determine whether there is a communication error simply by checking whether the value calculated based on the received command packet 402 is consistent with the data used for communication error checking contained in the command packet 402.

[0067] When the command packet 402 is received, the lens-side first communication unit 340a sets the RDY signal to H level, and the lens-side control unit 330 starts the first control process 404 (t22) based on the command packet 402.

[0068] After the first control processing 404 performed by the lens-side control unit 330 is completed, the lens-side first communication unit 340a can make the RDY signal become L level (t23). When the input RDY signal becomes L level, the body-side first communication unit 240a outputs the CLK signal 405.

[0069] The fuselage-side first communication unit 240a outputs a DATAB signal containing data packets 406 synchronously with the CLK signal 405. Additionally, the lens-side first communication unit 340a outputs a DATAL signal containing data packets 407 of a predetermined length synchronously with the CLK signal 405. Data packets 406 and 407 are represented by switching between H and L levels. After outputting the CLK signal 405 for a period corresponding to the data length of the data packets 406, the fuselage-side first communication unit 240a terminates the output of the CLK signal (t24).

[0070] Data packets 406 and 407 are variable-length data with the amount of data represented by command packet 402. Data packets 406 and 407 contain data for synchronization, data representing information about the camera body 2, data representing information about the interchangeable lens 3, data for communication error checking, etc.

[0071] The data packet 406 sent from the camera body 2 to the interchangeable lens 3 contains data indicating the driving amount of the moving component, data for transmitting settings and motion states within the camera body 2, etc.

[0072] The data packet 407 sent from the interchangeable lens 3 to the camera body 2 contains data indicating the model name of the interchangeable lens 3, data indicating the state of shake correction in the interchangeable lens 3, data related to the optical characteristics of the shooting optical system 360, etc.

[0073] The receiving device (interchangeable lens 3 or camera body 2) can determine whether there is a communication error simply by checking whether the value calculated based on the received data packets 406 and 407 is consistent with the data used for communication error checking contained in data packets 406 and 407.

[0074] When the transmission and reception of data packets 406 and 407 are completed, the lens-side first communication unit 340a makes the RDY signal become H level, and the lens-side control unit 330 starts the second control process 408 (t24) based on data packets 406 and 407.

[0075] (Explanation of the first and second control processes)

[0076] Next, examples of the first control process 404 and the second control process 408 for command data communication will be described.

[0077] For example, command packet 402 may contain a drive instruction for focusing lens 361a. As a first control process 404, lens-side control unit 330 generates data packet 407 indicating that a drive instruction for focusing lens 361a has been received.

[0078] Next, as part of the second control process 408, the lens-side control unit 330 sends an instruction to the lens drive unit 370a to move the focusing lens 361a by the amount of movement indicated by the data packet 406. This initiates the movement of the focusing lens 361a in the direction of the optical axis O. When the lens-side control unit 330 sends the movement instruction for the focusing lens 361a to the lens drive unit 370a, the lens-side first communication unit 340a considers the second control process 408 complete and sets the RDY signal to L level (t25).

[0079] Additionally, for example, command packet 402 may contain a start indication for hot-line communication. As a first control process 404, lens-side control unit 330 generates data packet 407 indicating receipt of the start indication for hot-line communication. Next, as a second control process 408, lens-side control unit 330 initiates hot-line communication via lens-side second communication unit 340b. When the start of hot-line communication is indicated, lens-side control unit 330 considers the second control process 408 completed and sets the RDY signal to L level (t25).

[0080] Furthermore, for example, command packet 402 may contain a drive instruction for shake correction. As a first control process 404, lens-side control unit 330 generates data packet 407 indicating that a drive instruction for shake correction lens 361b has been received.

[0081] Next, as part of the second control process 408, the lens-side control unit 330 sends an instruction to the lens drive unit 370b to move the shake correction lens 361b based on the correction rate (shake correction sharing ratio between the camera body 2 and the interchangeable lens 3) contained in the data packet 406, the instruction related to shake correction control, and the output of the shake sensor 390. This initiates the movement of the shake correction lens 361b in the direction intersecting the optical axis O. When the lens-side control unit 330 sends a drive start instruction for the shake correction lens 361b to the lens drive unit 370a, the lens-side first communication unit 340a considers the second control process 408 complete and sets the RDY signal to L level (t25).

[0082] <Instructions for Hotline Communication>

[0083] Next, use Figure 4 This section explains the hotline communication. Figure 4 The timing of the HCLK and HDATA signals is illustrated. In a hot-wire communication, an HDATA signal 503 is sent from the interchangeable lens 3 to the camera body 2 synchronously with an HCLK signal 502.

[0084] In the camera system 1 of this embodiment, before the start indication of receiving hot-wire communication, the conditions related to hot-wire communication are determined in advance between the interchangeable lens 3 and the camera body 2. These conditions include, for example, the data length (number of bytes) of the HDATA signal transmitted in a single hot-wire communication, the data contained in the HDATA signal and their order, the clock frequency of the HCLK signal, and the period (…). Figure 4 Tinterval), communication time in one cycle ( Figure 4 (e.g., Ttransmit). In this embodiment, the frequency of the HCLK signal is 2.5MHz, the data length of one hot-wire communication is longer than the command packet 402, the period of one hot-wire communication is 1 millisecond, and the communication time in one period is less than 75% of the transmission interval, but it is not limited to this. In addition, a hot-wire communication refers to the data transmission that takes place in one period of hot-wire communication, which is different from the hot-wire communication start indication to hot-wire communication end indication based on command data communication from the camera body 2.

[0085] First, the operation of the lens-side second communication unit 340b in hot-wire communication will be explained. When a start instruction for hot-wire communication is received via command data communication before time t31, the lens-side second communication unit 340b begins outputting an HCLK signal to the camera body 2 (t31). The HCLK signal is periodically output from the interchangeable lens 3. Figure 4 The signals are represented as HCLK signals 502, 502', ...

[0086] The second communication unit 340b on the lens side outputs an HDATA signal synchronously with the HCLK signal. The HDATA signal is represented by switching between H and L levels. One HDATA signal is a specified data length. Figure 4 The HDATA signal is represented as N bytes, each containing 8 bits from D0 to D7. To maintain a fixed length, an HDATA signal can also include unused bit and byte regions. Predetermined initial values ​​are input into the unused bit and byte regions. The HDATA signal is periodically output from the interchangeable lens 3 synchronously with HCLK signals 502, 502', ... Figure 4 The signals are represented as HDATA signals 503, 503', ...

[0087] When the HDATA signal transmission is completed (t32), the lens-side second communication unit 340b stops outputting the HCLK signal until the start of the next HDATA signal transmission at time t34. Time t31 to t32 is defined as one hot-line communication cycle, and time t31 to t34 is defined as one hot-line communication period. The lens-side second communication unit 340b begins the second hot-line communication from time t34.

[0088] The second communication unit 340b on the lens side periodically and continuously conducts hot-line communication until a termination instruction for hot-line communication is sent from the camera body 2 via command data communication.

[0089] The lens-side second communication unit 340b transmits HDATA signals 503, 503', ... to the body-side second communication unit 240b via its built-in serial communication unit. The lens-side second communication unit 340b, for example, uses DMA (Direct Memory Access) to efficiently transfer data stored in a data area of ​​memory (not shown) as HDATA signals. DMA is a function that automatically accesses data in memory without CPU intervention.

[0090] Next, the operation of the fuselage-side second communication unit 240b in hot-line communication will be described. In this embodiment, the fuselage-side second communication unit 240b enters a receptive state when the initialization process at power-on is completed, or when it is determined that a start instruction for hot-line communication has been sent via command data communication.

[0091] The transmission of HDATA signals begins from the interchangeable lens 3. After a predetermined time Terror0 elapses from the start time t31 (time t33), and after receiving a predetermined length of data (t32), the fuselage-side second communication unit 240b considers the received data as capable of normal communication. The predetermined time Terror0 is the time that allows for a margin in the communication time Ttransmit within one cycle, for example, set to 80% of one cycle. After receiving one HDATA signal, the fuselage-side second communication unit 240b also stands by in a receptive state. After one cycle elapses from time t31, it begins receiving the next HDATA signal (t34).

[0092] If the second communication unit 240b on the fuselage side fails to receive a specified length of data within a specified time Terror0 after the HDATA signal is sent from the lens-side communication unit 340, it is considered that normal communication is not possible (communication error) and the received data is discarded.

[0093] In addition, in hotline communication, the communication time (Ttransmit) in a cycle is preferably no more than 75% to enable communication error handling between cycles (during the period from time t33 to t34), but it is not limited to this.

[0094] <Hotline Data>

[0095] In a hotline communication, a hotline data 90 is sent from the interchangeable lens 3 to the camera body 2.

[0096] The hotline data 90 can contain at least two types of information for each moving component, including position information of the moving component and information different from the position information of the moving component. In this embodiment, the hotline data 90 includes: first data 91, which includes position information of the focusing lens 361a and information that can be used for movement control of the focusing lens 361a; and second data 92, which includes position information of the shake correction lens 361b and information that can be used for movement control of the shake correction lens 361b. The information contained in the first data 91 and the information contained in the second data can be the same or partially different.

[0097] The information, distinct from the position information of the moving component, is information that can be used for movement control of the moving component and can be set for each moving component. For example, it includes at least one of the following: the reliability of the position information, the movement status of the moving component, and the operating status of the operating component such as the indicator 375. This information and status are represented in numerical values ​​and identifiers in the lens-side control unit 330 and the lens-side second communication unit 340b, and are included in the hotline data 90.

[0098] In the case of focusing lens 361a, the information indicating the position of the moving member represents the relative or absolute position of focusing lens 361a in the direction of optical axis O, including the pulse count of the actuator of lens drive unit 370a and the detection value detected by lens drive unit 370a. In the case of jitter correction lens 361b, the information indicating the position of the moving member represents the relative or absolute position of jitter correction lens 361b in the plane intersecting optical axis O, including the coordinate value or movement amount of optical axis O' of jitter correction lens 361b in the plane intersecting optical axis O. In the case of zoom lens 361c, the information indicating the position of the moving member represents the relative or absolute position of zoom lens 361c in the direction of optical axis O, including the pulse count of the actuator of lens drive unit 370c and the detection value detected by lens drive unit 370c. In the case of aperture 362, the information indicating the position of the moving member represents the position of aperture blades in the plane intersecting optical axis O, including the aperture diameter (aperture value) formed by the aperture blades.

[0099] The reliability of location information is indicated by an identifier that shows whether the location information is valid or invalid, and a numerical value that indicates the reliability of the location information.

[0100] The movement state of a moving component is indicated by identifiers such as whether the moving component is in motion, whether the moving component is in a state where it can move, whether the moving component is being stopped, whether the moving component is being started, and the direction of movement of the moving component.

[0101] (Explanation of the second data point 92)

[0102] Figure 5 This is a diagram illustrating the information contained in the second data 92.

[0103] The second data 92 includes, for example, at least one of the following: data 92h to 92k related to the shake correction amount in the interchangeable lens 3; data 92l and 92m related to the shake amount in the shooting surface 260S calculated by the interchangeable lens 3; data 92n and 92o related to the residual shake amount calculated based on the detection signal detected by the shake sensor 390 and the position of the shake correction lens 361b; data 92a to 92d related to the shake state detected by the shake sensor 390; data 92e and 92f related to the reliability of the shake correction amount or the calculated shake amount; and data 92g related to the movement state of the shake correction lens 361b.

[0104] Data 92a-92d are related to the shake state detected by the shake sensor 390 and include an identifier selected by the lens-side control unit 330 based on the detection signal from the shake sensor 390. The lens-side control unit 330 determines the shake state based on the detection signal from the shake sensor 390. In this embodiment, the shake state is determined as a state of compositional change, a state of stable composition, or a state of being fixed on a tripod. The lens-side control unit 330 selects an identifier indicating whether the composition is changing, an identifier indicating whether the composition is stable, and an identifier indicating whether the tripod is fixed, and sends each identifier as hotline data 90. In addition, the lens-side control unit 330 performs shake correction control suitable for each shake state, such as changing the cutoff frequency of the detection signal.

[0105] Data 92a represents the shake state related to the angular shake in the X-axis direction output by the shake sensor 390. For example, the lens-side control unit 330 selects an identifier indicating whether the composition is changing, an identifier indicating whether the composition is stable, and an identifier indicating whether the tripod is fixed, based on the angular shake detection signal in the X-axis direction, and sets them as data 92a.

[0106] The difference between data 92b and data 92a is that the above judgment is made in the Y-axis direction.

[0107] The difference between data 92c and data 92a is that the above judgment is made for translation jitter.

[0108] The difference between data 92d and data 92a is that the above judgment is made for translational jitter in the Y-axis direction.

[0109] The body-side control unit 230 can determine the shake state of the interchangeable lens 3 based on data 92a-92d. Therefore, the body-side second control unit 230b can perform shake correction control to make the shake state consistent with the determination result in the interchangeable lens 3. Alternatively, the shake state can be determined in the body-side control unit 230 based on the detection result of the shake sensor 290, or the shake state determination based on the detection result of the shake sensor 290 can be omitted in the body-side control unit 230.

[0110] 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 based on the shake control state of the interchangeable lens 3. In this embodiment, shake control states can include still image stabilization, video stabilization, and non-shake correction. Non-shake correction refers to a state where shake correction is not performed because the lens drive unit 370b is not driven. Still image stabilization refers to a state where shake correction suitable for still image shooting is being performed based on a still image stabilization start indication sent from the camera body 2 via command data communication. Video stabilization refers to a state where shake correction suitable for video shooting and live view image shooting is being performed based on a video stabilization start indication sent from the camera body 2 via command data communication. Generally, it is set that the shake correction lens 361b has a larger range of motion and a stronger shake correction effect in video stabilization compared to still image stabilization.

[0111] The fuselage-side control unit 230 can know the movement state of the shake correction lens 361b based on the data 92g, and thus can reflect it to the shake correction control in the fuselage-side control unit 230.

[0112] Data 92h~92k are related to the amount of shake (shake correction amount) corrected in the interchangeable lens 3. They represent the value of the position of the shake correction lens 361b shown by the lens drive unit 370b, or the value of the amount of movement of the shake correction lens 361b calculated by the lens side control unit 330 based on the position of the shake correction lens 361b.

[0113] Data 92h represents the current position of the optical axis O' of the shake correction lens 361b in the X-axis direction. In this embodiment, data 92h is represented by converting the coordinate value detected in the X-axis direction within the interchangeable lens 3 into a coordinate value (image plane conversion value) on the shooting surface 260S of the shooting element 260. The image plane conversion value is calculated by multiplying the coordinate value of the shake correction lens 361b detected in the interchangeable lens 3 by the image stabilization factor. The image stabilization factor represents the amount of movement of the image plane in the shooting surface 260S relative to a unit movement of the shake correction lens 361b, and is a value that varies according to the focal length and shooting distance of the shooting optical system 360, and is stored in the lens-side storage unit 350, etc. The lens-side control unit 330 reads the image stabilization factor corresponding to the focal length and shooting distance at the time when the coordinate value of the shake correction lens 361b is detected from the lens-side storage unit 350, and calculates the image plane conversion value.

[0114] By calculating the image plane conversion value in the interchangeable lens 3, it is possible to achieve the effect of not needing to send the image stabilization coefficient corresponding to the focal length and shooting distance to the camera body 2, but the value before image plane conversion can also be sent via hot-wire communication.

[0115] The difference between data 92i and data 92h is that the above judgment is made in the Y-axis direction.

[0116] The difference between data 92j and data 92h is that data 92j is the shake correction amount calculated by the lens-side control unit 330 based on the position of the shake correction lens 361b. For example, the lens-side control unit can use the same value as data 92h as data 92j, or it can use the coordinate value representing the position of the shake correction lens 361b directly as data 92j without image plane conversion, or it can use the amount of movement of the shake correction lens 361b calculated based on its position as data 92j.

[0117] The difference between data 92k and data 92j is that the above judgment is made on the Y-axis.

[0118] The body-side control unit 230 can know the amount of shake (shake correction amount) that has been corrected in the interchangeable lens 3 based on data 92h to 92k, and thus can reflect it in the shake correction of the camera body 2.

[0119] The data 92l and 92m are related to the amount of shake (total shake) of the subject image on the shooting surface 260S calculated in the interchangeable lens 3, and are expressed by the values ​​calculated by the lens-side control unit 330 based on the detection signal of the shake sensor 390 and the image stabilization coefficient when the detection signal is output.

[0120] Data 92l will be represented by image plane conversion of the total amount of jitter detected in the X-axis direction in the interchangeable lens 3. The image plane conversion is as described above.

[0121] The difference between data 92m and data 92l is that the above judgment is made for the Y-axis.

[0122] The body-side control unit 230 can know the total amount of shake calculated in the interchangeable lens 3 based on the data 92l and 92m, thereby confirming whether the total amount of shake has been corrected.

[0123] Data 92n and 92o are related to the residual shake amount calculated based on the detection signal detected by the shake sensor 390 and the position of the shake correction lens 361b, and are values ​​calculated by the lens-side control unit 330. Here, the residual shake amount can be obtained by subtracting the shake correction amount represented by data 92j and 92k from the total shake amount represented by data 92l and 92m. Since the residual shake amount can also be calculated in the camera body 2, it can be omitted from the hotline data 90 when at least one of the shake correction amount and the current position of the shake correction lens 361b, as well as the total shake amount, is transmitted.

[0124] Data 92n represents the residual jitter in the X-axis direction that was not properly corrected in the interchangeable lens 3, converted to the image plane 260S of the image element 260. The image plane conversion is as described above.

[0125] The difference between data 92o and data 92n is that the above judgment is made on the Y-axis.

[0126] The body-side control unit 230 can know the amount of shake that remains even after shake correction control in the interchangeable lens 3 based on data 92n and 92o. Therefore, it can correct the shake that was not corrected in the interchangeable lens 3 without the body-side control unit 230 calculating the amount of shake based on the detection signal of the shake sensor 290.

[0127] The data 92e and 92f are related to the reliability of the position information of the shake correction lens 361b, the reliability of the calculated shake amount, and the reliability of the shake correction amount, and include the identifier selected by the lens-side control unit 330 based on the reliability of the data 92h to 92o. In this embodiment, the data 92e and 92f indicate whether the data 92h to 92o are valid respectively, but are not limited thereto.

[0128] The fuselage-side control unit 230 can determine the reliability of data 92h to 92o based on data 92e and 92f, thereby enabling it to take countermeasures such as discarding data with low reliability.

[0129] <Explanation of jitter correction>

[0130] The camera system 1 of this embodiment is configured to perform lens-side shake correction by driving the shake correction lens 361b with the lens drive unit 370b and body-side shake correction by driving the imaging element 260 with the sensor drive unit 265. Therefore, by performing lens-side shake correction by driving the shake correction lens 361b, and then performing body-side shake correction on the remaining shake even after lens-side shake correction, the shake correction effect can be improved. Furthermore, by coordinating lens-side shake correction and body-side shake correction, the shake correction effect can be further improved. When lens-side shake correction and body-side shake correction are coordinated, the shake state determined in the interchangeable lens 3 is transmitted to the camera body 2 via hot-wire communication, thus enabling the camera body 2 to control the shake state to be consistent with the interchangeable lens 3.

[0131] As described above, the lens-side control unit 330 determines the tripod fixed state, the state of composition change, and the state of composition stability as the shake state based on the detection signal from the shake sensor 390. In addition, the lens control unit 330 and the camera-side second control unit 230b can appropriately change the threshold and coefficient according to the shake state, thereby adjusting the shake correction effect.

[0132] For example, the movable range of the shake correction lens 361b or the shooting element 260 (hereinafter referred to as the movable part) and the frequency band of the shake to be corrected can be changed according to the shake state. In the tripod-fixed state, a shake detection signal in the tens of Hz frequency band that is easily generated when the tripod is fixed can be extracted for correction. In the state of composition change, the frequency band can be limited to a specific range, or the movable range can be reduced, so as not to correct the shake of the interchangeable lens 3 that the user desires due to the change in composition. In the state of composition stabilization, the movable range can be increased by expanding the frequency band range compared to the state of composition change, making the movable range consistent with the mechanical movable range, etc.

[0133] The lens-side control unit 330 calculates the total amount of shake detected on the interchangeable lens 3 side based on the detection signal from the shake sensor 390. The lens-side control unit 330 calculates the angular shake based on the detection signal from the angular velocity sensor 390a, calculates the translational shake based on the detection signal from the accelerometer 390b, and uses the angular shake and translational shake to calculate the total amount of shake.

[0134] The lens-side control unit 330 also reads the image stabilization coefficient at the time the detection signal is output and calculates the image plane conversion value based on the total shake and the image stabilization coefficient. At this time, the lens-side control unit 330 calculates the image plane conversion value without considering the drive range (mechanical movable range and controllable 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 controllable movable range refers to the movable range limited by user settings and shooting conditions.

[0135] The lens-side control unit 330 also considers the mechanical range of motion and the control range of motion, and calculates the amount of movement of the shake correction lens 361b in the X-axis and Y-axis directions. The amount of movement can be calculated as the coordinate values ​​(target position) of the target in the X-axis and Y-axis directions.

[0136] The lens-side control unit 330, which calculates the movement amount or target position of the shake correction lens 361b, outputs a drive signal to the lens drive unit 370b, thereby driving the shake correction lens 361b. Upon receiving the drive signal, the lens drive unit 370b moves the shake correction lens 361b along the X-axis and Y-axis directions, respectively, which intersect the optical axis O. Furthermore, the lens drive unit 370b periodically detects the position of the shake correction lens 361b in the X-axis and Y-axis directions and outputs this position as the current position to the lens-side control unit 330. The lens-side control unit 330 can directly use the values ​​output from the lens drive unit 370b as data 92h and 92i, or it can use values ​​obtained through operations such as image plane conversion as data 92h and 92i.

[0137] Furthermore, the lens-side control unit 330 calculates the residual shake amount in both the X-axis and Y-axis directions based on the difference between the detected current position and the target position of the shake correction lens 361b. Alternatively, the residual shake amount can be calculated based on the difference between the amount of movement to the target position calculated by the lens-side control unit 330 and the amount of movement calculated based on the current position of the shake correction lens 361b. The lens-side control unit 330 uses the image stabilization coefficient at the detected current position of the shake correction lens 361b to calculate the image plane conversion value of the residual shake amount.

[0138] The second control unit 230b on the fuselage side generates a drive signal based on at least one of the position information of the shake correction lens 361b received via hot-wire communication, the total shake amount received via hot-wire communication, the residual shake amount received via hot-wire communication, and the detection signal output from the shake sensor 290, and outputs it to the sensor drive unit 265. Upon receiving the drive signal, the sensor drive unit 265 moves the imaging element 260 along the X-axis and Y-axis directions intersecting the optical axis O, respectively. The drive amount of the imaging element 260 can be the residual shake amount received via hot-wire communication, or the drive amount required for shake correction calculated by the second control unit 230b on the fuselage side. The calculation of the drive amount in the second control unit 230b on the fuselage side can be based on the difference between the total shake amount received via hot-wire communication and the shake correction amount, or based on the output result of the shake sensor 290, or based on the output result of the shake sensor 290 and the information received via hot-wire communication. When calculating the drive amount by the second control unit 230b on the body side, it is preferable to consider the shake state determined in the interchangeable lens 3 by receiving it via hot-wire communication.

[0139] The following uses Figure 6 An example of image stabilization will be explained. Figure 6 This is a timing diagram illustrating the timing process in animation stabilization. Figure 6 This is an example of performing shake correction while repeatedly capturing the movement of a monitoring image, known as a live view image, for example, every 1 / 60th of a second.

[0140] exist Figure 6 Before the timing diagram, hot-line communication is initiated, and an instruction to start motion stabilization is sent from the camera body 2 to the interchangeable lens 3 via command data communication, thus initiating the drive performed by the lens drive unit 370b.

[0141] For example, the camera body 2 communicates with the interchangeable lens 3 at the end of each accumulation cycle performed by the imaging element 260. As shown at times t43, t44, t47, ..., the camera body-side first control unit 230a periodically performs command data communication based on the frame rate. Here, the command data communication performed at times t43, t44, t47, ... is used to send and receive information related to each accumulation cycle, such as sending shooting conditions from the camera body 2 to the interchangeable lens 3, and sending the focal length from the interchangeable lens 3 to the camera body 2. Furthermore, the information sent and received via command data communication and the information sent and received via hot-line data communication may have some overlap. Therefore, the information used by both the camera body-side first control unit 230a and the camera body-side second control unit 230b (e.g., position information of the shake correction lens 361b) can also be sent via both hot-line communication and command data communication. In this case, from the viewpoint of data volume, it is preferable to send coordinate values ​​as position information of the jitter correction lens 361b in hot-line communication, and send a value (difference of coordinate values) representing the amount of movement of the jitter correction lens 361b in command data communication.

[0142] In addition, command data communication that is not based on frame rate can also be performed between command data communications at times t43, t44, t47, ...

[0143] As shown at times t41, t42, ..., the lens-side control unit 330 generates hotline data 90 each time based on the hotline communication cycle and sends it from the lens-side second communication unit 340b to the camera body 2. The camera body-side second communication unit 240b outputs the hotline data 90 received at times t41, t42, ... to the camera body-side first control unit 230a and the camera body-side second control unit 230b, respectively.

[0144] exist Figure 6 In the diagram, data 92a-92d, 92g, and 92l-92o are shown as an example of the second data 92. In the curves representing data 92a-92d and 92l-92o, arrows indicate the timing of command data communication, and circles indicate the timing of hot-line communication.

[0145] Although Figure 6 The illustration is omitted, but the lens-side control unit 330 sets identifiers for data 92e and 92f to indicate the validity of data 92h to 92o respectively. Additionally, in Figure 6 In the middle, the lens-side control unit 330 sets the identifier for data 92g to indicate that it is in "animation stabilization".

[0146] exist Figure 6In this context, the curve representing data 92l to 92o is, for example, a single-axis example for the X-axis or Y-axis. Additionally, residual jitter is expressed as an exaggerated (scale-changed) representation of the difference between the total jitter and the jitter correction.

[0147] When it is desired to send information about the interchangeable lens 3 to the camera body 2 via command data communication without using hot-wire communication, only information marked with arrows at specific times can be sent. Therefore, even if the total shake exceeds the upper limit of the shake correction range, such as at times t48 to t49, the residual shake cannot be sent to the camera body 2 until the next command data communication at time t50.

[0148] However, in this embodiment, since information about the interchangeable lens 3 is sent to the camera body 2 via hot-wire communication, information about time points indicated by circles can be sent to the camera body 2 in addition to the information about time points marked with arrows. Therefore, residual shake can be sent to the camera body 2 during the period when the total shake exceeds the upper limit of the shake correction range (times t48 to t49).

[0149] With this configuration, in the camera body 2, for example, the second control unit 230b on the body side can perform shake correction on residual shake that has not been corrected in the interchangeable lens 3, thereby simplifying the control of shake correction and improving the effect of shake correction.

[0150] Furthermore, the body-side second control unit 230b can continuously identify the shake correction amount or total shake amount in the interchangeable lens 3 via hot-wire communication in short cycles, thus enabling shake correction control that matches the shake correction amount or total shake amount of the interchangeable lens 3. For example, the body-side second control unit 230b can control the correction of the amount obtained by subtracting the shake correction amount of the interchangeable lens 3 from the body-side total shake amount calculated based on the detection signal of the shake sensor 290, or it can control the correction of the amount obtained by subtracting the shake correction amount from the total shake amount of the interchangeable lens 3. In addition, the body-side second control unit 230b can also determine whether the total shake amount in the interchangeable lens 3 matches the body-side total shake amount calculated based on the detection signal of the shake sensor 290. Here, if the camera body 2 does not identify the shake correction amount in the interchangeable lens 3, there is a possibility that the shake correction effect of the interchangeable lens 3 and the shake correction effect of the camera body 2 cancel each other out or over-correct. However, according to this embodiment, since the shake correction amount and the total shake amount are transmitted via hot-wire communication, the camera body 2 and the interchangeable lens 3 can cooperate to improve the shake correction effect.

[0151] Based on the detection signal from the shake sensor 390, the lens-side control unit 330 sets the identifier indicating "tripper fixed state" in data 92a-92d during the period from t41 to t44, sets the identifier indicating "composition stable state" in data 92a-92d during the period from t45 to t46 and after t51, and sets the identifier indicating "composition change in progress" in data 92a-92d during the period from t47 to t51.

[0152] Here, when the shake status is transmitted via command data communication instead of hot-wire communication, even if the lens-side control unit 30 identifies a stable composition state as at times t51-t52, the shake status cannot be transmitted to the camera body 2 until the next command data communication time t52. Furthermore, even if the lens-side control unit 30 identifies a stable composition state as at times t45-t46, the shake status may sometimes change at the next command data communication time t47. However, in this embodiment, since the shake status is transmitted via hot-wire communication, it can be transmitted periodically to the camera body 2 at each time point indicated by the circle. Therefore, changes in the shake status detected in the interchangeable lens 3 can be transmitted to the camera body 2 at a faster cycle.

[0153] With this configuration, the camera body 2 can quickly identify the shake state determined in the interchangeable lens 3, thereby reducing the time when the shake state in the camera body 2 and the shake state in the interchangeable lens 3 are inconsistent. If the shake state of the interchangeable lens 3 and the camera body 2 are inconsistent, the shake correction effect of the interchangeable lens 3 will be inconsistent with the shake correction effect of the camera body 2, resulting in unnatural-looking live view images. However, according to this embodiment, by making the shake state consistent in the camera body 2 and the interchangeable lens 3, the shake correction effect can be improved as follows.

[0154] For example, the shake correction effect can be improved by changing the frequency band to be corrected and the movable range of the shake correction movable part according to the shake state. Furthermore, the shake correction effect can be further improved by making the shake state consistent in the interchangeable lens 3 and the camera body 2. Additionally, since the shake state is transmitted from the interchangeable lens 3 to the camera body 2 via hot-wire communication, the time it takes for the shake state to deviate between the interchangeable lens 3 and the camera body 2 can be shortened. If the shake state is transmitted from the interchangeable lens 3 to the camera body 2 only via command data communication without hot-wire communication, the time delay in detecting the shake state on the lens side in the camera body 2 increases the time it takes for the detection result to deviate between the interchangeable lens 3 and the camera body 2, resulting in a decrease in the user's experience of the viewfinder image and the actual scene image during shake correction (a sense of inconsistency). However, in this embodiment, the time it takes for the shake state to deviate between the interchangeable lens 3 and the camera body 2 can be reduced.

[0155] According to the above implementation method, the following effects can be obtained.

[0156] The interchangeable lens 3 can periodically report the position information of the shake correction lens 361b and information related to the amount of shake calculated based on the detection signal from the shake sensor 390 to the camera body 2 via hot-line communication independent of command data communication. Therefore, the interchangeable lens 3 enables the camera body 2 to identify the total or residual shake calculated based on the detection signal from the shake sensor 390 and perform shake correction in cooperation with the camera body 2. Furthermore, the interchangeable lens 3 can also send the position of the shake correction lens 361b detected in the direction intersecting the optical axis as position information of the shake correction lens 361b, thereby facilitating short-cycle hot-line communication. Additionally, the interchangeable lens 3 can perform image plane calculations on the position information and shake-related information and send them to the camera body 2, thereby reducing the image plane calculation load in the camera body 2.

[0157] The interchangeable lens 3 can periodically report the position information of the shake correction lens 361b and the information used to calculate the correction amount for shake correction based on the detection signal of the shake sensor 390 to the camera body 2 via hot-line communication independent of command data communication. Therefore, the information used for shake correction in the interchangeable lens 3 and the camera body 2 can be made consistent. Furthermore, the interchangeable lens 3 sends the shake state determined based on the detection signal of the shake sensor 390 to the camera body 2 via hot-line communication. Thus, shake correction that makes the shake state consistent in the interchangeable lens 3 and the camera body 2 is possible.

[0158] Furthermore, the interchangeable lens 3 can also receive shake correction related instructions from the camera body 2 via command data communication while conducting hot-wire communication. The interchangeable lens 3 periodically transmits data related to shake correction 361b and data related to the focusing lens 361a via hot-wire communication, thus enabling the simultaneous transmission of shake correction and focus-related information, and parallel performance of shake correction and focus control. Additionally, the output period of the detection signal from the shake sensor 390 is shorter than the hot-wire period, improving the accuracy of the information contained in each hot-wire data point.

[0159] This invention is not limited to the above-described contents. Other aspects considered within the scope of the technical concept of this invention are also included within the scope of this invention.

[0160] (Variation Example 1)

[0161] The above description illustrates an example of using DMA functionality in hot-line communication. Alternatively, hot-line data 90 can be generated by CPU intervention instead of using DMA. In Modification 1, the transmission of the HDATA signal is performed by the lens-side second communication unit 340b, and the generation of hot-line data 90 is performed by the lens-side control unit 330. With this configuration, hot-line communication and the generation of hot-line data 90 can be performed in parallel even without using DMA. However, the generation of hot-line data 90 is performed within a period not exceeding one cycle of hot-line communication.

[0162] (Variation Example 2)

[0163] The above description illustrates an example where the fuselage-side control unit 230 is divided into a fuselage-side first control unit 230a and a fuselage-side second control unit 230b. However, it is also possible to configure a single fuselage-side control unit 230 without dividing it into two units. In this case, the fuselage-side control unit 230 can directly control the sensor drive unit 265, and the communication line of the fuselage-side second communication unit 240b only needs to be connected to one fuselage-side control unit 230.

[0164] In addition, Figure 4 In the example of hot-wire communication, a clock-synchronized communication method using only the HCLK and HDATA signal lines is shown, where the data transmission direction is set from the interchangeable lens 3 to the camera body 2. However, an additional signal line can be added to enable data transmission in both directions. Alternatively, the configuration can be made to switch the input and output of the HDATA signal line, thereby enabling data communication in both directions.

[0165] Hot-wire communication is not limited to clock synchronization; UART (Asynchronous Serial Communication) can also be used. Alternatively, in addition to clock and data signal lines, a handshake signal line or a CS (chip select) signal line can be added, thereby synchronizing the timing of communication start between the lens-side control unit 330 and the body-side first control unit 230a and body-side second control unit 230b.

[0166] (Variation Example 3)

[0167] In the camera body 2, the sensor drive unit 265 that drives the imaging element 260 in the direction intersecting the optical axis O can be omitted, and image processing performed by the signal processing unit 270 can be used to correct the image position shift. Alternatively, both image correction based on the sensor drive unit 265 and image correction based on the signal processing unit 270 can be performed simultaneously in the camera body 2.

[0168] (Variation Example 4)

[0169] Alternatively, the camera can be configured to distribute the shake correction by determining the proportion between the interchangeable lens 3 and the camera body 2. For example, the proportion (correction rate) of shake correction performed between the interchangeable lens 3 and the camera body 2 can be predetermined, and this proportion is also included in the command data communication indicating the start of image stabilization. The lens-side control unit 330 moves the shake correction lens 361b to eliminate the shake amount obtained by multiplying the proportion distributed by the interchangeable lens 3 in the calculated total shake amount.

[0170] On the other hand, the second control unit 230b on the camera body side can also perform shake correction control to eliminate the total shake amount transmitted via hot-wire communication or the total shake amount calculated by the shake sensor 290, multiplied by the proportion shared by the camera body 2.

[0171] According to Variation 4, by pre-determining the sharing ratio of shake correction performed in the interchangeable lens 3 and the camera body 2, shake correction can be appropriately shared between the interchangeable lens 3 and the camera body 2.

[0172] The sharing of correction between the interchangeable lens 3 and the camera body 2 can be determined as a sharing ratio or as a specified correction amount. Alternatively, it can be determined that the camera body 2 corrects for shake exceeding the drive range of the shake correction lens 361b. Furthermore, the control drive range of the shake correction lens 361b can be sent to the camera body 2 via hot-wire communication, and the camera body 2 can then correct for shake exceeding that control drive range.

[0173] (Variation Example 5)

[0174] Alternatively, the interchangeable lens 3 and camera body 2 can be configured to share shake correction based on the components of the shake. For example, the interchangeable lens 3 can correct angular shake, while the camera body 2 corrects shake around the optical axis O and translational shake. Alternatively, the interchangeable lens 3 can correct angular shake and a predetermined amount of translational shake, while the camera body 2 corrects shake around the optical axis O and the remaining translational shake. The predetermined amount of translational shake can be a correction amount that does not adversely affect the optical performance of the shooting optical system 360. In the case of Modification 5, the lens-side control unit 330 can also include data related to the shake components that are not shared in the hotline data 90.

[0175] (Variation Example 6)

[0176] The second control unit 230b on the camera body side performs shake correction control suitable for the shake state based on the shake state transmitted by the hot wire data 90, but is not limited to this. In this embodiment, since a shake sensor 290 is also provided on the camera body 2, the second control unit 230b on the camera body side can perform shake correction control that takes into account both the hot wire data 90 and the detection signal from the shake sensor 290.

[0177] (Variation Example 7)

[0178] When the interchangeable lens 3 is equipped with an indicator 375, the image stabilization mode indicated by the indicator 375 of the interchangeable lens 3 can also be transmitted via hot-wire communication. Since the image stabilization mode can be set by either the indicator 375 of the interchangeable lens 3 or by the operating member 280 of the camera body 2, there is a possibility that the image stabilization mode setting is inconsistent between the camera body 2 and the interchangeable lens 3. In this embodiment, the frequency band of the shake to be corrected and the range of motion of the movable part can also be changed according to the image stabilization mode. When the image stabilization mode is a sports mode, the range of motion can be reduced because it can handle photography at shutter speeds faster than in normal mode. When the image stabilization mode is a normal mode, the range of motion can be increased by making it consistent with the mechanical range of motion, thereby improving the effect of shake correction.

[0179] In Modification 7, when the image stabilization modes are inconsistent between the camera body 2 and the interchangeable lens 3, the image stabilization mode of the camera body 2 is made consistent with the image stabilization mode indicated by the indicator 375 of the interchangeable lens 3. It is assumed that when the image stabilization modes are inconsistent between the camera body 2 and the interchangeable lens 3, the shake correction effect in the interchangeable lens 3 is inconsistent with the shake correction effect in the camera body 2, resulting in unnatural-looking live view images. In this embodiment, the operation of the operating member 280 is sent to the camera body-side first control unit 230a, and the indication of the indicator 375 is sent to the camera body-side first control unit 230a via hot-wire communication. Therefore, the camera body-side first control unit 230a can identify the image stabilization modes of the camera body 2 and the interchangeable lens 3, and can send the image stabilization mode of the interchangeable lens 3 to the camera body-side second control unit 230b, making the image stabilization modes of the camera body 2 and the interchangeable lens 3 consistent. In addition, the first control unit 230a on the body side can also remind the user of the inconsistency of the image stabilization mode in the display unit 285.

[0180] The disclosures of the following priority-based applications are incorporated herein by reference.

[0181] Japan Special Appeal No. 2018-137271 (applied on July 20, 2018)

[0182] Label Explanation

[0183] 1…Camera system; 2…Camera body; 3…Interchangeable lens; 90…Hot-wire data; 230…Body-side control unit; 235…Storage unit; 240…Body-side communication unit; 265…Sensor drive unit; 270…Signal processing unit; 330…Lens-side control unit; 340…Lens-side communication unit; 350…Lens-side storage unit; 360…Shooting optical system; 370…Lens drive unit

Claims

1. A camera body having a shake-correcting lens and being capable of mounting a camera accessory that forms an image of a subject, wherein, The camera body has: A first communication unit is configured to receive information from the camera accessory and send information to the camera accessory; and The second communication unit receives information from the camera accessory. The first communication unit sends an instruction from the second communication unit to the camera accessory to initiate communication. The second communication unit receives first information related to the position of the correction lens and second information indicating the camera accessory's shaking from the camera accessory.

2. The camera body according to claim 1, wherein, The first communication unit and the second communication unit communicate independently of each other. The second communication unit performs one-way communication to receive information from the camera accessory.

3. The camera body according to claim 1, wherein, The first communication unit sends a shake correction start instruction to the camera accessory.

4. The camera body according to claim 1, wherein, The signal lines of the second communication unit consist of signal lines that output signals from the camera accessory, but do not include signal lines that output signals from the camera body.

5. The camera body according to claim 1, wherein, The first communication unit performs the following communications: simultaneously sending information to and receiving information from the camera accessory; and only sending information to the camera accessory.

6. The camera body according to claim 1, wherein, The second communication unit periodically receives a specified amount of information.

7. The camera body according to claim 1, wherein, The camera body has: An imaging element that captures an image of the subject and is movable; and The control unit performs control to move the imaging element based on the first information and the second information.

8. A camera accessory capable of being mounted on a camera body and forming an image of a subject, wherein, The camera accessory includes: The testing department detects vibration. The correction lens is moved based on the detection result of the detection unit; The third communication unit is used to receive information from the camera body and send information to the camera body; and The fourth communication unit sends information to the camera body. The third communication unit receives an instruction from the camera body to begin communication with the fourth communication unit. When the communication start instruction is received, the fourth communication unit sends to the camera body first information related to the position of the correction lens and second information related to the shake detected by the detection unit.

9. The camera accessory according to claim 8, wherein, The third communication unit and the fourth communication unit communicate independently of each other. The fourth communication unit performs one-way communication to send information to the camera body.

10. The camera accessory according to claim 8, wherein, The third communication unit receives a shake correction start instruction from the camera body.

11. The camera accessory according to claim 8, wherein, The signal lines of the fourth communication unit consist of signal lines that output signals from the camera accessory, but do not include signal lines that output signals from the camera body.

12. The camera accessory according to claim 8, wherein, The fourth communication unit periodically receives a specified amount of information.

13. The camera accessory according to claim 8, wherein, The camera accessory has a focusing lens that moves along the optical axis. The fourth communication unit transmits information related to the position of the focusing lens.

14. A camera system comprising a camera body according to any one of claims 1 to 7 and a camera accessory according to any one of claims 8 to 13.

15. A communication method for communication between a camera accessory and a camera body, the camera accessory having a movable lens, wherein... The communication method includes: The first communication method enables bidirectional communication of information between the camera accessory and the camera body; and The second communication method involves one-way communication of information from the camera accessory to the camera body. The first communication method is used to communicate the instruction to start communication via the second communication method. The second communication means is used to communicate first information related to the position of the lens and second information indicating the shaking of the camera accessory.

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