Device and adapter device

Abstract

To make communication smooth between a camera and an adapter device, while increasing the speed of communication between the camera and an interchangeable lens device.SOLUTION: A camera 20 is connected with an interchangeable lens device 10 via one or more adapter devices 30, 40, and the camera has: lens-camera communication control units 207, 205 that communicate with the interchangeable lens device through a camera-lens communication channel connected to the interchangeable lens device from the camera via the adapter devices; and adapter-camera communication control units 209, 205 that communicate with the adapter devices through a camera-adapter communication channel provided between the adapter devices and adapter-camera communication control units separately from the camera-lens communication channel. The camera-lens communication channel includes a first data communication channel and a first notification channel, and the camera-adapter communication channel includes a second data communication channel and a second notification channel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a camera and an interchangeable lens device (hereinafter simply referred to as an interchangeable lens) that are capable of communicating with each other, and an adapter device (hereinafter simply referred to as an adapter) that is placed between the camera and the interchangeable lens. [Background technology]

[0002] In an interchangeable lens camera system that includes a camera with a detachable interchangeable lens, communication is performed so that the camera can control the operation of the interchangeable lens and the interchangeable lens can provide the camera with data necessary for that control and image capture. In particular, when capturing video for recording or video for live view display using an interchangeable lens, smooth lens control that matches the capture cycle is required, so it is necessary to synchronize the camera's capture timing with the interchangeable lens's control timing. Therefore, the camera must complete both receiving data from the interchangeable lens and sending commands, such as various instructions and requests, to the interchangeable lens within the capture cycle. However, as the amount of data the camera receives from the interchangeable lens increases and the capture cycle shortens (higher frame rates), faster and larger data communications are required.

[0003] In addition, an adapter such as a wide-angle converter or teleconverter (extender) may be attached between the camera and the interchangeable lens. In this case, commands are transmitted from the camera to the interchangeable lens and data is transmitted from the interchangeable lens to the camera via the adapter. Furthermore, in order to properly perform AF, AE, and other operations on the camera, not only data on the interchangeable lens but also data specific to the adapter is required. In the camera system disclosed in Patent Document 1, commands are transmitted from the camera to the adapter and data is transmitted from the adapter to the camera via a common communication channel, along with commands from the camera to the interchangeable lens and data from the interchangeable lens to the camera. In other words, one-to-many communications between the camera, the interchangeable lens, and the adapter are performed via a single communication channel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-037692 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in one-to-many communication using only one communication channel, for example, while data is being sent from the adapter to the camera, the camera cannot send commands to the interchangeable lens or receive data from the interchangeable lens, which hinders high-speed communication between the camera and the interchangeable lens.

[0006] The present invention provides a camera, an interchangeable lens device, and an adapter device that enable faster communication between the camera and the interchangeable lens device while also enabling smoother communication between the camera and the adapter device. [Means for solving the problem]

[0007] An apparatus according to one aspect of the present invention is an apparatus connectable to a camera, the apparatus comprising: a first communication control unit that communicates with the camera using a first communication channel; a second communication control unit that communicates with the camera using a second communication channel that is provided separately from the first communication channel; and an operation member that is operated by a user. and The first communication channel is a first data communication line used during data communication. and a second data communication line and a first data communication line and a second data communication line The second communication channel includes a first notification line used for notifying the timing of communication via the second communication channel. 3 data communication line and 3 a second notification line used to notify the timing of communication via the data communication line; only from Becoming The operation data of the operation member is transmitted via a second data communication line.

[0008] According to another aspect of the present invention, there is provided an adapter device for connecting a camera and an interchangeable lens. and an adapter device that can connect the above; a relay channel that forms part of a camera-lens communication channel for communication between a camera and an interchangeable lens; an adapter-camera communication control unit that communicates with the camera using a camera-adapter communication channel that is provided between the camera and the adapter and that is separate from the relay channel; and an operation member that is operated by a user. and The camera-lens communication channel is a first data communication line used for data communication. and a second data communication line and a first data communication line and a second data communication line and a first notification line used to notify the timing of communication via the camera-adapter communication channel. 3 a data communication line for the camera and the adapter device using the camera-adapter communication channel; and a second notification line for notifying the timing of communication between the camera and the adapter device using the camera-adapter communication channel. only from Becoming The operation data of the operation member is 3 The data is transmitted over a data communication line. [Effects of the Invention]

[0009] According to the present invention, it is possible to realize a camera, an interchangeable lens device, and an adapter device that enable communication between the camera and the adapter device while increasing the speed of communication between the camera and the interchangeable lens device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram showing the configuration of a camera system according to a first embodiment of the present invention. [Figure 2] 4 is a flowchart showing a lens control process in the first embodiment. [Figure 3] FIG. 4 is a diagram for explaining a first communication in the first embodiment. [Figure 4] 10 is a flowchart showing adapter information acquisition processing according to the first embodiment. [Figure 5]FIG. 3 is a diagram illustrating the data occupation status of each communication in the first embodiment. [Figure 6] FIG. 10 is a block diagram showing the configuration of a camera system according to a second embodiment of the present invention. [Figure 7] 10 is a flowchart showing a lens control process in the second embodiment. [Figure 8] FIG. 10 is a diagram for explaining the first communication when starting up the interchangeable lens from the camera in the second embodiment. [Figure 9] FIG. 10 is a diagram for explaining the first communication when the interchangeable lens is started from the interchangeable lens in the second embodiment. [Figure 10] 10 is a flowchart showing an adapter control process according to the second embodiment. [Figure 11] FIG. 10 is a diagram for explaining second communication in the first embodiment. [Figure 12] FIG. 10 is a diagram for explaining a third communication (one-to-many) in the first embodiment. [Figure 13] FIG. 10 is a diagram for explaining third communication (one-to-one) in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Example]

[0012] 1 shows the configuration of a camera system according to a first embodiment of the present invention. The camera system is composed of a camera 20, an interchangeable lens device (hereinafter referred to as interchangeable lens) 10, and two adapter devices (hereinafter referred to as adapters) 30 and 40 arranged between the camera 20 and the interchangeable lens 10. The camera system has a camera-lens communication channel 100 for first communication (hereinafter referred to as first communication channel 100) for transmitting commands such as instructions and requests from the camera 20 to the interchangeable lens 10. The camera system also has a lens-camera communication channel for second communication (hereinafter referred to as second communication channel 200) for transmitting optical data, status data, etc. from the interchangeable lens 10 to the camera 20 as a communication channel separate from the first communication channel 100. The camera system also has a camera-adapter communication channel for third communication (hereinafter referred to as third communication channel 300) for communicating commands and optical data of each adapter and data indicating its status, etc. between the camera 20 and the two adapters 30 and 40.

[0013] The interchangeable lens 10 has an imaging optical system including multiple movable optical components such as lenses and an iris. The camera 20 has an imaging element 204 that captures a subject image formed by the imaging optical system and generates a video signal using an output signal from the imaging element 204. The adapter 40 is removably connected (attached) to the mount 201 of the camera 20 at its mount 402. The adapter 30 is removably connected to the mount 401 of the adapter 40 at its mount 302. The adapter 30 is configured as an extender or wide converter, etc., and the adapter 40 is configured as an ND adapter, etc., and each has adapter optical components 309, 409 such as a variable magnification lens and an ND filter. Furthermore, the interchangeable lens 10 is removably connected to the mount 301 of the adapter 30 at its mount 101.

[0014] When all of the mounts 101, 301, 302, 401, 402, and 201 are connected, the first communication contacts 102, 303, 306, 403, 406, and 202 provided on each mount become conductive with each other, forming a camera-lens communication channel for performing the first communication. The first communication is used for communication by the camera 20 to control the operation of the movable optical member of the interchangeable lens 10.

[0015] Furthermore, when all of the mounts 101, 301, 302, 401, 402, and 201 are connected, the second communication contacts 103, 304, 307, 404, 407, and 202 provided on each mount become electrically connected to each other, forming a camera-lens communication channel for performing the second communication. The second communication is used to transmit optical data of the interchangeable lens 10 (hereinafter referred to as lens optical data) and data indicating the status of the interchangeable lens 10 (hereinafter referred to as lens status data) to the camera 20. Furthermore, when the mounts 101, 301, 302, 401, 402, and 201 are connected, the third communication contacts 104, 305, 308, 405, 408, and 203 provided on each mount become electrically connected to each other, forming a camera-adapter communication channel for performing the third communication. The third communication is one-to-many communication between the camera 20 and the two adapters 30 and 40. The third communication is used by the camera 20 to send commands to the adapters 30, 40 to control their operation. It is also used by the adapters 30, 40 to send optical data of the adapter optical members 309, 409 and operation data indicating user operations on the adapters 30, 40 to the camera 20. In the following description, the optical data of the adapters 30, 40 will be referred to as first adapter optical data and second adapter optical data. Furthermore, the operation data of the adapters 30, 40 will be referred to as first adapter operation data and second adapter operation data. The third communication is also used for communication between the interchangeable lens 10 and the adapters 30, 40.

[0016] In the interchangeable lens 10, the movable optical members in the imaging optical system described above are a focus lens 105, a magnification variable lens 106, an iris 107, and an anti-vibration lens 108. The focus lens 105 moves in the direction of the optical axis of the imaging optical system to perform focusing. The magnification variable lens 106 moves in the direction of the optical axis to perform magnification. The iris 107 adjusts the amount of light. The anti-vibration lens 108 moves (shifts) in a direction perpendicular to the optical axis direction to reduce blurring of the subject image caused by shaking of the camera system due to camera shake or the like.

[0017] The focus control unit 109 is composed of a focus actuator that moves the focus lens 105, a focus driver that controls the drive of the focus actuator, and a focus position sensor that detects the position of the focus lens 105. The zoom control unit 110 is composed of a zoom adapter that moves the variable magnification lens 106, a zoom driver that controls the drive of the zoom adapter, and a zoom position sensor that detects the position of the variable magnification lens 106. The iris control unit 111 has an iris driver that drives an iris motor provided in the iris 107, and an iris position sensor that detects the open / close position (aperture value) of the iris 107. The vibration reduction control unit 112 has an vibration reduction actuator that shifts the vibration reduction lens 108, an vibration reduction driver that controls the drive of the actuator, and a shift position sensor that detects the shift position of the vibration reduction lens 108.

[0018] The shake detection unit 113 is configured with a vibration gyroscope or the like, and detects the amount of camera shake, which is the amount of shake of the interchangeable lens 10 (that is, the camera system).

[0019] The lens control unit 114 controls the operations of the focus lens 105, the magnification variable lens 106, and the iris 107 through the focus, zoom, and iris control units 109 to 111 in response to lens control commands received from the camera control unit 205 in the camera 20. In addition, the lens control unit 114 controls the operation (shift) of the vibration-proof lens 108 through the vibration-proof control unit 112 in response to receiving the lens control commands. Furthermore, the lens control unit 114 transmits lens optical data and lens state data to the camera control unit 205. The lens control unit 114 communicates with the camera control unit 205 through the lens first communication unit 115 and the lens second communication unit 116, and communicates with the adapters 30 and 40 through the lens third communication unit 117.

[0020] The lens first communication unit 115, together with the lens control unit 114, constitutes a camera-lens communication control unit, and performs first communication with the camera control unit 205. The first communication is used to receive commands such as lens control commands from the camera control unit 205.

[0021] The lens second communication unit 116 performs second communication with the camera control unit 205. The second communication is used to transmit lens optical data and lens status data to the camera control unit 205. The lens third communication unit 117, together with the lens control unit 114, constitutes an adapter-lens communication control unit, and performs third communication with the adapter third communication units 310, 410 in the adapters 30, 40. The third communication with the adapter third communication units 310, 410 is also used to transmit lens optical data and lens status data from the lens control unit 114 to the adapter control units 311, 411.

[0022] The lens control unit 114 and the first to third lens communication units 115 to 117 are configured by a computer such as a CPU provided within the interchangeable lens 10. The lens operation member 118 is an operation member of the interchangeable lens 10 that is operated by the user, and is a switch, an electronic ring, or the like.

[0023] In the camera 20, the imaging element 204 is configured by a CMOS image sensor or the like, and performs photoelectric conversion (capturing) of a subject image. The camera control unit 205 converts an output signal from the imaging element 204 into a video signal and outputs it to the video display unit 206.

[0024] The camera control unit 205 also controls the operation of the interchangeable lens 10 by sending lens control commands to the lens control unit 114, and receives lens optical data and lens state data from the lens control unit 114. The camera control unit 205 communicates with the lens control unit 114 via a camera first communication unit 207 and a camera second communication unit 208, and communicates with the adapters 30 and 40 via a camera third communication unit 209.

[0025] The camera first communication unit 207, together with the camera control unit 205, constitutes a lens-camera communication control unit, and performs first communication with the lens first communication unit 115. As described above, the first communication is used to transmit commands such as lens control commands from the camera control unit 205 to the lens control unit 114, or to transmit data from the lens control unit 114 to the camera control unit 205. The camera second communication unit 208 performs second communication with the lens first communication unit 115. As described above, the second communication is used to receive lens optical data and lens state data from the lens control unit 114.

[0026] The camera third communication unit 209, together with the camera control unit 205, constitutes an adapter-camera communication control unit, and performs third communication with the adapter third communication units 310, 410. The third communication is used to transmit adapter control commands and adapter transmission request commands (commands requesting transmission of adapter-specific information) to the adapter control units 311, 411. Furthermore, the third communication is used to receive adapter-specific information from the adapter control units 311, 411. The adapter-specific information includes, for example, first and second adapter optical data and first and second adapter operation data. The camera control unit 205 and the camera first to third communication units 207-209 are configured by a computer such as a CPU provided within the camera 20. The first communication and the third communication differ from each other in at least one of the communication method, communication timing, communication speed (communication rate), and communication voltage.

[0027] Video display unit 206 is configured with a liquid crystal monitor or the like, and displays the video signal (captured video) from camera control unit 205. Camera operation member 210 is an operation member, such as a dial or switch, that is operated by the user in camera 20 to set imaging conditions.

[0028] In the adapters 30 and 40, the adapter optical members 309 and 409 described above are optical members for adding specific optical effects to the interchangeable lens 10, such as a variable magnification lens or an ND filter. In this embodiment, the adapter 30 is an extender having a variable magnification lens as the adapter optical member 309, and the adapter 40 is an ND adapter having an ND filter as the adapter optical member 409. Note that the adapter optical members may be something other than a variable magnification lens or an ND filter.

[0029] The adapter control units 311 and 411 control the operations of the adapters 30 and 40 (insertion and removal of the variable magnification lens and ND filter from the imaging optical path, etc.) in response to adapter control commands received from the camera control unit 205.

[0030] The adapter control units 311, 411 communicate with the camera control unit 205 and the lens control unit 114 via the adapter third communication units 310, 410. The adapter third communication units 310, 410, together with the adapter control units 311, 411, constitute a camera-adapter communication control unit and a lens-adapter communication control unit, and perform third communication with the camera third communication unit 209 and the lens third communication unit 117. As described above, the third communication with the camera third communication unit 209 is communication for receiving adapter control commands and adapter request commands from the camera control unit 205, and for transmitting first and second adapter optical data to the camera control unit 205. As described above, the third communication with the lens third communication unit 117 is used for receiving lens optical data and lens state data from the lens control unit 114.

[0031] The adapter control unit 311 and the adapter third communication unit 310 are configured by a CPU provided in the adapter 30. The adapter control unit 411 and the adapter third communication unit 410 are configured by a computer such as a CPU provided in the adapter 40.

[0032] The adapter operation members 312, 412 are operation members of the adapters 30, 40 that are operated by the user, and are, for example, switches or electronic rings. Here, predetermined functions are assigned to the operation of the adapter operation members 312, 412. Alternatively, a desired function may be assigned by the user via a setting means (not shown) of the camera 20. Examples of functions assigned to the operation of the adapter operation members 312, 412 include the following: When the adapter operation members 312, 412 are switches, the functions are at least one of turning the vibration isolation function on / off, setting the vibration isolation level of the vibration isolation function, and switching between autofocus and manual focus. When the adapter operation members 312, 412 are electronic rings, the functions are at least one of adjusting the aperture position (aperture diameter) of the interchangeable lens 10, adjusting the focus position, and adjusting the zoom position. At least one of the aperture position, focus position, and zoom position of the lens 10 is adjusted by an amount corresponding to the amount the electronic ring is operated.

[0033] Next, the process by which the camera 20 (camera control unit 205) controls the interchangeable lens 10 (lens control unit 114) will be described using the flowchart in Fig. 2. The camera control unit 205 and the lens control unit 114 each execute this process (and other processes described below) in accordance with an imaging control program, which is a computer program.

[0034] When the camera 20 is started in S201, the camera control unit 205 proceeds to S202. In S202, the camera control unit 205 supplies power to the interchangeable lens 10 and adapters 30 and 40 via a power supply mount contact (not shown).

[0035] Next, in S203, the camera control unit 205 causes the camera first communication unit 207 to detect the communication voltage used by the interchangeable lens 10, and sets the communication voltage used by the camera first communication unit 207 and the camera second communication unit 208 according to the detection result. Thereafter, the camera first communication unit 207 and the camera second communication unit 208 perform first communication and second communication with the lens first communication unit 115 and the lens second communication unit 116, respectively, using the set communication voltage. The process by which the camera first communication unit 207 detects the communication voltage of the interchangeable lens 10 will be described later.

[0036] Next, in S204, the lens control unit 114 transmits ID information (hereinafter referred to as lens ID) of the interchangeable lens 10, such as the lens name and lens specifications, to the camera control unit 205 via the lens first communication unit 115 (and the camera first communication unit 207). The camera control unit 205 receives the lens ID via the camera first communication unit 207. The lens control unit 114 also transmits lens status data indicating the current status (lens status) of the interchangeable lens 10 to the camera control unit 205 via the lens second communication unit 116 (and the camera second communication unit 208). The camera control unit 205 receives the lens status data via the camera second communication unit 208.

[0037] The lens state data includes the current positions of the focus lens 105, the magnification variable lens 106, the iris 107, and the vibration-proof lens 108 (hereinafter referred to as optical member positions) acquired from the focus, zoom, and iris control units 109, 110, and 111 and the vibration-proof control unit 112. The lens state data also includes a normalized value of the amount of camera shake acquired from the shake detection unit 113, and lens operation data indicating the amount and state of user operation acquired from the lens operation member 118. If the lens operation member 118 is an electronic ring, the lens operation data may include the amount of operation of the electronic ring per unit time. If the lens operation member 118 is a switch, the lens operation data may include the ON / OFF state of the switch.

[0038] Next, in S205, the camera control unit 205 determines the lens state data to be received from the lens control unit 114 through the second communication based on the lens state data acquired in S204. Then, a command requesting transmission of the determined lens state data is transmitted to the lens control unit 114 via the camera first communication unit 207 (and the lens first communication unit 115).

[0039] Next, in S206, the lens control unit 114 determines lens state data indicating the current lens state to be sent to the camera control unit 205 based on the above command received from the camera control unit 205 via the lens first communication unit 115 in S205.

[0040] Next, in S207, the lens control unit 114 transmits the determined lens state data to the camera control unit 205 via the lens second communication unit 116 (and the camera second communication unit 208).

[0041] Next, in S208, the camera control unit 205 determines the imaging conditions based on the lens state data received from the lens control unit 114 via the camera second communication unit 208, the magnification ratio of the adapter (extender) 30, and the transmittance of the adapter (ND adapter) 40. Then, imaging is performed under the determined imaging conditions. The imaging conditions include the subject distance, focal length, F-number, T-number, the amount of camera shake per unit time, and the shake correction angle for vibration reduction (the shift amount of the vibration reduction lens 108). The camera control unit 205 displays the generated captured image on the image display unit 206, and also superimposes numbers, symbols, marks, icons, etc. indicating the imaging conditions on the captured image. The method by which the camera control unit 205 acquires the magnification ratio and transmittance of the adapters 30 and 40 will be described later.

[0042] Next, in S209, the camera control unit 205 acquires operation data (hereinafter referred to as camera operation data) indicating user operations on the camera operation member 210, and also acquires first adapter operation data and second adapter operation data from the adapter operation members 312, 412. The camera operation data is data indicating settings of exposure (F-number, shutter speed, etc.) and zoom position by operating a dial or electronic ring, and instructions to perform / stop AF and image stabilization by operating a switch. The first and second adapter operation data will be described later. The process by which the camera control unit 205 acquires the first and second adapter operation data will be described later.

[0043] Next, in S210, the camera control unit 205 determines lens control data based on the lens state data acquired in S207, the camera operation data acquired in S209, and the first and second adapter operation data. Specifically, the camera control unit 205 acquires a phase difference from a phase difference sensor provided in the image sensor 204 in response to the ON state of a switch instructing the execution of AF, and calculates a defocus amount of the image pickup optical system from the phase difference. Furthermore, the camera control unit 205 determines a drive amount of the focus lens 105 required to achieve a focused state based on the calculated defocus amount. The camera control unit 205 also determines a drive amount of the magnification variable lens 106 based on data indicating the operation amount of the dial or electronic ring. Furthermore, the camera control unit 205 determines a drive amount of the iris 107 based on the exposure setting value set by the operation of the dial and the brightness level of a video signal generated using the output from the image sensor 204. The camera control unit 205 also determines whether to shift drive the image stabilization lens 108 in response to the ON / OFF state of a switch instructing the execution / stop of image stabilization.

[0044] In this way, the camera control unit 205 determines the lens control data including the drive amounts of the focus lens 105, the magnification lens 106, and the iris 107 and whether vibration reduction is possible.

[0045] Next, in S211, the camera control unit 205 transmits a lens control command including lens control data to the lens control unit 114 via the camera first communication unit 207 (and the lens first communication unit 115).

[0046] Next, in S212, the lens control unit 114 passes the lens control data included in the received lens control command to the focus, zoom, and iris control units 109, 110, and 111. The focus, zoom, and iris control units 109, 110, and 111 drive the focus lens 105, the zoom lens 106, and the iris 107 in accordance with the lens control data. The lens control unit 114 also notifies the stabilization control unit 112 of whether or not image stabilization is possible, which is included in the lens control data. If image stabilization is possible, the stabilization control unit 112 shifts and drives the stabilization lens 108 so as to reduce image shake in accordance with the amount of camera shake detected by the shake detection unit 113.

[0047] As explained above, in the initial communication (at system startup) between the camera 20 and the interchangeable lens 10, lens-specific information such as the name, specifications, and lens correction data of the interchangeable lens 10 is communicated. Thereafter, while the system is running, data indicating the state of the imaging optical system of the interchangeable lens 10, including focal length and focus position, data indicating the content of operations performed on the camera 20 by the user, the lens control data described above, and the like are communicated at predetermined timings.

[0048] Next, the process by which the camera first communication unit 207 detects the communication voltage of the interchangeable lens 10 and the communication process in the first communication will be described with reference to FIGS.

[0049] 3(a) shows the configuration of the first communication channel 100 for performing the first communication. In order to form the first communication channel 100 that connects the camera 20 to the interchangeable lens 10 via the adapters 30 and 40, the first communication contacts 102, 303, 306, 403, 406, and 202 are provided with the following terminals:

[0050] The first communication contact 303 includes a first communication LCLK terminal 303a, a first communication DCL terminal 303b, a first communication DLC terminal 303c, and a TYPE terminal 303d. The first communication contact 306 includes a first communication LCLK terminal 306a, a first communication DCL terminal 306b, a first communication DLC terminal 306c, and a TYPE terminal 306d. The first communication contact 403 includes a first communication LCLK terminal 403a, a first communication DCL terminal 403b, a first communication DLC terminal 403c, and a TYPE terminal 403d. The first communication contact 406 includes a first communication LCLK terminal 406a, a first communication DCL terminal 406b, a first communication DLC terminal 406c, and a TYPE terminal 406d.

[0051] First communication LCLK terminals 102a, 303a, 306a, 403a, 406a, and 202a are provided to form a line for a clock signal LCLK (hereinafter referred to as an LCLK line) output from the camera first communication unit 207. First communication DCL terminals 102b, 303b, 306b, 403b, 406b, and 202b are also provided to form a line for a camera data signal DCL (hereinafter referred to as a DCL line) output from the camera first communication unit 207. First communication DLC terminals 102c, 303c, 306c, 403c, 406c, and 202c are also provided to form a line for a lens data signal DLC (hereinafter referred to as a DLC line) output from the lens first communication unit 115. The DLC line and the DCL line each correspond to a first data communication channel used during data communication. The LCLK line corresponds to a first notification channel used to notify the timing of communication via the DCL line and the DLC line. The first communication is not limited to clock synchronous communication, which will be described later, but may also be asynchronous communication.

[0052] Furthermore, TYPE terminals 102d, 303d, 306d, 403d, 406d, and 202d are also provided to form lines for interchangeable lens type detection signals TYPE (hereinafter referred to as TYPE lines) for detecting the communication voltage of the interchangeable lens 10. The four lines between the first communication contacts 303, 306, 403, and 406 provided in the adapters 30 and 40 constitute a relay channel that forms part of the first communication channel 100.

[0053] 3(a), the LCLK line and the DCL line are pulled up within the interchangeable lens 10. In addition, the LCLK line and the DLC line are pulled up within the camera 20.

[0054] The LCLK line, DCL line, DLC line, and TYPE line in the adapters 30 and 40 are shorted between the first communication contacts 303 and 306 and between the first communication contacts 403 and 406, respectively.

[0055] The TYPE line is pulled down by a resistance value predetermined for each communication voltage within the interchangeable lens 10, and is pulled up by a resistance value predetermined within the camera 20. The camera first communication unit 207 detects the voltage value of the TYPE line and identifies the communication voltage of the interchangeable lens 10 from a voltage value determined from the resistance value within the interchangeable lens 10 and the resistance value within the camera 20.

[0056] 3(b) shows an example of the communication format of the first communication. This figure shows the signal waveforms on the LCLK line, DCL line, and DLC line. In the following description, the clock signal LCLK will be referred to as the LCLK signal, the camera data signal DCL transmitted and received on the DCL line will be referred to as the DCL signal, and the lens data signal DLC transmitted and received on the DLC line will be referred to as the DLC signal.

[0057] The camera first communication unit 207 outputs an LCLK signal to the LCLK line, and outputs 8-bit data B7 to B0 as a DCL signal to the DCL line in synchronization with the rising edge of the LCLK signal. The lens first communication unit 115 outputs 8-bit data B7 to B0 as a DLC signal to the DLC line in synchronization with the rising edge of the LCLK signal.

[0058] The camera first communication unit 207 receives 8 bits (B7 to B0) of data from the DLC line in synchronization with the rising edge of the LCLK signal. The lens first communication unit 115 receives 8 bits (B7 to B0) of data from the DLC line in synchronization with the rising edge of the LCLK signal. This allows the camera first communication unit 207 and the lens first communication unit 115 to exchange data with each other.

[0059] When the lens first communication unit 115 receives 8-bit data from the DCL line, it sets the voltage level of the LCLK line to Low for a predetermined time Tbusy, and then releases the Low level after the predetermined time Tbusy has elapsed. That is, it sets the LCLK line to High. The predetermined time Tbusy is the time during which the lens control unit 114 processes the received data, and during this time the camera first communication unit 207 does not transmit data to the lens first communication unit 115. By repeating this communication process, multiple bytes of data are communicated between the camera first communication unit 207 and the lens first communication unit 115 via the first communication.

[0060] The second communication may be one-way communication from the interchangeable lens 10 to the camera 20 using clock synchronous communication, as in the first communication, or may be start-stop synchronous communication. The third communication may also be two-way communication between the camera 20 and the adapters 30, 40 and between the interchangeable lens 10 and the adapters 30, 40, using clock synchronous communication or start-stop synchronous communication using a master-slave system or a token passing system.

[0061] 11(a) shows an example of a communication format for asynchronous communication performed in the second communication on the second communication channel 200. Here, an example is shown in which the format of the data to be communicated is 10 bits, including 1 start bit, 8 data bits, and 1 stop bit, making one frame. The data bits may be 7 bits or 16 bits, and may include a parity bit. The stop bits may also be 2 bits.

[0062] FIG. 11(b) shows a timing synchronization method for start-stop synchronous communication in the second communication. The camera control unit 205 (and the camera second communication unit 208) and the lens control unit 114 (and the lens second communication unit 117) transmit and receive data by operating their internal clocks according to a mutually predetermined clock frequency, i.e., clock rate. For example, the internal clock is set to a clock rate 16 times the communication rate between the camera control unit 205 and the lens control unit 114. The starting point for data sampling is determined by sampling the falling edge of the start bit of the received data with the internal clock, as shown as synchronization timing in the figure. Then, as shown as data sampling timing in the figure, data is latched at a position 8 clocks from this synchronization timing. This allows data to be captured at the center of each bit. By sampling data bit by bit in this way, data communication is performed using only one line for the second communication (lens-camera transmission channel: DLC2).

[0063] The third communication channel 300 is a communication channel provided to enable communication between the camera 20 and the adapters 30 and 40. The third communication channel 300 is used when the camera control unit 205 transmits a command instructing the adapter control units 311 and 411 and the lens control unit 114 to transition to a power-saving mode. Here, the power-saving mode is a mode in which power consumption is lower than during normal operation. For example, the power-saving mode is a mode in which data transmission and reception and driving of movable optical members and optical members 309 and 409 in the imaging optical system are prohibited. The third communication channel 300 is also used when transmitting a command indicating a communication partner in one-to-one communication. The third communication channel 300 is also used to transmit information unique to the adapter control units 30 and 40 to the camera control unit 205. The information unique to the adapter control units 30 and 40 will be described later.

[0064] 12 and 13, asynchronous communication performed using the third communication channel 300 will be described. The third communication channel 300 is composed of two signal lines: a notification channel CS used for communication of communication timing, and a data communication channel DATA used for sending and receiving data. Here, the data communication channel DATA corresponds to the second data communication channel used during data communication. The notification channel CS corresponds to the second notification channel used for notifying the timing of communication via the data communication channel DATA.

[0065] 12 shows a communication waveform of asynchronous communication performed in the third communication on the third communication channel 300. In particular, it shows an example of one-to-many communication in which data can be simultaneously transmitted from a data transmitting device to multiple data receiving devices. Specifically, it shows how the camera 20 transmits data, and then the adapter 30 (or adapter 30) transmits data. Hereinafter, communication performed between such one-to-many components is referred to as broadcast communication.

[0066] In FIG. 12, the signal outputs from the two adapters 30 and 40 (adapter control units 311 and 411) are shown together.

[0067] The signal level of the notification channel CS is configured to be High when all of the camera control unit 205, the adapter control units 311, 411, and the lens control unit 114 output High to the notification channel CS. On the other hand, the signal level of the notification channel CS is configured to be Low when at least one of the camera control unit 205, the adapter control units 311, 411, and the lens control unit 114 outputs Low to the notification channel CS.

[0068] In the third type of communication, the communication speed is set in advance on both the data sending side and the data receiving side, and data is communicated at a communication bit rate based on this setting. The communication bit rate indicates the amount of data that can be transferred in one second, and is measured in bps (bits per second).

[0069] When no data communication is taking place, the signal level of the data communication channel DATA is maintained at a high level. Next, to notify the data receiving side that data transmission has begun, the signal level of the data communication channel DATA is set to low for one bit period. This one bit period is called the start bit ST, and the data frame begins from the start bit ST. One byte of data is transmitted in the eight-bit period from the second bit to the ninth bit following the start bit ST.

[0070] The notification channel CS is connected to the camera control unit 205, the adapter control units 311 and 411, and the lens control unit 114, and each control unit can detect the signal level (voltage level) of the notification channel CS. In addition, the notification channel CS is pull-up connected to a power supply (not shown) arranged in the camera 20.

[0071] Each control unit can set the signal level of the notification channel CS, and when all control units 205, 311, 411, 114 set the signal level of the notification channel CS to Hi, the signal level of the communication channel CS becomes Hi. When any control unit sets the signal level of the notification channel CS to Low, the signal level of the communication channel CS becomes Low.

[0072] In the third communication, the camera control unit 205 (and the camera third communication unit 209) is the communication master, and the adapter control units 311 and 411 and the lens control unit 114 are communication slaves.

[0073] The camera control unit 205, which is the communication master, notifies the adapters 30, 40 and interchangeable lens 10, which are communication slaves, of the start of communication by outputting a low signal to the notification channel CS. Next, the camera control unit 205 transmits data to the adapters 30, 40 and the interchangeable lens 10 via the data communication channel DATA. Meanwhile, the adapter control units 311, 411 and the lens control unit 114 output a low signal to the notification channel CS in response to detecting the above-mentioned start bit ST via the data communication channel DATA. Note that at the time the adapter control units 311, 411 and the lens control unit 114 output a low signal to the notification channel CS, the camera control unit 205 is outputting a low signal, and therefore the signal level of the notification channel CS remains low.

[0074] The adapter control units 311, 411 and the lens control unit 114 notify a communication standby request by outputting a Low signal to the notification channel CS. The communication standby request is for temporarily suspending communication in the camera system, and the presence or absence of a communication standby request is determined by the signal level of the notification channel CS.

[0075] After transmitting all data, the camera control unit 205 outputs a High signal to the notification channel CS. After receiving the stop bit SP transmitted from the data communication channel DATA, the adapter control units 311 and 411 and the lens control unit 114 analyze the received data and perform internal processing corresponding to the received data. After that, they output a High signal to the notification channel CS after completing preparations for the next communication.

[0076] The camera control unit 205, adapter control units 311 and 411, and lens control unit 114 can confirm that each control unit is now in a state where it can perform the next communication, as the signal level of the notification channel CS has returned to High.

[0077] 12, the data transmitted by the camera control unit 205 includes a transmission request command to the adapter control units 311, 411, and subsequent data transmission by the adapter control units 311, 411 is performed by the adapter control units 311, 411. Specifically, after the signal level of the notification channel CS becomes High, the adapter control units 311, 411 output Low to the notification channel CS. This notifies the lens control unit 114 and the camera control unit 205 of the start of communication. Next, the adapter control units 311, 411 transmit data to the lens control unit 114 and the camera control unit 205 via the data communication channel DATA.

[0078] On the other hand, the lens control unit 114 and the camera control unit 205 output a low signal to the notification channel CS in response to detecting the start bit ST via the data communication channel DATA. Note that at the time when the lens control unit 114 and the camera control unit 205 output a low signal to the notification channel CS, the adapter control units 311 and 411 are outputting a low signal to the notification channel CS, so the signal level of the notification channel CS remains low.

[0079] After transmitting all data, the adapter control units 311 and 411 output a High signal to the notification channel CS. After receiving the stop bit SP transmitted from the data communication channel DATA, the lens control unit 114 and the camera control unit 205 analyze the received data and perform internal processing corresponding to the received data. After that, they output a High signal to the notification channel CS after completing preparations for the next communication.

[0080] The signal level of the notification channel CS becomes High when the camera control unit 205, the adapter control units 311 and 411, and the lens control unit 114 all output High to the notification channel CS. When the signal level of the notification channel CS returns to High, the camera control unit 205, the adapter control units 311 and 411, and the lens control unit 114 can confirm that each control unit is now in a state where it can perform the next communication.

[0081] 13 shows a communication waveform of asynchronous communication performed in the third communication on the third communication channel 300. In particular, it shows an example of individual communication between the camera 20 and one component (either the interchangeable lens 10 or the adapters 30, 40) selected by the camera 20 as a communication partner. Hereinafter, such one-to-one communication performed between components will be referred to as P2P communication.

[0082] Information indicating the communication slave that will be the communication partner in P2P communication is transmitted from the camera control unit 205 by broadcast communication. In P2P communication, the data transmitting side does not output Low to the notification channel CS, but transmits data to the data receiving side while maintaining the notification channel CS at High. In other words, the voltage level of the notification channel CS during data transmission from the camera 20 to the interchangeable lens 10 and adapter 30 is made different between broadcast communication and P2P communication.

[0083] When broadcast communication is switched to P2P communication, data transmission is first started from the camera control unit 205, which is the communication master.

[0084] FIG. 13 shows an example in which one byte of data is transmitted from the camera control unit 205 to the lens control unit 114, and then two bytes of data is transmitted from the lens control unit 114 to the camera control unit 205.

[0085] After the switching from broadcast communication to P2P communication is completed in each component of the camera system, the camera control unit 205 as the communication master transmits data to the lens control unit 114 via the data communication channel DATA. Upon completing the data transmission, the camera control unit 205 sets the signal level of the notification channel CS to Low output to notify a communication standby request. Then, after the camera control unit 205 is ready to receive data as the data receiving side, it returns the signal level of the notification channel CS to High output.

[0086] On the other hand, the lens control unit 114 recognizes that data transmission from the camera control unit 205 has been completed when the signal level of the notification channel CS becomes Low, and performs analysis of the received data and internal processing corresponding to the received data. In the example of Fig. 5, the data received from the camera control unit 205 includes a data transmission request from the lens control unit 114 to the camera control unit 205, and the lens control unit 114 also generates data to be transmitted to the camera control unit 205.

[0087] Thereafter, the signal level of the notification channel CS returns to High, and the lens control unit 114 recognizes that the communication standby request has been canceled, and transmits two bytes of data to the camera control unit 205.

[0088] When data transmission is completed, the lens control unit 114 changes the signal level of the notification channel CS to Low output and notifies a communication standby request. Then, after the lens control unit 114 is ready to receive data as the data receiving side, it returns the signal level of the notification channel CS to High output. Note that an adapter microcomputer 302 that is not selected as a communication partner in P2P communication does not change the output to the notification channel CS and is not involved in sending or receiving data.

[0089] The lens control unit 114 determines whether P2P communication is continuing or has been switched to broadcast communication based on the timing of data transmission from the camera control unit 205 after the signal level of the notification channel CS is returned to High.

[0090] The signal level of the notification channel CS while the camera control unit 205 is transmitting data is made different for broadcast communication and P2P communication. If the lens control unit 114 receives data from the camera control unit 205 while the signal level of the notification channel CS remains High (second voltage level), the lens control unit 114 determines that P2P communication is continuing. On the other hand, if the lens control unit 114 receives data from the camera control unit 205 after the signal level of the notification channel CS has changed to Low (first voltage level), the lens control unit 114 determines that the communication has been switched from P2P communication to broadcast communication.

[0091] As described above, in P2P communication, the data sending side notifies the data receiving side that the data sending side has completed sending data by changing the signal level of the notification channel CS from high output to low output. Therefore, in P2P communication, multiple data frames can be transmitted continuously until the data sending side changes the signal level of the notification channel CS. This enables high-speed communication between the camera 20 and accessory devices such as the interchangeable lens 10, adapter 30, and microcomputer 302. The data sending side then notifies a communication standby request by keeping the signal level of the notification channel CS at low output until it is ready to receive data as the data receiving side in the next communication.

[0092] Next, the process by which the camera control unit 205 acquires the magnification of the adapter optical element (variable lens) 309, the transmittance of the adapter optical element (ND filter) 409, and the first and second adapter operation data will be described using the flowchart of Figure 4.

[0093] S401 and S402 are the same as S201 and S202 in Fig. 2. After proceeding from S402 to S403, the camera control unit 205 transmits a command to the adapter control unit 311 via the camera third communication unit 209 (and the adapter third communication unit 310) requesting transmission of first adapter optical data, which is optical data of the adapter optical member 309.

[0094] Next, in S404, the adapter control unit 311 transmits the first adapter optical data stored in its internal memory to the camera control unit 205 via the adapter third communication unit 310 (and the camera third communication unit 209). The first adapter optical data is data indicating the magnification ratio of the adapter optical member 309.

[0095] Next, in S405, the camera control unit 205 sends a command to the adapter control unit 411 via the camera third communication unit 209 (and the adapter third communication unit 410) requesting the transmission of second adapter optical data, which is the optical data of the adapter optical member 409.

[0096] Next, in S406, the adapter control unit 411 transmits the second adapter optical data stored in its internal memory to the camera control unit 205 via the adapter third communication unit 410 (and the camera third communication unit 209). The second adapter optical data is data indicating the transmittance of the adapter optical member 409.

[0097] Next, in S407, the camera control unit 205 sends a command to the adapter control unit 311 via the camera third communication unit 209 (and the adapter third communication unit 310) requesting the transmission of the first adapter operation data, which is the operation data of the adapter operation member 312.

[0098] Next, in S408, the adapter control unit 311 acquires the operation amount and operation state from the adapter operation member 312. Then, data indicating these is transmitted as first adapter operation data to the camera control unit 205 via the adapter third communication unit 310 (and the camera third communication unit 209). If the adapter operation member 312 is an electronic ring, the first adapter operation data is data indicating the operation amount of the electronic ring per unit time. If the adapter operation member 312 is a switch, the first adapter operation data is data indicating the ON / OFF state of the switch.

[0099] Next, in S409, the camera control unit 205 sends a command to the adapter control unit 411 via the camera third communication unit 209 (and the adapter third communication unit 410) requesting the transmission of second adapter operation data, which is operation data for the adapter operation member 412.

[0100] Next, in S410, the adapter control unit 411 acquires the operation amount and operation state from the adapter operation member 412. Then, data indicating these is transmitted as second adapter operation data to the camera control unit 205 via the adapter third communication unit 310 (and the camera third communication unit 209). The second adapter operation data is the same data as the first adapter operation data. By repeating the processes from S407 to S410, the camera control unit 205 can periodically acquire the operation data of the adapter operation member 312 and the adapter operation member 412.

[0101] For example, if the adapter operation member 312 is assigned the function of adjusting the aperture position, the camera 20 instructs the interchangeable lens 10 to change the aperture position via the first communication channel 100 in accordance with the amount of operation of the adapter operation member 412 acquired in S410. If the adapter operation member 312 is assigned the function of turning the vibration reduction function on / off, the camera 20 instructs the interchangeable lens 10 to turn vibration reduction control on or off via the first communication channel 100 in accordance with the operation state (ON or OFF) of the adapter operation member 412 acquired in S410. The same applies to the adapter operation member 412. By operating the adapter operation members 312, 412, the user can control the state of the imaging optical system of the interchangeable lens 10.

[0102] In the above-described embodiment, the magnification and transmittance of each of the adapter optical members 309 and 409 are used as examples of the first adapter optical data and the second adapter optical data.

[0103] Information specific to adapter 30 and information specific to adapter 40 other than the first adapter optical data and the second adapter optical data may be communicated via third communication channel 300. The information specific to adapter 30 may include, for example, at least one of the name, specifications (specs), and correction data of adapter optical members 309 of adapter 30. Similarly, the information specific to adapter 40 may include, for example, at least one of the name, specifications (specs), and correction data of adapter optical members 409 of adapter 40. For example, at least one of the name, specifications (specs), adapter optical members 309, and correction data of adapter optical members 409 is transmitted to camera 20 during initial communication between camera 20 and adapter 30 and between camera 20 and adapter 40.

[0104] Furthermore, if the focal length information, light transmittance information, etc. change over time due to changes in the state of the imaging optical system of the interchangeable lens 10 or the adapter optical members 309, 409, etc., the adapter 30 or adapter 40 may transmit this updated data to the camera 20 in a normal state, such as when waiting to shoot. Through the above processing, the camera control unit 205 can obtain the magnification and transmittance of the adapter optical members 309, 409 immediately after the start of power supply, and can periodically obtain the operation amount and operation state of the adapter operation members 312, 412 after the start of power supply.

[0105] Next, the occupancy status of communication data in the first communication channel 100, the second communication channel 200, and the third communication channel 300 will be described with reference to Figures 5(a) and 5(b). In this description, it is assumed that the lens control command, lens state data, and adapter operation data all have the same size.

[0106] Figure 5(a) shows the occupancy status of communication data in a camera system as a comparative example provided with only one communication channel. The horizontal axis in the figure represents time. Ta1, Ta2, Ta3, and Ta4 represent the transmission times of lens control commands, lens status data, first adapter operation data, and second adapter operation data, respectively. Furthermore, Ca1 and Ca2 represent the transmission intervals between lens control commands and lens status data, respectively.

[0107] The lens transmission request command is a command (data) with which the camera control unit 205 requests the lens control unit 114 to transmit lens status data. In response to receiving the lens transmission request data, the lens control unit 114 transmits the lens status data to the camera control unit 205. The first adapter transmission request data and the second adapter transmission request command are data with which the camera control unit 205 requests the adapter control units 309 and 409 to transmit first adapter operation data and second adapter operation data, respectively. In response to receiving the first adapter transmission request data and the second adapter transmission request data, the adapter control units 311 and 411 transmit the first adapter operation data and the second adapter operation data to the camera control unit 205, respectively.

[0108] 5(a), the lens control command, lens status data, and first and second adapter operation data are communicated sequentially over one communication channel, so the transmission intervals Ca1 and Ca2 between the lens control data and the lens status data are long. Also, the adapter control units 311 and 411 need to support the same communication speed as the lens control unit 114 and the camera control unit 205.

[0109] On the other hand, Figure 5(b) shows the occupancy status of communication data in the camera system of this embodiment, which has the first, second, and third communication channels 300. The horizontal axis of the figure represents time. Tb1, Tb2, Tb3, and Tb4 represent the transmission times of the lens control command, lens status data, first adapter operation data, and second adapter operation data, respectively. Furthermore, Cb1 and Cb2 represent the transmission intervals between lens control commands and lens status data, respectively.

[0110] As shown in FIG. 5(b), the lens control commands, lens status data, and first and second adapter operation data are communicated via different communication channels. As a result, the camera control unit 205 performs the first communication regardless of whether the camera control unit 205 and the adapter control units 30 and 40 are engaged in the third communication. Furthermore, by communicating the lens control commands, lens status data, and first and second adapter operation data via different communication channels, the transmission interval Cb1 between lens control commands is significantly shorter than Ca1 shown in FIG. 5(a). Similarly, the transmission interval Cb2 between lens status data is also significantly shorter than Cb1. This allows the camera 20 to control the interchangeable lens 10 at higher speeds than the comparative example shown in FIG. 5(a).

[0111] Furthermore, in this embodiment, the devices connected to the first and second communication channels 200 are limited to the camera 20 and the interchangeable lens 10. This makes it possible to prevent signal degradation due to reflection of the communicated signal, compared to the comparative example in which another device (adapter) is connected to the communication channels of the camera 20 and the interchangeable lens 10. As a result, the communication speed between the camera 20 and the interchangeable lens 10 can be increased compared to the comparative example. Therefore, if the size of the communicated data is the same, Tb1 and Tb2 are shorter than Ta1 and Ta2. Furthermore, by limiting the devices connected to the second communication channel 200 to the camera 20 and the interchangeable lens 10, it is not necessary to send a lens transmission request command from the camera 20 to the interchangeable lens 10, and the transmission interval between lens status data can be shortened accordingly.

[0112] In this embodiment, the transmission times Tb3 and Tb4 of the first and second adapter operation data are longer than Tb3 and Tb4, respectively. This is because the communication rate of the third communication is set slower regardless of the communication rates of the first and second communications, eliminating the need for adapters 30 and 40 to support high-speed communication.

[0113] Furthermore, in this embodiment, the lens control commands, lens status data, first adapter operation data, and second adapter operation data can be communicated at any timing without being hindered by channel occupation by the communication of other data. For example, communication is possible not only during the initial communication that takes place when an interchangeable lens, adapters 30, 40, etc. are attached to camera 20, but also while camera 20 is waiting to shoot or during shooting operation.

[0114] As described above, according to this embodiment, various commands and data can be communicated at appropriate timing between the camera 20, the interchangeable lens 10, and the adapters 30 and 40 without being hindered by other communications. Furthermore, compared to when there is only one communication channel, various commands and data can be communicated stably at short intervals, improving the stability of interchangeable lens control and the operability of the adapter.

[0115] Furthermore, because only the camera 20 and the interchangeable lens 10 are connected to the first and second communication channels 200, the first and second communications can be performed at higher speeds and with higher functionality, further improving the controllability of the interchangeable lens. Furthermore, by having the camera 20 switch the communication voltage depending on the communication voltage of the interchangeable lens 10, multiple interchangeable lenses with different communication voltages can be connected to the camera 20. Furthermore, by performing the third communication between the camera 20 and the adapters 30 and 40 separately from the first and second communications, it is possible to eliminate the need for an adapter that is compatible with the high communication speeds of the camera 20 and the interchangeable lens 10. As a result, it is possible to realize a camera 20 that can accommodate both an older interchangeable lens that supports the first communication, which requires a higher communication voltage, but does not have contacts for the second and third communications, and a new interchangeable lens that supports the first, second, and third communications, which require lower communication voltages and are designed to reduce power consumption. In this case, the communication voltage for the first communication can be set lower for the new interchangeable lens, allowing communication at the same voltage as the second and third communications, which require lower communication voltages, thereby reducing the cost of the electrical circuitry of the new interchangeable lens.

[0116] In this embodiment, the case has been described where the first and second adapter operation data are communicated to the camera 20 from the adapters 30, 40 by the third communication. However, data related to the interchangeable lens 10 (for example, lens operation data) may also be communicated from the interchangeable lens 10 to the camera 20 via the lens third communication unit 117, the adapter third communication unit 310, and the camera third communication unit 209.

[0117] Furthermore, an interchangeable lens that communicates at a communication voltage different from that of the adapters 30 and 40 may be configured without the lens third communication unit 117 and the third communication contact 104. This prevents the lens third communication unit 117 and the adapter third communication unit 310 and 410 from being connected at communication voltages different from each other. [Example]

[0118] Next, a second embodiment of the present invention will be described with reference to Fig. 6. In this embodiment, the same components as those in the first embodiment will be denoted by the same reference numerals and will not be described again.

[0119] In this embodiment, the camera transitions the interchangeable lens and adapter individually between a normal operating state (first state, hereinafter referred to as the normal state) in which communication is performed, and a low-power consumption state (second state, hereinafter referred to as the sleep state) in which power consumption is lower than in the normal state and communication is not performed. In this embodiment, when the interchangeable lens is in the sleep state, the first communication channel 100 is used as a channel for transmitting a lens activation signal that activates the interchangeable lens. Also, in this embodiment, when the adapter is in the sleep state, the third communication channel 300 is used as a channel for transmitting an adapter activation signal that activates the adapter. The lens activation signal and adapter activation signal are transmitted to the interchangeable lens and adapter using a transmission method different from the first communication and third communication performed in the normal state.

[0120] 6, when the interchangeable lens 10′ is in a sleep state, the camera control unit 2201 in the camera 20′ transmits a lens activation signal to the lens control unit 2101 via the camera sleep state signal control unit 2202 and the first communication channel 100. Furthermore, when the interchangeable lens 10′ is in a sleep state, the lens control unit 2101 in the interchangeable lens 10′ receives the lens activation signal from the camera control unit 2201 via the first communication channel 100 and the lens sleep state signal control unit 2102. Furthermore, when the adapters 30′, 40′ are in a sleep state, the camera control unit 2201 transmits an adapter activation signal to the adapter control units 2301, 2401 in the adapters 30′, 40′ via the camera sleep state signal control unit 2202 and the third communication channel 300.

[0121] 7 shows the process in which the camera 20' transitions the interchangeable lens 10' from a normal operating state (hereinafter referred to as the normal state) to a sleep state, and then transitions the interchangeable lens 10' back to the normal state. The normal state of the interchangeable lens 10' refers to a state in which the interchangeable lens 10' performs first, second, and third communications, and the camera 20' can control the drive of movable optical members within the imaging optical system of the interchangeable lens 10'. The sleep state of the interchangeable lens 10' refers to a state in which the interchangeable lens 10' stops first, second, and third communications, and consumes less power than in the normal state.

[0122] The camera control unit 2201 starts processing in S701, and then in S702 acquires the camera operation data and the first and second adapter operation data described in the first embodiment. Then, the process proceeds to S703.

[0123] In S703, the camera control unit 2201 determines whether or not the time during which there is no change in the camera operation data or the first and second adapter operation data exceeds a predetermined time. In other words, it determines whether or not the no-operation time during which the operation members 207, 312, 412 of the camera 20' or the adapters 30', 40' are not operated by the user exceeds a predetermined time. If the no-operation time exceeds the predetermined time, the camera control unit 2201 proceeds to S704; otherwise (if there is an operation), the camera control unit 2201 repeats the processing of S703. The predetermined time is a time sufficient to determine that the user is not performing an operation for capturing an image, and is, for example, several seconds.

[0124] In S704, the camera control unit 2201 transmits a command requesting transition to a sleep state to the lens control unit 2101 via the camera first communication unit 207 (and the lens first communication unit 115). Then, the process proceeds to S705.

[0125] In S705, the lens control unit 2101 transitions the interchangeable lens 10′ to a sleep state in response to a request to transition to a sleep state received via the lens first communication unit 115. In the interchangeable lens 10′ in the sleep state, only the lens sleep state signal control unit 2102 operates.

[0126] Next, in S706, the camera control unit 2201 again acquires the camera operation data and the first and second adapter operation data, and then proceeds to S707.

[0127] In S707, the camera control unit 2201 determines whether there has been a change in the camera operation data or the first and second adapter operation data acquired in S702 and S706. In other words, it determines whether the operation members 207, 312, 412 of the camera 20' or adapters 30', 40' have been operated by the user. If the camera control unit 2201 determines that an operation has been performed, it proceeds to S708; otherwise (if no operation has been performed), it repeats the determination of S707.

[0128] In S708, the camera control unit 2201 outputs a lens activation signal to the first communication channel 100 via the camera sleep state signal control unit 2202. The process of outputting the lens activation signal to the first communication channel 100 will be described later.

[0129] Next, in S709, the lens sleep state signal control unit 2102, to which the lens activation signal has been input, activates the lens control unit 2101, and transitions the interchangeable lens 10' to the normal state, and then this processing ends.

[0130] By this processing, the camera control unit 2201 can transition only the interchangeable lens 10' from the normal state to the sleep state, and from the sleep state to the normal state.

[0131] Next, the process of outputting a lens activation signal to the first communication channel 100 will be described with reference to Fig. 8. Fig. 8 shows the signal waveforms on the LCLK line, DCL line, and DLC line when the camera sleep state signal control unit 2202 outputs a lens activation signal.

[0132] 7, when the camera sleep state signal control unit 2202 receives a lens activation signal from the camera control unit 2201, it outputs an LCLK signal to the LCLK line from time Tcl0 and also outputs a specific data bit string (B7 to B0) to the DCL line. The LCLK signal and the specific data bit string are transmitted to the lens sleep state signal control unit 2102 as a lens activation signal.

[0133] The lens sleep state signal control unit 2102 activates the lens control unit 2101 in response to detection of a change in at least one of the signals on the LCLK line and the DCL line during the sleep state. This causes the interchangeable lens 10' to transition to the normal state. After this, the lens first communication unit 115 outputs a low signal to the LCLK line for a predetermined time Tbusy, and cancels the low output at time Tc11 when the predetermined time Tbusy has elapsed. After this, the first communication shown in FIG. 3(b) can be performed between the camera control unit 2201 and the lens control unit 2101.

[0134] This process makes it possible to use the first communication channel 100 to transition only the interchangeable lens 10' from the sleep state to the normal state.

[0135] Next, we will explain the process of transitioning the interchangeable lens 10' from the sleep state to the normal state in response to the operation of the lens operation member 118, using Fig. 9. Fig. 9 shows the signal waveforms on the LCLK line, DCL line, and DLC line when the interchangeable lens 10' transitions from the sleep state to the normal state in response to the operation of the lens operation member 118.

[0136] 9, the lens sleep state signal control unit 2102 outputs a low signal to the DLC line as a lens activation request signal from time Tlc0. When the camera sleep state signal control unit 2202 detects a low signal on the DLC line, it causes the camera first communication unit 207 to output an LCLK signal to the LCLK line from time Tlc1, and to output a specific data bit sequence (B7 to B0) to the DCL line. The LCLK signal and the specific data bit sequence signal are transmitted to the lens sleep state signal control unit 2102 as a lens activation signal.

[0137] The lens sleep state signal control unit 2102 activates the lens control unit 2101 in response to detecting a change in at least one of the signals on the LCLK line and the DCL line when the interchangeable lens 10′ is in the sleep state. This causes the interchangeable lens 10′ to transition to the normal state. Thereafter, the lens first communication unit 115 cancels the low output of the DLC line at time Tlc2. Further thereafter, the lens first communication unit 115 outputs a low signal to the LCLK line for a predetermined time Tbusy, and cancels the low output when the predetermined time Tbusy has elapsed. After this, the first communication shown in FIG. 3B can be performed between the camera control unit 2201 and the lens control unit 2101.

[0138] This process makes it possible to transition only the interchangeable lens 10' to the normal state using the first communication channel 100 in response to the lens operation member 118 of the interchangeable lens 10' in the sleep state being operated.

[0139] Next, the process in which the camera 20' transitions the adapters 30', 40' from the normal state to the sleep state and then transitions the adapters 30', 40' back to the normal state will be described using the flowchart in Figure 10. The normal state of the adapters 30', 40' refers to a state in which the adapters 30', 40' are performing third communication and the camera 20' can control the drive of the movable optical members of the imaging optical system of the interchangeable lens 10'. The sleep state of the adapters 30', 40' refers to a state in which the adapters 30', 40' have stopped third communication and are consuming less power than in the normal state.

[0140] The camera control unit 2201 starts processing in S1001, and in S1002 acquires the camera operation data and lens operation data described in the first embodiment. Then, the process proceeds to S1003.

[0141] In S1003, the camera control unit 2201 determines whether or not a predetermined time has elapsed during which no change has occurred in the camera operation data or lens operation data. In other words, it determines whether or not a predetermined time has elapsed during which the operation members 207, 118 of the camera 20' or the interchangeable lens 10' have not been operated by the user. If the predetermined time has elapsed, the camera control unit 2201 proceeds to S1004; otherwise (if an operation has been performed), the camera control unit 2201 repeats the processing of S1003. The predetermined time is a time sufficient to determine that the user has not performed any operation for capturing an image, and is, for example, several seconds.

[0142] In S1004, the camera control unit 2201 transmits a command requesting transition to a sleep state to the adapter control units 2301 and 2401 via the camera third communication unit 209 (and the adapter third communication units 310 and 410). Then, the process proceeds to S1005.

[0143] In S1005, the adapter control units 2301 and 2401 respectively put the adapters 30' and 40' into a sleep state. In the sleep state adapters 30' and 40', only the adapter sleep state signal control units 2302 and 2402 operate.

[0144] Next, in S1006, the camera control unit 2201 again acquires camera operation data and lens operation data, and then proceeds to S1007.

[0145] In S1007, the camera control unit 2201 determines whether there is a change in the camera operation data or lens operation data acquired in S1002 and S1006. In other words, it determines whether the operation members 207, 118 of the camera 20' or interchangeable lens' have been operated by the user. If the camera control unit 2201 determines that an operation has been performed, it proceeds to S1008; otherwise (if no operation has been performed), it repeats the determination of S1007.

[0146] In S1008, the camera control unit 2201 outputs an adapter activation signal to the third communication channel 300 via the camera sleep state signal control unit 2202. The process of outputting the adapter activation signal to the third communication channel 300 is similar to the process of outputting the lens activation signal to the first communication channel 100 described above.

[0147] Next, in S1009, the adapter sleep state signal controllers 2302 and 2402 activate the adapter controllers 2301 and 2401, respectively, and cause the adapters 30' and 40' to transition to the normal state, after which this process is terminated.

[0148] By this processing, the camera control unit 2201 can transition only the adapters 30' and 40' from the normal state to the sleep state, and from the sleep state to the normal state.

[0149] Furthermore, the process of transitioning the adapters 30', 40' from the sleep state to the normal state in response to the operation of the adapter operation members 312, 412 is the same as the method of transitioning the interchangeable lens 10' to the normal state in response to the operation of the lens operation member 118, as described above. That is, in response to the operation of the adapter operation members 312, 412 of the adapters 30', 40' that are in the sleep state, an adapter startup request signal is sent to the camera 20' using the third communication channel 300. Then, an adapter startup signal is transmitted from the camera 20' to the adapters 30', 40' using the third communication channel 300. This makes it possible to transition only the adapters 30', 40' from the sleep state to the normal state.

[0150] According to this embodiment, the camera 20' can transition between the normal state and the sleep state without depending on the state of the interchangeable lens 10' and the adapters 30' and 40'. This allows appropriate power control to be performed depending on the usage status and type of the interchangeable lens and adapter. For example, if the camera 20' is battery-powered, by putting only the adapter into the sleep state when the camera 20' detects that the battery power is low, the camera's shooting time can be extended as much as possible.

[0151] In the embodiment described above, a case has been described in which two adapters are placed between the interchangeable lens 10 and the camera 20, but the number of adapters is not limited to this. The present invention can be applied to an interchangeable lens, camera, and adapters that constitute a camera system in which at least one adapter can be placed between the interchangeable lens 10 and the camera 20. (Other Examples) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0152] The embodiments described above are merely representative examples, and various modifications and alterations are possible to each embodiment when implementing the present invention. [Explanation of symbols]

[0153] 114 Lens control unit 115 Lens 1st Communication Unit 116 Lens 2nd communication unit 117 Lens 3rd Communication Unit 205 Camera control unit 207 Camera 1st Communication Unit 208 Camera 2nd Communication Unit 209 Camera 3rd Communication Department 310,410 Adapter 3rd communication part 311,411 Adapter control unit

Claims

1. A device connectable to a camera, a first communication control unit that communicates with the camera using a first communication channel; a second communication control unit that communicates with the camera using a second communication channel that is provided separately from the first communication channel; an operation member operated by a user, the first communication channel includes a first data communication line and a second data communication line used during data communication, and a first notification line used for notifying timing of communication via the first data communication line and the second data communication line; the second communication channel is composed of only a third data communication line used during data communication and a second notification line used for notifying the timing of communication via the third data communication line, The device is characterized in that operation data of the operation member is transmitted via the third data communication line.

2. The device according to claim 1 , wherein the second communication control unit transmits device-specific information to the camera.

3. The device of claim 2 , wherein the unique information includes optical data of the device.

4. The device described in any one of claims 1 to 3, characterized in that the second communication control unit sets the voltage level of the second notification line to a first level while transmitting data in a first communication method, and sets the voltage level of the second notification line to a second level higher than the first level while transmitting data in a second communication method different from the first communication method.

5. The device described in claim 4, characterized in that the second communication control unit receives, in the first communication method, communication partner designation data indicating the communication partner of the camera in the second communication method from the camera via the third data communication line.

6. 6. The device according to claim 1, wherein the first communication control unit performs communication regardless of whether the second communication control unit is in communication or not.

7. An adapter device that can connect a camera and an interchangeable lens, a relay channel forming a part of a camera-lens communication channel for communication between the camera and the interchangeable lens; an adapter-camera communication control unit that communicates with the camera using a camera-adapter communication channel that is provided between the camera and the adapter and is separate from the relay channel; an operation member operated by a user, the camera-lens communication channel includes a first data communication line and a second data communication line used during data communication, and a first notification line used for notifying timing of communication via the first data communication line and the second data communication line; the camera-adapter communication channel is composed of only a third data communication line used during data communication and a second notification line used for notifying the timing of communication between the camera and the adapter device using the camera-adapter communication channel; The adapter device is characterized in that operation data of the operation member is transmitted through the third data communication line.

8. The adapter device described in claim 7, characterized in that the adapter-camera communication control unit is capable of switching the communication method with the camera between a first communication method used for communication between the interchangeable lens, the adapter device, and the camera, and a second communication method used for communicating individually with the camera, in which the voltage level of the second notification line while transmitting data to a communication partner is different from that of the first communication method.

9. The adapter device described in claim 8, characterized in that the adapter-camera communication control unit sets the voltage level of the second notification line to a first level while transmitting data in the first communication method, and sets the voltage level of the second notification line to a second level higher than the first level while transmitting data in the second communication method.

10. The adapter device described in claim 8 or 9, characterized in that the adapter-camera communication control unit receives, in the first communication method, communication partner designation data indicating the communication partner of the camera in the second communication method from the camera via the third data communication line.

11. 11. The adapter device according to claim 7, wherein the adapter-camera communication control unit transmits information specific to the adapter device to the camera.

12. The adapter device according to claim 11, wherein the unique information includes optical data of the adapter device.

13. An adapter device described in any one of claims 7 to 12, characterized in that the adapter-camera communication control unit communicates with the interchangeable lens via a lens-adapter communication channel provided between the interchangeable lens and the adapter and separate from the relay channel.

14. An adapter device according to any one of claims 7 to 13, characterized in that the adapter-camera communication control unit performs communication regardless of whether communication using the camera-lens communication channel is currently being performed.

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