Camera body

Abstract

To provide a camera body capable of proper data communication. [Solution] The camera body is capable of attaching accessories and communicating with the accessories, and is capable of receiving information about movable members provided by the accessories in one or more communication specifications from the accessories and includes a first communication unit that performs unidirectional communication from the accessories, and a second communication unit that performs bidirectional communication with the accessories independently of the first communication unit, wherein the second communication unit receives a first value from the accessories that indicates the communication specifications of the first communication unit, and the first communication unit receives information about the movable members from the accessories in the communication specifications indicated by the first value, and does not have a terminal from which a signal is output from the camera body.

Description

Technical Field

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

Background Art

[0002] Conventionally, there is a camera system in which an accessory typified by an interchangeable lens can be attached to a camera body. Appropriate data communication needs to be performed between the accessory and the camera body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] According to a first aspect, a camera body is a camera body to which an accessory can be attached and that can communicate with the accessory, and can receive information regarding a movable member included in the accessory from the accessory in one or more communication specifications, and includes a first communication unit that performs unidirectional communication from the accessory, and a second communication unit that performs bidirectional communication with the accessory independently of the first communication unit. The second communication unit receives a first value indicating the communication specification of the first communication unit from the accessory, and the first communication unit receives information regarding the movable member from the accessory in the communication specification indicated by the first value, and does not include a terminal from which a signal is output from the camera body.

Brief Description of the Drawings

[0005] [Figure 1] It is a diagram showing a configuration example of a camera according to a first embodiment. [Figure 2] It is a diagram for explaining command data communication in the camera according to the first embodiment. [Figure 3]This diagram schematically shows the electrical connections of the lens-side connection and the body-side connection according to the first embodiment. [Figure 4] This diagram schematically shows the camera body mount as seen from the interchangeable lens side according to the first embodiment. [Figure 5] This diagram schematically shows the mount of the interchangeable lens as seen from the camera body side according to the first embodiment. [Figure 6] This is a diagram illustrating an example of a generation according to the first embodiment. [Figure 7] This figure shows an example of a generation determined in the camera according to the first embodiment. [Figure 8] This figure shows an example of processing and communication in a camera according to the first embodiment. [Figure 9] This figure illustrates an example of a method for calculating time Δt in a camera according to the first embodiment. [Figure 10] This figure shows the generation information transmitted and received between the interchangeable lens and the camera body in the camera according to the first embodiment, and the generation information used in hotline communication. [Figure 11] This figure shows the generation information transmitted and received between the interchangeable lens and the camera body in the camera according to the second embodiment, and the generation information used in hotline communication. [Figure 12] This figure shows the generation information transmitted and received between the interchangeable lens and the camera body in the camera according to the third embodiment, and the generation information used in hotline communication. [Figure 13] This figure shows the generation information transmitted and received between the interchangeable lens and the camera body in the camera according to the fourth embodiment, and the generation information used in hotline communication. [Modes for carrying out the invention]

[0006] (First Embodiment) Figure 1 shows an example of the configuration of a camera 1, which is an example of an imaging device according to the first embodiment. The camera 1 consists of a camera body 2 and an interchangeable lens 3, which is an attachable accessory. As the camera 1 consists of the camera body 2 and the interchangeable lens 3, it is sometimes referred to as a camera system.

[0007] The camera body 2 is provided with a body-side mount portion 201 to which an interchangeable lens 3 is attached. The interchangeable lens 3 is provided with a lens-side mount portion 301 to which it is attached to the camera body 2. The lens-side mount portion 301 and the body-side mount portion 201 are provided with a lens-side connection portion 302 and a body-side connection portion 202, respectively. The lens-side connection portion 302 and the body-side connection portion 202 are provided with multiple terminals, such as terminals for clock signals, data signals, and power supply terminals, which will be described later. The camera body 2 is equipped with a battery (not shown) for supplying power to the control units, drive units, etc., that are provided in the camera body 2 and the interchangeable lens 3, respectively, as will be described later. The interchangeable lens 3 is detachably attached to the body-side mount portion 201 of the camera body 2 by the lens-side mount portion 301.

[0008] When the interchangeable lens 3 is attached to the camera body 2, the terminals on the body-side connection part 202 and the terminals on the lens-side connection part 302 are electrically connected. This enables power supply from the camera body 2 to the interchangeable lens 3, as well as communication between the camera body 2 and the interchangeable lens 3.

[0009] First, let's explain the configuration of the interchangeable lens 3 in detail. The interchangeable lens 3 comprises a photographic optical system 31, an aperture diaphragm 32, a lens drive unit 33, a lens position detection unit 34, an aperture drive unit 35, a lens memory 36, and a lens control unit 37. The photographic optical system 31 is shown as a single lens for simplification in the diagram, but it includes multiple lenses, including a focus lens (focus adjustment lens), and when mounted on the camera body 2, it forms a subject image on the imaging surface of the image sensor 21. For example, the photographic optical system 31 may also include a zoom lens to change the focal length and an image stabilization lens (image stabilization lens) to reduce image blur (camera shake) in addition to the focus lens (focus adjustment lens). In practice, the aperture diaphragm 32 is provided, for example, between multiple lenses of the photographic optical system 31.

[0010] The lens drive unit 33 and the aperture drive unit 35 are each composed of, for example, a stepping motor, an ultrasonic motor, a DC motor, etc. The lens drive unit 33 controls the drive of the imaging optical system 31. For example, the lens drive unit 33 moves the focus lens forward and backward in the direction of the optical axis L based on a signal output from the lens control unit 37 to change the imaging position of the subject image by the imaging optical system 31. The aperture drive unit 35 drives the aperture diaphragm 32 to change the aperture diameter based on a signal output from the lens control unit 37. If the imaging optical system 31 includes a zoom lens and an image stabilization lens, the lens drive unit 33 may be equipped with drive sources for these to drive the zoom lens and the image stabilization lens, respectively. In this case, the lens drive unit 33 moves the zoom lens in the direction of the optical axis L based on a signal output from the lens control unit 37. The lens drive unit 33 also moves the image stabilization lens in a direction intersecting the optical axis L based on a signal output from the lens control unit 37. Furthermore, the lens drive unit 33 and the aperture drive unit 35 may include a drive circuit (drive IC, etc.) not shown that drives a stepping motor, ultrasonic motor, DC motor, etc.

[0011] The lens position detection unit 34 is composed of, for example, a photo interrupter and an encoder. The photo interrupter detects when the detected location of the imaging optical system 31 (for example, the support part of the focus lens) has passed a reference position (origin position) on the optical axis L, and outputs the detected signal to the lens control unit 37. The lens control unit 37 detects from the signal from the photo interrupter that the focus lens has passed the reference position (origin position). A so-called linear encoder is used as the encoder. The linear encoder generates two or more pulse signals, each with a different phase, and detects the amount and direction of movement of the focus lens based on the two or more pulse signals. The detected amount of movement is output as a pulse signal to the lens control unit 37. Alternatively, a magnetic encoder or the like may be used as the encoder to output pulse signals according to the absolute position.

[0012] If a stepping motor is used as the lens drive unit 33, an encoder is not required; the detection of passing the origin position can be done simply by using a photo interrupter. In this case, when the detected part of the imaging optical system 31 (for example, the support part of the focus lens) passes the photo interrupter of the lens position detection unit 34, a signal indicating that the imaging optical system 31 has passed the origin position is output to the lens control unit 37. To drive the imaging optical system 31, the lens control unit 37 outputs a pulse signal corresponding to the amount to move the lens to the drive circuit of the stepping motor of the lens drive unit 33, and the drive circuit of the lens drive unit 33 outputs a pulse signal corresponding to the amount of lens movement to the lens control unit 37 (corresponding to the pulse signal output from the lens control unit 37 to the drive circuit of the lens drive unit 33).

[0013] Furthermore, if the imaging optical system 31 includes a zoom lens or an image stabilization lens, the lens position detection unit 34 detects the amount of movement of the zoom lens and the image stabilization lens, and generates a signal representing the amount of movement or focal length of the zoom lens, or a signal representing the amount of movement or position of the image stabilization lens.

[0014] The lens control unit 37 is composed of a processor such as a CPU or FPGA, and memories such as a ROM and a RAM, and controls each part of the interchangeable lens 3 based on a control program. The lens control unit 37 controls the lens drive unit 33 and the aperture drive unit 35 to drive and control the imaging optical system 31 and the aperture stop 32 based on a control signal input from the body control unit 27 of the camera body 2 via the body-side connection unit 202 and the lens-side connection unit 302. For example, when a control signal indicating the moving direction, moving amount, moving speed, etc. of the focus lens is input from the body control unit 27 to the lens control unit 37, the lens control unit 37 sends an instruction to drive and control the lens drive unit 33 based on the control signal.

[0015] In addition, the lens control unit 37 detects the positions of the focus lens, zoom lens, etc. and transmits them to the camera body 2. When a stepping motor is used as the lens drive unit 33, the lens control unit 37 transmits the driving amount of the focus lens to the lens drive unit 33. A drive circuit (not shown) of the lens drive unit 33 drives the stepping motor. When the stepping motor is driven, a pulse signal corresponding to the driving amount is output from the drive circuit of the lens drive unit 33 to the lens control unit 37. The lens control unit 37 detects from the output of the photointerrupter of the lens position detection unit 34 that the focus lens or zoom lens has passed through the reference position (origin position), and further counts and integrates the pulse signal input from the encoder and the pulse signal corresponding to the driving amount of the stepping motor, thereby generating information (pulse position information) corresponding to the moving amount of the focus lens. The generated information (pulse position information) corresponding to the moving amount of the focus lens is transmitted to the camera body 2 by hotline communication described later.

[0016] The lens memory 36 is composed of, for example, a non-volatile storage medium or the like. Various information related to the interchangeable lens 3 is stored in the lens memory 36. For example, the lens memory 36 stores information such as the focal length and aperture value of the interchangeable lens, and information indicating the communication specifications that the interchangeable lens 3 can support during communication with the camera body 2. The information indicating this communication specification is called the generation of the interchangeable lens, which will be described later. The generation may also be referred to as generation information. The generation information of the interchangeable lens 3 is referred to as lens-side generation information. Writing data to the lens memory 36 and reading data from the lens memory 36 are controlled by the lens control unit 37. Note that the lens-side generation information may be stored in the memory inside the lens control unit 37.

[0017] Also, the lens control unit 37 includes a first lens communication unit 38 and a second lens communication unit 39. Although details will be described later, the first lens communication unit 38 performs command data communication with the first body communication unit 28 via the lens-side connection unit 302 and the body-side connection unit 202. The second lens communication unit 39 performs hotline communication with the second body communication unit 29 via the lens-side connection unit 302 and the body-side connection unit 202.

[0018] Next, the configuration of the camera body 2 will be described in detail. The camera body 2 includes an imaging element 21, a body memory 22, a display unit 23, an operation unit 24, a power supply unit 26, and a body control unit 27. The body control unit 27 is composed of a processor such as a CPU or FPGA, and a memory such as a ROM or RAM, and controls each part of the camera 1 based on a control program.

[0019] The body control unit 27 performs predetermined image processing on the signal output from the imaging element 21 to generate image data. The image processing includes known image processing such as tone conversion processing, color interpolation processing, and contour enhancement processing. Also, the body control unit 27 generates a control signal for controlling the driving of the imaging optical system 31 (driving of the focus lens, zoom lens, or vibration-proof lens) and the driving of the aperture 32.

[0020] Furthermore, the body control unit 27 performs the processing necessary for autofocus (AF) adjustment of the imaging optical system 31. Specifically, the body control unit 27 performs focus detection processing using a phase-difference detection method. The image sensor 21 has focus detection pixels, which are arranged in place of some of the imaging pixels that output the imaging signal, and in which a part of the photoelectric conversion unit within the pixel is shielded with a light-shielding film. The body control unit 27 calculates the amount of defocus using the focus detection signal output from the focus detection pixel using a phase-difference detection method. The body control unit 27 outputs a signal related to the calculated amount of defocus to the lens control unit 37. The lens control unit 37 drives the focus lens according to the amount of defocus. Note that the image sensor 21 may have a configuration in which multiple photoelectric conversion units are located within a single pixel, and there are pixels for both imaging and focus detection that output both the imaging signal and the focus detection signal.

[0021] Furthermore, the body control unit 27 can perform contrast detection-based focus detection processing instead of, or in addition to, phase-difference detection-based focus detection processing. That is, the body control unit 27 sequentially calculates the contrast evaluation value of the subject image based on the signal from the image sensor 21 while moving the focus lens of the imaging optical system 31 in the direction of the optical axis L. The body control unit 27 uses the position information (pulse position information) of the focus lens transmitted from the interchangeable lens 3 to associate the position of the focus lens with the contrast evaluation value. Then, the body control unit 27 calculates the in-focus position of the focus lens. The body control unit 27 outputs a signal corresponding to the calculated in-focus position to the lens control unit 37. The lens control unit 37 moves the focus lens to the in-focus position.

[0022] The power supply unit 26 has a power source and supplies power to the camera body 2 and the interchangeable lens 3. The power supply unit 26 is connected to the body-side connection unit 202 and the body control unit 27. Furthermore, the power supply unit 26 supplies power to the lens control unit 37 via the body-side connection unit 202 and the lens-side connection unit 302.

[0023] The image sensor 21 is, for example, a CMOS image sensor or a CCD image sensor. The image sensor 21 receives a light beam that has passed through the imaging optical system 31 and captures an image of the subject. Multiple pixels, each having a photoelectric conversion unit, are arranged in a two-dimensional plane in the row and column directions on the image sensor 21. The photoelectric conversion unit is composed of, for example, a photodiode (PD). The image sensor 21 converts the received light photoelectrically to generate a signal and outputs the generated signal to the body control unit 27.

[0024] The body memory 22 is composed of, for example, a non-volatile storage medium. The body memory 22 stores programs for controlling the camera body 2 and camera 1. The body memory 22 also stores information representing the generation of the camera body, which will be described later. In other words, it stores information indicating the communication specifications that the camera body 2 can support when communicating with the interchangeable lens 3. This information indicating the communication specifications is called the generation of the camera body, which will be described later. The generation may also be called generation information. The generation information of the camera body 2 is called the body-side generation information. Writing data to and reading data from the body memory 22 is controlled by the body control unit 27. Image data may be stored in the body memory 22 or in another storage medium. The body-side generation information may also be stored in the internal memory of the body control unit 27.

[0025] The display unit 23 displays images based on image data, shooting-related information such as shutter speed and aperture value, and menu screens. The operation unit 24 includes various setting switches such as a release button and a power switch, and outputs operation signals corresponding to each operation to the body control unit 27.

[0026] The body control unit 27 also includes a first body communication unit 28 and a second body communication unit 29. As will be described later, the first body communication unit 28 communicates command data with the first lens communication unit 38 via the body-side connection unit 202 and the lens-side connection unit 302. The second body communication unit 29 communicates via a hotline with the second lens communication unit 39 via the body-side connection unit 202 and the lens-side connection unit 302.

[0027] Next, command data communication will be explained. The first lens communication unit 38 and the first body communication unit 28 communicate in full duplex mode via the terminals of the lens-side connection unit 302 and the body-side connection unit 202, respectively. As will be described later using Figure 2, the first lens communication unit 38 and the first body communication unit 28 exchange four types of signals, for example, the RDY signal, CLK signal, DATAB signal, and DATAL signal.

[0028] The RDY signal is a signal indicating whether the first lens communication unit 38 is able to communicate, and the first lens communication unit 38 switches between a high level (H level) and a low level (L level). The RDY signal is a signal transmitted (output) to the first body communication unit 28. The CLK signal is a clock signal from the camera body side transmitted from the first body communication unit 28 to the first lens communication unit 38. The DATAB signal is a data signal transmitted from the first body communication unit 28 to the first lens communication unit 38. The DATAL signal is a data signal transmitted from the first lens communication unit 38 to the first body communication unit 28.

[0029] Next, we will explain the information (commands, data) transmitted and received in command data communication. The interchangeable lens 3 transmits response data (response data) to the camera body 2 via the DATAL signal, such as data regarding the optical characteristics of the photographic optical system 31 (such as the maximum aperture and aberrations), data regarding the infinity and close-focus positions of the focus lens, lens-side generation information, and the status of initialization in response to initialization commands from the camera body 2, which will be described later. On the other hand, the camera body 2 transmits response data (control data) to the interchangeable lens 3 via the DATAB signal, such as generation information indicating the communication specifications used for hotline communication, which will be described later, and control commands and control contents (control data) that instruct the driving of the focus lens, image stabilization lens, and zoom lens of the photographic optical system 31, the driving of the aperture diaphragm 32, and the initialization of the lens.

[0030] Figure 2 is a diagram illustrating command data communication in an imaging device according to the first embodiment. Figure 2 schematically shows an example of a timing chart for command data communication between the lens control unit 37 and the body control unit 27, and between the first lens communication unit 38 and the first body communication unit 28. The first lens communication unit 38 transmits and receives signals with the first body communication unit 28 using RDY signals, CLK signals, DATAB signals, and DATAL signals.

[0031] The signal level of the RDY signal indicates whether the first lens communication unit 38 is in a state where it can communicate. If the first lens communication unit 38 is in a state where it can communicate with the first body communication unit 28, the lens control unit 37 sets the signal level of the RDY signal to a low level (L level, e.g., ground voltage, reference voltage). If the first lens communication unit 38 is not in a state where it can communicate with the first body communication unit 28, the lens control unit 37 sets the signal level of the RDY signal to a high level (H level, e.g., power supply voltage). The first body communication unit 28 detects the signal level of the RDY signal, and the body control unit 27 determines whether the first lens communication unit 38 is in a state where it can communicate.

[0032] At time t1, when the RDY signal is at a low level (L level), the first body communication unit 28 outputs (transmits) a clock signal (CLK signal) to the first lens communication unit 38. That is, the first body communication unit 28 switches the signal level of the CLK signal, which was at a predetermined voltage (e.g., high level, power supply voltage) until time t1, to a high level and a low level (e.g., ground voltage, reference voltage) at a predetermined period after time t1. Also, during the period from time t1 to time t2, the first body communication unit 28 transmits a command packet 41 by DATAB signal in synchronization with the rising or falling edge of the CLK signal.

[0033] Furthermore, if the RDY signal is at a high level (H level), the first lens communication unit 38 is not accepting communication, and in this state, the first body communication unit 28 does not transmit commands and data to the first lens communication unit 38. In this case, the first body communication unit 28 fixes the signal levels of the CLK signal and the DATAB signal to a predetermined voltage (for example, a high level).

[0034] The lens control unit 37 checks the contents of the command packet 41 input from the first body communication unit 28 using a checksum or the like to determine whether the command packet 41 was received successfully. If the first lens communication unit 38 successfully receives the command packet 41, the lens control unit 37 raises the RDY signal to a high level at time t3. The lens control unit 37 also performs a first processing 51 according to the contents of the command packet 41. Once the first processing 51 is completed, the lens control unit 37 lowers the RDY signal to a low level at time t4. If the first lens communication unit 38 fails to successfully receive the command packet 41, the lens control unit 37 keeps the RDY signal at a low level and notifies the first body communication unit 28 that the command packet 41 was not received successfully.

[0035] When the first body communication unit 28 detects that the RDY signal has changed from a high level to a low level, it restarts outputting the CLK signal at time t5. Also, during the period from time t5 to time t6, the first body communication unit 28 transmits a data packet 42 by the DATAB signal, synchronized with the rising or falling edge of the CLK signal. Furthermore, during the same period from time t5 to time t6, the first lens communication unit 38 transmits a data packet 43 by the DATAL signal, synchronized with the rising or falling edge of the CLK signal input from the first body communication unit 28.

[0036] When the first lens communication unit 38 successfully receives a data packet 42 from the first body communication unit 28, the lens control unit 37 raises the RDY signal to a high level at time t7. The lens control unit 37 performs a second process 52 according to the contents of the data packet 42. Once the second process 52 is completed, the lens control unit 37 lowers the RDY signal to a low level at time t8.

[0037] The command packets 41 and data packets 42 output from the first body communication unit 28, as described above, indicate the contents of, for example, a request to initialize the interchangeable lens 3, a request for specific data, an instruction to drive a driven component of the photographic optical system 31 (e.g., a focus lens, an aperture diaphragm, etc.), or an instruction to start hotline communication by the second lens communication unit 39. The lens control unit 37 performs a process to generate the requested specific data or a process to drive a driven component as the first process 51 or the second process 52. The lens control unit 37 transmits, for example, flag data indicating the completion of the initialization of the interchangeable lens 3, data indicating optical characteristics, and data indicating that the driving of the instructed driven component has been completed as a data packet 43.

[0038] Next, we will explain the hotline communication in detail. As shown in Figure 1, the second lens communication unit 39 and the second body communication unit 29 perform unidirectional communication from the interchangeable lens 3 to the camera body 2 via the terminals of the lens-side connection unit 302 and the body-side connection unit 202, respectively. The second lens communication unit 39 transmits two types of signals to the second body communication unit 29, for example, an HCLK signal and an HDATA signal.

[0039] The HCLK signal is a clock signal from the interchangeable lens side transmitted from the second lens communication unit 39 to the second body communication unit 29. The HDATA signal is a data signal transmitted from the second lens communication unit 39 to the second body communication unit 29, and includes information regarding the lens positions of the focus lens, zoom lens, and image stabilization lens, as well as information regarding the aperture diameter of the aperture diaphragm 32. The second lens communication unit 39 transmits the HDATA signal to the second body communication unit 29 in synchronization with the periodic rising or falling edge of the HCLK signal. In this way, the second lens communication unit 39 and the second body communication unit 29 perform unidirectional communication, transmitting the clock signal and data signal from the second lens communication unit 39 to the second body communication unit 29.

[0040] The period of the CLK signal used for command data communication is approximately the same as, or shorter than, the period of the HCLK signal used for hotline communication. For example, the frequency of the CLK signal output from the camera body 2 to the interchangeable lens 3 is 8MHz, and the frequency of the HCLK signal output from the interchangeable lens 3 to the camera body 2 is approximately 2.5MHz to 8MHz.

[0041] Next, the electrical connections of the lens-side connector 302 and the body-side connector 202 will be described. Figure 3 is a schematic diagram showing the electrical connections of the lens-side connector 302 and the body-side connector 202. The body-side connector 202 has LDET(B) terminal, VBAT(B) terminal, PGND(B) terminal, V33(B) terminal, GND(B) terminal, RDY(B) terminal, DATAB(B) terminal, CLK(B) terminal, DATAL(B) terminal, HCLK(B) terminal, and HDATA(B) terminal. These 11 body-side terminals are collectively referred to as the body-side terminal group.

[0042] The LDET(B) terminal is used to detect the attachment and detachment of the interchangeable lens 3. The LDET(B) terminal is connected to the body control unit 27 via resistor R2. Power supply V33 supplied from the power supply unit 26 is connected between resistor R2 and the body control unit 27 via resistor R1, and the LDET(B) terminal is pulled up. The VBAT(B) terminal, PGND(B) terminal, V33(B) terminal, and GND(B) terminal are power supply terminals on the camera body side that are connected to the power supply unit 26. In Figure 3, the direction of the supplied power is indicated by arrows. The VBAT(B) terminal is used to supply power (supply power voltage) to the drive system of the interchangeable lens 3. The lens drive unit 33 of the interchangeable lens 3 is driven by the power supplied via the VBAT(B) terminal. The voltage applied by the power supply unit 26 to the VBAT(B) terminal is approximately 10V at most. The PGND(B) terminal is the ground terminal corresponding to the VBAT(B) terminal and is at ground potential (ground) relative to the power supply voltage of the drive system supplied by the VBAT(B) terminal.

[0043] The V33(B) terminal is used to supply power (supply power voltage) to the circuit system of the interchangeable lens 3. The power supplied from the power supply unit 26 via the V33(B) terminal operates the lens control unit 37 and other components. Each component, such as the lens control unit 37, operates with a smaller voltage and current compared to the lens drive unit 33. The voltage applied by the power supply unit 26 to the V33(B) terminal is approximately 3.3V at most. The GND(B) terminal is the grounding terminal corresponding to the V33(B) terminal and is the ground potential (ground) of the power supply voltage supplied to the circuit system by the V33(B) terminal.

[0044] The RDY(B) terminal, DATAB(B) terminal, CLK(B) terminal, DATAL(B) terminal, HCLK(B) terminal, and HDATA(B) terminal are communication terminals connected to the body control unit 27, and transmit and receive RDY signals, CLK signals, DATAB signals, DATAL signals, HCLK signals, and HDATA signals with the corresponding RDY(L) terminal, DATAB(L) terminal, CLK(L) terminal, DATAL(L) terminal, HCLK(L) terminal, and HDATA(L) terminal (described later). The RDY(B) terminal, DATAB(B) terminal, CLK(B) terminal, and DATAL(B) terminal are connected to the first body communication unit 28 of the body control unit 27 and are used for command data communication as described above. The HCLK(B) terminal and HDATA(B) terminal are connected to the second body communication unit 29 and are used for hotline communication as described above. In Figure 3, the signal flow is shown by arrows. The potential of the RDY(B) terminal indicates whether the interchangeable lens 3 is capable of command data communication. The DATAB(B) terminal is the terminal to which a signal is output towards interchangeable lens 3. The CLK(B) terminal is the terminal to which the clock signal from the camera body is output towards interchangeable lens 3.

[0045] The DATAL(B) terminal is the terminal into which the data signal from interchangeable lens 3 is input. The HCLK(B) terminal is the terminal to which the clock signal from interchangeable lens 3 is input. The HDATA(B) terminal is the terminal into which the data signal from interchangeable lens 3 is input.

[0046] The lens-side connector 302 has LDET(L) terminal, VBAT(L) terminal, PGND(L) terminal, V33(L) terminal, GND(L) terminal, RDY(L) terminal, DATAB(L) terminal, CLK(L) terminal, DATAL(L) terminal, HCLK(L) terminal, and HDATA(L) terminal. These 11 lens-side terminals are collectively referred to as the lens-side terminal group.

[0047] When the interchangeable lens 3 is attached to the camera body 2, the body-side terminals and lens-side terminals are electrically connected, as shown by the dashed lines in Figure 3. Specifically, the LDET(B) terminal is connected to the LDET(L) terminal, the VBAT(B) terminal is connected to the VBAT(L) terminal, the PGND(B) terminal is connected to the PGND(L) terminal, the V33(B) terminal is connected to the V33(L) terminal, the GND(B) terminal is connected to the GND(L) terminal, the RDY(B) terminal is connected to the RDY(L) terminal, the DATAB(B) terminal is connected to the DATAB(L) terminal, the CLK(B) terminal is connected to the CLK(L) terminal, the DATAL(B) terminal is connected to the DATAL(L) terminal, the HCLK(B) terminal is connected to the HCLK(L) terminal, and the HDATA(B) terminal is connected to the HDATA(L) terminal. The role of each lens-side terminal corresponds to the role of the body-side terminal it contacts.

[0048] The LDET(L) terminal is grounded via resistor R3. When the LDET(L) terminal makes contact with the LDET(B) terminal, the potential of the LDET(B) terminal is pulled down. The VBAT(L) terminal and PGND(L) terminal are connected to the lens drive unit 33 and aperture drive unit 35 via the lens control unit 37. A bypass capacitor C1 is connected between the VBAT(L) terminal and the PGND(L) terminal. The V33(L) terminal and GND(L) terminal are connected to the lens control unit 37. A bypass capacitor C2 is connected between the V33(L) terminal and the GND(L) terminal. The RDY(L) terminal, DATAB(L) terminal, CLK(L) terminal, DATAL(L) terminal, HCLK(L) terminal, and HDATA(L) terminal are each connected to the lens control unit 37. The RDY(L) terminal, DATAB(L) terminal, CLK(L) terminal, and DATAL(L) terminal are connected to the first lens communication unit 38 of the lens control unit 37 and are used for command data communication as described above. The HCLK(L) terminal and HDATA(L) terminal are connected to the second lens communication unit 39 and are used for hotline communication as described above.

[0049] After the control command from the body control unit 27 is transmitted to the lens control unit 37 of the interchangeable lens 3, the communication in which the control content (control data) from the body control unit 27 and the response content (response data) from the lens control unit 37 are transmitted and received in parallel is called command data communication. Command data communication is full-duplex communication. Command data communication is performed via digital data communication using the RDY(B) terminal, RDY(L) terminal, DATAB(B) terminal, DATAB(L) terminal, CLK(B) terminal, CLK(L) terminal, DATAL(B) terminal, and DATAL(L) terminal via the first body communication unit 28 and the first lens communication unit 38.

[0050] The body control unit 27 transmits various control commands and control contents to the interchangeable lens 3 via command data communication through the first body communication unit 28 and the first lens communication unit 38, and receives response contents from the interchangeable lens 3, thereby transmitting and receiving various information with the interchangeable lens 3. The control commands referred to here are, for example, commands to transmit lens information. The various information received from the interchangeable lens 3 are, for example, information indicating the model of the interchangeable lens 3 and optical characteristics such as the focal length of the imaging optical system 31. The various information transmitted to the interchangeable lens 3 are, for example, control contents such as the amount of lens drive and information indicating the model of the camera body 2. The control commands also include drive commands for focus lenses (not shown). The lens control unit 37 receives various control commands from the body control unit 27, receives various information from the body control unit 27, and transmits various information to the body control unit 27 via command data communication.

[0051] Figure 4(a) is a schematic diagram showing the mount of the camera body 2 as seen from the interchangeable lens 3 side. The body-side mount portion 201 has an annular reference surface of a certain width. Furthermore, the body-side mount portion 201 has a body-side first claw portion 129a, a body-side second claw portion 129b, a body-side third claw portion 129c, and a body-side fourth claw portion 129d. In the following description, these four claw portions will be collectively referred to as the body-side claw portion 129.

[0052] The body-side claw portions 129 are arranged at intervals from each other along the circular opening of the body-side mounting portion 201. As shown in Figure 4(a), the first body-side claw portion 129a is located in the upper right position, the second body-side claw portion 129b is located in the upper left position, the third body-side claw portion 129c is located in the lower left position, and the fourth body-side claw portion 129d is located in the lower right position.

[0053] The circumferential lengths of the first claw portion 129a to the fourth claw portion 129d on the body side are all different. Specifically, the first claw portion 129a on the body side is the longest, the third claw portion 129c on the body side is the second longest, the fourth claw portion 129d on the body side is the third longest, and the second claw portion 129b on the body side is the shortest.

[0054] The body-side claw portion 129 protrudes from the body-side mounting portion 201 toward the center of the opening, and on the circumference of the opening, there are portions where the body-side claw portion 129 is present and portions where it is not. In the following description, the space 140a between the body-side first claw portion 129a and the body-side fourth claw portion 129d on the circumference of the opening of the body-side mounting portion 201 will be referred to as the body-side first insertion / removal portion 140a. Similarly, the space 140b between the body-side first claw portion 129a and the body-side second claw portion 129b will be referred to as the body-side second insertion / removal portion 140b, the space 140c between the body-side second claw portion 129b and the body-side third claw portion 129c will be referred to as the body-side third insertion / removal portion 140c, and the space 140d between the body-side third claw portion 129c and the body-side fourth claw portion 129d will be referred to as the body-side fourth insertion / removal portion 140d. These four body-side insertion / removal sections are collectively referred to as the body-side insertion / removal section 140.

[0055] A body-side connection portion 202 is provided inside the opening of the body-side mounting portion 201. The body-side connection portion 202 has an arc shape corresponding to the annular shape of the body-side mounting portion 201. The body-side connection portion 202 is positioned parallel to the opening of the body-side mounting portion 201 and above the opening of the body-side mounting portion 201, preferably positioned in the center of the upper part as shown in Figure 4(a). As described above, the body-side connection portion 202 has a plurality of body-side terminals. The plurality of body-side terminals are arranged in an arc shape in a single line inside the body-side mounting portion 201 on the body-side connection portion 202. As shown in Figure 4(a), the plurality of body-side terminals are arranged from right to left as follows: HDATA(B), HCLK(B), DATAL(B), CLK(B), DATAB(B), RDY(B), GND(B), V33(B), PGND(B), VBAT(B), and LDET(B) on the far left, totaling 11 terminals. Each of the terminals on the camera body is a conductive pin. The terminals on the camera body are pushed in the -Z direction (Figure 1) by a spring or the like (not shown). The -Z direction is the direction toward the interchangeable lens 3 attached to the camera body 2, and is the direction of the subject.

[0056] The body-side mounting portion 201 has a hole through which the lock pin 142 passes. The hole through which the lock pin 142 passes is located to the upper right of the body-side fourth claw portion 129d. In other words, on the annular reference plane of the body-side mounting portion 201, the hole for the lock pin 142 is located between the region where the body-side fourth claw portion 129d is located and the region where the body-side first claw portion 129a is located within the opening of the body-side mounting portion 201. The lock pin 142 is pushed in the -Z direction (Figure 1) by a spring or the like (not shown).

[0057] Figure 4(b) is a schematic diagram of the camera body 2 mount with the body-side mount portion 201 removed, viewed from the interchangeable lens 3 side. A first leaf spring 141a is provided at a position corresponding to the body-side first claw portion 129a (the back side in the +Z direction of the body-side first claw portion 129a). Similarly, a second leaf spring 141b is provided at a position corresponding to the body-side second claw portion 129b (the back side of the body-side second claw portion 129b), a third leaf spring 141c is provided at a position corresponding to the body-side third claw portion 129c (the back side of the body-side third claw portion 129c), and a fourth leaf spring 141d is provided at a position corresponding to the body-side fourth claw portion 129d (the back side of the body-side fourth claw portion 129d). In the following description, these four leaf springs will be collectively referred to as leaf spring 141. The leaf spring 141 presses the lens-side claw portion, which will be described later, in the +Z direction (towards the camera body 2).

[0058] Figure 5 is a schematic diagram showing the mount of the interchangeable lens 3 as seen from the camera body 2. The interchangeable lens 3 includes the lens-side mount portion 301 and the lens-side connection portion 302 described in Figure 1. The lens-side mount portion 301 has an annular reference surface having a certain width. When the interchangeable lens 3 is attached to the camera body 2, the annular reference surface of the lens-side mount portion 301 contacts the annular reference surface of the body-side mount portion 201 described above. Furthermore, the lens-side mount portion 301 has a cylindrical portion extending in the direction of the optical axis on its inner circumference. The lens-side mount portion 301 has a lens-side first claw portion 139a, a lens-side second claw portion 139b, a lens-side third claw portion 139c, and a lens-side fourth claw portion 139d spaced apart from each other along the outer circumference of the cylindrical portion. In the following description, these four claw portions will be collectively referred to as the lens-side claw portion 139.

[0059] The lens-side claw portion 139 is provided in a direction that protrudes from the outer circumference of the cylindrical portion of the lens-side mount portion 301 toward the outside of the mount (radially from the optical axis L). As shown in Figure 5, the lens-side first claw portion 139a is located in the upper left position, the lens-side second claw portion 139b is located in the upper right position, the lens-side third claw portion 139c is located in the lower right position, and the lens-side fourth claw portion 139d is located in the lower left position. Behind the lens-side claw portion 139 (on the reference plane side of the lens-side mount portion 301), there is space for the corresponding body-side claw portion 129 to fit into when the interchangeable lens 3 is attached to the camera body 2.

[0060] A lens-side connection portion 302 is provided inside the opening of the lens-side mount portion 301. The lens-side connection portion 302 has an arc shape corresponding to the annular shape of the lens-side mount portion 301. The lens-side connection portion 302 is positioned parallel to the opening of the lens-side mount portion 301 and is located in the upper part of the opening of the lens-side mount portion 301, preferably in the center of the upper part as shown in Figure 5. As described above, the lens-side connection portion 302 has a plurality of lens-side terminals. The plurality of lens-side terminals are arranged in an arc shape in a single line inside the lens-side mount portion 301 on the lens-side connection portion 302. As shown in Figure 5, the plurality of lens-side terminals are arranged from right to left as follows: LDET(L), VBAT(L), PGND(L), V33(L), ​​GND(L), RDY(L), DATAB(L), CLK(L), DATAL(L), HCLK(L), and HDATA(L), totaling 11 terminals. The lens-side terminal group is arranged so that the conductive contact surface of each terminal is exposed in the +Z direction (Figure 1). The +Z direction is the direction in which the subject light that has passed through the imaging optical system 31 is directed toward the image sensor 21.

[0061] The lens-side mount portion 301 has a lock pin receiving portion 143. As shown in Figure 5, the lock pin receiving portion 143 is located to the upper left of the lens-side fourth claw portion 139d. In other words, the lock pin receiving portion 143 is located between the portion of the lens-side mount portion 301 corresponding to the lens-side first claw portion 139a and the portion corresponding to the lens-side fourth claw portion 139d. The lock pin receiving portion 143 is a groove into which the lock pin 142 fits when the interchangeable lens 3 is attached to the camera body 2. This groove is provided in the -Z direction (Figure 1) from the reference plane of the lens-side mount portion 301.

[0062] When the interchangeable lens 3 is attached to the camera body 2, multiple body-side terminals physically contact the corresponding multiple lens-side terminals. This contact electrically connects the multiple body-side terminals to the multiple lens-side terminals. In other words, the multiple body-side terminals and the multiple lens-side terminals become electrically conductive.

[0063] (Attaching interchangeable lenses) This section describes how to attach the interchangeable lens 3 to the camera body 2. When attaching the interchangeable lens 3 to the camera body 2, first, the body-side mount portion 201 and the lens-side mount portion 301 are placed opposite each other, the lens-side first claw portion 139a is aligned with the body-side first insertion / removal portion 140a, the lens-side second claw portion 139b is aligned with the body-side second insertion / removal portion 140b, the lens-side third claw portion 139c is aligned with the body-side third insertion / removal portion 140c, and the lens-side fourth claw portion 139d is aligned with the body-side fourth insertion / removal portion 140d. Then, the first claw portion 139a on the lens side is inserted into the first insertion / removal portion 140a on the body side, the second claw portion 139b on the lens side is inserted into the second insertion / removal portion 140b on the body side, the third claw portion 139c on the lens side is inserted into the third insertion / removal portion 140c on the body side, and the fourth claw portion 139d on the lens side is inserted into the fourth insertion / removal portion 140d on the body side. At this time, the LDET(L) terminal makes contact with the CLK(B) terminal, the VBAT(L) terminal makes contact with the DATAL(B) terminal, the PGND(L) terminal makes contact with the HCLK(B) terminal, and the V33(L) terminal makes contact with the HDATA(B) terminal.

[0064] From that state, rotate the interchangeable lens 3 in the mounting direction 144 shown in Figures 4(a) and 5. That is, the first claw portion 129a on the body side enters the space on the back of the first claw portion 139a on the lens side, the second claw portion 129b on the body side enters the space on the back of the second claw portion 139b on the lens side, the third claw portion 129c on the body side enters the space on the back of the third claw portion 139c on the lens side, and the fourth claw portion 129d on the body side enters the space on the back of the fourth claw portion 139d on the lens side. At this time, the multiple lens-side terminals make contact with the multiple body-side terminals in sequence. Alternatively, instead of the interchangeable lens 3, the camera body 2 may be rotated in the opposite direction to the mounting direction 144 shown in Figures 4(a) and 5.

[0065] When the lens-side claw portion 139 is inserted into the corresponding body-side insertion / removal portion 140 and rotated in the mounting direction 144, for example, the LDET(L) terminal will contact the CLK(B) terminal, DATAB(B) terminal, RDY(B) terminal, GND(B) terminal, V33(B) terminal, PGND(B) terminal, VBAT(B) terminal, and LDET(B) terminal in that order. For example, the VBAT(L) terminal will contact the DATAL(B) terminal, CLK(B) terminal, DATAB(B) terminal, RDY(B) terminal, GND(B) terminal, V33(B) terminal, PGND(B) terminal, and VBAT(B) terminal in that order. For example, the PGND(L) terminal will contact the HCLK(B) terminal, DATAL(B) terminal, CLK(B) terminal, DATAB(B) terminal, RDY(B) terminal, GND(B) terminal, V33(B) terminal, and PGND(B) terminal in that order. For example, the V33(L) terminal makes contact with the HDATA(B) terminal, HCLK(B) terminal, DATAL(B) terminal, CLK(B) terminal, DATAB(B) terminal, RDY(B) terminal, GND(B) terminal, and V33(B) terminal in that order. For example, the GND(L) terminal makes contact with the HDATA(B) terminal, HCLK(B) terminal, DATAL(B) terminal, CLK(B) terminal, DATAB(B) terminal, RDY(B) terminal, and GND(B) terminal in that order.

[0066] For example, the RDY(L) terminal makes contact with the HDATA(B) terminal, HCLK(B) terminal, DATAL(B) terminal, CLK(B) terminal, DATAB(B) terminal, and RDY(B) terminal in that order. For example, the DATAB(L) terminal makes contact with the HDATA(B) terminal, HCLK(B) terminal, DATAL(B) terminal, CLK(B) terminal, and DATAB(B) terminal in that order. For example, the CLK(L) terminal makes contact with the HDATA(B) terminal, HCLK(B) terminal, DATAL(B) terminal, and CLK(B) terminal in that order. For example, the DATAL(L) terminal makes contact with the HDATA(B) terminal, HCLK(B) terminal, and DATAL(B) terminal in that order. For example, the HCLK(L) terminal makes contact with the HDATA(B) terminal and HCLK(B) terminal in that order.

[0067] When the interchangeable lens 3 is rotated relative to the camera body 2 by a predetermined angle, it reaches the mounting completion position. In the mounting completion position, the corresponding body-side claw portion 129 and lens-side claw portion 139 face each other in the optical axis direction, and the lock pin 142 is pushed in the -Z direction in Figure 1 and enters the lock pin receiving portion 143. Once the lock pin 142 enters the lock pin receiving portion 143, the interchangeable lens 3 cannot be rotated to be removed from the camera body 2. In other words, when the body-side claw portion 129 and the lens-side claw portion 139 reach the predetermined mounting completion position, the relative position of the body-side mount portion 201 and the lens-side mount portion 301 is fixed. The lens-side claw portion 139 is pushed toward the body side (in the +Z direction in Figure 1) by the leaf spring 141. As a result, each of the multiple lens-side terminals contacts each of the multiple body-side terminals that correspond to each of them, and an electrical connection is made.

[0068] In the following description, the state in which the body-side claw portion 129 and the lens-side claw portion 139 have reached a predetermined mounting completion position is referred to as the mounting completion state. The state in which the lens-side claw portion 139 is rotating from the position in which it is inserted into the body-side insertion / removal portion 140 to just before the mounting completion position, or the state in which it is rotating from just before the mounting completion position to the insertion position, is referred to as the mounting in progress state.

[0069] When the lens is attached, the signal level of the LDET(B) terminal is pulled up and is at a high level. When the body control unit 27 detects that the signal level of the LDET(B) terminal is at a high level, it determines that the interchangeable lens 3 is not attached. When the interchangeable lens 3 is not attached, the body control unit 27 does not allow the power supply unit 26 to supply power to the VBAT(B) terminal and the V33(B) terminal.

[0070] When the lens is fully attached, the signal level of the LDET(B) terminal is pulled down to a low level, as described above (Figure 3). When the body control unit 27 detects that the signal level of the LDET(B) terminal has become low, it determines that the interchangeable lens 3 has been attached. Also, when the lens is fully attached, the lock pin 142 enters the lock pin receiving part 143, and a lock pin detection switch (not shown) that is linked to the lock pin 142 is turned on. When the body control unit 27 detects that the signal level of the LDET(B) terminal has become low and that the lock pin detection switch has been turned on, it starts supplying power to the V33(B) terminal to the power supply unit 26, that is, it supplies the power supply voltage to the circuit system. Note that the camera body 2 does not necessarily have to be equipped with a lock pin detection switch. If there is no lock pin detection switch, the power supply unit 26 should be instructed to start supplying power to the V33(B) terminal when it detects that the signal level of the LDET(B) terminal has become low.

[0071] When power is supplied to the V33(B) terminal, the power supply voltage is supplied to the lens control unit 37 of the interchangeable lens 3 through the V33(L) terminal, and the lens control unit 37 starts operating. The operating lens control unit 37 then permits initial communication with the body control unit 27 via command data communication. After the lens control unit 37 permits initial communication, the body control unit 27 starts initial communication. The initial communication includes a signal requesting power supply to the VBAT(L) terminal from the lens control unit 37. When the signal requesting power supply to the VBAT(L) terminal is sent from the lens control unit 37 to the body control unit 27, the body control unit 27 supplies power supply voltage to the VBAT(B) terminal, and initialization processing is performed between the camera body 2 and the interchangeable lens 3. During initialization processing, information necessary for various operations of the camera 1, such as shooting and focusing, is exchanged between the camera body 2 and the interchangeable lens 3, and the lens position of the interchangeable lens is moved to the reference position.

[0072] When the lens is fully mounted, if the user presses the unillustrated unlock button on the camera body 2, the lock pin 142 retracts from the lock pin receiving portion 143. This allows the relative position between the body-side mount portion 201 and the lens-side mount portion 301 to be changed. When the user presses the unillustrated unlock button, the body control unit 27 turns off the lock pin detection switch linked to the unlock button, stopping the power supply to the VBAT(B) terminal and V33(B) terminal of the power supply unit 26. From this state, if the interchangeable lens 3 is rotated in the opposite direction to the mounting direction 144 shown in Figures 4(a) and 5, the multiple lens-side terminals make contact with the multiple body-side terminals in the reverse order described above.

[0073] It is not necessary to stop the power supply in conjunction with the operation of the unlock button. In this case, the body control unit 27 stops the power supply to the VBAT(B) terminal and V33(B) terminal when it detects that the LDET(L) terminal and LDET(B) terminal have separated due to rotation in the opposite direction to the mounting direction 144 of the interchangeable lens 3, and that the signal level of the LDET(B) terminal has changed from a low level to a high level. This reduces the number of parts in the camera 1. Alternatively, the power supply to the VBAT(B) terminal and V33(B) terminal may be stopped when both the unlock button is pressed and the signal level of the LDET(B) terminal has changed from a low level to a high level. Alternatively, the body control unit 27 may stop supplying power to the VBAT(B) terminal and V33(B) terminal to the power supply unit 26 when it detects either the release button being pressed or the signal level of the LDET(B) terminal changing from a low level to a high level.

[0074] As explained above, during the attachment and removal of interchangeable lenses from the camera body (while attached), the lens-side terminals may come into contact with body-side terminals other than the terminals they should be corresponding to when attachment is complete. It is desirable that the arrangement of the lens-side terminals and body-side terminals minimizes problems caused by this contact during attachment and removal.

[0075] In this embodiment, the LDET(B) terminal is positioned at the very front of the multiple body-side terminals in the direction of lens mounting (arrow 144 in Figure 4(a)). That is, as described above, the LDET(B) terminal is located at the leftmost position of the group of body-side terminals in Figure 4(a). Similarly, the LDET(L) terminal is also positioned at the very front of the multiple lens-side terminals in the direction of lens mounting (arrow 144 in Figure 5). That is, as described above, the LDET(L) terminal is located at the rightmost position of the group of lens-side terminals in Figure 5. Therefore, the LDET(B) terminal does not come into contact with any other lens-side terminals until the lens mounting is complete. Consequently, the signal level of the LDET(B) terminal will not mistakenly become low during the lens mounting process, and the lens mounting will not be incorrectly recognized.

[0076] In this embodiment, the VBAT(B) terminal is positioned next to the LDET(B) terminal, that is, second from the front in the mounting direction. The VBAT(L) terminal is positioned next to the LDET(L) terminal, that is, second from the front in the mounting direction. This arrangement is to reduce the number of lens-side terminals that the VBAT(B) terminal on the camera body comes into contact with during the lens mounting process. Since the voltage applied to the VBAT(B) terminal is higher than that of the other terminals, if the VBAT(B) terminal comes into contact with a terminal other than the VBAT(L) terminal under circumstances where a high voltage is accidentally applied to the VBAT(B) terminal due to a malfunction of the camera 1, this high voltage may place an unexpected load on the electrical circuit inside the interchangeable lens. In this embodiment, since the VBAT(B) terminal is located next to the LDET(B) terminal, when the interchangeable lens 3 is mounted, the VBAT(B) terminal comes into contact with only the LDET(L) terminal among the multiple lens-side terminals. The LDET(L) terminal is grounded via a resistor (resistor R3 in Figure 3), so even if a high voltage is applied from the VBAT(B) terminal, it will not affect camera 1.

[0077] In this embodiment, the PGND(B) terminal is positioned next to the VBAT(B) terminal, i.e., third from the leading edge in the mounting direction. The PGND(L) terminal is positioned next to the VBAT(L) terminal, i.e., third from the leading edge in the mounting direction. The capacitor C1 connected to the VBAT(L) terminal stores charge from the high voltage supplied from the VBAT(B) terminal. When the interchangeable lens 3 is rotated in the removal direction (opposite to the mounting direction 144), the VBAT(L) terminal first contacts the PGND(B) terminal. The charge stored in the capacitor C1 is quickly discharged from the PGND(B) terminal, which is the ground terminal, and does not affect other circuits of the camera 1.

[0078] In this embodiment, the V33(B) terminal is positioned next to the PGND(B) terminal, i.e., fourth from the front in the mounting direction, and the GND(B) terminal is positioned next to it, i.e., fifth from the front. The V33(L) terminal is positioned next to the PGND(L) terminal, i.e., fourth from the front in the mounting direction, and the GND(L) terminal is positioned next to it, i.e., fifth from the front. The capacitor C2 connected to the V33(L) terminal stores charge from the voltage supplied from the V33(B) terminal. When the interchangeable lens 3 is rotated in the removal direction (opposite to the mounting direction 144), the V33(L) terminal first contacts the GND(B) terminal. The charge stored in the capacitor C2 is quickly discharged from the GND(B) terminal, which is the ground terminal, and does not affect other circuits of the camera 1.

[0079] The RDY(B) terminal is placed next to the GND(B) terminal, i.e., the 6th terminal from the front, the DATAB(B) terminal is placed next to it, i.e., the 7th terminal from the front, the CLK(B) terminal is placed next to it, i.e., the 8th terminal from the front, the DATAL(B) terminal is placed next to it, i.e., the 9th terminal from the front, the HCLK(B) terminal is placed next to it, i.e., the 10th terminal from the front, and the HDATA(B) terminal is placed next to it, at the very end.

[0080] The RDY(L) terminal is placed next to the GND(L) terminal, i.e., the 6th terminal from the front, the DATAB(L) terminal is placed next to it, i.e., the 7th terminal from the front, the CLK(L) terminal is placed next to it, i.e., the 8th terminal from the front, the DATAL(L) terminal is placed next to it, i.e., the 9th terminal from the front, the HCLK(L) terminal is placed next to it, i.e., the 10th terminal from the front, and the HDATA(L) terminal is placed next to it, at the very end.

[0081] Next, we will describe the effects of noise on the communication lines, which consist of each body-side terminal and each lens-side terminal. Hotline communication is a type of communication in which information is unilaterally transmitted to camera body 2 after communication has started, and it is performed at a high frequency (repeated in very short cycles). During hotline communication, the clock signal (H clock signal) from the interchangeable lens is sent from the HCLK(L) terminal to the HCLK(B) terminal. Since the clock signal is a signal that repeats between high and low levels in a short cycle, it can be a major noise source for other signals. Furthermore, since the clock signal (H clock signal) from the interchangeable lens transmitted from the HCLK(L) terminal to the HCLK(B) terminal is a signal output from interchangeable lens 3, even if noise is mistakenly superimposed on that clock signal, camera body 2 cannot recognize that noise. Thus, there is a possibility that the clock signal (H clock signal) flowing through the HCLK terminal may be a noise source, or that noise may be superimposed on the clock signal (H clock signal), which may cause malfunctions in camera 1. Examples of malfunctions include incorrect detection of interchangeable lens attachment or incorrect determination of whether command data communication is possible or not.

[0082] In this embodiment, the HCLK terminal is positioned away from the VBAT terminal, which is subjected to high voltage. The voltage and current of the VBAT terminal that drives the lens drive unit 33 of the interchangeable lens 3 fluctuate depending on the driving state of the lens drive unit 33. Therefore, fluctuations in the voltage and current of the VBAT terminal can become noise for other terminals. By separating the VBAT terminal from the HCLK terminal, it is possible to suppress the effect of noise caused by fluctuations in the voltage and current of the VBAT terminal on the clock signal (H clock signal). In other words, it is possible to suppress noise from being superimposed on the clock signal (H clock signal). As described above, the RDY terminal is used to indicate whether command communication is possible or not. In this embodiment, the HCLK terminal, which can be a source of noise, is placed away from the RDY terminal so as not to be adjacent to it. Therefore, it is possible to suppress the influence of noise from the clock signal (H clock signal) on the signal at the RDY terminal.

[0083] Furthermore, the HDATA and DATAL terminals are positioned on either side of the HCLK terminal. This arrangement minimizes the impact of noise from the HCLK terminal on terminals other than the HDATA and DATAL terminals. The signals flowing through the HDATA and DATAL terminals fluctuate less than the clock signal (H clock signal). Therefore, the impact of fluctuations in the clock signal (H clock signal) on terminals other than the HDATA and DATAL terminals is minimized.

[0084] Next, as mentioned above, command data communication is a bidirectional communication method that sends and receives information between the camera body 2 and the interchangeable lens 3. During command data communication, the clock signal (C clock signal) from the camera body is sent from the CLK(B) terminal to the CLK(L) terminal. The clock signal (C clock signal) transmitted at the CLK terminal can also be a source of noise for the same reasons mentioned earlier. Furthermore, if noise is superimposed on the clock signal (C clock signal), abnormalities will occur in command communication. Therefore, in this embodiment, the CLK terminal is positioned away from the VBAT terminal, which is subjected to high voltage. The voltage and current of the VBAT terminal that drives the lens drive unit 33 of the interchangeable lens 3 fluctuate depending on the driving state of the lens drive unit 33, so fluctuations in the voltage and current of the VBAT terminal can become noise for other terminals. Therefore, by separating the VBAT terminal from the CLK terminal, it is possible to suppress the effect of noise from the VBAT terminal on the clock signal (C clock signal). In other words, it is possible to suppress noise superimposed on the clock signal (C clock signal). Furthermore, the CLK terminal was positioned separately from the RDY terminal, which is used to indicate whether command communication is permitted or not.

[0085] Furthermore, if the HCLK terminal and the CLK terminal are placed adjacent to each other, one clock signal can affect the other clock signal, potentially becoming a noise source. In this embodiment, the DATAL terminal is placed between the CLK terminal and the HCLK terminal. Also, the DATAB terminal is placed between the CLK terminal and the RDY terminal. In other words, the DATAL terminal and the DATAB terminal are placed on both sides of the CLK terminal. This makes it possible to suppress the influence of noise originating from the CLK terminal on the camera 1. This is because the signals flowing through the DATAL terminal and the DATAB terminal fluctuate less than the clock signal (C clock signal), thus suppressing the influence of fluctuations in the clock signal (C clock signal) on terminals other than the DATAL terminal and the DATAB terminal. Placing the DATAL terminal between the CLK terminal and the HCLK terminal reduces the influence of fluctuations in the CLK terminal's clock signal (C clock signal) and the HCLK terminal's clock signal (H clock signal) on the DATAL terminal, as the signal flowing through the DATAL terminal fluctuates less than the clock signal of the CLK terminal (C clock signal) and the clock signal of the HCLK terminal (H clock signal).

[0086] As mentioned above, the level of the RDY terminal must be determined in order to perform command data communication. In other words, the signal level of the RDY terminal indicates whether command data can be communicated, so noise has a significant impact on the shooting operation. Now, consider the case where the body control unit 27 mistakenly perceives that command data can be communicated due to noise, even though it is not possible to communicate command data. In this case, the lens control unit 37 cannot receive the command data, but the body control unit 27 transmits the command data, and the body control unit 27 mistakenly perceives that control will be performed on the interchangeable lens 3 according to that command data. However, since the lens control unit 37 cannot accept the command data, control will not be performed according to the mistakenly transmitted command data. Therefore, the operation of the camera 1 will be impaired. For this reason, it is necessary to prevent noise from being superimposed on the signal of the RDY terminal. To prevent noise from being superimposed on the signal of the RDY terminal, it is desirable to place terminals on either side of the RDY terminal that carry relatively stable signals, that is, signals with little change in signal level per unit time. In this embodiment, the GND terminal and DATAB terminal are placed on either side of the RDY terminal. The GND terminal is stable because it is at ground potential, and the DATAB terminal also carries a more stable signal compared to the CLK and HCLK terminals. This approach helps to suppress the noise affecting the signal at the RDY terminal.

[0087] Next, the power (power supply voltage) supplied from the VBAT(B) terminal to the VBAT(L) terminal is used to drive the actuator (e.g., a stepping motor) of the lens drive unit 33 of the interchangeable lens 3. Therefore, the current flowing through the VBAT terminal fluctuates significantly depending on whether the actuator is driven or not. Such current fluctuations become a source of noise for signals flowing to other terminals. In this embodiment, the VBAT terminal is positioned away from the RDY terminal, DATAB terminal, CLK terminal, DATAL terminal used for command data communication, and the HCLK terminal and HDATA terminal used for hotline communication. Furthermore, the GND terminal, V33 terminal, and PGND terminal are placed between the VBAT terminal and the terminals used for these communications. This suppresses the impact of noise caused by fluctuations in the current flowing through the VBAT terminal on data communication.

[0088] Here's a summary of the terminal arrangement that takes noise into consideration, as explained above. The RDY terminal is positioned away from both the VBAT and HCLK terminals, which are sources of noise. This minimizes the impact of noise on the RDY terminal, which is used to indicate whether command data communication is possible or not. The HCLK terminal, which is a source of noise, is sandwiched between the HDATA and DATAL terminals, and the CLK terminal is sandwiched between the DATAL and DATAB terminals. In other words, the terminals are arranged in the following order from the rear end in the mounting direction: HDATA terminal, HCLK terminal, DATAL terminal, CLK terminal, and DATAB terminal. This suppresses the influence of noise caused by the clock signal on terminals such as the RDY terminal.

[0089] Furthermore, considering the effects of noise, the terminals for power supply and the terminals used for communication were arranged separately with the RDY terminal in between. More specifically, the terminals for power supply, namely the VBAT terminal, PGND terminal, V33 terminal, and GND terminal, are arranged in order from the front end in the mounting direction, with the RDY terminal in between. The terminals used for communication, namely the DATAB terminal, CLK terminal, DATAL terminal, HCLK terminal, and HDATA terminal, are arranged in order from the front end in the mounting direction, with the RDY terminal in between. This reduces the influence of the power supply terminals, such as the VBAT terminal, on the terminals used for communication. It also reduces the influence of noise from the power supply terminals, such as the VBAT terminal, and the communication terminals, such as the HCLK terminal and CLK terminal, on the RDY terminal.

[0090] The HCLK terminal, which receives the clock signal from the interchangeable lens used for hotline communication, and the CLK terminal, which receives the clock signal from the camera body used for command data communication, are positioned further apart from the VBAT terminal than the CLK terminal. This is because the clock signal sent to the interchangeable lens 3 via the CLK terminal is output by the body control unit 27 via the first body communication unit 28, but if noise is superimposed on the clock signal transmitted from the interchangeable lens to the camera body 2 via the HCLK(L) terminal through the second lens communication unit 39, the body control unit 27 will misinterpret it. Therefore, the noise superimposed on the clock signal at the HCLK terminal has a greater impact on the camera 1.

[0091] The HCLK terminal is positioned further away from the VBAT terminal than the GND terminal. Furthermore, a PGND terminal is placed between the GND terminal and the VBAT terminal. This shields the HCLK terminal, to which the clock signal used for hotline communication is sent, from noise originating from the VBAT terminal. The CLK terminal is positioned further away from the VBAT terminal than the GND terminal. Furthermore, a PGND terminal is placed between the GND terminal and the VBAT terminal. This shields the CLK terminal, to which the clock signal used for command data communication is sent, from noise originating from the VBAT terminal.

[0092] Using the terminals arranged in this manner, as described above, the interchangeable lens 3 and camera body 2 perform command data communication using the RDY signal, CLK signal, DATAB signal, and DATAL signal via the first lens communication unit 38 and the first body communication unit 28. In addition, the interchangeable lens 3 and camera body 2 perform hotline communication using the HCLK signal and HDATA signal via the second lens communication unit 39 and the second body communication unit 29. The communication path used for command data communication is provided separately from the communication path used for hotline communication, and command data communication and hotline communication can be performed in parallel. That is, even when the first lens communication unit 38 is performing command data communication with the first body communication unit 28, the second lens communication unit 39 can arbitrarily perform hotline communication with the second body communication unit 29. Also, even when the second lens communication unit 39 is performing hotline communication with the second body communication unit 29, the first lens communication unit 38 can arbitrarily perform command data communication with the first body communication unit 28.

[0093] (Terminal arrangement considering wear) The following describes the contact of each terminal when attaching or detaching the interchangeable lens 3 to the camera body 2. When attaching interchangeable lens 3 to camera body 2, the body-side terminals successively come into contact with the lens-side terminals. The same occurs when removing interchangeable lens 3 from camera body 2. In other words, the body-side terminals, which are pins protruding from the body-side connection part 202, and the lens-side terminals, which are exposed conductive contact surfaces, are rubbed against each other one after another. Because multiple interchangeable lenses are attached to and detached from a single camera body, the body-side terminals are more prone to wear than the lens-side terminals. In particular, the body-side terminals located towards the rear end in the direction in which interchangeable lens 3 is attached are rubbed against more lens-side terminals and experience more friction. Therefore, the tips of the pins of body-side terminals located towards the rear end are more prone to wear than those located towards the front end. Wear on the body-side terminals affects the contact with the lens-side terminals, which may lead to unstable data communication. In this embodiment, the LDET(B) terminal is positioned at the very front in the mounting direction, resulting in minimal wear on the LDET(B) terminal. This ensures good contact between the LDET(B) terminal and the LDET(L) terminal, reducing the possibility of false detection of the attachment or detachment of the interchangeable lens 3.

[0094] As mentioned above, in this embodiment, in order to suppress the influence of noise on communication, the CLK(B) terminal and HCLK(B) terminal are positioned away from the VBAT(B) terminal. In other words, the VBAT(B) terminal is positioned second from the front end in the mounting direction, and the CLK(B) terminal and HCLK(B) terminal are positioned at the rear end, away from the VBAT(B) terminal. Consequently, the CLK(B) terminal and HCLK(B) terminal experience more wear than the LDET(B) terminal and VBAT(B) terminal. In this embodiment, the CLK(B) terminal and HCLK(B) terminal are positioned very close to the first claw portion 129a on the body side. That is, the CLK(B) terminal and HCLK(B) terminal are positioned closer to the inner edge, which is the inner circumference edge of the first claw portion 129a on the body side, than the VBAT(B) terminal. In other words, the distance between the CLK(B) terminal and the inner edge of the body-side first claw portion 129a is shorter than the distance between the VBAT(B) terminal and the inner edge of the body-side first claw portion 129a, and the distance between the HCLK(B) terminal and the inner edge of the body-side first claw portion 129a is shorter than the distance between the VBAT(B) terminal and the inner edge of the body-side first claw portion 129a. As described above, there is a first leaf spring 141a on the back side of the body-side first claw portion 129a, and the first leaf spring 141a presses the lens-side first claw portion 139a in the +Z direction (Figure 1).

[0095] From the perspective of the first leaf spring 141a, the distance between the CLK(B) terminal and the first leaf spring 141a, and the distance between the HCLK(B) terminal and the first leaf spring 141a are both shorter than the distance between the VBAT(B) terminal and the first leaf spring 141a. Similarly, the LDET(B) terminal is the same as the VBAT(B) terminal; the distance between the CLK(B) terminal and the first leaf spring 141a, and the distance between the HCLK(B) terminal and the first leaf spring 141a are both shorter than the distance between the LDET(B) terminal and the first leaf spring 141a. As a result, the CLK(B) terminal and the HCLK(B) terminal are pressed more firmly against the lens-side terminal than the VBAT(B) terminal and the LDET(B) terminal.

[0096] On the lens side, the CLK(L) terminal and HCLK(L) terminal are positioned closer to the inner edge of the first claw portion 139a on the lens side than the VBAT(L) terminal. In other words, the distance between the CLK(L) terminal and the inner edge of the first claw portion 139a on the lens side is shorter than the distance between the VBAT(L) terminal and the inner edge of the first claw portion 139a on the lens side, and the distance between the HCLK(L) terminal and the inner edge of the first claw portion 139a on the lens side is shorter than the distance between the VBAT(L) terminal and the inner edge of the first claw portion 139a on the lens side. Therefore, when the mounting is complete, the CLK(L) terminal and HCLK(L) terminal located next to the first claw portion 139a on the lens side are pressed against the corresponding body-side terminals by the first leaf spring 141a.

[0097] Furthermore, the LDET(L) terminal is similar to the VBAT(L) terminal, and in the fully mounted state, the distance between the CLK(L) terminal and the first leaf spring 141a, and the distance between the HCLK(L) terminal and the first leaf spring 141a are both shorter than the distance between the LDET(L) terminal and the first leaf spring 141a. In this way, the CLK(L) terminal and HCLK(L) terminal exert a stronger pressing force against the body-side terminal than the LDET(L) terminal in the fully mounted state. This ensures that good contact is maintained even if the CLK(B) terminal and HCLK(B) terminal wear down, resulting in stable clock signals and stable data communication. Also, for example, even if the camera body 2 or interchangeable lens 3 is subjected to impact while the fully mounted state is maintained, the contact between the CLK(B) terminal and the CLK(L) terminal, and the contact between the HCLK(B) terminal and the HCLK(L) terminal are maintained.

[0098] Even if a portion of the lens-side first claw portion 139a is cut out, the entire area, including the protruding portion and the cut-out portion, located in the region facing the body-side first claw portion 129a, is considered the lens-side first claw portion. The cut-out can be made by dividing the lens-side claw portion into two or more parts in the circumferential direction, by cutting out a portion of the lens-side claw portion, or by cutting out at least a portion of the lens-side claw portion so that its radial length is shortened. The circumferential length of the lens-side claw portion may also be changed within the range that passes through the corresponding body-side insertion / removal portion. The same applies to the lens-side second claw portion 139b, the lens-side third claw portion 139c, and the lens-side fourth claw portion 139d. Furthermore, the radial thickness of the cylindrical portion can be changed as appropriate, and it may have a shape in which at least a portion protrudes inward from the cylindrical portion of this embodiment.

[0099] As described above, the CLK(B) terminal and HCLK(B) terminal experience more wear than the LDET(B) terminal and VBAT(B) terminal. In this embodiment, the CLK(B) terminal and HCLK(B) terminal are positioned very close to the body-side first claw portion 129a. That is, the CLK(B) terminal and HCLK(B) terminal are positioned closer to the inner edge of the body-side first claw portion 129a than the LDET(B) terminal and VBAT(B) terminal. In other words, the distance between the CLK(B) terminal and the inner edge of the body-side first claw portion 129a is shorter than the distance between the LDET(B) terminal and VBAT(B) terminal and the inner edge of the body-side first claw portion 129a, and the distance between the HCLK(B) terminal and the inner edge of the body-side first claw portion 129a is shorter than the distance between the LDET(B) terminal and VBAT(B) terminal and the inner edge of the body-side first claw portion 129a. As described above, there is a first leaf spring 141a on the back side of the body-side first claw portion 129a, and the first leaf spring 141a presses the lens-side first claw portion 139a in the +Z direction (Figure 1). From the perspective of the first leaf spring 141a, the distance between the CLK(B) terminal and the first leaf spring 141a, and the distance between the HCLK(B) terminal and the first leaf spring 141a are both shorter than the distance between the LDET(B) terminal and the VBAT(B) terminal and the first leaf spring 141a.

[0100] On the lens side, the CLK(L) terminal and HCLK(L) terminal are positioned closer to the inner edge of the first claw portion 139a on the lens side than the LDET(L) terminal and VBAT(L) terminal. In other words, the distance between the CLK(L) terminal and the inner edge of the first claw portion 139a on the lens side is shorter than the distance between the LDET(L) terminal and VBAT(L) terminal and the inner edge of the first claw portion 139a on the lens side, and the distance between the HCLK(L) terminal and the inner edge of the first claw portion 139a on the lens side is shorter than the distance between the LDET(L) terminal and VBAT(L) terminal and the inner edge of the first claw portion 139a on the lens side. Therefore, the CLK(L) terminal and HCLK(L) terminal located near the first claw portion 139a on the lens side are pressed against the corresponding body-side terminals by the first leaf spring 141a. As a result, the CLK(B) and HCLK(B) terminals are pressed more firmly against the lens-side terminals than the LDET(B) and VBAT(B) terminals. This ensures that good contact is maintained even if the CLK(B) and HCLK(B) terminals wear down, enabling stable communication. Furthermore, even if the camera body 2 or interchangeable lens 3 is subjected to impact while the lens is mounted, the contact between the CLK(B) and HCLK(B) terminals and the lens-side terminals is maintained.

[0101] In this embodiment, the CLK(B) terminal and the HCLK(B) terminal are also close to the body-side fourth claw portion 129d. That is, the CLK(B) terminal and the HCLK(B) terminal are positioned closer to the body-side fourth claw portion 129d than the VBAT(B) terminal and the LDET(B) terminal. In other words, the distance between the CLK(B) terminal and the body-side fourth claw portion 129d is shorter than the distance between the VBAT(B) terminal or the LDET(B) terminal and the body-side fourth claw portion 129d, and the distance between the HCLK(B) terminal and the body-side fourth claw portion 129d is shorter than the distance between the VBAT(B) terminal or the LDET(B) terminal and the body-side fourth claw portion 129d. As described above, there is a fourth leaf spring 141d on the back side of the body-side fourth claw portion 129d, and the fourth leaf spring 141d presses the lens-side fourth claw portion 139d in the +Z direction (Figure 1). Therefore, the CLK(B) terminal and HCLK(B) terminal, located near the fourth claw portion 139d on the lens side, are pressed more firmly against the lens-side terminal by the first leaf spring 141a and the fourth leaf spring 141d than the VBAT(B) terminal and LDET(B) terminal.

[0102] The distance between the CLK(B) terminal and the body-side first claw portion 129a (the same applies to the body-side fourth claw portion 129d, but this will be omitted below) is the straight-line distance between one end of the body-side first claw portion 129a and the CLK(B) terminal, or it may be defined as the straight-line distance between the other end of the body-side first claw portion 129a and the CLK(B) terminal. Alternatively, the distance between the CLK(B) terminal and the body-side first claw portion 129a may be defined as the straight-line distance between the midpoint of the body-side first claw portion 129a in the circumferential direction of the body-side mounting portion 201 and the CLK(B) terminal. The distance between other body-side terminals such as the HCLK(B) terminal, VBAT(B) terminal, LDET(B) terminal, etc., and the body-side first claw portion 129a is also a straight-line distance. The distance between the first leaf spring 141a (fourth leaf spring 141d) and the body-side terminal is also a straight-line distance.

[0103] The distance between the CLK(B) terminal and the body-side first claw portion 129a (the same applies to the body-side fourth claw portion 129d, but this is omitted below) may be defined as the arc-shaped distance between one end of the body-side first claw portion 129a and the CLK(B) terminal in the circumferential direction of the body-side mounting portion 201, or as the arc-shaped distance between the other end of the body-side first claw portion 129a and the CLK(B) terminal. Alternatively, the distance between the CLK(B) terminal and the body-side first claw portion 129a may be defined as the arc-shaped distance between the midpoint of the body-side first claw portion 129a in the circumferential direction of the body-side mounting portion 201 and the CLK(B) terminal. The distance between other body-side terminals such as the HCLK(B) terminal, VBAT(B) terminal, and LDET(B) terminal and the body-side first claw portion 129a may also be defined as an arc-shaped distance. The distance between the first leaf spring 141a (fourth leaf spring 141d) and the body-side terminal may also be defined as an arc-shaped distance.

[0104] The above describes the camera body 2, but the same applies to the interchangeable lens 3. In this embodiment, the CLK(L) terminal and HCLK(L) terminal are positioned very close to the lens-side first claw portion 139a. That is, the CLK(L) terminal and HCLK(L) terminal are positioned closer to the lens-side first claw portion 139a than the VBAT(L) terminal and LDET(L) terminal. In other words, the distance between the CLK(L) terminal and the lens-side first claw portion 139a is shorter than the distance between the VBAT(L) terminal or LDET(L) terminal and the lens-side first claw portion 139a, and the distance between the HCLK(L) terminal and the lens-side first claw portion 139a is shorter than the distance between the VBAT(L) terminal or LDET(L) terminal and the lens-side first claw portion 139a. The lens-side first claw portion 139a is pressed in the +Z direction (Figure 1) by the body-side first leaf spring 141a. Therefore, as described above, the CLK(L) terminal and HCLK(L) terminal, located near the first claw portion 139a on the lens side, are pressed more firmly against the body-side terminal by the first leaf spring 141a than the VBAT(L) terminal or LDET(L) terminal.

[0105] In this embodiment, as shown in Figure 4(a), the CLK(B) terminal and the HCLK(B) terminal are positioned within a sector (within an angle of 50 degrees) formed by the center position of the opening of the body-side mount portion 201 (i.e., the position of the optical axis L of the interchangeable lens 3) and the arc-shaped body-side first claw portion 129a. Alternatively, the CLK(B) terminal and the HCLK(B) terminal are positioned within a triangular region formed by the center position of the opening of the body-side mount portion 201 (i.e., the position of the optical axis L of the interchangeable lens 3) and both ends of the inner circumference of the body-side first claw portion 129a. Therefore, the first claw portion 129a on the body side does not lie on the extension of the dashed line 151 connecting the center position of the opening of the body-side mount portion 201 and the LDET(B) terminal, but the first claw portion 129a on the body side does lie on the extension of the dashed line 152 connecting the center position of the opening of the body-side mount portion 201 and the HCLK(B) terminal, and the first claw portion 129a on the body side does lie on the extension of the dashed line 153 connecting the center position of the opening of the body-side mount portion 201 and the CLK(B) terminal. As a result, when the mounting is complete, the CLK(B) terminal and the HCLK(B) terminal are pressed more firmly against the corresponding lens-side terminal than the LDET(B) terminal.

[0106] As shown in Figure 5, the CLK(L) terminal and HCLK(L) terminal are positioned within a sector (within an angle range of 60 degrees) formed by the center position of the opening of the lens-side mount portion 301 (i.e., the position of the optical axis L of the interchangeable lens 3) and the arc-shaped lens-side first claw portion 139a. Alternatively, the CLK(L) terminal and HCLK(L) terminal are positioned within a triangular region formed by the center position of the opening of the lens-side mount portion 301 (i.e., the position of the optical axis L of the interchangeable lens 3) and both ends of the outer circumference of the lens-side first claw portion 139a. Therefore, the lens-side first claw portion 139a does not exist on the extension of the dashed line 161 connecting the center position of the opening of the lens-side mount portion 301 and the LDET(L) terminal, but the lens-side first claw portion 139a exists on the extension of the dashed line 162 connecting the center position of the opening of the lens-side mount portion 301 and the HCLK(L) terminal, and the lens-side first claw portion 139a exists on the extension of the dashed line 163 connecting the center position of the opening of the lens-side mount portion 301 and the CLK(L) terminal. As a result, when the mounting is complete, the CLK(L) terminal and HCLK(L) terminal make more stable contact with the corresponding body-side terminal than the LDET(L) terminal. In other words, a stronger force is exerted on the CLK(L) terminal and HCLK(L) terminal than on the LDET(L) terminal when pressing against the body-side terminal. Therefore, even if the tips of the CLK(B) and HCLK(B) terminals are worn down, the communication of clock signals between the camera body 2 and the interchangeable lens 3 remains stable.

[0107] In this embodiment, we have described the CLK(B) terminal, CLK(L) terminal, HCLK(B) terminal, and HCLK(L) terminal, but the same applies to the other communication terminals, namely the HDA(B) terminal, HDA(L) terminal, DATAL(B) terminal, DATAL(L) terminal, DATAB(B) terminal, and DATAB(L) terminal. That is, the HDA(B) terminal, DATAL(B) terminal, and DATAB(B) terminal are positioned closer to the body-side first claw portion 129a and the first leaf spring 141a than the LDET(B) terminal and VBAT(B) terminal (the distance is shorter). As a result, the HDA(B) terminal, DATAL(B) terminal, and DATAB(B) terminal are pressed more firmly against the lens-side terminal than the VBAT(B) terminal and LDET(B) terminal, and can maintain good contact with the lens-side terminal. Furthermore, the HDATA(L), DATAL(L), and DATAB(L) terminals are positioned closer to the first claw portion 139a on the lens side than the LDET(L) and VBAT(L) terminals (the distance is shorter). As a result, the HDATA(L), DATAL(L), and DATAB(L) terminals are pressed more firmly against the body-side terminals than the VBAT(L) and LDET(L) terminals, maintaining good contact with the lens-side terminals.

[0108] Command data communication transmits and receives a value indicating the communication specifications for hotline communication between the interchangeable lens 3 and the camera body 2. This value is called a generation. This generation value is sometimes also called generation information. The generation is usually a non-negative integer, but it may also be a decimal. The generation may also be called a grade. Figure 6 is an explanatory diagram showing an example of a generation. Each generation indicates a different communication specification. This communication specification may also be called a communication method, communication procedure, or communication standard. This communication specification has at least one item related to communication. In the example shown in Figure 6, the communication specification has three items related to communication: the communication speed of the hotline communication, the communication interval of the hotline communication, and the number of data transmitted in the hotline communication. The communication specification indicated by a generation is not limited to having the three items described above, and may have any one or two items selected from the three items.

[0109] By using generations, it is possible to indicate different generations, for example, the 1st to 4th generations. Different generations indicate different communication specifications. Here, the values ​​of some items in the communication specifications may be the same across different generations. A higher number indicates a higher generation (grade). For example, the 4th generation is a higher generation (grade) than the 3rd generation. In addition to communication specifications, generations may also indicate other specifications. In the example shown in Figure 6, the generation indicates the sampling interval specification for data generation in addition to the communication specifications. Furthermore, in addition to the examples above, generations may also indicate specifications related to the function and capabilities of image stabilization, for example.

[0110] Here, the communication speed is the communication speed (clock frequency) of the data transmitted via hotline communication, that is, the speed at which data is transferred from the second lens communication unit 39 to the second body communication unit 29. The communication interval is the time interval at which data is transferred via hotline communication. Examples of data transmitted from the interchangeable lens 3 to the camera body 2 via hotline communication include information related to the drive of the focus lens (information related to the position of the focus lens, etc.), information related to the drive of the image stabilization lens (information related to the position of the image stabilization lens, etc.), information related to the zoom lens (information related to the state of the zoom lens, focal length information, etc.), and information related to the drive of the aperture diaphragm 32 (information related to the F-number, etc.). The sampling interval is the time interval at which data for transmission via hotline communication is sampled. For example, it is the interval at which the lens control unit 37 samples the pulse signal generated by the lens position detection unit 34.

[0111] In the example shown in Figure 6, the communication specifications for the first generation are V1 (unit: e.g., MHz), T1 (unit: e.g., msec), and N1 (integer) for the number of data points. For example, as the generation progresses (the grade increases), the communication speed becomes faster, the communication interval becomes shorter, and the number of data points increases. That is, in the communication specifications for the second generation, the communication speed is V2, which is faster than V1, the communication interval is T2, which is shorter than T1, and the number of data points is N2, which is greater than N1.

[0112] Furthermore, in the communication specifications for the third generation, the communication speed is V3, which is faster than V2; the communication interval is T3, which is shorter than T2; and the number of data points is N3, which is greater than N2. In the communication specifications for the fourth generation, the communication speed is V4, which is faster than V3; the communication interval is T4, which is shorter than T3; and the number of data points is N4, which is greater than N3. Note that each of V1~V4, T1~T4, and N1~N4 may be a predetermined fixed value or a value within a predetermined range. For example, the communication speed V1 may be a predetermined fixed value (e.g., 2.5MHz) or a predetermined communication speed range v1~v2 (e.g., 2~8MHz). Similarly, the communication interval T1 may be a predetermined eigenvalue (e.g., 1msec) or a predetermined communication interval range (e.g., 0.5~2msec).

[0113] As described above, the data transmitted via hotline communication includes information regarding the drive of the focus lens, the drive of the image stabilization lens, the drive of the aperture diaphragm, and the status of the zoom lens. For example, if the number of data points is N1, the data transmitted via hotline communication is information regarding the drive of the focus lens. If the number of data points is N2, in addition to information regarding the drive of the focus lens, information regarding the drive of the image stabilization lens is also transmitted via hotline communication. Furthermore, if the number of data points is N3, in addition to information regarding the drive of the focus lens and the drive of the image stabilization lens, information regarding the drive of the aperture diaphragm 32 is also transmitted via hotline communication. In addition, if the number of data points is N4, in addition to information regarding the drive of the focus lens, the drive of the image stabilization lens, and the drive of the aperture diaphragm 32, information regarding the status of the zoom lens is also transmitted via hotline communication.

[0114] In the example shown in Figure 6, the number of data transmitted via hotline communication, indicated by the generation, was explained as being included in the communication specification. However, this number of data may not be included in the communication specification and may be indicated separately by the generation. Also, in the example described above, the generation was explained as indicating the number of data. However, the generation may indicate the data transmitted via hotline communication. For example, the generation may indicate data transmitted via hotline communication such as information regarding the drive of the focus lens (information regarding the position of the focus lens, etc.), information regarding the drive of the image stabilization lens (information regarding the position of the image stabilization lens, etc.), information regarding the zoom lens (information regarding the state of the zoom lens, focal length information, etc.), and information regarding the drive of the aperture diaphragm 32 (information regarding the F-number, etc.).

[0115] Furthermore, in the example shown in Figure 6, the sampling interval specification shown for the first generation is S1 (unit: for example, msec). In the sampling interval specification shown for the second generation, the sampling interval is S2, which is shorter than S1; in the sampling interval specification shown for the third generation, the sampling interval is S3, which is shorter than S2; and in the sampling interval specification shown for the fourth generation, the sampling interval is S4, which is shorter than S3. Here, S1 to S4 may be predetermined fixed values ​​or values ​​within a predetermined range.

[0116] Furthermore, as the generation (grade) changes from the 1st to the 4th generation, the values ​​of all items in the communication specifications and other specifications do not need to change; the values ​​of one or more items may be changed. For example, the communication speed may increase as the generation progresses, but the communication interval and the number of data points may remain unchanged. As mentioned above, each generation of hotline communication may specify not only the communication specifications but also the sampling interval specifications and the image stabilization function / capacity. In this case, as the generation changes, the value of only one item in the communication specifications may be changed, or the values ​​of two or three items in the communication specifications may be changed, or furthermore, as the generation changes, the sampling interval specifications and the image stabilization function / capacity specifications may be changed in addition to the communication specifications.

[0117] Next, we will explain the relationship between the communication specifications indicated by each generation and the interchangeable lens 3 and camera body 2. Interchangeable lens 3 and camera body 2 that are capable of hotline communication according to the communication specifications indicated by the first generation will be referred to as the first-generation interchangeable lens 3 and the first-generation camera body 2, respectively. Similarly, interchangeable lens 3 and camera body 2 that are capable of hotline communication according to the communication specifications indicated by the second generation will be referred to as the second-generation interchangeable lens 3 and the second-generation camera body 2, respectively. Likewise, interchangeable lens 3 and camera body 2 that are capable of hotline communication according to the communication specifications indicated by the third generation will be referred to as the third-generation interchangeable lens 3 and the third-generation camera body 2, respectively. Interchangeable lens 3 and camera body 2 that are capable of hotline communication according to the communication specifications indicated by the fourth generation will be referred to as the fourth-generation interchangeable lens 3 and the fourth-generation camera body 2.

[0118] In this embodiment, multiple interchangeable lenses and multiple camera bodies, each having the ability to communicate using a common communication specification called "communication specification shown for the first generation," are collectively referred to as "first-generation interchangeable lenses" and "first-generation camera bodies," respectively. The same applies to the second, third, and fourth generations. "Communication specification shown for the first generation" may also be referred to as "first communication specification." "First-generation interchangeable lenses" and "first-generation camera bodies" may also be referred to as "first interchangeable lenses" and "first camera bodies," respectively.

[0119] Furthermore, interchangeable lenses 3 and camera bodies 2 corresponding to the communication specifications of each generation can also perform hotline communication according to the communication specifications of the earlier generation (lower numbered generation / lower grade). That is, a first-generation interchangeable lens 3 and a first-generation camera body 2 will both perform hotline communication according to the communication specifications of the first generation, but second-generation interchangeable lenses 3 and camera bodies 2 can support not only the communication specifications of the second generation but also the communication specifications of the first generation. In addition, third-generation interchangeable lenses 3 and camera bodies 2 can support the communication specifications of the first to third generations, respectively, and fourth-generation interchangeable lenses 3 and camera bodies 2 can support the communication specifications of the first to fourth generations, respectively. If a fourth-generation interchangeable lens 3 and a third-generation camera body 2 are combined, hotline communication can be performed according to one of the common communication specifications: the communication specifications of the third generation, the communication specifications of the second generation, or the communication specifications of the first generation. However, since camera body 2 does not support the communication specifications of the 4th generation, it is not possible to perform hotline communication in accordance with the communication specifications of the 4th generation. Alternatively, hotline communication will not be initiated.

[0120] Figure 7 is a table illustrating the generations of communication specifications used when performing hotline communication with a combination of a first- to fourth-generation interchangeable lens 3 and a first- to fourth-generation camera body 2. Figure 7 uses the generation of the camera body 2 on the horizontal axis and the generation of the interchangeable lens 3 on the vertical axis, illustrating the generations of communication specifications for hotline communication for each combination. As shown below, it is preferable to perform hotline communication using the communication specifications indicated by the highest generation (highest number generation, highest generation, highest grade) that can be adopted when combining the interchangeable lens 3 and the camera body 2. However, it is also acceptable to perform hotline communication using the communication specifications indicated by a lower generation instead of the highest generation. When a first-generation interchangeable lens 3 is attached to a first- to fourth-generation camera body 2, hotline communication will be performed in accordance with the communication specifications of the first generation in all cases.

[0121] When a second-generation interchangeable lens 3 is attached to a first- to fourth-generation camera body 2, hotline communication is performed with the first-generation camera body 2 according to the communication specifications of the first generation, and hotline communication is performed with the second- to fourth-generation camera bodies 2 according to the communication specifications of the second generation.

[0122] When a third-generation interchangeable lens 3 is attached to a first- to fourth-generation camera body 2, the following applies: The third-generation interchangeable lens 3 communicates via hotline with the first-generation camera body 2 according to the communication specifications of the first generation, with the second-generation camera body 2 according to the communication specifications of the second generation, and with the third to fourth-generation camera bodies 2 according to the communication specifications of the third generation. However, the third-generation interchangeable lens 3 may also communicate with the second-generation camera body 2 according to the communication specifications of the first generation, which is a lower generation (lower numbered generation / previous generation) rather than the highest generation (highest numbered generation / highest grade), and may also communicate with the third-generation and fourth-generation camera bodies 2 according to the communication specifications of the first or second generation.

[0123] When a fourth-generation interchangeable lens 3 is attached to a first- to fourth-generation camera body 2, the following occurs: The fourth-generation interchangeable lens 3 communicates via hotline with the first-generation camera body 2 according to the communication specifications of the first generation, and with the second-generation camera body 2 according to the communication specifications of the second generation. Furthermore, the fourth-generation interchangeable lens 3 communicates via hotline with the third-generation camera body 2 according to the communication specifications of the third generation, and with the fourth-generation camera body 2 according to the communication specifications of the fourth generation. Furthermore, the fourth-generation interchangeable lens 3 may communicate with the second-generation camera body 2 according to the communication specifications of the first generation, and may communicate with the third-generation camera body 2 according to the communication specifications of the first or second generation. In addition, it may communicate with the fourth-generation camera body 2 according to the communication specifications of the first, second, or third generation.

[0124] Next, we will explain the generation information transmitted from the interchangeable lens 3 to the camera body 2, and vice versa, during command data communication. During command data communication, data indicating, for example, lens-side generation information "1", "2", "3", or "4" is transmitted from the interchangeable lens 3 to the camera body 2. Lens-side generation information "1", "2", "3", or "4" indicates that the interchangeable lens 3 is the first generation, second generation, third generation, or fourth generation, respectively.

[0125] Furthermore, if the lens-side generation information is 1st generation, it indicates that interchangeable lens 3 is compatible with the communication specifications indicated by the 1st generation. Similarly, if the lens-side generation information is 2nd generation, it indicates that interchangeable lens 3 is compatible with both the communication specifications indicated by the 1st generation and the communication specifications indicated by the 2nd generation. If the lens-side generation information is 3rd generation, it indicates that interchangeable lens 3 is compatible with the communication specifications indicated by the 1st, 2nd, 3rd, and 3rd generations, and if the lens-side generation information is 4th generation, it indicates that interchangeable lens 3 is compatible with the communication specifications indicated by the 1st, 2nd, 3rd, and 4th generations.

[0126] Furthermore, the generation information transmitted from the camera body 2 to the interchangeable lens 3, as will be described later, is determined by the camera body 2 based on the lens-side generation information and the body-side generation information, and represents the generation that indicates the communication specifications used when the camera body 2 and the interchangeable lens 3 attached to the camera body 2 perform hotline communication. In command data communication, for example, generation information "1", "2", "3", or "4" is transmitted from the camera body 2 to the interchangeable lens 3. The generation information "1", "2", "3", or "4" indicates that the communication specifications used when performing hotline communication are indicated by the 1st generation, 2nd generation, 3rd generation, or 4th generation, respectively.

[0127] For example, if interchangeable lens 3, which only supports up to the second generation, transmits second-generation information (second generation) to camera body 2, which also only supports up to the second generation, camera body 2, which also supports up to the same generation (second generation), will transmit the highest generation, the second generation, to interchangeable lens 3. This transmission of the same generation information (second generation) from camera body 2 to interchangeable lens 3 indicates that camera body 2 is requesting interchangeable lens 3 to use the communication specifications indicated by the same generation (second generation).

[0128] Furthermore, if, for example, an interchangeable lens 3 that only supports up to the third generation is attached to a camera body 2 that is of a higher generation, the fourth generation, then the third generation generation information is transmitted from the interchangeable lens 3 to the camera body 2, and the camera body 2 transmits the generation information of the third generation, which is the highest generation common to both the camera body 2 and the interchangeable lens 3 and is lower than its own generation (fourth generation), to the interchangeable lens 3. This lower generation (third generation) generation information transmitted from the camera body 2 requests the interchangeable lens 3 to perform hotline communication according to the communication specifications indicated by the third generation, which is the highest generation that the interchangeable lens 3 supports.

[0129] Furthermore, if, for example, an interchangeable lens 3 that supports up to the 4th generation is attached to a camera body 2 that is of a lower generation, the 3rd generation, the interchangeable lens 3 will send 4th generation information to the camera body 2. However, since the camera body 2 does not support the communication specifications indicated by the 4th generation, it will send 3rd generation information, which is its highest generation, to the interchangeable lens 3. This lower generation (3rd generation) information sent from the camera body 2 to the interchangeable lens 3 requests that the interchangeable lens 3 perform hotline communication according to the communication specifications indicated by the 3rd generation, which is the highest generation supported by the camera body 2.

[0130] As mentioned above, each generation indicates a different communication specification. Each communication specification has at least one item related to communication, such as the communication speed of the hotline, the communication interval of the hotline, and the number of data transmitted via the hotline. The generation information indicates the communication specification that the interchangeable lens and camera body can communicate using the hotline.

[0131] The method for determining the generation of the communication specifications used in the hotline communication between the interchangeable lens 3 and the camera body 2 is described below in detail. When interchangeable lens 3 is attached to camera body 2, initialization communication is initiated between interchangeable lens 3 and camera body 2 using command data communication. During initialization communication, if a command requesting the transmission of lens-side generation information is sent from camera body 2 to interchangeable lens 3, the first lens communication unit 38 transmits the lens-side generation information stored in lens memory 36 to the first body communication unit 28 via command data communication. The body control unit 27 obtains the generation information of the attached interchangeable lens 3 via the first body communication unit 28 and determines the generation that indicates the communication specifications that interchangeable lens 3 can support. For example, if the generation information of interchangeable lens 3 is "3", which represents the third generation, the body control unit 27 recognizes that interchangeable lens 3 is capable of hotline communication according to the communication specifications indicated by the first, second, and third generations.

[0132] The body control unit 27 then determines the generation that indicates the communication specifications for hotline communication based on the lens-side generation information and the body-side generation information, as follows: The highest generation among the generations that are common to the generations that indicate the communication specifications that the interchangeable lens 3 can handle and the generations that indicate the communication specifications that the camera body 2 can handle is determined as the generation that indicates the communication specifications for hotline communication. For example, as described above, if the lens-side generation information transmitted from the interchangeable lens 3 is "3", meaning that the interchangeable lens 3 can communicate via hotline communication with the communication specifications indicated by the 1st, 2nd, and 3rd generations, and the body-side generation information is "4", representing the 4th generation, then the camera body 2 can communicate via hotline communication with the communication specifications indicated by the 1st, 2nd, 3rd, and 4th generations, so the highest generation among the generations common to the interchangeable lens 3 and the camera body 2, which is the 3rd generation, is selected.

[0133] As shown in Figure 7, the body control unit 27 selects the highest common generation between the generation representing the communication specifications of the interchangeable lens 3 and the generation representing the communication specifications of the camera body 2. The body control unit 27 then transmits the determined generation information to the first lens communication unit 38 via the first body communication unit 28. The body control unit 27 also controls (sets) various parts of the camera body 2 according to the communication specifications indicated by the determined generation. As a result, the camera body 2 can perform hotline communication with the attached interchangeable lens 3 according to the communication specifications indicated by the determined generation.

[0134] When command data communication is transmitted from the camera body 2 to the interchangeable lens 3, including commands and data containing generation information used for hotline communication, hotline communication is initiated. Specifically, when a command to set up hotline communication is sent from the camera body 2 to the interchangeable lens 3, generation information is also sent as part of the data packet of that command. To initiate hotline communication, the lens control unit 37 sets and controls each part of the interchangeable lens 3 so that it is in a state where hotline communication is possible, according to the communication specifications indicated by the generation information determined by the camera body 2, that is, the generation information obtained from the camera body 2 via the first lens communication unit 38. As a result, the interchangeable lens 3 can perform hotline communication with the camera body 2 according to the communication specifications indicated by the generation determined by the camera body 2. In this way, when a command to set up hotline communication and generation information of the first generation or higher are sent from the camera body 2 to the interchangeable lens 3, hotline communication is initiated from the interchangeable lens 3. That is, hotline communication is initiated when a command to set up hotline communication and generation information (a value indicating the generation information) indicating the communication specifications to be used for hotline communication are sent from the camera body 2 to the interchangeable lens 3.

[0135] Furthermore, the body control unit 27 may select a communication specification different from the one indicated by the highest generation among the generations to which both the interchangeable lens 3 and the camera body 2 are compatible. For example, if adopting the communication specification indicated by the highest generation would cause interference between the communication frequency and the drive frequency of the image sensor, this interference can be avoided by adopting the communication specification indicated by a lower generation.

[0136] In this embodiment, the interchangeable lens 3 transmits a generation indicating communication specifications, including items such as communication speed and communication interval, to the camera body 2 as lens-side generation information. By receiving the lens-side generation information, the camera body 2 can understand the communication specifications (communication speed, etc.) that the interchangeable lens 3 can support. Compared to the case where the camera body 2 is notified of the communication speed, communication interval, etc. that the interchangeable lens 3 can support through multiple individual communications, transmitting the lens-side generation information from the interchangeable lens 3 to the camera body 2 reduces the amount of data, shortens communication time and the number of communications. Furthermore, if the communication speed, communication interval, etc. that the interchangeable lens 3 can support were sent individually from the interchangeable lens 3 to the camera body 2, the camera body 2 would need to check whether there are any inconsistencies in the communication speed, communication interval, etc. sent from the interchangeable lens 3. However, in this embodiment, since the generation (generation information) indicates consistent communication specifications (communication speed, communication interval, etc.), the body control unit 27 does not need to check for inconsistencies in the communication speed, communication interval, etc. received from the interchangeable lens 3.

[0137] In the explanations so far, we have used the first, second, third, and fourth generations as examples of generational information, but generational information is not limited to these; it can also include fifth generation or higher.

[0138] Additionally, "0" can be used as the generation information value. A generation information value of "0" is not used to determine the generation that indicates the communication specification used in the hotline communication between the camera body 2 and the interchangeable lens 3 and to start communication, but rather to either not perform hotline communication or to stop hotline communication that has already been started. Even if a manual focus lens does not support autofocus, if the position of the focus lens can be detected, the detected focus lens position may be transmitted to the camera body 2 via hotline communication. However, for example, in the case of a manual focus lens that does not have a mechanism to detect the position of the focus lens, there is no need to transmit the focus lens position from the interchangeable lens 3 to the camera body 2 in the first place, and therefore there is no need to perform hotline communication to transmit the focus lens position. If there is no need to transmit any information other than the focus lens position to the camera body 2, there is no need to perform hotline communication between the interchangeable lens 3 and the camera body 2. Therefore, when an interchangeable lens 3 that does not support hotline communication and does not require such hotline communication is attached to the camera body 2, "0" is transmitted from the interchangeable lens 3 to the camera body 2 as the generation information value. In response, camera body 2 sends the value "0" to interchangeable lens 3 as a data packet indicating a command to set up hotline communication and generation information. When interchangeable lens 3 receives data packet "0", it does not initiate hotline communication with camera body 2.

[0139] Furthermore, the camera body 2 can terminate the hotline communication by sending the generation information value "0" to the interchangeable lens 3. The hotline communication initiated between the camera body 2 and the interchangeable lens 3 may be terminated when the camera body 2 is powered off by operating its power switch, when it is powered off after a certain period of inactivity (also called hibernation or sleep mode), when it enters image playback mode, or when it displays a menu. To terminate the hotline communication, the camera body 2 sends the value "0" as a data packet indicating the generation information and a command to set up the hotline communication to the interchangeable lens 3. The interchangeable lens 3 starts the hotline communication when it receives the generation information value "1" to "4" from the camera body 2 via command data communication, and terminates the hotline communication when it receives the generation information value "0" from the camera body 2 via command data communication. Note that the generation information parameter for not starting communication or stopping communication is not limited to "0" and may be a specific value such as "99".

[0140] Thus, a value of "0" or greater (an integer) can be used as generation information. When an integer of "1" or greater is transmitted from interchangeable lens 3 to camera body 2 as generation information, camera body 2 determines the generation that indicates the communication specifications it can communicate with. Interchangeable lens 3 then receives a command to set up hotline communication and the generation information of "1" or greater determined by camera body 2 from camera body 2, thereby initiating hotline communication. Furthermore, when interchangeable lens 3 sends "0" as generation information to camera body 2, camera body 2 recognizes that interchangeable lens 3 is an interchangeable lens that does not perform hotline communication, and camera body 2 sends "0" as generation information to interchangeable lens 3. Interchangeable lens 3 does not initiate hotline communication by receiving the command to set up hotline communication and the generation information of "0" from camera body 2. Note that if interchangeable lens 3 sends "0" as generation information to camera body 2, camera body 2 does not need to send "0" to interchangeable lens 3, nor does it need to send the command to set up hotline communication.

[0141] Furthermore, after interchangeable lens 3 receives a command from camera body 2 to set up hotline communication and generation information of "1" or higher determined by camera body 2, and starts hotline communication, if interchangeable lens 3 receives a command from camera body 2 to set up hotline communication and generation information of "0", interchangeable lens 3 will stop hotline communication. In cases where hotline communication is not performed, or when hotline communication that has been started is to be stopped, interchangeable lens 3 only needs to receive the command to set up hotline communication and generation information of "0" from camera body 2, so a dedicated command to stop hotline communication is not necessary. This reduces the number of commands. Also, the same command can be used to start and stop hotline communication, making control simpler. The transmission of generation information from camera body 2 to interchangeable lens 3 not only sends generation information indicating the communication specifications to be used for hotline communication, but also, when sent after the command to set up hotline communication, indicates whether to start hotline communication, not start hotline communication, or stop hotline communication that has already been started.

[0142] Figure 8 shows an example of hotline communication performed in accordance with the determination of generation information in camera 1, which is an imaging device according to the first embodiment. In Figure 8, the case in which a focus lens is driven as a lens is explained. Figure 8(a) schematically shows the temporal change of the actual position (L1) of the focus lens in the optical axis direction, Figure 8(b) shows the pulse signal output from the encoder of the lens position detection unit 34 in accordance with the movement of the focus lens, Figure 8(c) shows the sampling of the pulse signal by the lens control unit 37, Figure 8(d) shows command data communication (CD1~CD3) and hotline communication (HL1~HL6) between the camera body 2 and the interchangeable lens 3, and Figure 8(e) schematically shows the temporal change of the position (L2) of the focus lens when the camera body 2 restores the position (pulse position) of the focus lens based on the integrated value (pulse position information) of the pulse signal received in the hotline communication. In Figure 8, the horizontal axis of (a) to (e) is a common time axis.

[0143] The curve L1 in Figure 8(a) schematically represents the temporal change in the position of the focus lens, with the horizontal axis representing time and the vertical axis representing the position of the focus lens in the optical axis L direction. Figure 8(b) shows the pulse signals output from the encoder of the lens position detection unit 34 described above. The number of these pulse signals corresponds to the amount of movement of the focus lens, and is a pulse signal that is generated each time the focus lens is driven and moves by a predetermined amount, and is generated more frequently when the change in the position of the focus lens is large. In other words, the faster the movement speed of the focus lens, the more frequently pulse signals are generated per unit time. The lens control unit 37 integrates the above pulse signals and transmits the pulse position information of the focus lens (the position of the focus lens expressed as the number of integrated pulses) from the interchangeable lens 3 to the camera body 2 via each hotline communication. Note that the pulse signals in Figure 8(b) may also be pulse signals output from the drive circuit of the lens drive unit 33. The curve L2 in Figure 8(e) schematically represents the temporal change in the position of the focus lens reproduced by the camera body 2 based on the pulse position information received in each hotline communication, with the horizontal axis representing time and the vertical axis representing the position of the focus lens in the optical axis L direction.

[0144] As mentioned above, command data communication and hotline communication are conducted using different communication channels. However, in Figure 8(d), command data communication (CD1~CD3) and hotline communication (HL1~HL6) are shown together. Command data communication (CD1~CD3) is indicated by dashed double arrows, and hotline communication (HL1~HL6) is indicated by solid arrows. Command data communication is bidirectional communication between the camera body 2 and the interchangeable lens 3, while hotline communication is communication from the interchangeable lens 3 to the camera body 2.

[0145] In command data communication CD1, the lens control unit 37 of the interchangeable lens 3 transmits the lens-side generation information of the interchangeable lens 3 to the first body communication unit 28 of the camera body 2 via the first lens communication unit 38. When the body control unit 27 of the camera body 2 receives the lens-side generation information of the interchangeable lens 3 from the first body communication unit 28, it determines the generation that indicates the communication specifications for hotline communication, as described above, based on that lens-side generation information and the body-side generation information held by the camera body 2 itself.

[0146] In command data communication CD2, the first body communication unit 28 transmits a command packet and a data packet to the first lens communication unit 38 requesting the setting of hotline communication. This data packet contains generation information indicating the communication specifications determined by the body control unit 27. When the first lens communication unit 38 receives the command packet and data packet requesting the setting of hotline communication, the lens control unit 37 performs processing to set and control each part of the interchangeable lens 3 so that communication is possible according to the communication specifications indicated by the generation information contained in the data packet. In addition, during command data communication CD2, information corresponding to the shift time Δt, which will be described later, is transmitted from the interchangeable lens 3 to the camera body 2.

[0147] As shown in Figure 8(c), upon receiving a command packet and data packet (command data communication CD2) requesting the setting of hotline communication, the lens control unit 37 starts sampling pulse signals from the lens position detection unit 34 at time t1. By sampling (counting) the pulse signals, the lens control unit 37 becomes capable of generating information on the integrated value of the pulse signals sampled within the sampling time. The second lens communication unit 39 becomes capable of transmitting the integrated value of the pulse signals from the origin position detected by the photointerrupter (pulse position information) to the camera body 2. Alternatively, the pulse signal may be sampled before time t1, and after receiving CD2, the pulse position information may be transmitted to the camera body 2 from time t1.

[0148] The first body communication unit 28 transmits a signal (drive command) instructing the focus lens to be driven as command data communication CD3 to the first lens communication unit 38. The lens control unit 37 starts the movement of the focus lens based on this drive command.

[0149] As shown in Figure 8(c), the lens control unit 37 samples (counts) the pulse signals output from the lens position detection unit 34 at sampling intervals that conform to the sampling interval specifications indicated by the determined generation. First, the lens control unit 37 samples the pulse signals output from the lens position detection unit 34 from time t1 to time t2 and generates pulse position information by integrating the pulse signals. Then, from time t2 onward, the lens control unit 37 samples the pulse signals output from the lens position detection unit 34 at sampling intervals that conform to the sampling interval specifications indicated by the determined generation. As described above, the lens control unit 37 continues sampling the pulse signals until it receives a generation information value of "0" which instructs the termination of hotline communication.

[0150] In the hotline communication HL1, the second lens communication unit 39 transmits the integrated value of the pulse signals sampled between time t1 and time t2 (in the example in Figure 8, the integrated value of the pulse signals is 1) as pulse position information to the second body communication unit 29.

[0151] In hotline communication HL2, the second lens communication unit 39 transmits pulse position information to the second body communication unit 29, which is represented by the number of pulses obtained by adding the integrated value of the pulse signals sampled from time t1 to time t2 (in the example in Figure 8, the number of pulses is 1) and the integrated value of the pulse signals sampled between time t2 and time t3 (in the example in Figure 8, the number of pulses is 2) (in the example in Figure 8, the number of added pulses is 3). In hotline communication HL3, HL4, HL5, HL6, etc., the second lens communication unit 39 transmits pulse position information to the second body communication unit 29, which is represented by the number of pulses obtained by adding the number of pulses sampled in each period t3-t4, t4-t5, t5-t6, t6-t7, etc. to the integrated number of pulses sampled before that period. Furthermore, the hotline communications by the second lens communication unit 39 and the second body communication unit 29 are performed at the communication speed and communication interval indicated by the communication specifications of the generation determined by the body control unit 27, as described above. In this embodiment, the communication speed is 2.5 MHz and the communication interval is 1 msec. That is, HL1, HL2, HL3, HL4, HL5, HL6... are transmitted from the lens control unit 37 to the body control unit 27 every 1 msec, synchronized to a clock frequency of 2.5 MHz.

[0152] As described above, the intervals from time t1 to time t2, from time t2 to time t3, from time t3 to time t4, from time t4 to time t5, from time t5 to time t6, and from time t6 to time t7 are the sampling intervals specified in the sampling interval specifications of the determined generation. Furthermore, the intervals between hotline communications HL1-HL2, HL2-HL3, HL3-HL4, HL4-HL5, and HL5-HL6 are the communication intervals specified in the communication specifications for the determined generation. In this embodiment, the sampling interval and the communication interval are the same time interval. Of course, the sampling interval and the communication interval may be different intervals from each other. For example, the communication interval may be twice the sampling interval.

[0153] The pulse position information, represented by the cumulative number of pulse signals repeatedly received at each communication interval by the second body communication unit 29, is sequentially stored in the body memory 22 of the camera body 2. The transfer of pulse position information to the body memory 22 is performed, for example, by DMA (Direct Memory Access). The body control unit 27 refers to the pulse position information stored in the body memory 22 at an arbitrary timing (for example, the timing when the vertical synchronization signal of the image sensor is output; in Figure 8, time ta between time t6 and time t7) and calculates the time (time t2 to t6 on the interchangeable lens side) when each pulse position information was generated in the interchangeable lens 3 using a method described later. By associating each pulse position information with the generation time of those pulse position information, the body control unit 27 determines the position of the focus lens at each time, as shown by the curve L2 in Figure 8(e). Furthermore, the position information repeatedly received by the second body communication unit 29 at each communication interval is not limited to pulse position information represented by the number of accumulated pulse signals. The second body communication unit 29 may receive pulse signals sampled by the lens control unit 37 of the interchangeable lens 3 within the sampling period, and the body control unit 27 may accumulate the pulse signals to generate pulse position information for the lens.

[0154] The pulse position information, associated with the generation time, is used, for example, in the phase-detection autofocus described above. The body control unit 27 calculates the amount of defocus using the focus detection signal output from the image sensor 21, as described above. Based on the calculated amount of defocus, the body control unit 27 generates a signal to instruct the focus lens to move and outputs the generated drive instruction signal (drive command) to the lens control unit 37 via command data communication. The lens control unit 37 controls the drive of the focus lens and transmits the pulse position information to the body control unit 27. Based on the pulse position information, the body control unit 27 determines the position of the focus lens at each time point and checks how far the focus lens has moved relative to the amount of movement (defocus amount) instructed to the lens control unit 37.

[0155] Furthermore, the pulse position information associated with the generation time can be used for the contrast AF described above. The body control unit 27 associates the pulse position information of the focus lens with the contrast evaluation value based on the generation time of the pulse position information and the generation time of the signal from the image sensor 21 used to calculate the contrast evaluation value. This allows the body control unit 27 to understand the position of the focus lens and the contrast evaluation value at each time. The body control unit 27 calculates the pulse position of the focus lens where the contrast evaluation value peaks as the focus position. Then, the body control unit 27 generates a signal to instruct the drive of the focus lens based on the calculated focus position and outputs the generated drive instruction signal (drive command) to the lens control unit 37 via command data communication. The lens control unit 37 performs drive control to move the focus lens to the focus position and adjusts the focus.

[0156] Here, we describe the discrepancies that may occur in the lens position reconstructed by the camera body 2 due to differences in the clock timing between the camera body 2 and the interchangeable lens 3. The camera body 2 and the interchangeable lens 3 operate using separate clocks. That is, the camera body 2 generates its own clock within itself, and the interchangeable lens 3 generates its own clock within itself. The frequency of the clock within the camera body 2 and the frequency of the clock within the interchangeable lens 3 may be the same or different. If the camera body 2 and the interchangeable lens 3 generate clocks of the same frequency and their clock timings (rising and falling edges) are perfectly synchronized, the camera body 2 can determine the generation time of the signal generated by the interchangeable lens 3. However, if the clock timings of the camera body 2 and the interchangeable lens 3, i.e., the clock frequency and the rising and falling edges of the clocks, are different, the camera body 2 cannot accurately determine the time when the interchangeable lens 3 generated the signal, resulting in a time discrepancy between the actual lens position and the lens position reconstructed by the camera body 2.

[0157] The following describes how the camera body 2 calculates the time (times t2 to t6 on the interchangeable lens side) when the interchangeable lens 3 generates pulse position information (integrated value of pulse signals) when the clock timing of the camera body 2 and the interchangeable lens 3 are different. As described above using Figures 8(b) to (d), the pulse position information is generated by the lens control unit 37 sampling pulse signals from the lens position detection unit 34 or the lens drive unit 33 at a predetermined period. The sampling of pulse signals by the lens control unit 37 is performed according to the clock signal used inside the interchangeable lens 3 (hereinafter referred to as the lens clock signal). That is, in Figure 8, the times t2, t3, t4, t5, t6, t7, ... when the pulse signal is sampled and the integrated value of the pulse signal is generated are synchronized with the rising or falling edge of the lens clock signal. This lens clock signal is a different clock signal from the CLK signal supplied from the camera body 2.

[0158] The body control unit 27 determines the time when pulse signal sampling began, based on the time when command data communication CD2 was performed, for example, to set up hotline communication. In order for the body control unit 27 to determine the time when the lens control unit 37 generated the integrated value of the pulse signal based on the time of command data communication CD2, the lens control unit 37 calculates the time from the time of command data communication CD2 to the time t1 when pulse signal sampling began (the shift time Δt shown in Figure 8(d)) using a method described later. The lens control unit 37 transmits the information corresponding to the calculated shift time Δt to the camera body 2 via command data communication CD2.

[0159] The body control unit 27 of the camera body 2 acquires information corresponding to the shift time Δt from the interchangeable lens 3, and uses the shift time Δt to calculate the generation time of pulse position information, which is the integrated value of pulse signals from the transmission time of command data communication CD2. In this way, the body control unit 27 calculates the generation time of pulse position information based on the transmission time of command data communication CD2.

[0160] Figure 9 is a diagram illustrating an example of a method for calculating the shift time Δt in an imaging device according to the first embodiment. Note that the times t-1, t0, t1, and t2 in Figure 9 correspond to the times t-1, t0, t1, and t2 in Figure 8, respectively. Command packet 44 and data packet 45 are command packets and data packets transmitted from the camera body 2 to the interchangeable lens 3 by the command data communication CD2 shown in Figure 8. Command packet 44 is a signal instructing the setting of hotline communication, and data packet 45 is a signal containing generation information determined by the camera body 2.

[0161] The trigger signals that latch the pulse signals shown at times t-1, t1, and t2 in Figure 9 are trigger signals that are repeatedly generated at a predetermined period S based on the lens clock signal output by the lens control unit 37 of the interchangeable lens 3. The predetermined period S is the sampling interval in Figure 8(c), which is the sampling interval explained in Figure 6 and is indicated by the generation information. The lens control unit 37 uses this trigger signal to sample (latch) the pulse signals from the lens position detection unit 34 or the lens drive unit 33 at the sampling interval S.

[0162] Here, we will explain how to calculate the shift time Δt. As a prerequisite, when the interchangeable lens 3 is attached to the camera body 2 and power supply from the camera body 2 begins, the lens control unit 37 latches the pulse signal at a sampling interval S in accordance with the specifications it can handle. Figure 9 shows the time from time t-1 onwards of the latch immediately before the command data communication CD2 is performed. After the lens control unit 37 successfully receives the command packet 44 of the command data communication CD2 and sets the RDY signal to a high level, it sets the RDY signal to a low level at time t0. The lens control unit 37 detects the time from time t-1 to time t0 and calculates the shift time Δt by subtracting the time from time t-1 to time t0 from the period S from time t-1 to time t1. Specifically, the lens control unit 37 detects the time from time t-1 to time t0 by counting the lens clock signal from time t-1 to the falling edge of the RDY signal using an internal counter circuit or the like. The lens control unit 37 then outputs information indicating the shift time Δt to the body control unit 27 via command data communication CD2.

[0163] Furthermore, when the lens control unit 37 receives the data packet 45, it transitions the RDY signal from a low level to a high level. As mentioned above, the data packet 45 contains generation information, and the lens control unit 37 starts hotline communication according to the communication specifications indicated by the generation determined by the camera body 2. The lens control unit 37 also generates a trigger signal at a sampling interval S corresponding to the sampling interval specifications indicated by the determined generation, and performs pulse signal sampling (see Figure 8). The lens control unit 37 counts the pulse signals from the lens position detection unit 34 or the lens drive unit 33 that occur during the interval S from time t1 to time t2. The number of sampled pulse signals is transmitted from the interchangeable lens 3 to the camera body 2 in the hotline communication HL1 shown in Figure 8.

[0164] The body control unit 27 obtains information indicating the shift time Δt from the lens control unit 37 via command data communication CD2. Based on the shift time Δt and the sampling interval S, the body control unit 27 calculates the generation time of the pulse position information, i.e., the time when the pulse signal output from the encoder of the lens position detection unit 34 or the lens drive unit 33 was sampled. For example, the body control unit 27 calculates (determines) the time t0+Δt+S, obtained by adding the shift time Δt and the sampling interval S to the falling edge time t0 of the RDY signal, as the generation time t2 of the pulse position information. The body control unit 27 also calculates the generation times t3, t4, t5, and t6 of the pulse position information as t2+S, t2+2S, t2+3S, and t2+4S, respectively.

[0165] In this embodiment, the camera body 2 acquires a time Δt related to the time it takes for pulse position information, which is obtained by integrating pulse signals, to be generated, and uses this time Δt to calculate the position information of the focus lens. Therefore, the time delay between the position of the focus lens calculated and restored by the camera body 2 and the actual position of the focus lens in the interchangeable lens 3 can be reduced. The following will explain, in comparison with a comparative example, how the time delay between the restored focus lens position and the actual focus lens position is reduced (the time Δt, which is the cause of the delay, is canceled out).

[0166] The comparative example calculates the position of the focus lens without obtaining an accurate shift time Δt. Since the body control unit 27 does not have an accurate shift time Δt from the lens control unit 37, it uses a fixed value equivalent to the shift time to calculate the generation time of the lens position information. However, since the generation of the lens position information is performed using a trigger signal (a signal based on the lens clock signal used inside the interchangeable lens 3) that is asynchronous with the clock signal (CLK signal) from the camera body 2, the shift time changes depending on the timing of the command to set up hotline communication sent from the camera body 2 (the falling edge timing of the RDY signal in the embodiment shown in Figure 9). As a result, if the shift time is set to a fixed value, an error occurs when associating the pulse position information with the generation time, resulting in a difference between the actual position of the focus lens and the calculated position. Note that the hotline communication clock signal (HCLK signal) is generated based on the lens clock signal and output from the interchangeable lens 3 to the camera body 2.

[0167] In this embodiment, the position of the focus lens is restored using the time difference Δt between the timing when the command signal is transmitted and the timing when the lens control unit 37 actually measures (samples) the pulse signal. As a result, the time difference between the restored focus lens position and the actual focus lens position is reduced. This makes it possible to suppress errors when determining the position of the focus lens to be the focus position in autofocus, for example.

[0168] Figure 10 is an explanatory diagram of the generation information transmitted from the interchangeable lens 3 to the camera body 2, the generation information transmitted from the camera body 2 to the interchangeable lens 3, and the generation information indicating the communication specifications used when data is transmitted from the interchangeable lens 3 via hotline communication in the camera of the first embodiment. CD1 and CD2 in Figure 10 indicate command data communication, as in Figure 8, and HL indicates hotline communication.

[0169] In the camera of the first embodiment, the fourth-generation interchangeable lens 3 and camera body 2 can also perform hotline communication according to the communication specifications of the previous generation (lower numbered generation / lower grade), thus supporting the communication specifications of the first to fourth generations, respectively. As shown in Figure 10, in command data communication CD1, the first lens communication unit 38 of the interchangeable lens 3 transmits "4" as lens-side generation information to the first body communication unit 28 via command data communication. The body control unit 27 receives the transmitted lens-side generation information "4" via the first body communication unit 28. The body control unit 27 of the fourth-generation camera body 2 determines the fourth generation, which is the highest generation among the generations common to the interchangeable lens 3 and the camera body 2, as the generation indicating the communication specifications for hotline communication. The body control unit 27 then transmits the determined fourth-generation generation information "4" to the first lens communication unit 38 via the first body communication unit 28. Subsequently, according to the communication specifications indicated by the fourth generation, the interchangeable lens 3 transmits data to the camera body 2 via hotline communication.

[0170] According to the above-described embodiment, the following effects and advantages can be obtained. (1) The interchangeable lens 3 transmits generation information indicating the communication specifications for hotline communication to the camera body 2 via command data communication. In this way, the camera body 2 can understand the communication specifications (communication speed, etc.) that the interchangeable lens 3 can handle by referring to the generation information transmitted from the interchangeable lens 3 via command data communication. Therefore, proper communication can be performed between the camera body 2 and the interchangeable lens 3. Furthermore, compared to individually sending data transmitted by hotline communication, such as data on communication speed and communication interval, information on the drive of the focus lens (information on the position of the focus lens, etc.), and information on the drive of the image stabilization lens (information on the position of the image stabilization lens, etc.), from the interchangeable lens 3 to the camera body 2, the amount of data transmitted from the interchangeable lens 3 to the camera body 2 can be reduced, and the communication time and number of communications required to determine the communication specifications between the interchangeable lens 3 and the camera body 2 can be shortened. Here, the number of values ​​in the generation information is less than the total number of combinations of communication specifications and data indicated in the generation information. Furthermore, if the communication specifications (communication speed, communication interval, etc.) and sampling interval specifications indicated by the generation information are individually transmitted from the interchangeable lens 3 to the camera body 2, the camera body 2 needs to check whether there are any inconsistencies in the individual pieces of information. In this embodiment, consistent communication specifications (communication speed, communication interval, etc.) and sampling interval specifications are set and stored as generation information indicating these specifications, so once the generation information is received, the camera body 2 does not need to check whether there are any inconsistencies. Furthermore, according to the communication specifications indicated by the generation determined by the camera body 2, the interchangeable lens 3 transmits information (lens position information) about the driven component (such as the focus lens) generated by the generation unit (lens control unit 37) to the camera body 2 via hotline communication. Therefore, since the position information of the driven component, such as the focus lens, can be transmitted from the interchangeable lens 3 to the camera body 2 at high speed using hotline communication, the autofocus operation is accelerated.

[0171] (2) The interchangeable lens 3 includes a lens control unit 37 that repeatedly generates information about the driven member (such as the focus lens) (pulse position information of the lens), transmits this information to the camera body 2, calculates the time difference Δt from the time it receives a signal from the camera body 2 to start communication until the lens control unit 37 generates information about the driven member, and transmits the time difference Δt to the camera body 2. In this way, the camera body 2 can determine the position of the focus lens at each time point by using the pulse position information of the lens and the time difference Δt. Furthermore, in this embodiment, the camera body 2 reconstructs and generates the position of the focus lens using the time difference Δt. Therefore, the error between the position of the focus lens reconstructed by the camera body 2 and the actual position of the focus lens in the interchangeable lens 3 can be reduced.

[0172] (3) The CLK terminal is positioned further away from the VBAT terminal than the GND terminal. Furthermore, a PGND terminal is placed between the GND terminal and the VBAT terminal. This shields the CLK terminal, to which the clock signal used for command data communication is sent, from noise originating from the VBAT terminal, thereby enabling stable command data communication. As a result, generation information can be reliably transmitted and received between the camera body 2 and the interchangeable lens 3.

[0173] (Second Embodiment) Next, a camera according to the second embodiment will be described. The configuration common to the first embodiment described above will be omitted from the explanation. In the camera of the second embodiment, under certain circumstances, the camera body 2 transmits generation information lower than the highest generation it can handle to the interchangeable lens 3. Figure 11 is an explanatory diagram of the generation information transmitted from the interchangeable lens 3 to the camera body 2, the generation information transmitted from the camera body 2 to the interchangeable lens 3, and the generation information indicating the communication specifications used when data is transmitted from the interchangeable lens 3 via hotline communication in the camera of the second embodiment. CD1 and CD2 in Figure 11 indicate command data communication, similar to Figure 8, and HL indicates hotline communication.

[0174] In the camera of the second embodiment, for example, the fourth-generation interchangeable lens 3 and camera body 2 shown in Figure 11 can also perform hotline communication according to the communication specifications of the previous generation (lower numbered generation / lower grade), and are therefore compatible with the communication specifications of the first to fourth generations, respectively. As shown in Figure 11, in command data communication CD1, the first lens communication unit 38 of the interchangeable lens 3 transmits "4" as lens-side generation information to the first body communication unit 28 via command data communication. The body control unit 27 receives the transmitted lens-side generation information "4" via the first body communication unit 28.

[0175] In the camera of the second embodiment, for example, in situations where the battery charge level of the camera body 2 is low, the body control unit 27 of the fourth-generation camera body 2 transmits generation information "3" of the third generation, which is lower than the fourth generation, the highest generation common to the interchangeable lens 3 and the camera body 2, to the first lens communication unit 38 via the first body communication unit 28 in order to operate in a lower generation with lower power consumption. The lens control unit 37 of the interchangeable lens 3 receives generation information "3" via the first lens communication unit 38, and then, according to the communication specifications indicated by the third generation, the interchangeable lens 3 transmits data to the camera body 2 via hotline communication. Other operations of the camera of the second embodiment are the same as those described with reference to Figures 8 and 9. The body control unit 27 of the camera body 2 may also select any communication specification from among the communication specifications that the camera body 2 can support, and transmit generation information indicating the selected communication specification to the first lens communication unit 38 via the first body communication unit 28. In this case, the body control unit 27 of the camera body 2 may select any communication specification from among the communication specifications that the camera can support, without recognizing whether the transmitted generation information is of the same generation as the interchangeable lens 3 and the camera body 2, or regardless of whether it is of the same generation as the interchangeable lens 3 and the camera body 2.

[0176] In the second embodiment, the camera operates in a lower-power generation mode in certain situations, such as when the battery charge level of the camera body 2 is low. To achieve this, the camera body 2 transmits generation information lower than the highest generation it can support to the interchangeable lens 3. The interchangeable lens 3 then transmits data to the camera body 2 via hotline communication according to the communication specifications indicated by the generation information received from the camera body 2. This enables the camera in the second embodiment to operate in a lower-power generation mode in certain situations.

[0177] (Third embodiment) Next, a camera according to the third embodiment will be described. The configuration common to the first embodiment described above will be omitted from the description. In the camera of the third embodiment, in certain situations, the camera body 2 transmits generation information lower than the highest generation that the camera body 2 can support to the interchangeable lens 3, and if the generation information received from the camera body 2 and the generation information transmitted from the interchangeable lens 3 to the camera body 2 are different, the interchangeable lens 3 transmits data to the camera body 2 via hotline communication according to the communication specifications indicated by the generation information transmitted from the interchangeable lens 3 to the camera body 2.

[0178] Figure 12 is an explanatory diagram of the generation information transmitted from the interchangeable lens 3 to the camera body 2, the generation information transmitted from the camera body 2 to the interchangeable lens 3, and the generation information indicating the communication specifications used when data is transmitted from the interchangeable lens 3 via hotline communication, in the camera of the third embodiment. CD1 and CD2 in Figure 12 indicate command data communication, as in Figure 8, and HL indicates hotline communication.

[0179] In the third embodiment of the camera, for example, the fourth-generation interchangeable lens 3 and camera body 2 shown in Figure 12 can also perform hotline communication according to the communication specifications of the previous generation (lower numbered generation / lower grade), and are therefore compatible with the communication specifications of the first to fourth generations, respectively. As shown in Figure 12, in command data communication CD1, the first lens communication unit 38 of the interchangeable lens 3 transmits "4" as lens-side generation information to the first body communication unit 28 via command data communication. The body control unit 27 receives the transmitted lens-side generation information "4" via the first body communication unit 28.

[0180] In the camera of the third embodiment, similar to the camera of the second embodiment, in situations such as when the battery charge level of the camera body 2 is low, the body control unit 27 of the fourth-generation camera body 2 transmits generation information "3" of the third generation, which is lower than the fourth generation, the highest generation that the camera body 2 can support, to the first lens communication unit 38 via the first body communication unit 28 in order to perform hotline communication using a communication specification that consumes less power. The lens control unit 37 of the interchangeable lens 3 receives generation information "3" via the first lens communication unit 38. Alternatively, the body control unit 27 of the camera body 2 may select any communication specification from among the communication specifications that the camera body 2 can support and transmit generation information indicating the selected communication specification to the first lens communication unit 38 via the first body communication unit 28. In this case, the body control unit 27 of the camera body 2 may select any communication specification from among the communication specifications that the camera can support, without recognizing whether the transmitted generation information is of the same generation as the interchangeable lens 3 and the camera body 2, or regardless of whether it is of the same generation as the interchangeable lens 3 and the camera body 2.

[0181] Here, the generation information "3" received by the interchangeable lens 3 from the camera body 2 is different from the generation information "4" transmitted from the interchangeable lens 3 to the camera body 2. In such cases, the interchangeable lens 3 of the camera in the third embodiment transmits data to the camera body 2 via hotline communication according to the communication specifications indicated by the fourth generation, which is the highest generation that the interchangeable lens 3 can support. Other operations of the camera in the third embodiment are the same as those described with reference to Figures 8 and 9.

[0182] Thus, in the camera of the third embodiment, if the generation information received from the camera body 2 differs from the generation information transmitted from the interchangeable lens 3 to the camera body 2, the interchangeable lens 3 transmits data to the camera body 2 via hotline communication according to the communication specifications indicated by the fourth generation transmitted from the interchangeable lens 3 to the camera body 2. This makes it possible to take advantage of the performance of the interchangeable lens 3, for example, by performing operations such as faster focus adjustment.

[0183] (Fourth embodiment) Next, the camera of the fourth embodiment will be described. The configuration common to the first embodiment described above will not be explained. In the camera of the fourth embodiment, similar to the camera of the third embodiment, in certain situations, the camera body 2 transmits generation information lower than the highest generation that the camera body 2 can support to the interchangeable lens 3, and if the generation information received from the camera body 2 and the highest generation information that the interchangeable lens 3 can support are different, the interchangeable lens 3 transmits data to the camera body 2 via hotline communication according to the communication specifications indicated by the generation that the interchangeable lens 3 can support.

[0184] Figure 13 is an explanatory diagram of the generation information transmitted from the interchangeable lens 3 to the camera body 2, the generation information transmitted from the camera body 2 to the interchangeable lens 3, and the generation information indicating the communication specifications used when data is transmitted from the interchangeable lens 3 via hotline communication, in the camera of the fourth embodiment. CD1 and CD2 in Figure 13 indicate command data communication, as in Figure 8, and HL indicates hotline communication.

[0185] In the camera of the fourth embodiment, the camera body 2 can also perform hotline communication according to the communication specifications of the previous generation (lower numbered generation / lower grade). For example, in the example shown in Figure 13, the fourth-generation camera body 2 is capable of hotline communication according to the communication specifications of the first to fourth generations. In contrast, the interchangeable lens 3 is capable of hotline communication according to the communication specifications of only one generation and is not capable of hotline communication according to the communication specifications of the previous generation (lower numbered generation / lower grade). In the example shown in Figure 13, the interchangeable lens 3 is capable of hotline communication according to the communication specifications of the fourth generation and is not capable of hotline communication according to the communication specifications of the first to third generations.

[0186] In the camera of the fourth embodiment, as shown in Figure 13, in command data communication CD1, the first lens communication unit 38 of the interchangeable lens 3 transmits "4" as lens-side generation information to the first body communication unit 28 via command data communication. The body control unit 27 receives the transmitted lens-side generation information "4" via the first body communication unit 28.

[0187] In the camera of the fourth embodiment, for example, when the battery charge level of the camera body 2 is low, the body control unit 27 of the fourth-generation camera body 2 transmits generation information "3" of the third generation, which is lower than the fourth generation, the highest generation that the camera body 2 can support, to the first lens communication unit 38 via the first body communication unit 28 in order to perform hotline communication using a communication specification that consumes less power. The lens control unit 37 of the interchangeable lens 3 receives the generation information "3" via the first lens communication unit 38. The body control unit 27 of the camera body 2 may also select any communication specification from among the communication specifications that the camera body 2 can support and transmit generation information indicating the selected communication specification to the first lens communication unit 38 via the first body communication unit 28. In this case, the body control unit 27 of the camera body 2 may select any communication specification from among the communication specifications that the camera can support without recognizing whether the transmitted generation information is a common generation between the interchangeable lens 3 and the camera body 2, or regardless of whether it is a common generation between the interchangeable lens 3 and the camera body 2.

[0188] Here, the generation information "3" received by the interchangeable lens 3 from the camera body 2 is different from the generation information "4" that the interchangeable lens 3 is compatible with. In such a case, the interchangeable lens 3 of the camera in the fourth embodiment transmits data to the camera body 2 via hotline communication according to the communication specifications indicated by the fourth generation that the interchangeable lens 3 is compatible with. Other operations of the camera in the fourth embodiment are the same as those described with reference to Figures 8 and 9.

[0189] Thus, in the camera of the fourth embodiment, if the generation information received from the camera body 2 differs from the generation information that the interchangeable lens 3 can support, the interchangeable lens 3 transmits data to the camera body 2 via hotline communication according to the communication specifications indicated by the generation information that the interchangeable lens 3 can support. This makes it possible to take advantage of the performance of the interchangeable lens 3, for example, by performing operations such as faster focus adjustment. Furthermore, even if the interchangeable lens 3 only supports one generation, it is possible to transmit data to the camera body 2 via hotline communication.

[0190] The following modifications are also within the scope of the present invention, and it is possible to combine one or more of these modifications with the embodiments described above.

[0191] (Variation 1) In the embodiment described above, an example was described in which full-duplex communication is performed as command data communication between the first lens communication unit 38 and the first body communication unit 28. However, the first lens communication unit 38 and the first body communication unit 28 may also be configured to perform half-duplex communication as command data communication.

[0192] (Modification 2) In the embodiment described above, the lens control unit 37 calculates the time from time t0 to time t1 in Figure 9 as the shift time Δt, and the body control unit 27 calculates the generation time of the lens position information using the shift time Δt calculated by the lens control unit 37. However, the lens control unit 37 may also calculate the time from time t0 to time t2 in Figure 9 (shift time Δt2) and output the shift time Δt2 to the camera body 2. In this case, the body control unit 27 calculates the generation time of the lens position information using the shift time Δt2.

[0193] For example, the body control unit 27 calculates (determines) the time t0 + Δt2, which is obtained by adding a shift time Δt2 to the falling edge time t0 of the RDY signal, as the lens position information generation time t2. The body control unit 27 also calculates the lens position information generation times t3, t4, t5, and t6 as t2+S, t2+2S, t2+3S, and t2+4S, respectively.

[0194] (Variation 3) In the above-described embodiment, the lens control unit 37 has a first lens communication unit 38 and a second lens communication unit 39, but these may be combined into a single lens communication unit instead of having them individually. Similarly, the body control unit 27 has a first body communication unit 28 and a second body communication unit 29, but these may be combined into a single body communication unit instead of having them individually.

[0195] (Modification 4) In the above embodiment, interchangeable camera lenses were used as an example of accessories, but accessories are not limited to interchangeable lenses. For example, teleconverters, wide-angle converters, or extension rings that are attached between the camera body and the interchangeable lens to change the focal length of the interchangeable lens may also be used. Alternatively, it can be applied to mount adapters that allow accessories, including interchangeable lenses of other mount standards, to be attached to the camera body mount standard described above. In other words, it can be applied similarly to any accessory that is attached to the camera body mount and used. In that case, the lens-side terminal group, lens-side claw portion 139, first and second lens communication portions 38, 39, etc. correspond to the accessory-side terminal group, accessory-side protrusion portion, accessory-side communication portion, etc. of each respective accessory. In the above embodiment, the accessory is attached to a camera body. However, the camera body may also be a mount adapter that allows interchangeable lenses of the above-mentioned mount standard to be attached to a camera body with a different mount standard than the above-mentioned mount standard, and the above-mentioned accessory may be attached to that mount adapter.

[0196] (Variation 5) In the embodiment described above, the interchangeable lens 3 transmits information to the camera body 2 at the communication interval specified in the communication specifications of the determined generation. However, the interchangeable lens 3 does not necessarily have to transmit data at every communication interval specified in the communication specifications of the determined generation. The communication interval sent by the interchangeable lens 3 may be an integer multiple of the communication interval specified in the communication specifications of the determined generation; for example, the communication interval sent by the interchangeable lens 3 may be twice the communication interval specified in the communication specifications of the determined generation. In that case, the camera body 2 can receive all the data sent from the interchangeable lens 3 at intervals twice the communication interval specified in the communication specifications of the determined generation. Of course, it is not necessary to transmit at twice the communication interval; the generated data may be transmitted irregularly rather than periodically, as long as it is synchronized with the communication interval specified in the communication specifications of the determined generation. Alternatively, the communication interval at which the interchangeable lens 3 sends data may be three times the communication interval specified in the communication specifications of the determined generation.

[0197] Although various embodiments and modifications have been described above, the present invention is not limited to these. The above embodiments and modifications may be combined. Furthermore, other embodiments that can be conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0198] 1...Camera (camera system), 2...Camera body, 3...Interchangeable lens, 27...Body control unit, 28...First body communication unit, 29...Second body communication unit, 37...Lens control unit, 38...First lens communication unit, 39...Second lens communication unit

Claims

[Claim 1] A camera body to which an accessory can be attached and which can communicate with the accessory, the camera body being capable of receiving information from the accessory regarding a movable member of the accessory in one or more communication specifications, and a first communication unit that performs unidirectional communication from the accessory, A second communication unit, independent of the first communication unit, performs bidirectional communication with the accessory, Equipped with, The second communication unit receives a first value from the accessory that indicates the communication specifications of the first communication unit. The first communication unit is a camera body that receives information about the moving member from the accessory and does not have a terminal from which a signal is output, according to the communication specifications indicated by the first value.

Images