Accessories

Abstract

To provide an accessory which enables appropriate data communication with a camera body.SOLUTION: An accessory, which can be mounted on a camera body and can communicate with the camera body, includes a transmission part capable of transmitting information on a member to be driven driven by a drive part to the camera body by one or more communication specifications, and a reception part for receiving a first value indicating the communication specifications of transmitting the information from the camera body, wherein the transmission part and the reception part can be mutually independently communicated with each other, the first value indicates that the information on the member to be driven is transmitted to the camera body, and the transmission part transmits the information on the member to be driven by the communication specification indicated by the first value to the camera body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an accessory. [Background technology]

[0002] Conventionally, there are camera systems in which accessories such as interchangeable lenses can be attached to the camera body, and proper data communication is required between the accessory and the camera body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-85423 Summary of the Invention

[0004] According to a first aspect, an accessory is attachable to a camera body and capable of communicating with the camera body, and includes a transmitter capable of transmitting information relating to a driven member driven by a driver to the camera body using one or more communication specifications, and a receiver that receives from the camera body a first value indicating the communication specification for transmitting the information to the camera body, wherein the transmitter and the receiver are capable of communicating independently of each other, The first value is a value that is determined based on the communication speed of the transmitting unit, the communication interval of the information by the transmitting unit, the number of pieces of information, and the number of pieces of information of the driven member to which the information is transmitted. kinds A combination of The transmission unit transmits information about the driven member to the camera body in accordance with the communication specification indicated by the first value. According to a second aspect, an accessory is an accessory capable of communicating with a camera body, and includes a first communication unit that receives a first value indicating a plurality of specifications including the number of data to be communicated and a communication interval, and a second communication unit that communicates independently of the first communication unit and transmits information about a movable member in accordance with the communication specifications indicated by the first value, wherein the first value is: The communication speed of the second communication unit capable of transmitting information about a driven member driven by a drive unit to the camera body using one or more communication specifications, the communication interval of the information by the second communication unit, the number of pieces of information, and the driven member to which the information is transmitted. Types of A combination of It is a single value that indicates [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 illustrates an example of the configuration of a camera according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating command data communication in the camera according to the first embodiment. [Figure 3] 3A and 3B are diagrams illustrating electrical connections between a lens-side connector and a body-side connector according to the first embodiment. [Figure 4] FIG. 2 is a diagram schematically showing a mount of a camera body as viewed from the interchangeable lens side in the first embodiment. [Figure 5] FIG. 2 is a diagram showing a schematic view of an interchangeable lens mount as seen from the camera body side in the first embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of a generation according to the first embodiment. [Figure 7] FIG. 4 is a diagram showing an example of a generation determined in the camera according to the first embodiment. [Figure 8] FIG. 4 is a diagram showing an example of a generation determined in the camera according to the first embodiment. [Figure 9] FIG. 2 illustrates an example of processing and communication in the camera according to the first embodiment. [Figure 10] 5A to 5C are diagrams for explaining an example of a method for calculating a time Δt in the camera according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] (First embodiment) 1 is a diagram showing an example of the configuration of a camera 1, which is an example of an imaging device according to a first embodiment. The camera 1 is made up of a camera body 2 and an interchangeable lens 3, which is an attachable accessory. As the camera 1 is made up of the camera body 2 and the interchangeable lens 3, it is sometimes called a camera system.

[0007] The camera body 2 is provided with a body-side mount unit 201 to which the interchangeable lens 3 is attached. The interchangeable lens 3 is provided with a lens-side mount unit 301 to which it is attached to the camera body 2. The lens-side mount unit 301 and the body-side mount unit 201 are provided with a lens-side connection unit 302 and a body-side connection unit 202, respectively. The lens-side connection unit 302 and the body-side connection unit 202 are each provided with a plurality of terminals, such as terminals for clock signals, terminals for data signals, and terminals for power supply, which will be described later. The interchangeable lens 3 is detachably attached to the body-side mount unit 201 of the camera body 2 by the lens-side mount unit 301.

[0008] When the interchangeable lens 3 is attached to the camera body 2, a terminal provided on the body side connection part 202 is electrically connected to a terminal provided on the lens side connection part 302. This enables power to be supplied from the camera body 2 to the interchangeable lens 3 and communication between the camera body 2 and the interchangeable lens 3.

[0009] First, the configuration of the interchangeable lens 3 will be described in detail. The interchangeable lens 3 includes a photographic optical system 31, an aperture diaphragm 32, a lens driver 33, a lens position detector 34, an aperture driver 35, a lens memory 36, and a lens controller 37. While the photographic optical system 31 is illustrated as a single lens for simplicity, it actually includes multiple lenses including a focus lens (focus adjustment lens), and forms a subject image on the imaging surface of the image sensor 21 when attached to the camera body 2. For example, the photographic optical system 31 may include, in addition to the focus lens (focus adjustment lens), a zoom lens that changes the focal length and an anti-vibration lens (blur correction lens) that reduces image blur (camera shake). In practice, the aperture diaphragm 32 is provided, for example, between the multiple lenses of the photographic optical system 31.

[0010] The lens driver 33 and the aperture driver 35 are each configured, for example, by a stepping motor, an ultrasonic motor, a DC motor, or the like. The lens driver 33 controls the driving of the photographic optical system 31. For example, the lens driver 33 moves the focus lens forward or backward along the optical axis L based on a signal output from the lens controller 37, thereby changing the position at which a subject image is formed by the photographic optical system 31. The aperture driver 35 drives the aperture diaphragm 32 to change the aperture diameter based on a signal output from the lens controller 37. If the photographic optical system 31 includes a zoom lens or an anti-vibration lens, the lens driver 33 may be provided with drive sources for these components to drive the zoom lens or the anti-vibration lens, respectively. In this case, the lens driver 33 moves the zoom lens along the optical axis L based on a signal output from the lens controller 37. The lens driver 33 moves the anti-vibration lens in a direction intersecting the optical axis L based on a signal output from the lens controller 37. Furthermore, the lens driving unit 33 and the aperture driving unit 35 may include a driving circuit (driver IC or the like) (not shown) that drives a stepping motor, an ultrasonic motor, a DC motor or the like.

[0011] The lens position detection unit 34 is composed of, for example, a photointerrupter and an encoder. The photointerrupter detects that a detected portion of the imaging optical system 31 (for example, a support portion of the focus lens) has passed a reference position (origin position) on the optical axis L, and outputs a detected signal to the lens control unit 37. The lens control unit 37 detects that the focus lens has passed the reference position (origin position) based on the signal from the photointerrupter. The encoder is a so-called linear encoder. The linear encoder generates two or more pulse signals with different phases, 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, outputting a pulse signal according to the absolute position.

[0012] If a stepping motor is used as the lens driver 33, an encoder need not be used, and a photointerrupter may be used to detect that the photographing optical system 31 has passed the origin position. In this case, when a detected portion of the photographing optical system 31 (for example, a support portion of the focus lens) passes the photointerrupter of the lens position detector 34, a signal indicating that the photographing optical system 31 has passed the origin position is output to the lens controller 37. To drive the photographing optical system 31, the lens controller 37 outputs a pulse signal corresponding to the amount of lens movement to a drive circuit of the stepping motor of the lens driver 33, and the drive circuit of the lens driver 33 outputs a pulse signal corresponding to the amount of lens movement (corresponding to the pulse signal output from the lens controller 37 to the drive circuit of the lens driver 33) to the lens controller 37.

[0013] In addition, if the photographing optical system 31 includes a zoom lens or an anti-vibration lens, the lens position detection unit 34 detects the amount of movement of the zoom lens or the amount of movement of the anti-vibration 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 movement position of the anti-vibration lens.

[0014] The lens control unit 37 is configured with a processor such as a CPU or FPGA, and memories such as ROM or RAM, and controls each unit of the interchangeable lens 3 based on a control program. The lens control unit 37 drives and controls the photographic optical system 31 and the aperture diaphragm 32 using the lens drive unit 33 and the diaphragm drive unit 35 based on control signals input from the body control unit 27 of the camera body 2 via the body side connector 202 and the lens side connector 302. For example, when a control signal indicating the movement direction, movement amount, movement speed, etc. of the focus lens is input from the body control unit 27, the lens control unit 37 sends an instruction to drive and control the lens drive unit 33 based on the control signal.

[0015] Furthermore, the lens control unit 37 detects the positions of the focus lens, zoom lens, etc., and sends this information to the camera body 2. When a stepping motor is used as the lens drive unit 33, the lens control unit 37 sends the amount of drive 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 amount of drive is output from the drive circuit of the lens drive unit 33 to the lens control unit 37. The lens control unit 37 detects that the focus lens or zoom lens has passed the reference position (origin position) from the output of the photointerrupter of the lens position detection unit 34, and further counts and accumulates pulse signals input from the encoder and pulse signals corresponding to the drive amount of the stepping motor to generate information (pulse position information) corresponding to the movement amount of the focus lens. The generated information (pulse position information) corresponding to the amount of movement of the focus lens is transmitted to the camera body 2 via hotline communication, which will be described later.

[0016] The lens memory 36 is configured, for example, by a non-volatile storage medium. The lens memory 36 stores various information related to the interchangeable lens 3. For example, the lens memory 36 stores the focal length and maximum aperture value of the interchangeable lens, as well as information indicating the communication specifications that the interchangeable lens 3 is compatible with when communicating with the camera body 2. This information indicating the communication specifications is referred to as 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. The lens-side generation information may be stored in memory internal to the lens control unit 37.

[0017] The lens control unit 37 also has a first lens communication unit 38 and a second lens communication unit 39. As will be described in detail later, the first lens communication unit 38 performs command and 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, we will explain in detail the configuration of the camera body 2. The camera body 2 comprises an image sensor 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 made up of a processor such as a CPU or FPGA, and memories such as ROM and RAM, and controls each unit of the camera 1 based on a control program.

[0019] The body control unit 27 generates image data by performing predetermined image processing on the signal output from the image sensor 21. Image processing includes well-known image processing such as tone conversion processing, color interpolation processing, and edge enhancement processing. The body control unit 27 also generates control signals for controlling the driving of the photographic optical system 31 (the driving of the focus lens, the zoom lens, and the vibration reduction lens) and the driving of the aperture diaphragm 32.

[0020] The body control unit 27 also performs processing required for autofocus (AF) of the photographic 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 that replace some of the imaging pixels that output imaging signals, and have part of the photoelectric conversion units within the pixels shielded by a light-shielding film. The body control unit 27 calculates the defocus amount using the phase difference detection method using the focus detection signals output from the focus detection pixels. The body control unit 27 outputs a signal related to the calculated defocus amount to the lens control unit 37. The lens control unit 37 drives the focus lens in accordance with the defocus amount. Note that the image sensor 21 may also be configured to have a pixel for both imaging and focus detection, with multiple photoelectric conversion units within one pixel, and outputting an imaging signal and a focus detection signal.

[0021] Furthermore, the body control unit 27 can also perform contrast detection focus detection processing instead of or in addition to phase difference detection 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 photographing optical system 31 in the direction of the optical axis L. The body control unit 27 associates the position of the focus lens with the contrast evaluation value using focus lens position information (pulse position information) transmitted from the interchangeable lens 3. 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 inside of the camera body 2 and the interchangeable lens 3. The power supply unit 26 is connected to the body side connector 202 and the body control unit 27. The power supply unit 26 also supplies power to the lens control unit 37 via the body side connector 202 and the lens side connector 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 photographing optical system 31 and captures an image of a subject. The image sensor 21 has a plurality of pixels, each having a photoelectric conversion unit, arranged in a two-dimensional plane in the row and column directions. The photoelectric conversion unit is formed of, for example, a photodiode (PD). The image sensor 21 photoelectrically converts the received light 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 the camera 1. The body memory 22 also stores information indicating the generation of the camera body, which will be described later, i.e., information indicating the communication specifications that the camera body 2 is compatible with when communicating with the interchangeable lens 3. This information indicating the communication specifications is referred to as the generation of the camera body, which will be described later. The generation may also be referred to as generation information. The generation information of the camera body 2 is referred to as body-side generation information. The writing of data to the body memory 22 and the reading of data from the body memory 22 are controlled by the body control unit 27. Note that image data may be stored in the body memory 22, or may be stored in a separate storage medium. The body-side generation information may also be stored in memory internal to the body control unit 27.

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

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

[0027] Next, command and data communication will be described. The first lens communication unit 38 and the first body communication unit 28 perform full-duplex communication via the respective terminals of the lens side connection unit 302 and the body side connection unit 202. 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, a RDY signal, a CLK signal, a DATAB signal, and a DATAL signal.

[0028] The RDY signal is a signal that indicates whether communication with the first lens communication unit 38 is possible, and is switched between a high level (H level) and a low level (L level) by the first lens communication unit 38. The RDY signal is a signal that is transmitted (output) to the first body communication unit 28. The CLK signal is a camera body-side clock signal that is transmitted from the first body communication unit 28 to the first lens communication unit 38. The DATAB signal is a data signal that is transmitted from the first body communication unit 28 to the first lens communication unit 38. The DATAL signal is a data signal that is transmitted from the first lens communication unit 38 to the first body communication unit 28.

[0029] Next, the information (commands, data) sent and received in command data communication will be described. The interchangeable lens 3 sends to the camera body 2, by means of a DATAL signal, for example, data related to the optical characteristics (maximum aperture, aberrations, etc.) of the photographic optical system 31, data related to the infinity position and close position of the focus lens, lens generation information, and response contents (response data) such as the status of initialization in response to an initialization command from the camera body 2 (described later). On the other hand, the camera body 2 sends to the interchangeable lens 3, by means of a DATAB signal, for example, generation information indicating the communication specifications used for hotline communication (described later), control instructions (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, lens initialization, etc.

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

[0031] The signal level of the RDY signal indicates whether or not the first lens communication unit 38 is in a state where communication is possible. When the first lens communication unit 38 is in a state where communication is possible 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, for example, ground voltage or reference voltage). When the first lens communication unit 38 is in a state where communication is not possible 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, for example, 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 or not the first lens communication unit 38 is in a state where communication is possible.

[0032] At time t1, when the RDY signal is at 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, alternately between high level and low level (e.g., ground voltage, reference voltage) at a predetermined cycle after time t1. Furthermore, during the period from time t1 to time t2, the first body communication unit 28 transmits command packets 41 using the DATAB signal in synchronization with the rising or falling edges of the CLK signal.

[0033] When 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 or 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 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, and determines whether the command packet 41 was received correctly. If the first lens communication unit 38 received the command packet 41 correctly, the lens control unit 37 sets the RDY signal to high level at time t3. The lens control unit 37 also performs a first process 51 according to the contents of the command packet 41. When the first process 51 is completed, the lens control unit 37 sets the RDY signal to low level at time t4. If the first lens communication unit 38 did not receive the command packet 41 correctly, the lens control unit 37 keeps the RDY signal at low level and notifies the first body communication unit 28 that the command packet 41 was not received correctly.

[0035] When the first body communication unit 28 detects that the RDY signal has changed from high to low, it starts outputting the CLK signal again at time t5. Furthermore, from time t5 to time t6, the first body communication unit 28 transmits a data packet 42 using the DATAB signal in synchronization 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 using the DATAL signal in synchronization 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 the data packet 42 from the first body communication unit 28, the lens control unit 37 sets the RDY signal to high level at time t7. The lens control unit 37 performs a second process 52 according to the contents of the data packet 42. When the second process 52 is completed, the lens control unit 37 sets the RDY signal to low level at time t8.

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

[0038] Next, hotline communication will be described in detail. The second lens communication unit 39 and second body communication unit 29 shown in Fig. 1 perform one-way communication from the interchangeable lens 3 to the camera body 2 via the respective terminals of the lens side connection unit 302 and the body side connection unit 202. 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 on the interchangeable lens side that is transmitted from the second lens communication unit 39 to the second body communication unit 29. The HDATA signal is a data signal that is transmitted from the second lens communication unit 39 to the second body communication unit 29, and includes information about the lens positions of the focus lens, zoom lens, and image stabilization lens described above, and information about 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 edges of the HCLK signal. In this way, the second lens communication unit 39 and the second body communication unit 29 perform unidirectional communication in which a clock signal and a data signal are transmitted 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. The frequency of the CLK signal output from the camera body 2 to the interchangeable lens 3 is, for example, 8 MHz, and the frequency of the HCLK signal output from the interchangeable lens 3 to the camera body 2 is, for example, 2.5 MHz to 8 MHz.

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

[0042] The LDET(B) terminal is a terminal used to detect attachment / detachment of the interchangeable lens 3. The LDET(B) terminal is connected to the body control unit 27 via a resistor R2. A power supply V33 supplied from the power supply unit 26 via a resistor R1 is connected between the resistor R2 and the body control unit 27, 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 FIG. 3, the direction of the supplied power is indicated by an arrow. The VBAT(B) terminal is a terminal used to supply power (supply power supply 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 that the power supply unit 26 applies to the VBAT(B) terminal is a maximum of approximately 10 V. The PGND(B) terminal is a ground terminal corresponding to the VBAT(B) terminal, and serves as the ground potential (ground) for the power supply voltage of the drive system supplied by the VBAT(B) terminal.

[0043] The V33(B) terminal is a terminal used to supply power (supply power supply voltage) to the circuit system of the interchangeable lens 3. The lens control unit 37 and other components are operated by power supplied from the power supply unit 26 via the V33(B) terminal. Components such as the lens control unit 37 operate at lower voltages and currents than the lens drive unit 33. The voltage applied by the power supply unit 26 to the V33(B) terminal is a maximum of approximately 3.3 V. The GND(B) terminal is a ground terminal corresponding to the V33(B) terminal, and serves as the ground potential (ground) for 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 the RDY signal, CLK signal, DATAB signal, DATAL signal, HCLK signal, and HDATA signal to and from 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 and 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 FIG. 3, the signal flow is indicated by arrows. The potential of the RDY(B) terminal indicates whether the interchangeable lens 3 is capable of command and data communication. The DATAB (B) terminal is a terminal through which a signal is output toward the interchangeable lens 3. The CLK (B) terminal is a terminal through which a clock signal from the camera body side is output toward the interchangeable lens 3.

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

[0046] The lens side connection unit 302 has an LDET(L) terminal, a VBAT(L) terminal, a PGND(L) terminal, a V33(L) terminal, a GND(L) terminal, a RDY(L) terminal, a DATAB(L) terminal, a CLK(L) terminal, a DATAL(L) terminal, an HCLK(L) terminal, and an 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, and the V33(B) terminal is connected to the V33(L) terminal. The (L) terminal is connected to the GND(B) terminal, the GND(L) terminal is connected to the GND(B) terminal, the RDY(L) terminal is connected to the RDY(B) 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 terminal it comes into contact with on the body.

[0048] The LDET(L) terminal is grounded via resistor R3. When the LDET(L) terminal comes into 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 driver 33 and the aperture driver 35 via the lens controller 37. A so-called bypass capacitor C1 is connected between the VBAT(L) terminal and the PGND(L) terminal. The V33(L) terminal and the GND(L) terminal are connected to the lens controller 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 controller 37. The RDY(L), DATAB(L), CLK(L), and DATAL(L) terminals are connected to the first lens communication unit 38 of the lens control unit 37 and are used for command and data communication as described above. The HCLK(L) and HDATA(L) terminals are connected to the second lens communication unit 39 and are used for hotline communication as described above.

[0049] After transmitting a control command (command) from the body control unit 27 to the lens control unit 37 of the interchangeable lens 3, 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 sent and received in parallel is called command data communication. Command data communication is full-duplex communication. Command data communication is performed by 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 details to the interchangeable lens 3 by command data communication via the first body communication unit 28 and the first lens communication unit 38, and transmits and receives various information to and from the interchangeable lens 3 by receiving responses from the interchangeable lens 3. The control commands referred to here are, for example, commands to transmit lens information. Examples of the various information received from the interchangeable lens 3 include model information about the interchangeable lens 3 and information indicating optical characteristics such as the focal length of the imaging optical system 31. Examples of the various information transmitted to the interchangeable lens 3 include control details such as the lens drive amount and model information about the camera body 2. Note that the control commands also include commands to drive a focus lens (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 by command data communication.

[0051] 4(a) is a diagram showing a schematic view of 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 with a certain width. The body-side mount portion 201 also has a first body-side claw portion 129a, a second body-side claw portion 129b, a third body-side claw portion 129c, and a fourth body-side claw portion 129d. In the following description, these four claw portions will be collectively referred to as the body-side claw portions 129.

[0052] The body side claws 129 are arranged at intervals along the circular opening of the body side mount part 201. As shown in Fig. 4(a), the first body side claw 129a is arranged at the upper right position, the second body side claw 129b at the upper left position, the third body side claw 129c at the lower left position, and the fourth body side claw 129d at the lower right position.

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

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

[0055] A body-side connection portion 202 is provided inside the opening of the body-side mount portion 201. The body-side connection portion 202 has an arc-like shape corresponding to the annular shape of the body-side mount portion 201. The body-side connection portion 202 is arranged above the opening of the body-side mount portion 201, parallel to the opening of the body-side mount portion 201, and is preferably arranged in the center of the upper part as shown in FIG. 4(a). The body-side connection portion 202 has multiple body-side terminals as described above. The multiple body-side terminals are arranged in a line in an arc shape on the body-side connection portion 202 inside the body-side mount portion 201. The multiple body-side terminals are arranged in 11 terminals from the right as shown in FIG. 4(a), including 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 leftmost side. The body-side terminals are each a conductive pin. The body-side terminals are pushed in the -Z direction (Fig. 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 toward the subject.

[0056] The body side mount 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 mount portion 201, the hole of the lock pin 142 is located between the area in the opening of the body side mount portion 201 where the body side fourth claw portion 129d is present and the area where the body side first claw portion 129a is present. The lock pin 142 is pushed in the -Z direction (FIG. 1) by a spring or the like (not shown).

[0057] 4(b) is a schematic diagram of the mount of the camera body 2 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 first body-side claw 129a (on the rear side of the first body-side claw 129a in the +Z direction). Similarly, a second leaf spring 141b is provided at a position corresponding to the second body-side claw 129b (on the rear side of the second body-side claw 129b), a third leaf spring 141c is provided at a position corresponding to the third body-side claw 129c (on the rear side of the third body-side claw 129c), and a fourth leaf spring 141d is provided at a position corresponding to the fourth body-side claw 129d (on the rear side of the fourth body-side claw 129d). In the following description, these four leaf springs will be collectively referred to as leaf springs 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] 5 is a diagram showing a schematic view of the mount of the interchangeable lens 3 as seen from the camera body 2. The interchangeable lens 3 has the lens side mount portion 301 and the lens side connection portion 302 described above in FIG. The lens-side mount unit 301 has an annular reference surface with a certain width. When the interchangeable lens 3 is attached to the camera body 2, the annular reference surface of the lens-side mount unit 301 comes into contact with the annular reference surface of the body-side mount unit 201 described above. The lens-side mount unit 301 also has a cylindrical portion on its inner periphery that extends in the optical axis direction. The lens-side mount unit 301 has a first lens-side claw 139a, a second lens-side claw 139b, a third lens-side claw 139c, and a fourth lens-side claw 139d spaced apart from one another along the outer periphery of the cylindrical portion. In the following description, these four claws will be collectively referred to as the lens-side claw 139.

[0059] The lens-side claws 139 are provided in a direction that protrudes from the outer periphery of the cylindrical portion of the lens-side mount portion 301 toward the outside of the mount (in a radial direction from the optical axis L). As shown in Fig. 5, the first lens-side claw 139a is located at the upper left, the second lens-side claw 139b at the upper right, the third lens-side claw 139c at the lower right, and the fourth lens-side claw 139d at the lower left. Behind the lens-side claws 139 (the reference surface side of the lens-side mount portion 301), there is a space into which the corresponding body-side claw 129 fits when the interchangeable lens 3 is attached to the camera body 2.

[0060] A lens side connection unit 302 is provided inside the opening of the lens side mount unit 301. The lens side connection unit 302 has an arc-like shape that corresponds to the shape of the annular lens side mount unit 301. The lens side connection unit 302 is arranged in the upper part of the opening of the lens side mount unit 301, parallel to the opening of the lens side mount unit 301, and is preferably arranged in the center of the upper part as shown in FIG. 5. The lens side connection unit 302 has multiple lens side terminals as described above. The multiple lens side terminals are arranged in a line in an arc shape on the lens side connection unit 302 inside the lens side mount unit 301. The multiple lens side terminals are arranged in 11 terminals from the right side as shown in FIG. 5: LDET(L), VBAT(L), PGND(L), V33(L), ​​GND(L), RDY(L), DATAB(L), CLK(L), DATAL(L), HCLK(L), and HDATA(L). The lens-side terminal group is arranged so that the conductive contact surfaces are exposed in the +Z direction (FIG. 1), which is the direction in which subject light passing through the photographic optical system 31 travels toward the image sensor 21.

[0061] The lens side mount section 301 has a lock pin receiving portion 143. As shown in FIG. 5, the lock pin receiving portion 143 is located to the upper left of the lens side fourth claw 139d. In other words, the lock pin receiving portion 143 is located between the portion of the lens side mount section 301 that corresponds to the lens side first claw 139a and the portion that corresponds to the lens side fourth claw 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 (FIG. 1) from the reference plane of the lens side mount section 301.

[0062] When the interchangeable lens 3 is attached to the camera body 2, the body terminals come into physical contact with the corresponding lens terminals. This contact electrically connects the body terminals to the lens terminals. In other words, the body terminals and the lens terminals are electrically connected.

[0063] (Attaching interchangeable lenses) The following 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 section 201 and the lens side mount section 301 are aligned to face each other, and the first lens side claw section 139a is aligned with the first body side insertion / removal section 140a, the second lens side claw section 139b is aligned with the second body side insertion / removal section 140b, the third lens side claw section 139c is aligned with the third body side insertion / removal section 140c, and the fourth lens side claw section 139d is aligned with the fourth body side insertion / removal section 140d. Then, the first lens-side claw 139a is inserted into the first body-side insertion / removal portion 140a, the second lens-side claw 139b is inserted into the second body-side insertion / removal portion 140b, the third lens-side claw 139c is inserted into the third body-side insertion / removal portion 140c, and the fourth lens-side claw 139d is inserted into the fourth body-side insertion / removal portion 140d. At this time, the LDET(L) terminal contacts the CLK(B) terminal, the VBAT(L) terminal contacts the DATAL(B) terminal, the PGND(L) terminal contacts the HCLK(B) terminal, and the V33(L) terminal contacts the HDATA(B) terminal.

[0064] From this state, the interchangeable lens 3 is rotated in the mounting direction 144 shown in FIGS. 4(a) and 5. That is, the first body-side claw 129a enters the space behind the first lens-side claw 139a, the second body-side claw 129b enters the space behind the second lens-side claw 139b, the third body-side claw 129c enters the space behind the third lens-side claw 139c, and the fourth body-side claw 129d enters the space behind the fourth lens-side claw 139d. At this time, the lens-side terminals come into contact with the body-side terminals in sequence. Note that the camera body 2, rather than the interchangeable lens 3, may be rotated in the direction opposite to the mounting direction 144 shown in FIGS. 4(a) and 5.

[0065] When the lens-side claws 139 are inserted into the corresponding body-side insertion / removal sections 140 and rotated in the mounting direction 144, for example, the LDET(L) terminal contacts 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 contacts 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 contacts 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 contacts 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 contacts 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 contacts 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 contacts 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 contacts the HDATA(B) terminal, HCLK(B) terminal, DATAL(B) terminal, and CLK(B) terminal in that order. For example, the DATAL(L) terminal contacts the HDATA(B) terminal, HCLK(B) terminal, and DATAL(B) terminal in that order. For example, the HCLK(L) terminal contacts the HDATA(B) terminal and HCLK(B) terminal in that order.

[0067] When the interchangeable lens 3 is rotated by a predetermined angle relative to the camera body 2, it reaches the fully attached position. At the fully attached position, the corresponding body-side claw 129 and lens-side claw 139 face each other in the optical axis direction, and the lock pin 142 is pushed in the -Z direction in FIG. 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 remove it from the camera body 2. In other words, when the body-side claw 129 and lens-side claw 139 reach the predetermined fully attached position, the relative positions of the body-side mount portion 201 and the lens-side mount portion 301 are fixed. The lens-side claw 139 is pushed toward the body (in the +Z direction in FIG. 1) by the leaf spring 141. As a result, each of the multiple lens-side terminals comes into contact with each of the multiple corresponding body-side terminals, and is electrically connected.

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

[0069] In the attached state, 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 cause the power supply unit 26 to supply power to the VBAT(B) terminal and the V33(B) terminal.

[0070] In the attachment-completed state, the signal level of the LDET(B) terminal is pulled down to low, as described above ( FIG. 3 ). When the body control unit 27 detects that the signal level of the LDET(B) terminal has gone low, it determines that the interchangeable lens 3 has been attached. Furthermore, in the attachment-completed state, the lock pin 142 enters the lock pin receiving portion 143, and a lock pin detection switch (not shown) 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 gone low and that the lock pin detection switch has been turned on, it causes the power supply unit 26 to start supplying power to the V33(B) terminal, i.e., to supply power supply voltage to the circuitry. The camera body 2 does not necessarily need to be equipped with a lock pin detection switch. If the camera body 2 does not have a lock pin detection switch, it may be configured to cause the power supply unit 26 to start supplying power to the V33(B) terminal when it detects that the signal level of the LDET(B) terminal has gone low.

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

[0072] When the user presses the unlock button (not shown) on the camera body 2 in the fully attached state, the lock pin 142 retracts from the lock pin receiving portion 143. This makes it possible to change the relative positions of the body-side mount portion 201 and the lens-side mount portion 301. When the user presses the unlock button (not shown), the body control unit 27 turns off the lock pin detection switch linked to the unlock button, causing the power supply unit 26 to stop supplying power to the VBAT(B) terminal and V33(B) terminal. From this state, when the interchangeable lens 3 is rotated in the direction opposite to the attachment direction 144 shown in FIGS. 4(a) and 5, the lens-side terminals come into contact with the body-side terminals in the reverse order to that described above.

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

[0074] As explained above, when an interchangeable lens is being attached to or removed from a camera body (in the mounted state), the lens terminals come into contact with body terminals other than the corresponding terminals when attachment is complete. It is desirable that the arrangement of the lens terminals and body terminals minimize problems caused by contact during attachment and removal.

[0075] In this embodiment, of the multiple body-side terminals, the LDET(B) terminal is located at the very end in the lens attachment direction (arrow 144 in FIG. 4(a)). That is, as described above, the location of the LDET(B) terminal is the leftmost of the group of body-side terminals in FIG. 4(a). Of the multiple lens-side terminals, the LDET(L) terminal is also located at the very end in the lens attachment direction (arrow 144 in FIG. 5). That is, as described above, the location of the LDET(L) terminal is the rightmost of the group of lens-side terminals in FIG. 5. Therefore, the LDET(B) terminal does not come into contact with lens-side terminals other than the LDET(L) terminal until attachment of the attached lens is complete. Therefore, the signal level of the LDET(B) terminal does not erroneously become low during the process of attaching an interchangeable lens, and the attachment of the lens is not erroneously recognized.

[0076] In this embodiment, the VBAT(B) terminal is located next to the LDET(B) terminal, i.e., the second terminal from the front end in the mounting direction. The VBAT(L) terminal is located next to the LDET(L) terminal, i.e., the second terminal from the front end in the mounting direction. This is done to reduce the number of lens-side terminals that the camera body-side VBAT(B) terminal comes into contact with during the lens mounting process. Because the voltage applied to the VBAT(B) terminal is higher than 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 circuitry within the interchangeable lens. In this embodiment, because the VBAT(B) terminal is located next to the LDET(B) terminal, when the interchangeable lens 3 is attached, only the LDET(L) terminal comes into contact with the VBAT(B) terminal among the multiple lens-side terminals. The LDET(L) terminal is grounded via a resistor (resistor R3 in Figure 3), so that even if a high voltage is applied from the VBAT(B) terminal, it will not affect the camera 1.

[0077] In this embodiment, the PGND(B) terminal is located next to the VBAT(B) terminal, i.e., the third terminal from the end in the mounting direction. The PGND(L) terminal is located next to the VBAT(L) terminal, i.e., the third terminal from the end in the mounting direction. The high voltage supplied from the VBAT(B) terminal is charged in the capacitor C1 connected to the VBAT(L) terminal. When the interchangeable lens 3 is rotated in the removal direction (the opposite direction to the mounting direction 144), the VBAT(L) terminal first comes into contact with the PGND(B) terminal. The charge accumulated in the capacitor C1 is quickly discharged from the PGND(B) terminal, which is a ground terminal, and does not affect other circuits of the camera 1.

[0078] In this embodiment, the V33(B) terminal is located next to the PGND(B) terminal, i.e., the fourth terminal from the end in the mounting direction, and the GND(B) terminal is located next to that, i.e., the fifth terminal from the end. The V33(L) terminal is located next to the PGND(L) terminal, i.e., the fourth terminal from the end in the mounting direction, and the GND(L) terminal is located next to that, i.e., the fifth terminal from the end. The voltage supplied from the V33(B) terminal is stored as a charge in the capacitor C2 connected to the V33(L) 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 a ground terminal, and does not affect other circuits in the camera 1.

[0079] The RDY(B) terminal is placed next to the GND(B) terminal, i.e., the sixth terminal from the front end, and next to that, i.e., the seventh terminal from the front end, the DATAB(B) terminal is placed next to that, i.e., the eighth terminal from the front end, the CLK(B) terminal is placed next to that, i.e., the ninth terminal from the front end, the DATAL(B) terminal is placed next to that, i.e., the tenth terminal from the front end, and next to that, the HCLK(B) terminal is placed at the very back.

[0080] The RDY(L) terminal is placed next to the GND(L) terminal, i.e., the sixth terminal from the front end, and next to that, i.e., the seventh terminal from the front end, the DATAB(L) terminal is placed next to that, i.e., the eighth terminal from the front end, the CLK(L) terminal is placed next to that, i.e., the ninth terminal from the front end, and next to that, the HCLK(L) terminal is placed, i.e., the tenth terminal from the front end, and next to that, the HDATA(L) terminal is placed at the very back.

[0081] Next, we will discuss the impact of noise on the communication line consisting of each body-side terminal and each lens-side terminal. Once communication begins, hotline communication involves the unilateral transmission of information to the camera body 2, occurring at high frequency (repeated at very short intervals). During hotline communication, the interchangeable lens clock signal (H clock signal) is sent from the HCLK(L) terminal to the HCLK(B) terminal. Because the clock signal alternates between high and low levels at short intervals, it can be a significant noise source for other signals. Furthermore, because the interchangeable lens clock signal (H clock signal) sent from the HCLK(L) terminal to the HCLK(B) terminal is a signal output by the interchangeable lens 3, even if noise is accidentally introduced into this clock signal, the camera body 2 cannot detect it. Thus, the clock signal (H clock signal) flowing through the HCLK terminal can be a noise source, or noise can be introduced into the clock signal (H clock signal), potentially causing malfunctions of the camera 1. Examples of malfunctions include incorrect detection of the attachment of an interchangeable lens or misidentification of command and data communication.

[0082] In this embodiment, the HCLK terminal is located away from the VBAT terminal, which is subjected to a high voltage. The voltage and current of the VBAT terminal, which drives the lens driver 33 of the interchangeable lens 3, fluctuate depending on the driving state of the lens driver 33, and therefore fluctuations in the voltage and current of the VBAT terminal can become noise for other terminals. Therefore, by separating the VBAT terminal from the HCLK terminal, it is possible to prevent noise caused by fluctuations in the voltage and current of the VBAT terminal from affecting the clock signal (H clock signal). In other words, it is possible to prevent noise from being carried over to the clock signal (H clock signal). As mentioned above, the RDY terminal is a terminal used to indicate whether command communication is possible. In this embodiment, the HCLK terminal, which can be a noise source, is located away from the RDY terminal so that it is not adjacent to it. This makes it possible to prevent noise from the clock signal (H clock signal) from affecting the signal at the RDY terminal.

[0083] Additionally, the HDATA and DATAL terminals are located on either side of the HCLK terminal. This reduces the impact of noise from the HCLK terminal on terminals other than the HDATA and DATAL terminals. The signals that flow through the HDATA and DATAL terminals fluctuate less than the clock signal (H clock signal). This reduces the impact of fluctuations in the clock signal (H clock signal) on terminals other than the HDATA and DATAL terminals.

[0084] Next, as described above, command data communication is communication in which information is sent and received bidirectionally between the camera body 2 and the interchangeable lens 3. During command data communication, the CLK (B) terminal is connected to the CLK (C) terminal. The clock signal (C clock signal) from the camera body is sent to the K(L) terminal. The clock signal (C clock signal) sent from the CLK terminal can also be a source of noise for the same reasons as mentioned above. Furthermore, if noise is introduced into the clock signal (C clock signal), an abnormality will occur in command communication. Therefore, in this embodiment, the CLK terminal is located away from the VBAT terminal, which is subjected to a high voltage. The voltage and current of the VBAT terminal, which drives the lens driver 33 of the interchangeable lens 3, fluctuates depending on the driving state of the lens driver 33, and therefore 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 prevent noise from the VBAT terminal from affecting the clock signal (C clock signal). In other words, it is possible to prevent noise from being introduced into the clock signal (C clock signal). In addition, the CLK terminal is placed away from the RDY terminal, which is used to indicate whether command communication is possible or not.

[0085] Furthermore, if the HCLK terminal and the CLK terminal are adjacent to each other, one clock signal may affect the other clock signal and become a noise source. In this embodiment, the DATAL terminal is placed between the CLK terminal and the HCLK terminal. Furthermore, 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 impact of noise caused by 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), and therefore the impact of fluctuations in the clock signal (C clock signal) on terminals other than the DATAL terminal and the DATAB terminal can be suppressed. When the DATAL terminal is placed between the CLK terminal and the HCLK terminal, the signal that flows through the DATAL terminal fluctuates less than the clock signal at the CLK terminal (C clock signal) or the clock signal at the HCLK terminal (H clock signal), so it is possible to prevent fluctuations in the clock signal at the CLK terminal (C clock signal) from affecting the clock signal at the HCLK terminal (H clock signal), and prevent fluctuations in the clock signal at the HCLK terminal (H clock signal) from affecting the clock signal at the CLK terminal (C clock signal).

[0086] As mentioned above, the level of the RDY terminal must be determined to communicate command data. Since the signal level of the RDY terminal indicates whether command data can be communicated, noise significantly affects the shooting operation. Consider a case where the body control unit 27 erroneously recognizes that command data communication is possible due to noise, even though command data communication is not possible. 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 erroneously recognizes that control based on the command data is performed on the interchangeable lens 3. However, because the lens control unit 37 cannot accept the command data, control based on the erroneously transmitted command data is not performed. This causes problems with the operation of the camera 1. Therefore, it is necessary to prevent noise from being introduced into the RDY terminal signal. To prevent noise from being introduced into the RDY terminal signal, it is desirable to place terminals on both sides of the RDY terminal through which a relatively stable signal, i.e., a signal with little change in signal level per unit time, flows. In this embodiment, a GND terminal and a DATAB terminal are located on both sides of the RDY terminal. The GND terminal is stable because it is at ground potential, and the DATAB terminal is also a terminal through which a more stable signal flows than the CLK and HCLK terminals. This makes it possible to reduce the effects of noise on the RDY terminal signal.

[0087] Next, the power (power supply voltage) supplied from the VBAT(B) terminal to the VBAT(L) terminal is used to drive an 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 varies greatly depending on whether the actuator is driven or not. Such current fluctuations become a source of noise for signals flowing through other terminals. In this embodiment, the VBAT terminal is located away from the RDY terminal, DATAB terminal, CLK terminal, and DATAL terminal used for command and data communication, and the HCLK terminal and HDATA terminal used for hotline communication. Furthermore, the GND terminal, V33 terminal, and PGND terminal are located between the VBAT terminal and the terminals used for these communications. This reduces the impact of noise caused by fluctuations in the current flowing through the VBAT terminal on data communication.

[0088] The above-described terminal arrangement that takes noise into consideration will now be summarized. The RDY pin is located away from the VBAT pin and HCLK pin, which are noise sources, so that it is not adjacent to them. This reduces the impact of noise on the RDY pin, which is used to indicate whether command and data communication is possible. The HCLK terminal, which is a noise source, is sandwiched between the HDATA and DATAL terminals, and the CLK terminal is sandwiched between the DATAL and DATAB terminals. In other words, the arrangement from the rear end in the mounting direction is HDATA, HCLK, DATAL, CLK, and DATAB. This reduces the impact of noise caused by clock signals on terminals such as the RDY terminal.

[0089] Furthermore, to take into consideration the effects of noise, the power supply terminals and the terminals used for communication are spaced apart across the RDY terminal. More specifically, the power supply terminals VBAT, PGND, V33, and GND are located in this order from the front end of the RDY terminal, while the communication terminals DATAB, CLK, DATAL, HCLK, and HDATA are located in this order from the rear end. This reduces the impact of power supply terminals such as the VBAT terminal on terminals used for communication. It also reduces the impact of noise on the RDY terminal from power supply terminals such as the VBAT terminal and terminals used for communication such as the HCLK and CLK terminals.

[0090] Of the HCLK terminal, which sends a clock signal from the interchangeable lens side used for hotline communication, and the CLK terminal, which sends a clock signal from the camera body side used for command and data communication, the HCLK terminal is located farther from the VBAT terminal than the CLK terminal. This is because the clock signal sent to the interchangeable lens 3 at the CLK terminal is output by the body control unit 27 via the first body communication unit 28, but the clock signal sent from the interchangeable lens, which is sent from the interchangeable lens 3 to the camera body 2 via the second lens communication unit 39 and the HCLK(L) terminal, will be misrecognized by the body control unit 27 if noise is carried on the clock signal. For this reason, noise carried on the clock signal from the HCLK terminal has a greater impact on the camera 1.

[0091] The HCLK terminal is positioned farther from the VBAT terminal than the GND terminal. Furthermore, a PGND terminal is placed between the GND and VBAT terminals. This allows noise originating from the VBAT terminal to be shielded from the HCLK terminal, which sends the clock signal used for hotline communication. The CLK terminal is positioned farther from the VBAT terminal than the GND terminal. Furthermore, a PGND terminal is placed between the GND and VBAT terminals. This allows noise originating from the VBAT terminal to be shielded from the CLK terminal, which sends the clock signal used for command and data communication.

[0092] Using the terminal groups arranged in this manner, as described above, the interchangeable lens 3 and camera body 2 perform command and 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. The interchangeable lens 3 and camera body 2 also 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 and data communication is separate from the communication path used for hotline communication, and command and data communication and hotline communication can be performed in parallel. That is, even when the first lens communication unit 38 is performing command and data communication with the first body communication unit 28, the second lens communication unit 39 can also perform hotline communication with the second body communication unit 29. 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 also perform command and data communication with the first body communication unit 28.

[0093] (Terminal placement taking wear into consideration) The following describes the contacts of the various terminals when attaching or detaching the interchangeable lens 3 to the camera body 2. When attaching the interchangeable lens 3 to the camera body 2, the body-side terminals come into contact with the lens-side terminals one after another. The same is true when removing the interchangeable lens 3 from the camera body 2. That is, the body-side terminals, which are pins protruding from the body-side connection part 202, rub against the lens-side terminals, which are exposed conductive contact surfaces, one after another. Because multiple interchangeable lenses are attached to and detached from a single camera body, the body-side terminals are more susceptible to wear than the lens-side terminals. In particular, the body-side terminals located closer to the rear end of the interchangeable lens 3 in the attachment direction are rubbed against a larger number of lens-side terminals and experience more friction. Therefore, the pin tips of body-side terminals located closer to the rear are more likely to wear out than those of body-side terminals located closer to the front. Wear on the body-side terminals affects contact with the lens-side terminals, which can lead to unstable data communication. In this embodiment, the LDET(B) terminal is located at the very front end in the attachment direction, so the LDET(B) terminal is subject to the least wear. This ensures good contact between the LDET(B) terminal and the LDET(L) terminal, reducing the possibility of false detection of attachment or detachment of the interchangeable lens 3.

[0094] As described above, in this embodiment, the CLK(B) terminal and the HCLK(B) terminal are located away from the VBAT(B) terminal to prevent noise from affecting communication. That is, the VBAT(B) terminal is located second from the front end in the mounting direction, and the CLK(B) terminal and the HCLK(B) terminal are located toward the rear end, away from the VBAT(B) terminal. Therefore, the CLK(B) terminal and the HCLK(B) terminal are subject to more wear than the LDET(B) terminal and the VBAT(B) terminal. In this embodiment, the CLK(B) terminal and the HCLK(B) terminal are located close to the body-side first claw 129a. That is, the CLK(B) terminal and the HCLK(B) terminal are located closer to the inner periphery of the body-side first claw 129a than the VBAT(B) terminal. In other words, the distance between the CLK(B) terminal and the inner peripheral edge of the body-side first claw 129a is shorter than the distance between the VBAT(B) terminal and the inner peripheral edge of the body-side first claw 129a, and the distance between the HCLK(B) terminal and the inner peripheral edge of the body-side first claw 129a is shorter than the distance between the VBAT(B) terminal and the inner peripheral edge of the body-side first claw 129a. As described above, the first leaf spring 141a is located on the back side of the body-side first claw 129a, and the first leaf spring 141a presses the lens-side first claw 139a in the +Z direction (FIG. 1).

[0095] Even 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 to the VBAT(B) terminal, the LDET(B) terminal is also shorter than 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. This configuration means that the CLK(B) terminal and the HCLK(B) terminal are pressed more strongly 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 the HCLK(L) terminal are also arranged closer to the inner periphery of the lens side first claw portion 139a than the VBAT(L) terminal. The distance between the K(L) terminal and the inner peripheral edge of the lens-side first claw 139a is shorter than the distance between the VBAT(L) terminal and the inner peripheral edge of the lens-side first claw 139a, and the distance between the HCLK(L) terminal and the inner peripheral edge of the lens-side first claw 139a is shorter than the distance between the VBAT(L) terminal and the inner peripheral edge of the lens-side first claw 139a. Therefore, the CLK(L) terminal and HCLK(L) terminal near the lens-side first claw 139a are pressed against the corresponding body-side terminals by the first leaf spring 141a when the camera is fully attached.

[0097] Similarly to the VBAT(L) terminal, 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 when the camera is fully attached. This configuration ensures that the CLK(L) terminal and the HCLK(L) terminal exert a stronger force against the body-side terminals than the LDET(L) terminal when the camera is fully attached. This allows the CLK(B) terminal and the HCLK(B) terminal to maintain good contact even if they wear, stabilizing their respective clock signals and enabling stable data communication. Furthermore, even if the camera body 2 or the interchangeable lens 3 receives an impact while the camera is fully attached, 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 139a is cut out, the entire lens-side first claw is defined as the protruding portion located in the area facing the body-side first claw 129a and the cutout portion. The cutout may be formed by dividing the lens-side claw into two or more sections in the circumferential direction, by cutting out a portion of the lens-side claw, or by cutting out at least a portion of the lens-side claw so that its radial length is shortened. The circumferential length of the lens-side claw may be varied within a range that passes through the corresponding body-side insertion / removal portion. The same applies to the lens-side second claw 139b, the lens-side third claw 139c, and the lens-side fourth claw 139d. The radial thickness of the cylindrical portion may be varied as needed, and at least a portion of the cylindrical portion may protrude inward from the cylindrical portion of this embodiment.

[0099] As described above, the CLK(B) terminal and the HCLK(B) terminal are subject to greater wear than the LDET(B) terminal and the VBAT(B) terminal. In this embodiment, the CLK(B) terminal and the HCLK(B) terminal are disposed close to the body-side first claw 129a. That is, the CLK(B) terminal and the HCLK(B) terminal are disposed closer to the inner periphery of the body-side first claw 129a than the LDET(B) terminal and the VBAT(B) terminal. In other words, the distance between the CLK(B) terminal and the inner periphery of the body-side first claw 129a is shorter than the distance between the LDET(B) terminal or the VBAT(B) terminal and the inner periphery of the body-side first claw 129a, and the distance between the HCLK(B) terminal and the inner periphery of the body-side first claw 129a is shorter than the distance between the LDET(B) terminal or the VBAT(B) terminal and the inner periphery of the body-side first claw 129a. As described above, the first leaf spring 141a is located on the back side of the body-side first claw 129a, and the first leaf spring 141a presses the lens-side first claw 139a in the +Z direction (FIG. 1). Even 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 first leaf spring 141a or the distance between the VBAT(B) terminal and the first leaf spring 141a.

[0100] On the lens side, the CLK(L) terminal and HCLK(L) terminal are also positioned closer to the inner periphery of the lens-side first claw 139a than the LDET(L) terminal and VBAT(L) terminal. In other words, the distance between the CLK(L) terminal and the inner periphery of the lens-side first claw 139a is shorter than the distance between the LDET(L) terminal or VBAT(L) terminal and the inner periphery of the lens-side first claw 139a, and the distance between the HCLK(L) terminal and the inner periphery of the lens-side first claw 139a is shorter than the distance between the LDET(L) terminal or VBAT(L) terminal and the inner periphery of the lens-side first claw 139a. Therefore, the CLK(L) terminal and HCLK(L) terminal near the lens-side first claw 139a 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 strongly against the lens-side terminals than the LDET(B) and VBAT(B) terminals. This allows good contact to be maintained even if the CLK(B) and HCLK(B) terminals wear out, ensuring stable communication. Furthermore, for example, even if the camera body 2 or interchangeable lens 3 receives an impact while it is still attached, 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 located near the body-side fourth claw 129d. That is, the CLK(B) terminal and the HCLK(B) terminal are located closer to the body-side fourth claw 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 129d is shorter than the distance between the VBAT(B) terminal or the LDET(B) terminal and the body-side fourth claw 129d, and the distance between the HCLK(B) terminal and the body-side fourth claw 129d is shorter than the distance between the VBAT(B) terminal or the LDET(B) terminal and the body-side fourth claw 129d. As described above, the fourth leaf spring 141d is located on the back side of the body-side fourth claw 129d, and the fourth leaf spring 141d presses the lens-side fourth claw 139d in the +Z direction (FIG. 1). Therefore, the CLK(B) terminal and HCLK(B) terminal near the lens side fourth claw portion 139d are pressed more stably and strongly against the lens side terminals 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 first body-side claw 129a (the same applies to the fourth body-side claw 129d, but will not be discussed further below) refers to the linear distance between one end of the first body-side claw 129a and the CLK(B) terminal. Alternatively, the distance between the CLK(B) terminal and the first body-side claw 129a may be determined by the linear distance between the other end of the first body-side claw 129a and the CLK(B) terminal. Alternatively, the distance between the CLK(B) terminal and the first body-side claw 129a may be determined by the linear distance between the CLK(B) terminal and the midpoint of the first body-side claw 129a in the circumferential direction of the body-side mount 201. The distances between other body-side terminals, such as the HCLK(B) terminal, the VBAT(B) terminal, and the LDET(B) terminal, and the first body-side claw 129a are also linear distances. The distance between the first leaf spring 141a (fourth leaf spring 141d) and the body-side terminals is also linear distance.

[0103] The distance between the CLK(B) terminal and the first body-side claw 129a (the same applies to the fourth body-side claw 129d, but will not be described below) may be defined as the arc-shaped distance between one end of the first body-side claw 129a and the CLK(B) terminal in the circumferential direction of the body-side mount 201, or the arc-shaped distance between the other end of the first body-side claw 129a and the CLK(B) terminal. Alternatively, the distance between the CLK(B) terminal and the first body-side claw 129a may be defined as the arc-shaped distance between the CLK(B) terminal and a midpoint of the first body-side claw 129a in the circumferential direction of the body-side mount 201. The distances between other body-side terminals, such as the HCLK(B) terminal, the VBAT(B) terminal, and the LDET(B) terminal, and the first body-side claw 129a may also be defined as arc-shaped distances. The distance between the first plate spring 141a (fourth plate spring 141d) and the body-side terminal may also be defined as an arc-shaped distance.

[0104] While the above description has been given for the camera body 2, the same applies to the interchangeable lens 3. In this embodiment, the CLK(L) terminal and the HCLK(L) terminal are located immediately adjacent to the lens-side first claw 139a. That is, the CLK(L) terminal and the HCLK(L) terminal are located closer to the lens-side first claw 139a than the VBAT(L) terminal and the LDET(L) terminal. In other words, the distance between the CLK(L) terminal and the lens-side first claw 139a is shorter than the distance between the VBAT(L) terminal or the LDET(L) terminal and the lens-side first claw 139a, and the distance between the HCLK(L) terminal and the lens-side first claw 139a is shorter than the distance between the VBAT(L) terminal or the LDET(L) terminal and the lens-side first claw 139a. The lens-side first claw 139a is pressed in the +Z direction (FIG. 1) by the body-side first leaf spring 141a. Therefore, as described above, the CLK(L) terminal and HCLK(L) terminal near the lens-side first claw portion 139a are pressed more strongly against the body-side terminal by the first leaf spring 141a than the VBAT(L) terminal or LDET(L) terminal.

[0105] 4(a), in this embodiment, the CLK(B) terminal and the HCLK(B) terminal are arranged inside a sector (within a range of an angle of 50) formed by the center position of the opening of the body side mount unit 201 (i.e., the position of the optical axis L of the interchangeable lens 3) and the arc-shaped body side first claw 129a. Alternatively, the CLK(B) terminal and the HCLK(B) terminal are arranged inside a triangular area formed by the center position of the opening of the body side mount unit 201 (i.e., the position of the optical axis L of the interchangeable lens 3) and both ends of the inner periphery of the body side first claw 129a. Therefore, the body-side first claw 129a does not exist on the extension of the dash-dotted line 151 connecting the center position of the opening of the body-side mount section 201 and the LDET(B) terminal, but the body-side first claw 129a exists on the extension of the dash-dotted line 152 connecting the center position of the opening of the body-side mount section 201 and the HCLK(B) terminal, and the body-side first claw 129a exists on the extension of the dash-dotted line 153 connecting the center position of the opening of the body-side mount section 201 and the CLK(B) terminal. As a result, in the fully attached state, the CLK(B) terminal and the HCLK(B) terminal are pressed more strongly against the corresponding lens-side terminals than the LDET(B) terminal.

[0106] 5, the CLK(L) terminal and the HCLK(L) terminal are arranged inside a sector (within a range of an angle of 60°) formed by the center position of the opening of the lens side mount unit 301 (i.e., the position of the optical axis L of the interchangeable lens 3) and the arc-shaped lens side first claws 139a. Alternatively, the CLK(L) terminal and the HCLK(L) terminal are arranged inside a triangular area formed by the center position of the opening of the lens side mount unit 301 (i.e., the position of the optical axis L of the interchangeable lens 3) and both ends on the outer periphery of the lens side first claws 139a. Therefore, the lens-side first claw 139a is not present on the extension of the dash-dotted line 161 connecting the center position of the opening of the lens-side mount unit 301 and the LDET(L) terminal, but the lens-side first claw 139a is present on the extension of the dash-dotted line 162 connecting the center position of the opening of the lens-side mount unit 301 and the HCLK(L) terminal, and the lens-side first claw 139a is present on the extension of the dash-dotted line 163 connecting the center position of the opening of the lens-side mount unit 301 and the CLK(L) terminal. As a result, in the fully attached state, the CLK(L) terminal and HCLK(L) terminal contact the corresponding body-side terminal more stably than the LDET(L) terminal. In other words, the CLK(L) terminal and HCLK(L) terminal are pressed against the body-side terminal with a stronger force than the LDET(L) terminal. Therefore, even if the tips of the CLK(B) terminal and HCLK(B) terminal are worn, clock signal communication between the camera body 2 and the interchangeable lens 3 is carried out stably.

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

[0108] A value indicating the communication specifications of hotline communication is transmitted and received between the interchangeable lens 3 and the camera body 2 via command data communication. This value is called a generation. This generation value is sometimes referred to as generation information. A generation is usually an integer greater than or equal to 0, but may also be a decimal. A generation may also be called a grade. FIG. 6 is an explanatory diagram showing an example of a generation. A generation indicates different communication specifications. This communication specification may also be called a communication system, communication method, or communication standard. This communication specification has at least one communication-related item. In the example shown in FIG. 6, the communication specification has three communication-related items: the communication speed of hotline communication, the communication interval of hotline communication, and the number of data transmitted in hotline communication. The communication specifications indicated by the generation are not limited to having the three items described above, and may also have one or two items selected from the three items.

[0109] By using the generation, different generations can be indicated, for example, 1st to 4th generations. The communication specifications indicated differ depending on the generation. Here, the values ​​of some items of the communication specifications indicated may be the same between different generations. A generation with a larger number is called a higher generation (grade). For example, the 4th generation is a higher generation (grade) than the 3rd generation. Furthermore, the generation may indicate other specifications in addition to the communication specifications. In the example shown in Figure 6, the generation indicates the specifications of the sampling interval for data generation in addition to the communication specifications. Furthermore, in addition to the above example, the generation may also indicate specifications related to the functions and capabilities of image stabilization, for example.

[0110] Here, the communication speed is the communication speed (clock frequency) of data communicated via hotline communication, i.e., 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 relating to the drive of the focus lens (information relating to the position of the focus lens, etc.), information relating to the drive of the vibration-proof lens (information relating to the position of the vibration-proof lens, etc.), information relating to the zoom lens (information relating to the state of the zoom lens, focal length information, etc.), and information relating to the drive of the aperture diaphragm 32 (information relating to the F-number, etc.). The sampling interval is the time interval at which data to be transmitted 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 FIG. 6, the communication specifications indicated by the first generation have a communication speed of V1 (unit: MHz, for example), a communication interval of T1 (unit: msec, for example), and the number of data items is N1 (an integer). For example, as the generation progresses (the grade increases), the communication speed becomes faster, the communication interval becomes shorter, and the number of data items increases. That is, the communication specifications indicated by the second generation have a communication speed of V2, which is faster than V1, a communication interval of T2, which is shorter than T1, and the number of data items is N2, which is greater than N1.

[0112] In the third-generation communication specifications, 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 bits is N3, which is greater than N2. In the fourth-generation communication specifications, 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 bits is N4, which is greater than N3. Each of V1 to V4, T1 to T4, and N1 to 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., 2.5 MHz) or a predetermined communication speed range v1 to v2 (e.g., 2 to 8 MHz). The communication interval T1 may be a predetermined unique value (e.g., 1 msec) or a predetermined communication interval range (e.g., 0.5 to 2 msec).

[0113] As described above, examples of data transmitted through hotline communication include information related to the drive of the focus lens, the drive of the vibration-reduction lens, the drive of the aperture diaphragm, and the state of the zoom lens. For example, when the number of data is N1, the data transmitted through hotline communication is information related to the drive of the focus lens. When the number of data is N2, in addition to information related to the drive of the focus lens, information related to the drive of the vibration-reduction lens is also transmitted through hotline communication. When the number of data is N3, in addition to information related to the drive of the focus lens and information related to the drive of the vibration-reduction lens, information related to the drive of the aperture diaphragm 32 is also transmitted through hotline communication. When the number of data is N4, in addition to information related to the drive of the focus lens, information related to the drive of the vibration-reduction lens, and information related to the drive of the aperture diaphragm 32, information related to the state of the zoom lens is also transmitted through hotline communication.

[0114] In the example shown in FIG. 6, the number of pieces of data transmitted by hotline communication indicated by the generation has been described as being included in the communication specifications. However, this number of pieces of data may not be included in the communication specifications and may be indicated by the generation separately from the communication specifications. Also, in the example described above, the generation has been described as indicating the number of pieces of data. However, the generation may also indicate the data transmitted by hotline communication. For example, the generation may indicate data transmitted by 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 vibration-proof lens (information regarding the position of the vibration-proof 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] 6, the sampling interval specification indicated by the first generation is S1 (unit: msec, for example). The sampling interval specification indicated by the second generation is S2, which is shorter than S1, the sampling interval specification indicated by the third generation is S3, which is shorter than S2, and the sampling interval specification indicated by the fourth generation is S4, which is shorter than S3. Here, S1 to S4 may be predetermined fixed values ​​or values ​​within a predetermined range.

[0116] Note that as the generations (grades) change from the first to the fourth generation, it is not necessary for all values ​​of the communication specifications and other specifications to change; instead, the values ​​of one or more of the specifications may change. For example, as the generation progresses, the communication speed may increase, but the communication interval and the number of data items may remain unchanged. As described above, each generation of hotline communication may specify, in addition to the communication specifications, the sampling interval specifications and the image stabilization functions and capabilities. In this case, as the generation changes, the value of only one item of the communication specifications may change, or the values ​​of two or three items of the communication specifications may change. Furthermore, as the generation changes, the sampling interval specifications and the image stabilization functions and capabilities may change in addition to the communication specifications.

[0117] Next, the relationship between the communication specifications indicated by the generations and the interchangeable lens 3 and camera body 2 will be explained. An interchangeable lens 3 and a camera body 2 capable of hotline communication using the communication specifications indicated by the first generation will be referred to as a first-generation interchangeable lens 3 and a first-generation camera body 2, respectively. Furthermore, an interchangeable lens 3 and a camera body 2 capable of hotline communication using the communication specifications indicated by the second generation will be referred to as a second-generation interchangeable lens 3 and a second-generation camera body 2, respectively. Similarly, an interchangeable lens 3 and a camera body 2 capable of hotline communication using the communication specifications indicated by the third generation will be referred to as a third-generation interchangeable lens 3 and a third-generation camera body 2, respectively. An interchangeable lens 3 and a camera body 2 capable of hotline communication using the communication specifications indicated by the fourth generation will be referred to as a fourth-generation interchangeable lens 3 and a fourth-generation camera body 2, respectively.

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

[0119] Interchangeable lenses 3 and camera bodies 2 that support the communication specifications indicated by each generation can also perform hotline communication according to the communication specifications indicated by the previous generation (the generation with the smaller number, lower grade). In other words, a first-generation interchangeable lens 3 and a first-generation camera body 2 both perform hotline communication according to the communication specifications indicated by the first generation, but a second-generation interchangeable lens 3 and camera body 2 can support not only the communication specifications indicated by the second generation but also the communication specifications indicated by the first generation. Furthermore, a third-generation interchangeable lens 3 and camera body 2 can support the communication specifications indicated by the first to third generations, respectively, and a fourth-generation interchangeable lens 3 and camera body 2 can support the communication specifications indicated by the first to fourth generations, respectively. If a fourth-generation interchangeable lens 3 is combined with a third-generation camera body 2, hotline communication can be performed according to the common communication specifications indicated by the third generation, the second generation, or the first generation. However, because camera body 2 does not support the communication specifications specified by the fourth generation, hotline communication according to the communication specifications specified by the fourth generation cannot be performed, or hotline communication will not be initiated.

[0120] Fig. 7 is a table explaining the generations indicating the communication specifications used when performing hotline communication when a first- to fourth-generation interchangeable lens 3 is combined with a first- to fourth-generation camera body 2. Fig. 7 shows the generation of the camera body 2 on the horizontal axis and the generation of the interchangeable lens 3 on the vertical axis, and explains the generations indicating the 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 possible generation (the generation with the largest number, the highest generation, the highest grade) when the interchangeable lens 3 and camera body 2 are combined. However, hotline communication may also be performed using the communication specifications indicated by a lower generation rather than the highest generation. When a first-generation interchangeable lens 3 is attached to a first-generation to fourth-generation camera body 2, hotline communication is carried out in accordance with the communication specifications specified by 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 specified by the first generation, and hotline communication is performed with the second- to fourth-generation camera body 2 according to the communication specifications specified by the second generation.

[0122] When a third-generation interchangeable lens 3 is attached to a first- to fourth-generation camera body 2, the following occurs: The third-generation interchangeable lens 3 performs hotline communication with the first-generation camera body 2 according to the communication specifications indicated by the first generation, with the second-generation camera body 2 according to the communication specifications indicated by the second generation, and with the third- and fourth-generation camera bodies 2 according to the communication specifications indicated by the third generation. Note that the third-generation interchangeable lens 3 may communicate with the second-generation camera body 2 according to the communication specifications indicated by the first generation, which is the lower generation (the generation with the lowest number, the previous generation) rather than the highest generation (the generation with the highest number, the highest generation, the highest rank), and may communicate with the third-generation camera body 2 and the fourth-generation camera body 2 according to the communication specifications indicated by 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 performs hotline communication with the first-generation camera body 2 according to the communication specifications specified by the first generation, and with the second-generation camera body 2 according to the communication specifications specified by the second generation. Furthermore, the fourth-generation interchangeable lens 3 performs hotline communication with the third-generation camera body 2 according to the communication specifications specified by the third generation, and with the fourth-generation camera body 2 according to the communication specifications specified by the fourth generation. Note that a fourth-generation interchangeable lens 3 may communicate with a second-generation camera body 2 according to the communication specifications indicated for the first generation, and may communicate with a third-generation camera body 2 according to the communication specifications indicated for the first or second generation. Also, a fourth-generation interchangeable lens 3 may communicate with a fourth-generation camera body 2 according to the communication specifications indicated for the first, second, or third generation.

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

[0125] Note that lens-side generation information being first generation indicates that the interchangeable lens 3 is compatible with the communication specifications indicated by the first generation. Similarly, lens-side generation information being second generation indicates that the interchangeable lens 3 is compatible with both the communication specifications indicated by the first generation and the communication specifications indicated by the second generation. Lens-side generation information being third generation indicates that the interchangeable lens 3 is compatible with the communication specifications indicated by the three generations, first, second, and third, and lens-side generation information being fourth generation indicates that the interchangeable lens 3 is compatible with the communication specifications indicated by the four generations, first, second, third, and fourth.

[0126] Furthermore, the generation information sent 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 hotline communication is performed between the camera body 2 and the interchangeable lens 3 attached to the camera body 2. In command data communication, generation information "1," "2," "3," or "4," for example, is sent 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 hotline communication are indicated by the first generation, second generation, third generation, or fourth generation, respectively.

[0127] For example, when second generation information (second generation) is sent from an interchangeable lens 3 that only supports up to the second generation to a camera body 2 that only supports up to the second generation, the camera body 2 also supports up to the same generation (second generation), and so sends the highest generation, second generation, to the interchangeable lens 3. Sending this same generation information (second generation) from the camera body 2 to the interchangeable lens 3 indicates that the camera body 2 is requesting the interchangeable lens 3 to use the communication specifications indicated by the same generation (second generation).

[0128] Furthermore, for example, if an interchangeable lens 3 that is compatible only up to the third generation is attached to a camera body 2 of a higher generation, the fourth generation, the interchangeable lens 3 will send generation information of the third generation to the camera body 2, and the camera body 2 will send generation information of the highest generation common to the camera body 2 and the interchangeable lens 3, in this case the third generation, which is a generation (lower) than its own generation (fourth generation), to the interchangeable lens 3. This lower generation (third generation) generation information sent from the camera body 2 requests the interchangeable lens 3 to perform hotline communication in accordance with the communication specifications indicated by the third generation, which is the highest generation compatible with the interchangeable lens 3.

[0129] Furthermore, for example, if an interchangeable lens 3 that is compatible with up to the fourth generation is attached to a camera body 2 that is of the third generation, which is a lower generation, the interchangeable lens 3 will transmit fourth-generation generation information to the camera body 2, but because the camera body 2 does not itself support the communication specifications indicated by the fourth generation, it will transmit its own highest generation, the third generation, information to the interchangeable lens 3. This generation information that is lower for the interchangeable lens 3 (third generation) transmitted from the camera body 2 requests the interchangeable lens 3 to perform hotline communication in accordance with the communication specifications indicated by the third generation, which is the highest generation that the camera body 2 supports.

[0130] As described above, the generation indicates a different communication specification. The communication specification includes at least one communication-related item, such as the communication speed of hotline communication, the communication interval of hotline communication, and the number of data items transmitted in hotline communication. The generation information indicates the communication specification under which the interchangeable lens and the camera body can communicate via hotline communication.

[0131] A method for determining the generation that indicates the communication specifications used in hotline communication between the interchangeable lens 3 and the camera body 2 will be specifically described below. When the interchangeable lens 3 is attached to the camera body 2, initialization communication begins between the interchangeable lens 3 and the camera body 2 using command data communication. During the initialization communication, a command requesting the transmission of lens-side generation information is sent from the camera body 2 to the interchangeable lens 3, and the first lens communication unit 38 transmits the lens-side generation information stored in the lens memory 36 to the first body communication unit 28 via command data communication. The body control unit 27 acquires the generation information of the attached interchangeable lens 3 via the first body communication unit 28, and determines the generation indicating the communication specifications compatible with the interchangeable lens 3. For example, if the generation information of the interchangeable lens 3 is "3," representing the third generation, the body control unit 27 recognizes that the 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 indicating the communication specifications for hotline communication based on the lens-side generation information and the body-side generation information as follows: The body control unit 27 determines the highest common generation among the generations indicating the communication specifications compatible with the interchangeable lens 3 and the generations indicating the communication specifications compatible with the camera body 2 as the generation indicating the communication specifications for hotline communication. For example, if the lens-side generation information sent from the interchangeable lens 3 as described above is "3," meaning that the interchangeable lens 3 is capable of hotline communication using the communication specifications indicated by the first, second, and third generations, and the body-side generation information is "4," indicating the fourth generation, then the camera body 2 is capable of hotline communication using the communication specifications indicated by the first, second, third, and fourth generations, and therefore selects the third generation, which is the highest common generation among the generations common to the interchangeable lens 3 and the camera body 2.

[0133] 7, the body control unit 27 selects the highest common generation between the generation indicating the communication specifications supported by the interchangeable lens 3 and the generation indicating the communication specifications supported by 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) each unit of the camera body 2 in accordance with the communication specifications indicated by the determined generation. This enables the camera body 2 to perform hotline communication with the attached interchangeable lens 3 in accordance with the communication specifications indicated by the determined generation.

[0134] Hotline communication begins when, through command data communication, a command and data including generation information to be used for hotline communication are sent from the camera body 2 to the interchangeable lens 3. Specifically, when a command to set up hotline communication is sent from the camera body 2 to the interchangeable lens 3, the generation information is also sent as part of the data packet for that command. When hotline communication begins, the lens control unit 37 sets and controls each unit of the interchangeable lens 3 so that hotline communication is possible in accordance with the communication specifications indicated by the generation information determined by the camera body 2, i.e., the generation information acquired from the camera body 2 via the first lens communication unit 38. This enables the interchangeable lens 3 to perform hotline communication with the camera body 2 in accordance with 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 for the first generation or higher are transmitted from the camera body 2 to the interchangeable lens 3, hotline communication is initiated from the interchangeable lens 3. In other words, hotline communication is initiated when the camera body 2 transmits to the interchangeable lens 3 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.

[0135] The body control unit 27 may select a communication specification different from the communication specification indicated by the highest generation among the generations compatible with both the interchangeable lens 3 and the camera body 2. For example, if adopting the communication specification indicated by the highest generation causes interference between the communication frequency and the drive frequency of the image sensor or the like, this interference can be avoided by adopting the communication specification indicated by a lower generation.

[0136] As described above, 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 ascertain the communication specifications (communication speed, etc.) that the interchangeable lens 3 can support. Compared to notifying the camera body 2 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, and shortens the communication time and number of communications. Furthermore, when the communication speed, communication interval, etc. that the interchangeable lens 3 can support 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 communication speed, communication interval, etc. transmitted from the interchangeable lens 3. However, in this embodiment, the generation (generation information) indicates consistent communication specifications (communication speed, communication interval, etc.), so 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 explanation so far, the first, second, third, and fourth generations have been used as examples of generation information, but the generation information is not limited to these and may be fifth or higher generation information.

[0138] In the example described using Figure 7, a configuration was shown in which each generation of interchangeable lens 3 is also capable of hotline communication according to the communication specifications indicated by the previous generation (the generation with a smaller number, the lower grade). Next, an example will be described in which an interchangeable lens 3 is capable of hotline communication only according to the communication specifications indicated by one generation, but is not compatible with hotline communication according to the communication specifications indicated by the previous generation (the generation with a smaller number, the lower grade).

[0139] 8 is a table showing the generations of communication specifications used when hotline communication is performed when an interchangeable lens 3 is capable of hotline communication only in accordance with the communication specifications indicated by one of the first to fourth generations, for example, and such an interchangeable lens 3 is combined with a first to fourth generation camera body 2. Here, the camera body 2 is also capable of hotline communication in accordance with the communication specifications indicated by the previous generation (a generation with a smaller number, a lower grade), as in the example described using FIG.

[0140] FIG. 8 is a table showing the generations of camera bodies 2 along the horizontal axis and the generations of interchangeable lenses 3 along the vertical axis, illustrating the generations indicating the communication specifications for hotline communication for each combination. The following describes the case where an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the first generation is attached to a camera body 2 of each generation. When an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the first generation is attached to a first-generation camera body 2, the first lens communication unit 38 transmits "1" as lens-side generation information to the first body communication unit 28 via command data communication during initial communication. The body control unit 27 receives the transmitted lens-side generation information "1" via the first body communication unit 28. The body control unit 27 of the first-generation camera body 2 determines that the first generation, which is the highest generation common to the interchangeable lens 3 and camera body 2, is the generation indicating the communication specifications for hotline communication. The body control unit 27 then transmits the determined generation information of the first generation to the first lens communication unit 38 via the first body communication unit 28. Thereafter, hotline communication is performed between the interchangeable lens 3 and the camera body 2 in accordance with the communication specifications indicated by the first generation.

[0141] When an interchangeable lens 3 capable of communication via hotline communication that is compatible only with the communication specifications indicated by the first generation is attached to a camera body 2 of the second, third, or fourth generation, a similar exchange of command and data communication takes place between the interchangeable lens 3 and the camera body 2, and the first generation, which is the highest generation common to the interchangeable lens 3 and the camera body 2, is determined to be the generation that indicates the communication specifications for hotline communication, and hotline communication is carried out between the interchangeable lens 3 and the camera body 2 in accordance with the communication specifications indicated by the first generation.

[0142] Next, a case will be described where an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the second generation is attached to a camera body 2 of any generation. When an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the second generation is attached to a second-generation camera body 2, during initial communication, the first lens communication unit 38 transmits "2" 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 "2" via the first body communication unit 28. The body control unit 27 of the second-generation camera body 2 determines the second generation, which is the highest generation 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 generation information of the second generation to the first lens communication unit 38 via the first body communication unit 28. Thereafter, hotline communication is performed between the interchangeable lens 3 and the camera body 2 in accordance with the communication specifications indicated by the second generation.

[0143] When an interchangeable lens 3 capable of communication via hotline communication that is only compatible with the communication specifications indicated by the second generation is attached to a third or fourth generation camera body 2, a similar exchange of command and data communication takes place between the interchangeable lens 3 and the camera body 2, and the second generation, which is the highest generation common to the interchangeable lens 3 and the camera body 2, is determined to be the generation that indicates the communication specifications for hotline communication, and hotline communication is carried out between the interchangeable lens 3 and the camera body 2 in accordance with the communication specifications indicated by the second generation.

[0144] If an interchangeable lens 3 capable of hotline communication that only supports the communication specifications indicated by the second generation is attached to a first-generation camera body 2, hotline communication will not function properly or will not start because there is no common generation between the interchangeable lens 3 and the camera body 2.

[0145] Next, a case will be described where an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the third generation is attached to a camera body 2 of any generation. When an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the third generation is attached to a third-generation camera body 2, during initial communication, the first lens communication unit 38 transmits "3" 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 "3" via the first body communication unit 28. The body control unit 27 of the third-generation camera body 2 determines the third generation, which is the highest generation 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 generation information of the third generation to the first lens communication unit 38 via the first body communication unit 28. Thereafter, hotline communication is performed between the interchangeable lens 3 and the camera body 2 in accordance with the communication specifications indicated by the third generation.

[0146] When an interchangeable lens 3 capable of communication via hotline communication that is only compatible with the communication specifications indicated by the third generation is attached to a fourth-generation camera body 2, a similar exchange of command data communication takes place between the interchangeable lens 3 and the camera body 2, and the third generation, which is the highest generation common to the interchangeable lens 3 and the camera body 2, is determined to be the generation that indicates the communication specifications for hotline communication, and hotline communication is carried out between the interchangeable lens 3 and the camera body 2 in accordance with the communication specifications indicated by the third generation.

[0147] If an interchangeable lens 3 capable of hotline communication that only supports the communication specifications indicated by the third generation is attached to a first- or second-generation camera body 2, hotline communication will not function properly or will not start because there is no common generation between the interchangeable lens 3 and the camera body 2.

[0148] Next, a case will be described in which an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the fourth generation is attached to a camera body 2 of any generation. When an interchangeable lens 3 capable of hotline communication compliant only with the communication specifications indicated by the fourth generation is attached to a fourth-generation camera body 2, during initial communication, the first lens communication unit 38 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 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 to the first lens communication unit 38 via the first body communication unit 28. Thereafter, hotline communication is performed between the interchangeable lens 3 and the camera body 2 in accordance with the communication specifications indicated by the fourth generation.

[0149] If an interchangeable lens 3 capable of hotline communication that only supports the communication specifications indicated by the fourth generation is attached to a camera body 2 of the first, second, or third generation, hotline communication will not function properly or will not start because there is no common generation between the interchangeable lens 3 and the camera body 2.

[0150] Furthermore, the value "0" can be used as the generation information value. A generation information value of "0" is not used to determine the generation indicating the communication specifications used in hotline communication between the camera body 2 and the interchangeable lens 3 and start communication, but rather to indicate that hotline communication will not be performed or to stop hotline communication that has already started. Even if a manual focus lens that does not support autofocus is used, if the focus lens position can be detected, the detected focus lens position can be transmitted to the camera body 2 via hotline communication. However, for example, with a manual focus lens that does not have a mechanism for detecting the focus lens position, 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 there is no need for hotline communication to transmit the focus lens position. If there is no need to transmit information other than the focus lens position to the camera body 2, there is no need for 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 hotline communication is attached to the camera body 2, the value "0" is transmitted as the generation information value from the interchangeable lens 3 to the camera body 2. In response, the camera body 2 sends a command to set up hotline communication together with a data packet indicating generation information with the value "0" to the interchangeable lens 3. When the interchangeable lens 3 receives the data packet "0", hotline communication with the camera body 2 does not begin.

[0151] The camera body 2 can also end hotline communication by sending the generation information value "0" to the interchangeable lens 3. Hotline communication initiated between the camera body 2 and the interchangeable lens 3 may be terminated when the camera body 2 is turned off by operating its power switch, when the camera body 2 is turned off after a certain period of inactivity (also known as hibernation or sleep mode), when the camera is in image playback mode, or when a menu is displayed. To terminate hotline communication, the camera body 2 sends the interchangeable lens 3 a command to set up hotline communication and a data packet indicating generation information with a value of "0." The interchangeable lens 3 starts hotline communication when it receives a generation information value of "1" to "4" from the camera body 2 via command data communication, and terminates hotline communication when it receives a generation information value of "0" from the camera body 2 via command data communication. Note that the generation information parameter for not starting communication or for terminating communication is not limited to "0," and may be a specific value such as "99."

[0152] In this way, any value (integers) equal to or greater than "0" can be used as generation information. When an integer equal to or greater than "1" is sent from the interchangeable lens 3 to the camera body 2 as generation information, the camera body 2 determines the generation indicating the communication specifications with which the camera body 2 can communicate, and the interchangeable lens 3 begins hotline communication by receiving from the camera body 2 a command to set up hotline communication and the generation information equal to or greater than "1" determined by the camera body 2. Furthermore, when the interchangeable lens 3 sends "0" as the generation information to the camera body 2, the camera body 2 recognizes that the interchangeable lens 3 is an interchangeable lens that does not perform hotline communication, and the camera body 2 sends "0" as the generation information to the interchangeable lens 3. The interchangeable lens 3 does not start hotline communication upon receiving the command to set up hotline communication and the generation information that is "0" from the camera body 2. Note that when the interchangeable lens 3 sends "0" as the generation information to the camera body 2, the camera body 2 does not need to send "0" to the interchangeable lens 3, and does not need to send the hotline communication setting command either.

[0153] Furthermore, after the interchangeable lens 3 receives from the camera body 2 a command to set up hotline communication and generation information of "1" or greater determined by the camera body 2 and starts hotline communication, if the interchangeable lens 3 receives from the camera body 2 a command to set up hotline communication and generation information of "0", the interchangeable lens 3 stops the hotline communication. In this way, when not performing hotline communication or when stopping hotline communication that has already started, the interchangeable lens 3 simply needs to receive a command to set up hotline communication and generation information that is "0" from the camera body 2, so there is no need for a dedicated command to stop hotline communication. This makes it possible to reduce the number of commands. Also, because the same command can be used to start and stop hotline communication, control is simplified. The transmission of generation information from the camera body 2 to the interchangeable lens 3 not only sends generation information indicating the communication specifications to be used for hotline communication, but also indicates, by being sent after a command to set up hotline communication, whether to start hotline communication, not to start hotline communication, or to stop hotline communication that has already started.

[0154] FIG. 9 shows an example of hotline communication performed in accordance with the determination of generation information in camera 1, an imaging device according to the first embodiment. FIG. 9 illustrates the case where a focus lens is driven as a lens. FIG. 9(a) schematically illustrates the temporal change in the actual position (L1) of the focus lens in the optical axis direction. FIG. 9(b) illustrates the pulse signal output from the encoder of lens position detection unit 34 in response to movement of the focus lens. FIG. 9(c) illustrates the sampling of the pulse signal by lens control unit 37. FIG. 9(d) illustrates command data communication (CD1-CD3) and hotline communication (HL1-HL6) between camera body 2 and interchangeable lens 3. FIG. 9(e) schematically illustrates the temporal change in the focus lens position (L2) when the focus lens position (pulse position) is restored in camera body 2 based on the integrated value (pulse position information) of the pulse signal received via hotline communication. In FIGS. 9(a) to 9(e), the horizontal axis is the common time axis.

[0155] The curve L1 in Figure 9(a) shows a schematic representation of the temporal change in focus lens position, with the horizontal axis representing time and the vertical axis representing the position of the focus lens along the optical axis L. Figure 9(b) shows the pulse signals output from the encoder of the lens position detection unit 34. The number of these pulse signals corresponds to the amount of movement of the focus lens. These pulse signals are generated each time the focus lens is driven and moved a predetermined distance. The greater the change in focus lens position, the more frequently pulse signals are generated per unit time. The lens control unit 37 integrates the pulse signals and generates focus lens pulse position information (the focus lens position expressed as the integrated number of pulses). This information is then transmitted from the interchangeable lens 3 to the camera body 2 via hotline communication. The pulse signals in Figure 9(b) may be pulse signals output from the drive circuit of the lens drive unit 33. Curve L2 in Figure 9(e) shows a schematic representation of the temporal change in the position of the focus lens reproduced in 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 along the optical axis L.

[0156] As mentioned above, command data communication and hotline communication are carried out using different communication paths, but in Figure 9(d) command data communication (CD1 to CD3) and hotline communication (HL1 to HL6) are shown together. Command data communication (CD1 to CD3) is indicated by a dashed double-headed arrow, and hotline communication (HL1 to HL6) is indicated by a solid arrow. Command data communication is two-way communication between the camera body 2 and the interchangeable lens 3, and hotline communication is communication from the interchangeable lens 3 to the camera body 2.

[0157] 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 via the first lens communication unit 38 to the first body communication unit 28 of the camera body 2. When the lens-side generation information of the interchangeable lens 3 is received by the first body communication unit 28, the body control unit 27 of the camera body 2 determines the generation indicating the communication specifications for performing hotline communication as described above, based on the lens-side generation information and the body-side generation information that the camera body 2 itself has.

[0158] In command data communication CD2, the first body communication unit 28 transmits a command packet and a data packet requesting the setting up of hotline communication to the first lens communication unit 38. 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 the data packet requesting the setting up of hotline communication, the lens control unit 37 performs processing to set and control each unit of the interchangeable lens 3 so that communication is possible in accordance with the communication specifications indicated by the generation information included in the data packet. In the command data communication CD2, information corresponding to a time lag Δt, which will be described later, is transmitted from the interchangeable lens 3 to the camera body 2.

[0159] 9(c), upon receiving a command packet and a data packet (command data communication CD2) requesting the setting up of hotline communication, the lens control unit 37 starts sampling the 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 to the camera body 2 the integrated value (pulse position information) of the pulse signals from the origin position detected by the photointerrupter. Alternatively, sampling of the pulse signal may be performed before time t1, and after CD2 is received, pulse position information may be transmitted to the camera body 2 from time t1.

[0160] The first body communication unit 28 transmits a signal (drive command) instructing the focus lens to be driven to the first lens communication unit 38 as command data communication CD3. starts moving the focus lens based on this drive command.

[0161] 9(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. The lens control unit 37 first samples the pulse signals output from the lens position detection unit 34 between time t1 and time t2, and generates pulse position information by integrating the pulse signals. Then, from time t2 onward, the lens control unit 37 continues to sample 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 the value "0" of the generation information, which instructs it to end hotline communication.

[0162] In hotline communication HL1, the second lens communication unit 39 transmits the integrated value of the pulse signal sampled between time t1 and time t2 (in the example of Figure 9, the integrated value of the pulse signal is 1) as pulse position information to the second body communication unit 29.

[0163] In hotline communication HL2, the second lens communication unit 39 transmits pulse position information represented by the number of pulses (in the example of FIG. 9, the number of pulses is 1 pulse) obtained by adding together the integrated value of pulse signals sampled from time t1 to time t2 (in the example of FIG. 9, the number of pulses is 1 pulse) and the integrated value of pulse signals sampled between time t2 and time t3 (in the example of FIG. 9, the number of pulses is 2 pulses) to the second body communication unit 29. In hotline communications HL3, HL4, HL5, HL6, etc., the second lens communication unit 39 transmits pulse position information represented by the number of pulses obtained by adding each number of pulses sampled in periods t3 to t4, t4 to t5, t5 to t6, t6 to t7, etc. to the integrated number of pulses sampled previously. Note that each hotline communication by the second lens communication unit 39 and the second body communication unit 29 is performed at the communication speed and communication interval of the communication specifications indicated by 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. In other words, HL1, HL2, HL3, HL4, HL5, HL6, etc. are transmitted from the lens control unit 37 to the body control unit 27 every 1 msec in synchronization with a clock frequency of 2.5 MHz.

[0164] 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 sampling intervals according to the sampling interval specifications indicated by the determined generations. Furthermore, the interval between hotline communications HL1 and HL2, the interval between hotline communications HL2 and HL3, the interval between hotline communications HL3 and HL4, the interval between hotline communications HL4 and HL5, and the interval between hotline communications HL5 and HL6 are the communication intervals of the communication specifications indicated by the determined generations. 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. For example, the communication interval may be twice the sampling interval.

[0165] Pulse position information, which is represented by the accumulated number of pulse signals repeatedly received by the second body communication unit 29 at each communication interval, is sequentially stored in the body memory 22 of the camera body 2. The pulse position information is transferred to the body memory 22, for example, by DMA (Direct Memory Access). The body control unit 27 references the pulse position information stored in the body memory 22 at any given time (for example, the time when a vertical synchronization signal from the image sensor is output; in FIG. 9, this is time ta between times t6 and t7), and calculates the time when each piece of pulse position information was generated in the interchangeable lens 3 (times t2 to t6 on the interchangeable lens side) using a method described below. The body control unit 27 associates each piece of pulse position information with the time at which that pulse position information was generated, thereby determining the position of the focus lens at each time, as shown by curve L2 in FIG. 9(e). It should be noted that 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 accumulated number of 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 a sampling period, and the body control unit 27 may accumulate the pulse signals to generate pulse position information of the lens.

[0166] Pulse position information associated with the generation time is used, for example, in the phase-difference AF described above. As described above, the body control unit 27 calculates the defocus amount using the focus detection signal output from the image sensor 21. The body control unit 27 generates a signal that instructs driving of the focus lens based on the calculated defocus amount, and outputs the generated drive instruction signal (drive command) to the lens control unit 37 via command data communication. The lens control unit 37 drives and controls the focus lens, and also transmits pulse position information to the body control unit 27. The body control unit 27 determines the position of the focus lens at each time based on the pulse position information, and confirms how far the focus lens has moved relative to the focus lens movement amount (defocus amount) instructed to the lens control unit 37.

[0167] Furthermore, pulse position information associated with the generation time can be used for the contrast AF described above. The body control unit 27 associates the focus lens pulse position information 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 grasp the position of the focus lens and the contrast evaluation value at each time. The body control unit 27 calculates the focus lens pulse position at which the contrast evaluation value peaks as the in-focus position. The body control unit 27 then generates a signal instructing the focus lens to be driven based on the calculated in-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 in-focus position, thereby performing focus adjustment.

[0168] Here, we will discuss discrepancies that can occur in the lens position reconstructed and generated 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 a clock for its own use within the camera body 2, while the interchangeable lens 3 generates a clock for its own use within the interchangeable lens 3. The clock frequencies within the camera body 2 and the interchangeable lens 3 may be the same or different. If the camera body 2 and the interchangeable lens 3 generate clocks with the same frequency and the clock timing (rising and falling edges) are perfectly synchronized, the camera body 2 can determine the time at which the signal generated by the interchangeable lens 3 was generated. However, if the clock timing between the camera body 2 and the interchangeable lens 3, i.e., the clock frequencies or rising and falling edges of the clock, differ, the camera body 2 will not be able to accurately determine the time at which the signal was generated by the interchangeable lens 3, resulting in a time discrepancy between the actual lens position and the lens position reconstructed and generated by the camera body 2.

[0169] The following describes a method by which the camera body 2 calculates the times (times t2 to t6 on the interchangeable lens side) at which the interchangeable lens 3 generated pulse position information (integrated value of pulse signals) when the clock timings of the camera body 2 and the interchangeable lens 3 are different. As described above with reference to FIGS. 9(b) to 9(d), the pulse position information is generated by the lens control unit 37 sampling the pulse signal from the lens position detection unit 34 or the lens drive unit 33 at a predetermined cycle. The lens control unit 37 samples the pulse signal in accordance with a clock signal used inside the interchangeable lens 3 (hereinafter referred to as the lens clock signal). That is, in FIG. 9, times t2, t3, t4, t5, t6, t7, and so on, at which 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.

[0170] The body control unit 27 determines the time when sampling of the pulse signal started, based on the time when command data communication CD2 was performed to set up hotline communication, for example. 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 sampling of the pulse signal started (the delay time Δt shown in FIG. 9(d)) using a method described below. The lens control unit 37 transmits information corresponding to the calculated delay time Δt to the camera body 2 via command data communication CD2.

[0171] The body control unit 27 of the camera body 2 acquires information corresponding to the time delay Δt from the interchangeable lens 3, and uses the time delay Δt to calculate the time of generation of the pulse position information, which is the integrated value of the pulse signal from the time of transmission of the command data communication CD2. In this way, the body control unit 27 calculates the time of generation of the pulse position information based on the time of transmission of the command data communication CD2.

[0172] Fig. 10 is a diagram illustrating an example of a method for calculating the delay time Δt in the imaging device according to the first embodiment. Note that times t-1, t0, t1, and t2 in Fig. 10 correspond to times t-1, t0, t1, and t2 in Fig. 9, respectively. A command packet 44 and a data packet 45 are command packets and data packets transmitted from the camera body 2 to the interchangeable lens 3 via command data communication CD2 shown in Fig. 9. The command packet 44 is a signal that instructs the setting of hotline communication, and the data packet 45 is a signal that includes generation information determined by the camera body 2.

[0173] The trigger signal that latches the pulse signals shown at times t-1, t1, and t2 in Fig. 10 is a trigger signal that is repeatedly generated at a predetermined cycle S based on the lens clock signal output by the lens control unit 37 of the interchangeable lens 3. The predetermined cycle S is the sampling interval in Fig. 9(c), which is the sampling interval described in Fig. 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.

[0174] Here, we will explain how to calculate the delay time Δt. As a premise, 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 a pulse signal at a sampling interval S that conforms to the specifications it can support. FIG. 10 shows the time from time t-1 onward of the latch immediately before command data communication CD2 is performed. After successfully receiving the command packet 44 of command data communication CD2 and setting the RDY signal to a high level, the lens control unit 37 sets the RDY signal to a low level at time t0. The lens control unit 37 calculates the delay time Δt by detecting the time from time t-1 to time t0 and 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 during the period from time t-1 to the falling edge of the RDY signal using an internal counter circuit or the like. Then, the lens control unit 37 outputs information indicating the time difference Δt to the body control unit 27 via command data communication CD2.

[0175] Furthermore, upon receiving the data packet 45, the lens control unit 37 transitions the RDY signal from low to high. Furthermore, as described above, the data packet 45 includes generation information, and the lens control unit 37 initiates hotline communication in accordance with the communication specifications indicated by the generation determined by the camera body 2. Furthermore, the lens control unit 37 generates a trigger signal at a sampling interval S according to the sampling interval specifications indicated by the determined generation, and performs sampling processing of the pulse signal (see FIG. 9 ). The lens control unit 37 counts the pulse signals of the lens position detection unit 34 or the lens drive unit 33 that are generated 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 via hotline communication HL1 in FIG. 9 .

[0176] The body control unit 27 acquires information indicating the delay time Δt from the lens control unit 37 via command data communication CD2. Based on the delay 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, which is the sum of the delay time Δt and the sampling interval S to the falling 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.

[0177] In the present embodiment, the camera body 2 acquires a time lag Δt relating to the time at which pulse position information obtained by integrating pulse signals is generated, and calculates focus lens position information using the time lag Δt. This makes it possible to reduce the time delay between the focus lens position calculated and restored by the camera body 2 and the actual focus lens position in the interchangeable lens 3. Below, we will explain how the time delay between the restored focus lens position and the actual focus lens position is reduced (the time lag Δt, which is the cause of the delay, is canceled) by comparing it with a comparative example.

[0178] In the comparative example, the focus lens position is calculated without obtaining the accurate time lag Δt. Since the body control unit 27 does not receive the accurate time lag Δt from the lens control unit 37, it instead uses a fixed value corresponding to the time lag to calculate the generation time of the lens position information. However, since the lens position information is generated using a trigger signal (a signal based on a lens clock signal used inside the interchangeable lens 3) that is asynchronous with the clock signal (CLK signal) from the camera body 2, the time lag changes depending on the timing when a command instructing hotline communication setup is sent from the camera body 2 (in the embodiment shown in FIG. 10, the timing of the falling edge of the RDY signal). As a result, if the time lag were set to a fixed value, an error would occur when correlating pulse position information with the generation time, resulting in a difference between the actual position of the focus lens and the calculated position. A 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.

[0179] In this embodiment, the focus lens position is restored using the time lag Δt between the timing at which the command signal is transmitted and the timing at which the lens control unit 37 actually measures (samples) the pulse signal, thereby reducing the time lag between the restored focus lens position and the actual focus lens position. As a result, for example, it is possible to suppress errors when determining the focus lens position to be used as the in-focus position in autofocus.

[0180] According to the above-described embodiment, the following effects can be obtained. (1) Generation information indicating the communication specifications for hotline communication is transmitted from the interchangeable lens 3 to the camera body 2 via command data communication. This allows the camera body 2 to determine the communication specifications (such as communication speed) that the interchangeable lens 3 can support by referencing the generation information transmitted from the interchangeable lens 3 via command data communication. This allows for proper communication between the camera body 2 and the interchangeable lens 3. Furthermore, compared to sending data transmitted via hotline communication individually from the interchangeable lens 3 to the camera body 2, such as data on communication speed and communication interval, information on the drive of the focus lens (such as information on the position of the focus lens), and information on the drive of the vibration-proof lens (such as information on the position of the vibration-proof lens), the amount of data transmitted from the interchangeable lens 3 to the camera body 2 can be reduced, thereby shortening the communication time and number of communications required to determine the communication specifications between the interchangeable lens 3 and the camera body 2. Here, the number of values ​​of the generation information is fewer than the number of all combinations of communication specifications and data indicated by the generation information. Furthermore, when 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, it is necessary for the camera body 2 to check whether there are any contradictions 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, there is no need for the camera body 2 to check whether there are any contradictions. Furthermore, in accordance with 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 member (such as the focus lens) generated by the generation unit (lens control unit 37) to the camera body 2 via hotline communication. Therefore, position information about the driven member, such as the focus lens, can be transmitted at high speed from the interchangeable lens 3 to the camera body 2 using hotline communication, thereby speeding up autofocus operations.

[0181] (2) The interchangeable lens 3 repeatedly generates information (lens pulse position information) about a driven member (such as a focus lens), transmits that information to the camera body 2, and includes a lens control unit 37 that calculates a delay time Δt from the time a signal instructing the start of communication is received from the camera body 2 until the lens control unit 37 generates the information about the driven member, and transmits the delay time Δt to the camera body 2. As a result, the camera body 2 can determine the position of the focus lens at each time by using the lens pulse position information and the delay time Δt. Furthermore, in this embodiment, the camera body 2 reconstructs and generates the position of the focus lens using the delay time Δt. This makes it possible to reduce the error between the focus lens position reconstructed by the camera body 2 and the actual focus lens position in the interchangeable lens 3.

[0182] (3) The CLK terminal is positioned farther from the VBAT terminal than the GND terminal. Furthermore, a PGND terminal is located between the GND terminal and the VBAT terminal. This shields the CLK terminal, which sends the clock signal used for command and data communication, from noise caused by the VBAT terminal, ensuring stable command and data communication. This ensures reliable transmission and reception of generation information between the camera body 2 and the interchangeable lens 3.

[0183] The following modifications are also within the scope of the present invention, and one or more of the modifications may be combined with the above-described embodiment.

[0184] (Variation 1) In the above-described embodiment, an example has been described in which full-duplex communication is performed for command and 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 perform half-duplex communication for command and data communication.

[0185] (Variation 2) In the embodiment described above, an example has been described in which the lens control unit 37 calculates the time from time t0 to time t1 in Fig. 10 as the delay time Δt, and the body control unit 27 calculates the generation time of the lens position information using the delay 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 Fig. 10 (delay time Δt2) and output the delay 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 delay time Δt2.

[0186] For example, the body control unit 27 calculates (determines) time t0+Δt2, which is the RDY signal fall time t0 plus a delay time Δt2, as the lens position information generation time t2. The body control unit 27 also calculates lens position information generation times t3, t4, t5, and t6 as t2+S, t2+2S, t2+3S, and t2+4S, respectively.

[0187] (Variation 3) In the embodiment described above, the lens control unit 37 has the first lens communication unit 38 and the second lens communication unit 39, but these may not be provided separately and may instead be communicated by a single lens communication unit. Also, the body control unit 27 has the first body communication unit 28 and the second body communication unit 29, but these may not be provided separately and may instead be communicated by a single body communication unit.

[0188] (Variation 4) In the above embodiment, an interchangeable lens for a camera was used as an example of an accessory. However, accessories are not limited to interchangeable lenses. For example, accessories such as a teleconverter, wide-angle converter, or close-up ring that are attached between the camera body and the interchangeable lens to change the focal length of the interchangeable lens may also be used. The present invention may also be applied to a mount adapter that allows accessories, including interchangeable lenses with other mount standards, to be attached to the mount standard of the camera body. In other words, the present invention may be applied to any accessory that is attached to the mount of the camera body. In this case, the lens-side terminal group, lens-side claw 139, first and second lens communication units 38, 39, etc. correspond to the accessory-side terminal group, accessory-side protrusion, accessory-side communication unit, etc. of the respective accessories. In the above embodiment, the accessories are attachable to a camera body, but the above camera body may also be a mount adapter that allows an interchangeable lens of the above mount standard to be attached to a camera body that differs from the above mount standard, and the above accessory may be configured to be attachable to that mount adapter.

[0189] (Variation 5) In the above-described embodiment, the interchangeable lens 3 transmits information to the camera body 2 at the communication interval specified by the communication specifications indicated by the determined generation. However, the interchangeable lens 3 does not necessarily have to transmit data at every communication interval specified by the communication specifications indicated by the determined generation. The communication interval specified by the interchangeable lens 3 may be an integer multiple of the communication interval specified by the communication specifications indicated by the determined generation, for example, twice the communication interval specified by the communication specifications indicated by the determined generation. In this case, the camera body 2 can receive all data transmitted from the interchangeable lens 3 at intervals twice the communication interval specified by the communication specifications indicated by the determined generation. Of course, data may be transmitted irregularly rather than periodically, as long as the generated data is synchronized with the communication interval specified by the communication specifications indicated by the determined generation, rather than at double the communication interval. Alternatively, the communication interval specified by the interchangeable lens 3 may be three times the communication interval specified by the communication specifications indicated by the determined generation.

[0190] Although various embodiments and modifications have been described above, the present invention is not limited to these. The above-described embodiments and modifications may be combined. Furthermore, other aspects that are 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]

[0191] 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

1. An accessory that can be attached to a camera body and can communicate with the camera body, a transmitter capable of transmitting information relating to a driven member driven by a drive unit to the camera body using one or more communication specifications; a receiving unit that receives, from the camera body, a first value that indicates a communication specification for transmitting the information to the camera body; Equipped with the transmitting unit and the receiving unit are capable of communicating independently of each other, the first value is a single value indicating a combination of a communication speed of the transmitter, an interval at which the information is communicated by the transmitter, the number of pieces of information, and the type of the driven member to which the information is transmitted; The transmitter is an accessory that transmits information about the driven member to the camera body in accordance with the communication specification indicated by the first value.

2. The accessory according to claim 1 , The accessory, wherein the first value indicates at least one of a communication speed or a communication interval as the communication specification.

3. The accessory according to claim 1 or 2, An accessory in which the first value indicates that at least one of information regarding the driven member, the state of the driven member and the position of the driven member, is to be transmitted to the camera body.

4. The accessory according to any one of claims 1 to 3, An accessory in which the first value indicates that at least one of information regarding the driven member, information regarding the focus lens, information regarding the vibration-proof lens, information regarding the zoom lens, and information regarding the aperture diaphragm, is to be sent to the camera body.

5. The accessory according to any one of claims 1 to 4, The first value indicates a time interval for acquiring information about the driven member.

6. The accessory according to any one of claims 1 to 5, The transmitter transmits information about the driven member to the camera body in synchronization with a clock signal output from the accessory.

7. An accessory capable of communicating with a camera body, a first communication unit that receives a first value indicating a plurality of specifications including the number of data to be communicated and a communication interval; a second communication unit that communicates independently of the first communication unit and transmits information about the movable member in accordance with the communication specification indicated by the first value; Equipped with An accessory in which the first value is a single value that indicates a combination of the communication speed of the second communication unit, which is capable of transmitting information regarding a driven member driven by a drive unit to the camera body using one or more communication specifications, the communication interval of the information by the second communication unit, the number of pieces of information, and the type of the driven member to which the information is transmitted.

8. The accessory of claim 7 , wherein when the first communication unit receives a first value, the accessory initiates communication with the second communication unit.

9. The accessory described in claim 7 or claim 8, wherein the first communication unit transmits a second value indicating a communication specification by which the accessory can transmit information about the movable member, and after transmitting the second value, receives the first value which is less than or equal to the second value.

10. An accessory described in any one of claims 7 to 9, wherein the first communication unit communicates in synchronization with a first clock signal, and the second communication unit communicates in synchronization with a second clock signal different from the first clock signal.

11. the first communication unit performs bidirectional communication; The accessory according to any one of claims 7 to 10, wherein the second communication unit performs one-way communication with the camera body.

12. The accessory according to any one of claims 1 to 11, which is an interchangeable lens.

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