Camera, camera system, and adapter device

Abstract

The present invention relates to a camera, a camera system, and an adapter device. It can speed up the communication between the camera and the interchangeable lens device and make the communication between the camera and the adapter device smooth. The camera includes: a lens-camera communication controller that is connected to the interchangeable lens device via at least one adapter device and communicates with the interchangeable lens device through a camera-lens communication channel that is connected from the camera to the interchangeable lens device via the adapter device; and an adapter-camera communication controller that communicates with the adapter device through a camera-adapter communication channel that is separately provided between the camera and the adapter device 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.

Description

[0001] (This application is a divisional application of an application with an application date of May 30, 2018, an application number of 2018800363603, and an invention title of "Camera, Interchangeable Lens Device, Adapter Device, Control Method, and Storage Medium".) Technical Field

[0002] The present invention relates to a camera system including a camera, an interchangeable lens device (hereinafter simply referred to as an interchangeable lens) capable of communicating with each other, and an adapter device (hereinafter simply referred to as an adapter) located between the camera and the interchangeable lens. Background Art

[0003] In an interchangeable lens type camera system including a camera to which an interchangeable lens is detachably attached, communication is performed for the camera to control the operation of the interchangeable lens and for the interchangeable lens to provide the camera with data required for control and imaging of the interchangeable lens. In particular, when imaging a recording moving image and a live view display moving image using an interchangeable lens, smooth lens control is required at an imaging cycle, and thus it is necessary to synchronize the imaging timing of the camera and the control timing of the interchangeable lens. Therefore, the camera needs to complete data reception from the interchangeable lens and transmission of commands such as various instructions and requests to the interchangeable lens within the imaging cycle. However, as the amount of data received by the camera from the interchangeable lens increases or the imaging cycle becomes shorter (or the frame rate becomes higher), it is necessary to perform a large amount of data communication at a higher speed.

[0004] An adapter such as a wide-angle magnifier or a teleconverter (doubler) can be installed between the camera and the interchangeable lens. In this case, command transmission from the camera to the interchangeable lens and data transmission from the interchangeable lens to the camera are performed via the adapter. In addition, in order to achieve appropriate AF, AE, etc. in the camera, not only data related to the interchangeable lens but also data inherent to the adapter are required. The camera system disclosed in Patent Document 1 performs command transmission from the camera to the adapter and data transmission from the adapter to the camera through a communication channel common to the communication channels for command transmission from the camera to the interchangeable lens and data transmission from the interchangeable lens to the camera. In other words, one communication channel is used to achieve one-to-many communication among the camera, the interchangeable lens, and the adapter.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-037692 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, in one-to-many communication using only a single communication channel, for example, during data transmission from an adapter to a camera, the camera cannot send a command to or receive data from a replaceable lens. As a result, fast communication between the camera and the replaceable lens is hindered.

[0010] The present invention provides a camera, a replaceable lens device, and an adapter device that can each speed up communication between a camera and a replaceable lens device and facilitate communication between the camera and an adapter device.

[0011] Solutions for Solving the Problems

[0012] A camera according to one aspect of the present invention, wherein a replaceable lens device is connected to the camera via at least one adapter device, the camera comprising: a lens-camera communication controller configured to communicate with the replaceable lens device through a camera-lens communication channel that connects the camera to the replaceable lens device via the adapter device; and an adapter-camera communication controller configured to communicate with the adapter device via a camera-adapter communication channel that is separately provided from the camera-lens communication channel between the camera and the adapter device, wherein the camera-lens communication channel includes a first data communication channel used during data communication and a first notification channel for notifying the timing of communication via the first data communication channel, and wherein the camera-adapter communication channel includes a second data communication channel used during data communication and a second notification channel for notifying the timing of communication via the second data communication channel.

[0013] A camera system including the above-described camera, a replaceable lens connected to the camera, and an adapter device connected to the camera and the replaceable lens also constitutes another aspect of the present invention.

[0014] An adapter device according to another aspect of the present invention, to which a camera and a replaceable lens are connected, the adapter device comprising: a relay channel for forming part of a camera-lens communication channel for communication between the camera and the replaceable lens; and an adapter-camera communication controller configured to communicate with the camera via a camera-adapter communication channel that is separate from the relay channel and is provided between the adapter and the camera, wherein the camera-lens communication channel includes a first data communication channel used during data communication and a first notification channel for notifying the timing of communication via the first data communication channel, and wherein the camera-adapter communication channel includes a second data communication channel used during data communication and a second notification channel for notifying the timing of communication via the second data communication channel.

[0015] A replaceable lens device according to another aspect of the present invention, which is connected to an adapter device and connected to a camera via the adapter device, the replaceable lens device comprising: a first lens-camera communication controller configured to communicate with the camera via a camera-lens communication channel that is connected from the camera to the replaceable lens via the adapter device; and a second lens-camera communication controller configured to communicate with the camera via a communication channel including a camera-adapter communication channel that is separate from the camera-lens communication channel and is connected to the camera and the adapter, wherein the first camera-lens communication channel includes a first data communication channel used during data communication and a first notification channel for notifying the timing of communication via the first data communication channel, and wherein the communication channel including the camera-adapter communication channel includes a second data communication channel used during data communication and a second notification channel for notifying the timing of communication via the second data communication channel.

[0016] A control method for a camera, the camera being connected to a replaceable lens device via at least one adapter device, the control method comprising the steps of: communicating with the replaceable lens device via a camera-lens communication channel that is connected from the camera to the replaceable lens device via the adapter device, and communicating with the adapter device via a camera-adapter communication channel that is provided separately from the camera-lens communication channel between the camera and the adapter device; and using the data obtained by communicating with the replaceable lens device to control the operation of the replaceable lens, and using the data obtained by communicating with the adapter device to control the operation of the adapter device, wherein the camera-lens communication channel includes a first data communication channel used during data communication and a first notification channel for notifying the timing of communication via the first data communication channel, and wherein the camera-adapter communication channel includes a second data communication channel used during data communication and a second notification channel for notifying the timing of communication via the second data communication channel.

[0017] The imaging control program as a computer program for executing the above control method also constitutes another aspect of the present invention.

[0018] Effects of the Invention

[0019] The present invention can implement a camera, a replaceable lens device, and an adapter device that can each speed up the communication between the camera and the replaceable lens device and make the communication between the camera and the adapter device smooth. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a block diagram showing the structure of a camera system according to a first embodiment of the present invention.

[0021] Figure 2 is a flowchart showing the lens control process according to the first embodiment.

[0022] Figure 3 is a diagram for explaining the first communication according to the first embodiment.

[0023] Figure 4 is a flowchart showing the adapter information acquisition process according to the first embodiment.

[0024] Figure 5 is a diagram for explaining the data occupancy status of each communication according to the first embodiment.

[0025] Figure 6 is a block diagram showing the structure of a camera system according to a second embodiment of the present invention.

[0026] Figure 7 is a flowchart showing the lens control process according to the second embodiment.

[0027] Figure 8 is a diagram for explaining the first communication when a detachable lens is started from a camera according to the second embodiment.

[0028] Figure 9 is a diagram for explaining the first communication when the detachable lens is started from the detachable lens according to the second embodiment.

[0029] Figure 10 is a flowchart showing the adapter control process according to the second embodiment.

[0030] Figure 11 is a diagram for explaining the second communication according to the first embodiment.

[0031] Figure 12 is a diagram for explaining the third communication (one-to-many) according to the first embodiment.

[0032] Figure 13 is a diagram for explaining the third communication (one-to-one) according to the first embodiment. DETAILED DESCRIPTION

[0033] Now, with reference to the accompanying drawings, a description of an embodiment according to the present invention will be given.

[0034] First Embodiment

[0035] Figure 1 shows the structure of a camera system according to the first embodiment of the present invention. The camera system includes a camera 20, a detachable lens device (hereinafter referred to as a detachable lens) 10, and two adapter devices (hereinafter referred to as adapters) 30 and 40 provided between the camera 20 and the detachable lens 10. The camera system has a first communication camera-lens communication channel 100 (hereinafter referred to as the first communication channel 100) for sending commands used for instructions and requests from the camera 20 to the detachable lens 10. In addition, the camera system includes a second communication lens-camera communication channel (hereinafter referred to as the second communication channel 200) separate from the communication channel 100 for sending data indicating optical data, status, etc. from the detachable lens 10 to the camera 20. The camera system further includes a third communication camera-adapter communication channel (hereinafter referred to as the third communication channel 300) for communicating data indicating commands, optical data of each adapter, status, etc. between the camera 20 and the two adapters 30 and 40.

[0036] The interchangeable lens 10 has an imaging optical system that includes a plurality of movable optical elements such as lenses and an aperture stop or diaphragm (variable aperture). The camera 20 includes an image sensor 204 for photographing a subject image formed by the imaging optical system, and generates an image signal using an output signal from the image sensor 204. The adapter 40 is detachably connected (attached) to the attachment member 201 of the camera 20 at the attachment member 402. The adapter 30 is detachably connected to the attachment member 401 of the adapter 40 at its attachment member 302. The adapter 30 includes a teleconverter or a wide-angle converter, etc., and the adapter 40 includes an ND adapter, etc., and includes adapter optical elements 309 and 409 such as a zoom lens and an ND filter, respectively. Further, the interchangeable lens 10 is detachably connected to the attachment member 301 of the adapter 30 at its attachment member 101.

[0037] When the attachment members 101, 301, 302, 401, 402, and 201 are all connected together, first communication contacts 102, 303, 306, 403, 406, and 202 provided to the respective attachment members are electrically connected to each other, and a camera-lens communication channel is formed for first communication. The first communication is for communication used by the camera 20 to control the operation of the movable optical elements of the interchangeable lens 10.

[0038] When the mounting members 101, 301, 302, 401, 402, and 201 are all connected together, the second communication contacts 103, 304, 307, 404, 407, and 202 provided to the respective mounting members are electrically connected to each other, and a camera-lens communication channel for second communication is formed. The second communication is used to send optical data of the interchangeable lens 10 (hereinafter referred to as lens optical data) and data indicating the state of the interchangeable lens 10 (hereinafter referred to as lens state data) to the camera 20. Further, by connecting the mounting members 101, 301, 302, 401, 402, and 201, the third communication contacts 104, 305, 308, 405, 408, and 203 provided to the respective mounting members are electrically connected to each other to form a camera-adapter communication channel for third communication. The third communication is a one-to-many communication between the camera 20 and the two adapters 30 and 40. The third communication is used for the camera 20 to send commands for controlling the operations of the adapters 30 and 40 to the adapters 30 and 40. Further, the third communication is used to send the optical data of the adapter optical elements 309 and 409 and operation data indicating user operations on the adapters 30 and 40 from the adapters 30 and 40 to the camera 20. In the following description, the optical data of the respective adapters 30 and 40 are referred to as first adapter optical data and second adapter optical data. The operation data of the respective adapters 30 and 40 are 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 and 40.

[0039] In the interchangeable lens 10, the movable optical elements in the above-described imaging optical system include a focusing lens 105, a zoom lens 106, a diaphragm 107, and an image stabilization lens 108. The focusing lens 105 moves in the optical axis direction of the imaging optical system to perform focusing. The zoom lens 106 moves in the optical axis direction to perform zooming. The diaphragm 107 adjusts the amount of light. The image stabilization lens 108 moves (shifts) in a direction perpendicular to the optical axis direction to reduce blurring of the subject image caused by camera shake due to hand shake or the like.

[0040] The focus controller 109 includes a focus actuator for moving the focus lens 105, a focus driver for controlling the drive of the focus lens 105, and a focus position sensor for detecting the position of the focus lens 105. The zoom controller 110 includes a zoom adapter for moving the zoom lens 106, a zoom driver for controlling the drive of the zoom lens 106, and a zoom position sensor for detecting the position of the zoom lens 106. The aperture controller 111 includes an aperture driver for driving an aperture motor provided to the aperture 107 and an aperture position sensor for detecting the open / closed position (F value or aperture value) of the aperture 107. The image stabilization controller 112 includes an image stabilization actuator for shifting the image stabilization lens 108, an image stabilization driver for controlling the drive of the image stabilization lens 108, and a shift position sensor for detecting the shift position of the image stabilization lens 108.

[0041] The shake detector 113 includes a vibration gyroscope or the like, and detects the camera shake amount that is the shake amount of the interchangeable lens 10 (or the camera system).

[0042] The lens controller 114 controls the operations of the focus lens 105, the zoom lens 106, and the aperture 107 through the focus controller 109, the zoom controller 110, and the aperture controller 111 according to a lens control command received from the camera controller 205 in the camera 20. The lens controller 114 controls the operation (shift) of the image stabilization lens 108 through the image stabilization controller 112 in response to receiving the lens control command. The lens controller 114 sends lens optical data and lens status data to the camera controller 205. The lens controller 114 communicates with the camera controller 205 through the first lens communicator 115 and the second lens communicator 116, and communicates with the adapters 30 and 40 through the third lens communicator 117.

[0043] The first lens communicator 115 and the lens controller 114 together constitute a camera-lens communication controller, and perform a first communication with the camera controller 205. The first communication is for receiving commands such as lens control commands from the camera controller 205.

[0044] The second lens communicator 116 performs a second communication with the camera controller 205. The second communication is for sending lens optical data and lens status data to the camera controller 205. The third lens communicator 117 and the lens controller 114 together constitute an adapter-lens communication controller, and perform a third communication with the third adapter communicators 310 and 410 in the adapters 30 and 40. The third communication with the third adapter communicators 310 and 410 is also for sending lens optical data and lens status data from the lens controller 114 to the adapter controllers 311 and 411.

[0045] The lens controller 114 and the first to third lens communicators 115 to 117 include a computer such as a CPU provided in the interchangeable lens 10. The lens operation member 118 is an operation member operated by a user in the interchangeable lens 10, and includes a switch, an electronic ring, or the like.

[0046] In the camera 20, the image sensor 204 includes a CMOS image sensor or the like, and performs photoelectric conversion (shooting) on the subject image. The camera controller 205 converts the output signal from the image sensor 204 into an image signal, and outputs the image signal to the image display unit 206.

[0047] In addition, the camera controller 205 sends a lens control command to the lens controller 114 to control the operation of the interchangeable lens 10, and receives lens optical data and lens status data from the lens controller 114. The camera controller 205 communicates with the lens controller 114 through the first camera communicator 207 and the second camera communicator 208, and communicates with the adapters 30 and 40 through the third camera communicator 209.

[0048] The first camera communicator 207 and the camera controller 205 together constitute a lens-camera communication controller, and perform first communication with the first lens communicator 115. As described above, the first communication is used to send a command such as a lens control command from the camera controller 205 to the lens controller 114, or to send data from the lens controller 114 to the camera controller 205. The second camera communicator 208 performs second communication with the first lens communicator 115. As described above, the second communication is used to receive lens optical data and lens status data from the lens controller 114.

[0049] The third camera communicator 209 and the camera controller 205 together constitute an adapter-camera communication controller, and perform third communication with the third adapter communicators 310 and 410. The third communication is used to send an adapter control command and an adapter transmission request command (a command for requesting transmission of adapter-specific information) to the adapter controllers 311 and 411. In addition, the third communication is used to receive adapter-specific information from the adapter controllers 311 and 411. The adapter-specific information includes, for example, first adapter optical data and second adapter optical data, and first adapter operation data and second adapter operation data. The camera controller 205 and the first to third camera communicators 207 to 209 include a computer such as a CPU provided in the camera 20. In the first communication and the third communication, at least one of the communication method, communication timing, communication speed (communication rate), and communication voltage is different from each other.

[0050] The image display unit 206 includes a liquid crystal monitor or the like, and displays an image signal (captured image) from the camera controller 205. The camera operation member 210 is an operation member that is operated by a user in the camera 20 to set imaging conditions, and includes a dial or a switch or the like.

[0051] In the adapters 30 and 40, the above-described adapter optical elements 309 and 409 are optical elements for adding a specific optical effect to the interchangeable lens 10, and include a zoom lens or an ND filter or the like. In the present embodiment, the adapter 30 is a teleconverter having a zoom lens as the adapter optical element 309, and the adapter 40 is an ND adapter having an ND filter as the adapter optical element 409. The adapter optical element may be a member other than a zoom lens or an ND filter.

[0052] The adapter controllers 311 and 411 control the operations of the adapters 30 and 40 (insertion into and withdrawal from the imaging optical paths of the zoom lens and the ND filter) according to the adapter control commands received from the camera controller 205.

[0053] The adapter controllers 311 and 411 communicate with the camera controller 205 and the lens controller 114 via the third adapter communicators 310 and 410. The third adapter communicators 310 and 410, together with the adapter controllers 311 and 411, constitute a camera-adapter communication controller and a lens-adapter communication controller, and perform third communication with the third camera communicator 209 and the third lens communicator 117. As described above, the third communication with the third camera communicator 209 is for receiving the adapter control command and the adapter request command from the camera controller 205 and sending the first adapter optical data and the second adapter optical data to the camera controller 205. As described above, the third communication with the third lens communicator 117 is for receiving the lens optical data and the lens status data from the lens controller 114.

[0054] The adapter controller 311 and the third adapter communicator 310 include a CPU provided in the adapter 30. The adapter controller 411 and the third adapter communicator 410 include a computer such as a CPU provided in the adapter 40.

[0055] The adapter operation members 312 and 412 are operation members in the adapters 30 and 40 that are operated by the user, and include switches, electronic rings, and the like. Here, predetermined functions are assigned to the operations of the adapter operation members 312 and 412. Optionally, functions preferred by the user are assigned by a setting unit (not shown) of the camera 20. Example functions of the operations of the adapter operation members 312 and 412 include, for example, the following. When the adapter operation members 312 and 412 are switches, these functions are at least one of ON / OFF of the image stabilization function, setting of the image stabilization level of the image stabilization function, and switching between autofocus and manual focus. When the adapter operation members 312 and 412 are electronic rings, the functions of the adapter operation members 312 and 412 are at least one of an adjustment function of the aperture position (aperture diameter) of the interchangeable lens 10, an adjustment function of the focus position, and an adjustment function of the zoom position. The aperture position, the focus position, and the zoom position are adjusted in the lens 10 by an adjustment amount corresponding to the operation amount of the electronic ring.

[0056] Now referring to Figure 2 the flowchart in, a description will be given of the process of controlling the interchangeable lens 10 (lens controller 114) by the camera 20 (camera controller 205). The camera controller 205 and the lens controller 114 each execute this process (and each process described later) according to a shooting control program that is a computer program.

[0057] When the camera 20 is started in S201, the camera controller 205 proceeds to S202. In step S202, the camera controller 205 supplies power to the interchangeable lens 10 and the adapters 30 and 40 via a power supply mounting contact (not shown).

[0058] In step S203, the camera controller 205 causes the first camera communicator 207 to detect the communication voltage used by the interchangeable lens 10, and sets the communication voltages used by the first camera communicator 207 and the second camera communicator 208 based on the detection result. Thereafter, the first camera communicator 207 and the second camera communicator 208 perform first communication and second communication with the first lens communicator 115 and the second lens communicator 116, respectively, using the set communication voltages. The process of the first camera communicator 207 detecting the communication voltage of the interchangeable lens 10 will be described later.

[0059] Next, in S204, the lens controller 114 sends ID information (hereinafter referred to as lens ID) such as the lens name and lens specifications of the interchangeable lens 10 to the camera controller 205 through the first lens communicator 115 (and the first camera communicator 207). The camera controller 205 receives the lens ID via the first camera communicator 207. The lens controller 114 sends lens status data indicating the current state (lens state) of the interchangeable lens 10 to the camera controller 205 through the second lens communicator 116 (and the second camera communicator 208). The camera controller 205 receives the lens status data via the second camera communicator 208.

[0060] The lens status data includes the current positions of the focus lens 105, the zoom lens 106, the aperture 107, and the image stabilization lens 108 (hereinafter referred to as optical element positions) (hereinafter referred to as lens image data) obtained from the focus controller 109, the zoom controller 110, the aperture controller 111, and the image stabilization controller 112. The lens status data includes a value obtained by normalizing the camera shake amount obtained from the shake detector 113, and lens operation data indicating the operation amount and operation state of the user operation obtained from the lens operation member 118. When the lens operation member 118 is an electronic ring, the operation amount per unit time of the electronic ring can be included in the lens operation data. If the lens operation member 118 is a switch, the ON / OFF state of the switch can be included in the lens operation data.

[0061] Next, in S205, the camera controller 205 determines the lens status data received from the lens controller 114 through the second communication based on the lens status data obtained in S204. Then, a command requesting the determined lens status data is sent to the lens controller 114 via the first camera communicator 207 (and the first lens communicator 115).

[0062] In step S206, the lens controller 114 determines the lens status data indicating the current lens state to be sent to the camera controller 205 based on the command received from the camera controller 205 via the first lens communicator 115 in step S205.

[0063] Next, in S207, the lens controller 114 sends the determined lens status data to the camera controller 205 through the second lens communicator 116 (and the second camera communicator 208).

[0064] In step S208, the camera controller 205 determines imaging conditions based on the lens state data received from the lens controller 114 via the second camera communicator 208, the zoom ratio of the adapter (teleconverter) 30, and the transmittance of the adapter (ND adapter) 40. Then, imaging is performed under the imaging conditions. The imaging conditions include the subject distance, focal length, F value, T value, the amount of camera shake per unit time, and the shake correction angle for image stabilization (the displacement amount of the image stabilization lens 108). The camera controller 205 displays the generated captured image and numbers, symbols, marks, icons, etc. indicating the imaging conditions superimposed on the captured image on the image display unit 206. A method for the camera controller 205 to obtain the zoom ratio and transmittance of the adapters 30 and 40 will be described later.

[0065] In step S209, the camera controller 205 obtains operation data indicating a user operation on the camera operation member 210 (hereinafter referred to as camera operation data), and obtains first adapter operation data and second adapter operation data from the adapter operation members 312 and 412. The camera operation data is data indicating exposure (F value, shutter speed, etc.) and zoom position settings performed by operating a dial or an electronic ring, and an instruction for AF / image stabilization execution / stop by operating a switch, etc. The first adapter operation data and the second adapter operation data will be described later. In addition, a process for the camera controller 205 to obtain the first adapter operation data and the second adapter operation data will be described later.

[0066] In step S210, the camera controller 205 determines lens control data based on the lens state data obtained in step S207, and the camera operation data, the first adapter operation data, and the second adapter operation data obtained in step S209. More specifically, the camera controller 205 obtains a phase difference from the phase difference sensor provided in the image sensor 204 in response to the turning on of a switch indicating the execution of AF, and uses the phase difference to calculate the defocus amount of the imaging optical system. In addition, the camera controller 205 determines the driving amount of the focusing lens 105 for obtaining a focused state based on the calculated defocus amount. The camera controller 205 determines the driving amount of the zoom lens 106 based on data indicating the operation amount of the dial or the electronic ring. In addition, the camera controller 205 determines the driving amount of the aperture 107 based on the exposure setting value set by operating the dial and the luminance level of the image signal generated using the output from the image sensor 204. In addition, the camera controller 205 determines whether the image stabilization lens 108 can be driven based on the turning on and off of a switch indicating the execution and stop of image stabilization.

[0067] In this manner, the camera controller 205 determines lens control data including the driving amounts of the focusing lens 105, the zoom lens 106, and the aperture 107, and whether image stabilization is available.

[0068] Next, in S211, the camera controller 205 sends a lens control command including the lens control data to the lens controller 114 via the first camera communicator 207 (and the first lens communicator 115).

[0069] Next, in S212, the lens controller 114 passes the lens control data included in the received lens control command to the focus controller 109, the zoom controller 110, and the aperture controller 111. The focus controller 109, the zoom controller 110, and the aperture controller 111 drive the focusing lens 105, the zoom lens 106, and the aperture 107 according to the lens control data. The lens controller 114 notifies the image stabilization controller 112 whether image stabilization is available in the lens control data. When image stabilization is permitted, the image stabilization controller 112 shifts the image stabilization lens 108 according to the amount of camera shake detected by the shake detector 113 to reduce image shake.

[0070] As described above, in the initial communication between the camera 20 and the interchangeable lens 10 (when the system is started), lens inherent information such as the name, specifications, and lens correction data of the interchangeable lens 10 is communicated. During subsequent system startups, data of the imaging optical system of the interchangeable lens 10 indicating the state including the focal length and the focus position, data indicating the content of the operation performed by the user on the camera 20, and the above-mentioned lens control data, etc. are communicated at a predetermined timing.

[0071] Now referring to Figure 3 (a) and 3(b), a description will be given of the process of the first camera communicator 207 detecting the communication voltage of the interchangeable lens 10 and the communication process in the first communication.

[0072] Figure 3 (a) shows the structure of the first communication channel 100 for performing the first communication. In order to form the first communication channel 100 connecting from 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 have the following terminals.

[0073] 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.

[0074] The first communication LCLK terminals 102a, 303a, 306a, 403a, 406a, and 202a are provided to form a line for a clock signal LCLK output from the first camera communicator 207 (hereinafter referred to as the LCLK line). The first communication DCL terminals 102b, 303b, 306b, 403b, 406b, and 202b are also provided to form a line for a camera data signal DCL output from the first camera communicator 207 (hereinafter referred to as the DCL line). In addition, the first communication DLC terminals 102c, 303c, 306c, 403c, 406c, and 202c are also provided to form a lens data signal DLC line (hereinafter referred to as the DLC line) output from the first lens communicator 115. Each of the DLC line and the DCL line corresponds to a first data communication channel used during data communication. The LCLK line corresponds to a first notification channel for notifying the timing of communication via the DCL line or the DLC line. The first communication is not limited to the clock synchronization communication described later and can be performed by asynchronous communication.

[0075] The TYPE terminals 102d, 303d, 306d, 403d, 406d, and 202d are also provided to form a replaceable lens type detection signal TYPE line (hereinafter referred to as the TYPE line) for detecting the communication voltage of the replaceable lens 10. 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.

[0076] As Figure 3 (a) shows, in the replaceable lens 10, the LCLK line and the DCL line are pulled up. In the camera 20, the LCLK line and the DLC line are pulled up.

[0077] The LCLK line, DCL line, DLC line, and TYPE line in the adapters 30 and 40 are short-circuited between the first communication contacts 303 and 306 and between the first communication contacts 403 and 406, respectively.

[0078] The TYPE line is pulled down by a predetermined resistance value for each communication voltage in the interchangeable lens 10 and is pulled up by a predetermined resistance value in the camera 20. The first camera communicator 207 detects the voltage value of the TYPE line and designates the communication voltage of the interchangeable lens 10 based on the voltage value determined according to the resistance value in the interchangeable lens 10 and the resistance value in the camera 20.

[0079] Figure 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 is referred to as the LCLK signal, the camera data signal DCL transmitted and received through the DCL line is referred to as the DCL signal, and the lens data signal DLC transmitted and received through the DLC line is referred to as the DLC signal.

[0080] The first camera communicator 207 outputs the LCLK signal to the LCLK line and outputs eight-bit data B7 to B0 as the DCL signal to the DCL line in synchronization with the rising edge of the LCLK signal. The first lens communicator 115 outputs eight-bit data B7 to B0 as the DLC signal to the DLC line in synchronization with the rising edge of the LCLK signal.

[0081] The first camera communicator 207 receives eight-bit (B7 to B0) data from the DLC line in synchronization with the rising edge of the LCLK signal. The first lens communicator 115 receives eight-bit (B7 to B0) data from the DCL line in synchronization with the rising edge of the LCLK signal. Thus, the first camera communicator 207 and the first lens communicator 115 can communicate data with each other.

[0082] When receiving eight-bit data from the DCL line, the first lens communicator 115 sets the voltage level of the LCLK line to low for a predetermined time Tbusy and releases the low level when the predetermined time Tbusy has elapsed. In other words, the first lens communicator 115 sets the voltage level to high. The predetermined time Tbusy is the time for processing the data received by the lens controller 114, and during this time, the first camera communicator 207 does not send data to the first lens communicator 115. By repeating this communication process, multiple bytes of data communication are performed between the first camera communicator 207 and the first lens communicator 115 through the first communication.

[0083] In the second communication, the one-way communication from the interchangeable lens 10 to the camera 20 can be performed by the same clock-synchronized communication as the first communication, or can be performed by asynchronous communication. The third communication can be performed by synchronous communication or asynchronous communication, such as by a master-slave method or a token passing method, as two-way communication between the camera 20 and the adapters 30 and 40 and between the interchangeable lens 10 and the adapters 30 and 40.

[0084] Figure 11 (a) shows an example of a communication format of asynchronous communication performed in the second communication on the second communication channel 200. Here, one frame is shown as an exemplary format of data to be communicated, and the frame includes ten bits or one start bit, eight data bits, and one end bit. The data bits can be seven bits or sixteen bits and can include parity bits. The end bit can have two bits.

[0085] Figure 11 (b) shows a timing synchronization method of asynchronous communication in the second communication. The camera controller 205 (and the second camera communicator 208) and the lens controller 114 (and the second lens communicator 117) send and receive data in synchronization with an internal clock according to a predetermined clock frequency or clock rate. For example, the internal clock is set to a clock rate 16 times higher than the communication rate between the camera controller 205 and the lens controller 114. As shown by the synchronization timing in the figure, the starting point of data sampling is determined by sampling the falling edge of the start bit of the data received in synchronization with the internal clock. As shown by the data sampling timing in the figure, the data is latched at the position of eight clocks starting from this synchronization timing. Thus, the data can be captured at the center of each bit. By performing this data sampling on each bit, data communication is performed using only one second communication line (lens-camera transmission channel: DLC2).

[0086] 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 to send commands for instructing a transition to a power saving mode from the camera controller 205 to the adapter controllers 311 and 411 and the lens controller 114. Here, the power saving mode is a mode in which the power consumption is lower than that in normal operation. For example, the power saving mode is a mode in which data transmission and reception are prohibited, and driving of movable optical elements and optical elements 309 and 409 in the imaging optical system is prohibited. In addition, the third communication channel 300 is also used to send commands for indicating a communication partner in one-to-one communication. The third communication channel 300 is also used to send information inherent to the adapter controllers 30 and 40 to the camera controller 205. The information inherent to the adapter controllers 30 and 40 will be described later.

[0087] Now refer to Figure 12 andFigure 13 Asynchronous communication using the third communication channel 300 will be described. The third communication channel 300 includes two signal lines, namely, a notification channel CS for communicating communication timing and a data communication channel DATA for transmitting 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 for notifying the timing of communication via the data communication channel DATA.

[0088] Figure 12 The communication waveform of the asynchronous communication performed in the third communication of the third communication channel 300 is shown. In particular, Figure 12 An exemplary one-to-many communication in which data can be simultaneously transmitted from a device on the data transmission side to multiple devices on the data reception side is shown. More specifically, the camera 20 transmits data, and then the adapter 30 (or adapter 40) transmits data. Hereinafter, the communication performed by such one-to-many component elements will be referred to as broadcast communication.

[0089] Figure 12 An integrated signal output from two adapters 30 and 40 (adapter controllers 311 and 411) is shown.

[0090] When the camera controller 205, the adapter controller 311, the adapter controller 411, and the lens controller 114 are all configured to output high to the notification channel CS, the signal level of the notification channel CS becomes high. On the other hand, when at least one of the camera controller 205, the adapter controller 311, the adapter controller 411, and the lens controller 114 outputs low to the notification channel CS, the signal level of the notification channel CS becomes low.

[0091] In the third communication, the communication speed is set in advance on both the data transmission side and the data reception side, and data communication is performed at a communication bit rate based on this setting. The communication bit rate represents the amount of data that can be transmitted per second, and its unit is bps (bits per second).

[0092] When no data communication is being performed, the signal level of the data communication channel DATA remains at a high level. Then, in order to notify the data reception side of the start of data transmission, the signal level of the data communication channel DATA is set to low and maintained for one bit period. This one bit period will be referred to as the start bit ST, and the data frame starts with the start bit ST. One byte of data is transmitted during the eight-bit period from the second bit to the ninth bit after the start bit ST.

[0093] The notification channel CS is connected to the camera controller 205, adapter controllers 311 and 411, and lens controller 114, and each controller 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 source (not shown) provided in the camera 20.

[0094] Each controller can set the signal level of the notification channel CS, and all controllers 205, 311, 411, and 114 set the signal level of the notification channel CS to high so that the signal level of the communication channel CS becomes high. Additionally, when one of the controllers sets the signal level of the notification channel CS to low, the signal level of the communication channel CS becomes low.

[0095] In the third communication, the camera controller 205 (and the third camera communicator 209) is used as the communication master device and the adapter controllers 311 and 411, and lens controller 114 are used as communication slave devices for communication.

[0096] The camera controller 205, as the communication master device, notifies the start of communication to the adapters 30 and 40 and the interchangeable lens 10, which are the communication slave devices, by outputting low to the notification channel CS. Then, the camera controller 205 transmits data to the adapters 30 and 40 and the interchangeable lens 10 via the data communication channel DATA. On the other hand, the adapter controllers 311 and 411 and the lens controller 114 output low to the notification channel CS in response to detecting the above-mentioned start bit ST via the data communication channel DATA. When the adapter controllers 311 and 411 and the lens controller 114 output low to the notification channel CS, the signal level of the notification channel CS remains low due to the camera controller 205 outputting low.

[0097] The adapter controllers 311 and 411 and the lens controller 114 notify a communication standby request by outputting low to the notification channel CS. The communication standby request is used to temporarily stop communication in the camera system, and the presence or absence of the communication standby request is determined based on the signal level of the notification channel CS.

[0098] After sending all the data, the camera controller 205 outputs high to the notification channel CS. After receiving the end bit SP sent from the data communication channel DATA, the adapter controllers 311 and 411 and the lens controller 114 perform analysis of the received data and internal processing corresponding to the received data. After that, after completing the preparation for the next communication, high is output to the notification channel CS.

[0099] When the signal level of the notification channel CS returns to high, the camera controller 205, the adapter controllers 311 and 411, and the lens controller 114 confirm that they are ready for the next communication.

[0100] In Figure 12 the data sent by the camera controller 205 includes transmission request commands for the adapter controllers 311 and 411, and after the adapter controllers 311 and 411 perform data transmission, the adapter controllers 311 and 411 provide data transmission. More specifically, after the signal level of the notification channel CS becomes high, the adapter controllers 311 and 411 output low to the notification channel CS. This notifies the start of communication to the lens controller 114 and the camera controller 205. Then, the adapter controllers 311 and 411 send data to the lens controller 114 and the camera controller 205 via the data communication channel DATA.

[0101] On the other hand, the lens controller 114 and the camera controller 205 output low to the notification channel CS in response to detecting the above-mentioned start bit ST via the data communication channel DATA. When the lens controller 114 and the camera controller 205 output low to the notification channel CS, the adapter controllers 311 and 411 output low to the notification channel CS, so the signal level of the notification channel CS remains low.

[0102] After sending all the data, the adapter controllers 311 and 411 output high to the notification channel CS. After receiving the end bit SP sent from the data communication channel DATA, the lens controller 114 and the camera controller 205 perform analysis of the received data and internal processing corresponding to the received data. Then, after completing the preparation for the next communication, high is output to the notification channel CS.

[0103] When the camera controller 205, the adapter controllers 311 and 411, and the lens controller 114 all output high to the notification channel CS, the signal level of the notification channel CS becomes high. When the signal level of the notification channel CS returns to high, the camera controller 205, the adapter controllers 311 and 411, and the lens controller 114 can confirm that they are ready for the next communication.

[0104] Figure 13 Shows the communication waveform of the asynchronous communication performed in the third communication of the third communication channel 300. Specifically, shows an example of communication between the camera 20 and one component (one of the interchangeable lens 10 and the adapters 30 and 40) selected by the camera 20 as the communication partner. Hereinafter, the communication performed by such one-on-one components will be referred to as P2P communication.

[0105] Information indicating a communication slave device that is a communication partner in P2P communication is transmitted from the camera controller 205 via broadcast communication. In P2P communication, the data transmission side does not output low to the notification channel CS, but transmits data to the data reception side while maintaining the notification channel CS at a high level. In other words, the voltage level of the notification channel CS during data transmission from the camera 20 to the interchangeable lens 10 and the adapter 30 is different between broadcast communication and P2P communication.

[0106] When the broadcast communication is switched to P2P communication, data transmission starts from the camera controller 205 which is the communication master device first.

[0107] Figure 13 An example is shown in which after one-byte data is transmitted from the camera controller 205 to the lens controller 114, two-byte data is transmitted from the lens controller 114 to the camera controller 205.

[0108] After the switching from broadcast communication to P2P communication is completed in each component constituting the camera system, the camera controller 205 which is the communication master device transmits data to the lens controller 114 via the data communication channel DATA. When the data transmission is completed, the camera controller 205 notifies a communication standby request by setting the signal level of the notification channel CS to a low output. Then, after the preparation for receiving data is completed for the data reception side, the camera controller 205 returns the signal level of the notification channel CS to a high output.

[0109] On the other hand, the lens controller 114 recognizes that the data transmission from the camera controller 205 is completed because 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 Figure 5 the example, the data received from the camera controller 205 includes a data transmission request from the lens controller 114 to the camera controller 205, and the lens controller 114 generates data to be transmitted to the camera controller 205.

[0110] After that, when the signal level of the notification channel CS returns to high, the lens controller 114 which has recognized the cancellation of the communication standby request transmits two-byte data to the camera controller 205.

[0111] When the data transmission ends, the lens controller 114 notifies a communication standby request by setting the signal level of the notification channel CS to a low output. Then, after the data reception preparation is completed for the data reception side, the lens controller 114 returns the signal level of the notification channel CS to a high output. The adapter microcomputer 302 that is not selected as the communication partner in P2P communication does not change the output to the notification channel CS or does not participate in data transmission / reception.

[0112] After returning the signal level of the notification channel CS to high, the lens controller 114 determines whether to continue the P2P communication or switch to the broadcast communication according to the data transmission timing from the camera controller 205.

[0113] The signal level of the notification channel CS during the data transmission by the camera controller 205 is made different between the broadcast communication and the P2P communication. When receiving data from the camera controller 205 while the signal level of the notification channel CS remains high (the second voltage level), the lens controller 114 determines that the P2P communication continues. On the other hand, when receiving data from the camera controller 205 after changing the signal level of the notification channel CS to the low level (the first voltage level), the lens controller 114 determines that the P2P communication has been switched to the broadcast communication.

[0114] As described above, in the P2P communication, the data transmission side changes the signal level of the notification channel CS from the high output to the low output to notify the data receiving side of the completion of data transmission by the data transmission side. Therefore, in the P2P communication, a plurality of data frames can be continuously transmitted until the data transmission side changes the signal level of the notification channel CS. Thereby, high-speed communication can be performed between the camera 20 and accessory devices such as the interchangeable lens 10, the adapter 30, and the microcomputer 302. Then, the data transmission side notifies the communication standby request by maintaining the low signal output level of the notification channel CS until the data receiving side in the next communication completes the data reception preparation.

[0115] Now referring to Figure 4 the flowchart in, the process in which the camera controller 205 acquires the magnification of the adapter optical element (zoom lens) 309, the transmittance of the adapter optical element (ND filter) 409, and the first adapter operation data and the second adapter operation data will be described.

[0116] S401 and S402 are the same as S201 and S202 in Figure 2 The camera controller 205 that enters S403 from S402 sends a command for requesting the adapter controller 311 to send the first adapter optical data, which is the optical data of the adapter optical element 309, via the third camera communicator 209 (and the third adapter communicator 310).

[0117] In step S404, the adapter controller 311 sends the first adapter optical data stored in the internal memory to the camera controller 205 via the third adapter communicator 310 (and the third camera communicator 209). The first adapter optical data is data indicating the magnification of the adapter optical element 309.

[0118] In step S405, the camera controller 205 sends, via the third camera communicator 209 (and the third adapter communicator 410), a command to the adapter controller 411 for requesting the adapter controller 411 to send second adapter optical data that is optical data of the adapter optical element 409.

[0119] In step S406, the adapter controller 411 sends, via the third adapter communicator 410 (and the third camera communicator 209), the second adapter optical data stored in the internal memory to the camera controller 205. The second adapter optical data is data indicating the transmittance of the adapter optical element 409.

[0120] Next, in step S407, the camera controller 205 sends, via the third camera communicator 209 (and the third adapter communicator 310), a command to the adapter controller 311 for requesting the adapter controller 311 to send first adapter operation data that is operation data of the adapter operation member 312.

[0121] Next, in S408, the adapter controller 311 acquires the operation amount and the operation state from the adapter operation member 312. Then, the data for indicating the operation amount and the operation state is sent as the first adapter operation data to the camera controller 205 via the third adapter communicator 310 (and the third camera communicator 209). When 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. When the adapter operation member 312 is a switch, the data indicates the ON / OFF state of the switch.

[0122] In step S409, the camera controller 205 sends, via the third camera communicator 209 (and the third adapter communicator 410), a command to the adapter controller 411 for requesting the adapter controller 411 to send second adapter operation data that is operation data of the adapter operation member 412 to the camera controller 205.

[0123] Next, in S410, the adapter controller 411 acquires the operation amount and the operation state from the adapter operation member 412. Then, the data for indicating the operation amount and the operation state is sent as the second adapter operation data to the camera controller 205 via the third adapter communicator 310 (and the third camera communicator 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 controller 205 can periodically acquire the operation data of the adapter operation member 312 and the adapter operation member 412.

[0124] For example, when the aperture position adjustment function is assigned to the adapter operation member 312, the camera 20 instructs the interchangeable lens 10 to change the aperture position via the first communication channel 100 according to the operation amount of the adapter operation member 412 acquired in S410. When the ON / OFF function of the image stabilization function is assigned to the adapter operation member 312, the camera 20 instructs the interchangeable lens 10 to turn on or off the image stabilization control via the first communication channel 100 according to the operation state (ON or OFF) of the adapter operation member 412 acquired in S410. The same applies to the adapter operation member 412. The user can control the state of the imaging optical system of the interchangeable lens 10 through the operations of the adapter operation members 312 and 412.

[0125] The above embodiments have described the magnification and transmittance of the adapter optical elements 309 and 409 as exemplary first adapter optical data and second adapter optical data.

[0126] Information inherent to the adapter 30 or the adapter 40 other than the first adapter optical data and the second adapter optical data can be communicated via the third communication channel 300. The information inherent to the adapter 30 can include, for example, at least one of the name and specifications of the adapter 30 and the correction data of the adapter optical element 309. Similarly, the information inherent to the adapter 40 can include, for example, at least one of the name and specifications of the adapter 40 and the correction data of the adapter optical element 409. For example, during the initial communication between the camera 20 and the adapter 30 and between the camera 20 and the adapter 40, at least one of the name, specifications, and correction data of the adapter optical elements 309 and 409 is sent to the camera 20.

[0127] In addition, when the state of the imaging optical system of the interchangeable lens 10 or the adapter optical elements 309 or 409, etc. changes, and thus the focal length information, light transmittance information, etc. change over time, the adapters 30 and 40 can send this updated data to the camera 20 in a normal state such as during ongoing imaging standby. With the above processing, the camera controller 205 can acquire the magnification and transmittance of the adapter optical elements 309 and 409 immediately after power-on, and periodically acquire the operation amount and operation state of the adapter operation members 312 and 412 from the start of power-on.

[0128] Now referring to Figure 5 (a) and (b), a description will be given of the occupancy status of the communication data in the first communication channel 100, the second communication channel 200, and the third communication channel 300. This description assumes that the lens control command, the lens state data, and the adapter operation data all have the same size.

[0129] Figure 5 (a) shows the occupancy status of communication data in the communication channel in a camera system as a comparative example having only one communication channel. The horizontal axis in the figure indicates time. Ta1, Ta2, Ta3, and Ta4 respectively indicate the transmission times of the lens control command, lens status data, first adapter operation data, and second adapter operation data. Ca1 and Ca2 respectively indicate the transmission intervals between the lens control commands and between the lens status data.

[0130] The lens transmission request command is a command (data) for the camera controller 205 to request the lens controller 114 to transmit the lens status data. The lens controller 114 transmits the lens status data to the camera controller 205 in response to receiving the lens transmission request data. The first adapter transmission request data and the second adapter transmission request command are data for the camera controller 205 to request the adapter controllers 309 and 409 to transmit the first adapter operation data and the second adapter operation data respectively. In response to receiving the first adapter transmission request data and the second adapter transmission request data, the adapter controllers 311 and 411 respectively transmit the first adapter operation data and the second adapter operation data to the camera controller 205.

[0131] In Figure 5 (a), since the lens control command, lens status data, and first adapter operation data and second adapter operation data are sequentially communicated in a single communication channel, the transmission interval Ca1 between the lens control data and the transmission interval Ca2 between the lens status data become longer. The adapter controllers 311 and 411 need to correspond to a communication speed that is the same as the communication speed with the lens controller 114 and the camera controller 205.

[0132] On the other hand, Figure 5 (b) shows the occupancy status of communication data in a camera system having a first communication channel, a second communication channel, and a third communication channel 300 according to the present embodiment. The horizontal axis in the figure indicates time. Tb1, Tb2, Tb3, and Tb4 respectively indicate the transmission times of the lens control command, lens status data, first adapter operation data, and second adapter operation data. Cb1 and Cb2 respectively indicate the transmission intervals between the lens control commands and between the lens status data.

[0133] As Figure 5As shown in (b), the lens control command, the lens status data, and the first adapter operation data and the second adapter operation data are communicated through communication channels different from each other. Thus, regardless of whether the camera controller 205 is performing the third communication with the adapter controllers 30 and 40, the camera controller 205 performs the first communication. In addition, since the lens control command, the lens status data, and the first adapter operation data and the second adapter operation data are communicated through communication channels different from each other, the transmission interval Cb1 between the lens control commands is sufficiently shorter than Figure 5 Ca1 shown in (a). Similarly, the transmission interval Cb2 between the lens status data is also sufficiently shorter than Cb1. Thus, the camera 20 can control the interchangeable lens 10 at a higher speed than Figure 5 the comparative example of (a).

[0134] In this embodiment, the devices connected to the first communication channel and the second communication channel 200 are limited to the camera 20 and the interchangeable lens 10. Thus, compared with the case where other devices (adapters) are connected to the communication channels of the camera 20 and the interchangeable lens 10 as in the comparative example, signal degradation due to reflection of signals to be communicated can be prevented. As a result, the communication speed between the camera 20 and the interchangeable lens 10 can be made higher than in the comparative example. Therefore, if the data size of the communication is the same, Tb1 and Tb2 are shorter than Ta1 and Ta2. In addition, since the devices connected to the second communication channel 200 are limited 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 the lens status data can be shortened.

[0135] In this embodiment, the transmission times Tb3 and Tb4 of the first adapter operation data and the second adapter operation data are longer than Tb3 and Tb4. By setting the communication rate of the third communication to be slower regardless of the communication rates of the first communication and the second communication, this eliminates the need for the adapters 30 and 40 to support high-speed communication.

[0136] In addition, in this embodiment, the lens control command, the lens status data, the first adapter operation data, and the second adapter operation data can be communicated at an arbitrary communication timing without being hindered by channel occupancy due to other data communication. For example, communication can be performed not only during the initial communication when the interchangeable lens and the adapters 30 and 40 are attached to the camera 20, but also during the imaging standby or the ongoing imaging operation in the camera 20.

[0137] As described above, in this embodiment, various commands and data are communicated between the camera 20, the interchangeable lens 10, and the adapters 30 and 40 at an appropriate communication timing without being hindered by other communications. Compared with the case where there is only one communication channel, various commands and data can be communicated more stably at short intervals, and the stability of interchangeable lens control, the operability of the adapters, etc. can be improved.

[0138] In addition, since only the camera 20 and the interchangeable lens 10 are connected to the first communication channel and the second communication channel 200, the first communication and the second communication can be made high-speed and high-functional, and the controllability of the interchangeable lens can be further improved. Further, when the camera 20 switches the communication voltage according to the communication voltage of the interchangeable lens 10, a plurality of interchangeable lenses having different communication voltages can be connected to the camera 20. In addition, by performing the third communication between the camera 20 and the adapters 30 and 40 separately from the first communication and the second communication, there is no need to use an adapter that matches the high communication speed of the camera 20 and the interchangeable lens 10. As described above, for example, a camera 20 that can mount both an old interchangeable lens and a new interchangeable lens can be realized, where the old interchangeable lens corresponds to the first communication having a high communication voltage and does not have contacts for the second communication and the third communication, and the new interchangeable lens corresponds to the first communication, the second communication, and the third communication having a low communication voltage in order to achieve low power consumption. In this case, since the new interchangeable lens can set a low communication voltage for the first communication and can communicate at the same voltage as the low communication voltages of the second communication and the third communication, the circuit cost for the new interchangeable lens can be reduced.

[0139] This embodiment has described that the adapters 30 and 40 communicate the first adapter operation data and the second adapter operation data to the camera 20 through the third communication. However, the interchangeable lens 10 can communicate data (such as lens operation data, etc.) related to the interchangeable lens 10 to the camera 20 via the third lens communicator 117, the third adapter communicator 310, and the third camera communicator 209.

[0140] In addition, an interchangeable lens that communicates at a communication voltage different from that of the adapters 30 and 40 may not have the third lens communicator 117 or the third communication contact 104. This structure can prevent the third lens communicator 117 and the third adapter communicators 310 and 410 from being connected at different communication voltages.

[0141] Second Embodiment

[0142] Now refer to Figure 6, a description of a second embodiment of the present invention will be given. In this embodiment, elements corresponding to those in the first embodiment will be denoted by the same reference numerals, and descriptions of these elements will be omitted.

[0143] In this embodiment, the camera causes the interchangeable lens and the adapter to transfer between a normal operation state (a first state: hereinafter referred to as the normal state) where communication is provided and a low power consumption state (a second state: hereinafter referred to as the "sleep state") where communication is not provided and the power consumption is lower than that in the normal state. When the interchangeable lens is in the sleep state, this embodiment uses the first communication channel 100 as a channel for transmitting a lens start signal for starting the interchangeable lens. When the adapter is in the sleep state, this embodiment uses the third communication channel 300 as a channel for transmitting an adapter start signal for starting the adapter. The lens start signal and the adapter start signal are transmitted to the interchangeable lens and the adapter by a transmission method different from the first communication and the third communication performed in the normal state.

[0144] In Figure 6 , when the interchangeable lens 10' is in the sleep state, the camera controller 2201 in the camera 20' transmits a lens start signal to the lens controller 2101 via the camera sleep state signal controller 2202 and the first communication channel 100. When the interchangeable lens 10' is in the sleep state, the lens controller 2101 in the interchangeable lens 10' receives the lens start signal from the camera controller 2201 via the first communication channel 100 and the lens sleep state signal controller 2102. In addition, when the adapters 30' and 40' are in the sleep state, the camera controller 2201 transmits an adapter start signal to the adapter controllers 2301 and 2401 in the adapters 30' and 40' via the camera sleep state signal controller 2202 and the third communication channel 300.

[0145] Figure 7 The flowchart in shows the process in which the camera 20' causes the interchangeable lens 10' to transfer from the normal operation state (hereinafter referred to as the normal state) to the sleep state and to return to the normal state. The normal state of the interchangeable lens 10' means a state in which the interchangeable lens 10' can perform the first communication, the second communication, and the third communication, and the camera 20' can control the driving of the movable optical element in the imaging optical system of the interchangeable lens 10'. The sleep state of the interchangeable lens 10' indicates a state in which the interchangeable lens 10' stops the first communication, the second communication, and the third communication and consumes less power than in the normal state.

[0146] In step S702, the camera controller 2201 that has started processing in S701 acquires the camera operation data described in the first embodiment, as well as the first adapter operation data and the second adapter operation data. Then, the process proceeds to S703.

[0147] In S703, the camera controller 2201 determines whether the time during which the camera operation data or the first adapter operation data and the second adapter operation data have not changed exceeds a predetermined time. In other words, it determines whether the inactivity time during which the user has not operated the operation members 207, 312, and 412 of the camera 20' or the adapters 30' and 40' exceeds a predetermined time. If the inactivity time exceeds the predetermined time, the camera controller 2201 proceeds to S704; otherwise (if there is an operation), the camera controller 2201 repeats the process of S703. The predetermined time is a time sufficient to determine that the user is not performing a shooting operation, such as a few seconds or the like.

[0148] In S704, the camera controller 2201 sends a command for requesting the lens controller 2101 to transition to the sleep state via the first camera communicator 207 (and the first lens communicator 115). Then, the process proceeds to S705.

[0149] In S705, in response to the request to transition to the sleep state received via the first lens communicator 115, the lens controller 2101 transitions the interchangeable lens 10' to the sleep state. In the interchangeable lens 10' in the sleep state, only the lens sleep state signal controller 2102 operates.

[0150] In step S706, the camera controller 2201 acquires the camera operation data, as well as the first adapter operation data and the second adapter operation data, again. Then, the process proceeds to S707.

[0151] In S707, the camera controller 2201 determines whether the camera operation data or the first adapter operation data and the second adapter operation data acquired in S702 and S706 have changed. In other words, it determines whether the user has operated the operation members 207, 312, and 412 of the camera 20' or the adapters 30' and 40'. When it is determined that an operation has been performed, the camera controller 2201 proceeds to step S708; otherwise (if there is no operation), the determination in step S707 is repeated.

[0152] In S708, the camera controller 2201 outputs a lens start signal to the first communication channel 100 via the camera sleep state signal controller 2202. The process of outputting the lens start signal to the first communication channel 100 will be described later.

[0153] Next, in S709, the lens sleep state signal controller 2102 that has received the lens start signal activates the lens controller 2101 and transfers the interchangeable lens 10' to the normal state. Then, this process ends.

[0154] Through this process, the camera controller 2201 can only transfer the interchangeable lens 10' from the normal state to the sleep state and from the sleep state to the normal state.

[0155] Now referring to Figure 8 , the process of outputting the lens start signal to the first communication channel 100 will be described. Figure 8 The signal waveforms on the LCLK line, DCL line, and DLC line when the camera sleep state signal controller 2202 outputs the lens start signal are shown.

[0156] When the lens start signal is input from the camera controller 2201 in step S708 of Figure 7 , the camera sleep state signal controller 2202 outputs the LCLK signal to the LCLK line starting from time Tcl0 and outputs a specific data bit string (B7 to B0). The LCLK signal and the specific data bit string signal are sent as the lens start signal to the lens sleep state signal controller 2102.

[0157] The lens sleep state signal controller 2102 activates the lens controller 2101 in response to detecting a change in at least one of the LCLK line and DCL line in the sleep state. Thereby, the interchangeable lens 10' is transferred to the normal state. Thereafter, the first lens communicator 115 outputs low to the LCLK line for a predetermined time Tbusy and cancels the low output at time Tc11 when the predetermined time Tbusy has elapsed. Thereafter, the first communication as shown in Figure 3 (b) can be performed between the camera controller 2201 and the lens controller 2101.

[0158] This process can use the first communication channel 100 to only transfer the interchangeable lens 10' from the sleep state to the normal state.

[0159] Now referring to Figure 9 , a description of the process of transferring the interchangeable lens 10' from the sleep state to the normal state according to the operation of the lens operation member 118 will be given. Figure 9 The signal waveforms on the LCLK line, DCL line, and DLC line when the interchangeable lens 10' is transferred from the sleep state to the normal state according to the operation of the lens operation member 118 are shown.

[0160] When the lens sleep state signal controller 2102 detects the operation of the lens operation member 118, the lens sleep state signal controller 2102 starts fromFigure 9 From the time Tlc0 shown, a low output as a lens start request signal is sent to the DLC line. When the camera sleep state signal controller 2202 detects a low on the DLC line, the first camera communicator 207 outputs an LCLK signal to the LCLK line from the time Tlc1, and outputs a specific data bit string (B7 to B0) to the DCL line. The LCLK signal and the specific data bit string signal are sent as a lens start signal to the lens sleep state signal controller 2102.

[0161] The lens sleep state signal controller 2102 activates the lens controller 2101 in response to detecting a change in at least one of the LCLK line and the DCL line in the sleep state of the interchangeable lens 10'. Thereby, the interchangeable lens 10' transitions to the normal state. Thereafter, the first lens communicator 115 cancels the low output on the DLC line at the time Tlc2. Thereafter, the first lens communicator 115 outputs a low to the LCLK line and maintains it for a predetermined time Tbusy, and cancels the low output when the predetermined time Tbusy has elapsed. Thereafter, the first communication Figure 3 as shown in (b) can be performed between the camera controller 2201 and the lens controller 2101.

[0162] This process can use the first communication channel 100 to transition only the interchangeable lens 10' to the normal state in response to an operation of the lens operation member 118 of the interchangeable lens 10' in the sleep state.

[0163] Now referring to Figure 10 the flowchart in, the process of the camera 20' transitioning the adapters 30' and 40' from the normal state to the sleep state and then transitioning the adapters 30' and 40' back to the normal state will be described. The normal state of the adapters 30' and 40' is a state in which the adapters 30' and 40' can perform the third communication, and the camera 20' can control the driving of the movable optical elements of the imaging optical system of the interchangeable lens 10'. The sleep state of the adapters 30' and 40' indicates a state in which the adapters 30' and 40' stop the third communication and consume less power than in the normal state.

[0164] In step S1002, the camera controller 2201 that has started the process in S1001 acquires the camera operation data and the lens operation data described in the first embodiment. Then, the process proceeds to S1003.

[0165] In S1003, the camera controller 2201 determines whether the time during which the camera operation data or the lens operation data has not changed exceeds a predetermined time. In other words, it determines whether the non-operation time during which the user does not operate the operation member 207 of the camera 20' or the operation member 118 of the interchangeable lens 10' exceeds a predetermined time. If the non-operation time exceeds the predetermined time, the camera controller 2201 proceeds to S1004; otherwise (if there is an operation), the camera controller 2201 repeats the process of S1003. The predetermined time is a time sufficient to determine that the user is not performing a shooting operation, such as a few seconds, etc.

[0166] In S1004, the camera controller 2201 sends a command for requesting the adapter controllers 2301 and 2401 to transition to the sleep state via the third camera communicator 209 (and the third adapter communicators 310 and 410). Then, the process proceeds to S1005.

[0167] In S1005, the adapter controllers 2301 and 2401 respectively cause the adapters 30' and 40' to transition to the sleep state. Among the adapters 30' and 40' in the sleep state, only the adapter sleep state signal controllers 2302 and 2402 operate.

[0168] In step S1006, the camera controller 2201 acquires the camera operation data and the lens operation data again. Then, the process proceeds to S1007.

[0169] In S1007, the camera controller 2201 determines whether the camera operation data or the lens operation data acquired in S1002 and S1006 has changed. In other words, it determines whether the user has operated the operation member 207 of the camera 20' or the operation member 118 of the interchangeable lens 10'. If the camera controller 2201 determines that an operation has been performed, the process proceeds to step S1008; otherwise (if there is no operation), the determination in step S1007 is repeated.

[0170] In S1008, the camera controller 2201 outputs an adapter start signal to the third communication channel 300 via the camera sleep state signal controller 2202. The process of outputting the adapter start signal to the third communication channel 300 is the same as the process of outputting the lens start signal to the first communication channel 100 described above.

[0171] Next, in S1009, the adapter sleep state signal controllers 2302 and 2402 respectively start the adapter controllers 2301 and 2401 and cause the adapters 30' and 40' to transition to the normal state. Then, this process ends.

[0172] This process enables the camera controller 2201 to transfer only the adapters 30' and 40' between the normal state and the sleep state, and vice versa.

[0173] In addition, the process of transferring the adapters 30' and 40' from the sleep state to the normal state according to the operations of the adapter operation members 312 and 412 is the same as the method of transferring the interchangeable lens 10' to the normal state according to the operation of the lens operation member 118 described above. In other words, in response to the operations of the adapter operation members 312 and 412 of the adapters 30' and 40' in the sleep state, an adapter start request signal is sent to the camera 20' using the third communication channel 300. Then, an adapter start signal is sent from the camera 20' to the adapters 30' and 40' using the third communication channel 300. Thus, only the adapters 30' and 40' can be transferred from the sleep state to the normal state.

[0174] According to this embodiment, the camera 20' can transfer the interchangeable lens 10' and the adapters 30' and 40' between the normal state and the sleep state without depending on their states. Therefore, appropriate power control can be performed according to the usage and type of the interchangeable lens and the adapters. For example, when the camera 20' is battery-powered and the camera 20' detects a decrease in battery power, only the adapters can be placed in the sleep state, thereby enabling the camera to take pictures for as long as possible.

[0175] The above embodiment has described two adapters arranged between the interchangeable lens 10 and the camera 20, but the number of adapters is not limited to this embodiment. The present invention is applicable to the interchangeable lens, the camera, and the adapter that constitute a camera system in which at least one adapter can be provided between the interchangeable lens 10 and the camera 20.

[0176] Other Embodiments

[0177] The present invention can provide a program for implementing one or more functions of the above embodiments to a system or device via a network or a storage medium, and can be implemented by one or more processors in a computer of the system or device configured to read and execute the program. The present invention can also be implemented by a circuit (e.g., ASIC) that implements one or more functions.

[0178] The above embodiments are merely representative examples, and various modifications and changes can be made to these embodiments when implementing the present invention.

Claims

1. A camera, wherein a replaceable lens device can be connected to the camera via at least one adapter device, and the camera includes: A lens-camera communication controller configured to communicate with the replaceable lens device by using a camera-lens communication channel; And An adapter-camera communication controller configured to communicate with the adapter device by using a camera-adapter communication channel separately provided from the camera-lens communication channel, wherein the camera-lens communication channel includes a first data communication line used during data communication and a first notification line for notifying the timing of communication between the camera and the replaceable lens device, wherein the camera-adapter communication channel includes a second data communication line used during data communication and a second notification line for notifying the timing of communication between the camera and the adapter device, and wherein the adapter-camera communication controller is configured to switch between a first communication method for communicating among the replaceable lens device, the at least one adapter device, and the camera, and a second communication method for communicating separately with the replaceable lens device or the at least one adapter device and being different from the first communication method in terms of the voltage level of the second notification line during data transmission to a communication partner.

2. The camera according to claim 1, wherein, Regardless of whether the adapter-camera communication controller is communicating, the lens-camera communication controller communicates.

3. The camera according to claim 1 or 2, wherein, The communication between the camera and the replaceable lens device and the communication between the camera and the adapter device are different from each other in at least one of communication method, communication timing, communication rate, and communication voltage.

4. The camera according to claim 1 or 2, wherein The lens-camera communication controller sends a lens control command for controlling the operation of the replaceable lens device to the replaceable lens device.

5. The camera according to claim 1 or 2, wherein, The adapter-camera communication controller receives the inherent information of the adapter device from the adapter device.

6. The camera according to claim 5, wherein, The inherent information includes the optical data of the adapter device.

7. The camera according to claim 1 or 2, wherein, The adapter-camera communication controller receives operation data for indicating a user operation on the adapter device from the adapter device.

8. The camera according to claim 1 or 2, wherein, The lens-camera communication controller detects the communication voltage used by the replaceable lens device in the camera-lens communication channel and sets the communication voltage to be used for communication with the replaceable lens device in the camera-lens communication channel according to the detection result.

9. The camera according to claim 1 or 2, wherein, The adapter-camera communication controller receives data related to the replaceable lens device from the replaceable lens device by using the camera-adapter communication channel.

10. The camera according to claim 1 or 2, wherein, The lens-camera communication controller and the adapter-camera communication controller each communicate separately to transfer the replaceable lens device and the adapter device from a first state of communication to a second state of non-communication.

11. The camera according to claim 10, wherein, The lens-camera communication controller transmits, via a communication method different from the communication in the first state, a lens activation signal for transferring the interchangeable lens device from the second state to the first state or a lens activation request signal for requesting transfer of the second state of the interchangeable lens device output from the interchangeable lens device to the first state, by using the camera-lens communication channel.

12. The camera according to claim 10, wherein, The adapter-camera communication controller transmits, via a communication method different from the communication in the first state, an adapter activation signal for transferring the adapter device from the second state to the first state or an adapter activation request signal for requesting transfer of the second state of the adapter device output from the adapter device to the first state, by using the camera-adapter communication channel.

13. The camera according to claim 1, wherein, The adapter-camera communication controller sets the voltage level of the second notification line during data transmission in the first communication method to a first level, and sets the voltage level of the second notification line during data transmission in the second communication method to a second level higher than the first level.

14. The camera according to claim 1, wherein, The adapter-camera communication controller transmits, in the first communication method, communication partner specifying data for indicating the communication partner of the camera in the second communication method, by using the second data communication line.

15. A camera system, comprising: A camera according to any one of claims 1 to 14; An interchangeable lens device connected to the camera; And An adapter device connected to the camera and the interchangeable lens device.

16. An adapter device to which a camera and an interchangeable lens device can be connected, the adapter device comprising: A relay channel for forming a part of a camera-lens communication channel for communication between the camera and the interchangeable lens device; And An adapter-camera communication controller configured to communicate with the camera by using a camera-adapter communication channel separately provided from the relay channel, wherein the camera-lens communication channel includes a first data communication line used during data communication and a first notification line for notifying the timing of communication between the camera and the interchangeable lens device, wherein the camera-adapter communication channel includes a second data communication line used during data communication and a second notification line for notifying the timing of communication between the camera and the adapter device, and wherein the adapter-camera communication controller is configured to switch between a first communication method for communication among the interchangeable lens device, the adapter device, and the camera and a second communication method for communicating separately with the interchangeable lens device or the camera and different from the first communication method in terms of the voltage level of the second notification line during data transmission to a communication partner.

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