Cameras and accessory devices.

Abstract

To cause a camera to perform authentication communication with a plurality of accessory devices in a short time.SOLUTION: An imaging apparatus 200 has a camera control unit 205 that controls communication with a plurality of accessory devices 100, 300 performed by using a signal transfer channel CS used for transfer of signals between the plurality of accessory devices and a data communication channel DATA used for data communication between the plurality of accessory devices. The camera control unit can perform, by using the data communication channel, first communication being the data communication with the plurality of accessory devices and second communication being individual data communication with a specific accessory device. Every time the camera control unit detects output of a signal indicating standing by for the first communication to the signal transfer channel from one accessory device of the plurality of accessory devices not authenticated by the camera, the camera control unit performs authentication communication with the one accessory device, and thereby sequentially authenticates the plurality of accessory devices.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD

[0001] The present invention relates to a camera system including a mutually communicable camera and accessory devices such as interchangeable lenses and adapters. BACKGROUND ART

[0002] In an interchangeable-lens camera system including a camera to which an interchangeable lens can be attached and detached, communication is performed for the camera to control the operation of the interchangeable lens and for the interchangeable lens to provide data required for the control and imaging to the camera. In particular, when capturing moving images for recording or moving images for live view display using an interchangeable lens, smooth lens control matching the imaging cycle is required, so 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 the reception of data from the interchangeable lens and the transmission of commands such as various instructions and requests to the interchangeable lens within one imaging cycle. However, an increase in the amount of data received by the camera from the interchangeable lens or a shortening of the imaging cycle (an increase in frame rate) has led to a demand for higher-speed communication of large amounts of data.

[0003] In addition, an adapter such as a wide converter or a teleconverter (extender) may be connected between the camera and the interchangeable lens, and these adapters also communicate with the camera in the same manner as the interchangeable lens. For this reason, the camera system requires a communication system that enables the camera to perform one-to-many communication with a plurality of accessory devices including the interchangeable lens and the adapter. As a communication method for realizing one-to-many communication between a communication master and a plurality of communication slaves, there is the I2C communication method disclosed in Non-Patent Document 1. PRIOR ART DOCUMENTS NON-PATENT DOCUMENTS

[0004] Non-Patent Document 1 NXP Corporation Document: I2C Bus Specification and User Manual Rev5.0J-2 - October 9, 2012 [Internet search URL as of May 20, 2017: http: / / www.nxp.com / documents / user_manual / UM10204_JA.pdf] [Overview of the Initiative] [Means for solving the problem]

[0005] The accessory device of the present invention is an accessory device that can be attached to and detached from a camera, The aforementioned accessory device, together with other accessory devices, is connected to the camera. Attached In this state, using a first communication channel including a communication channel between the other accessory device and the camera The camera is equipped with a receiving unit that receives an instruction signal different from the clock signal transmitted from the camera, and the instruction signal includes identification information assigned to an accessory attached to the camera, and instructions from the camera. toga Includes If, in the above state, the other accessory device is not identified by the camera, then individual communication with the camera using the first communication channel will not be performed. It is characterized by the following: [Brief explanation of the drawing]

[0006] [Figure 1] A block diagram showing the configuration of the camera system in Embodiment 1 of the present invention. [Figure 2] This diagram shows the communication circuit between the camera (camera microcontroller), interchangeable lens (lens microcontroller), and adapter (adapter microcontroller) in Example 1. [Figure 3] A diagram showing the communication format in Example 1. [Figure 4] A diagram showing the communication waveform in broadcast communication in Example 1. [Figure 5] A diagram showing the communication waveform in P2P communication in Example 1. [Figure 6] This figure shows the communication waveform during communication mode switching in Example 1. [Figure 7A] A flowchart illustrating camera processing in broadcast communication in Example 1. [Figure 7B] A flowchart illustrating the processing of interchangeable lenses and adapters in broadcast communication in Example 1. [Figure 8A]A flowchart illustrating camera processing in P2P communication in Example 1. [Figure 8B] A flowchart illustrating the processing of interchangeable lenses and adapters in P2P communication in Example 1. [Figure 9] A diagram showing the communication waveform during the authentication communication process in Example 1. [Figure 10] A flowchart illustrating the authentication communication process in Example 1. [Figure 11] This figure shows the communication circuit between the camera (camera microcontroller), interchangeable lens (lens microcontroller), and adapter (adapter microcontroller) in Embodiment 2 of the present invention. [Figure 12] This figure shows the communication waveform during the authentication communication process in Example 2. [Figure 13] A flowchart illustrating the authentication communication process in Example 2. [Figure 14] A diagram illustrating other communication channels. [Modes for carrying out the invention]

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Examples]

[0008] Figure 1 shows the configuration of a camera system including a camera 200, which is an embodiment 1 of the present invention, and an accessory device, an interchangeable lens 100, and an intermediate adapter device (hereinafter simply referred to as "adapter") 300. In this embodiment, the camera 200 is shown in a state where the interchangeable lens 100 is connected via the adapter 300 (a state in which multiple accessory devices are connected).

[0009] Figure 1 shows an example camera system in which one adapter 300 is connected between the camera 200 and the interchangeable lens 100, but multiple adapters may be linked together and connected between the camera 200 and the interchangeable lens 100.

[0010] In the camera system of the present embodiment, communication is performed between the camera 200, the interchangeable lens 100, and the adapter 300 using a plurality of communication methods. The camera 200, the interchangeable lens 100, and the adapter 300 transmit control commands and data (information) via their respective communication units. Each communication unit supports a plurality of communication methods, and can switch to the same communication method in synchronization with each other according to the type of data to be communicated and the purpose of communication, so that the optimal communication method can be selected for various situations.

[0011] First, a more specific configuration of the interchangeable lens 100, the camera 200, and the adapter 300 will be described.

[0012] The interchangeable lens 100 and the adapter 300 are mechanically and electrically connected via a mount 400 that serves as a coupling mechanism. Similarly, the adapter 300 and the camera 200 are mechanically and electrically connected via a mount 401 that serves as a coupling mechanism. The interchangeable lens 100 and the adapter 300 acquire power from the camera 200 via power supply terminal portions (not shown) provided on the mounts 400 and 401. Then, power necessary for the operation of various actuators described later, the lens microcomputer 111, and the adapter microcomputer 302 is supplied. The interchangeable lens 100, the camera 200, and the adapter 300 communicate with each other via communication terminal portions (shown in FIG. 2) provided on the mounts 400 and 401.

[0013] The interchangeable lens 100 includes an imaging optical system. The imaging optical system includes, in order from the subject OBJ side, a field lens 101, a zoom lens 102 that performs zooming, and an aperture unit 114 that adjusts the light amount. Furthermore, the imaging optical system includes an image stabilization lens 103 that reduces (corrects) image blur, and a focus lens 104 that performs focus adjustment.

[0014] The variable magnification lens 102 and the focus lens 104 are held by lens retaining frames 105 and 106, respectively. The lens retaining frames 105 and 106 are guided to move in the optical axis direction (shown by dashed lines in the figure) by guide axes (not shown) and are driven in the optical axis direction by stepping motors 107 and 108. The stepping motors 107 and 108 move the zoom lens 102 and the focus lens 104 in synchronization with the drive pulses, respectively.

[0015] The image stabilization lens 103 reduces image shake caused by camera shake (such as hand shake) by shifting in a direction perpendicular to the optical axis of the imaging optical system.

[0016] The lens microcomputer (hereinafter referred to as "lens microcontroller") 111 is a lens control unit (accessory control unit) that controls the operation of each part within the interchangeable lens 100. The lens microcontroller 111 also receives control commands and transmission request commands sent from the camera 200 via the lens communication unit (accessory communication unit) 112, which includes a lens communication interface circuit. The lens microcontroller 111 performs lens control corresponding to the control commands and transmits lens data corresponding to the transmission request commands to the camera 200 via the lens communication unit 112.

[0017] Furthermore, the lens microcontroller 111 responds to control commands related to magnification and focusing by outputting drive signals to the zoom drive circuit 119 and focus drive circuit 120 to drive the stepping motors 107 and 108. This enables zoom processing to control the magnification operation of the zoom lens 102 and AF (autofocus) processing to control the focus adjustment operation of the focus lens 104.

[0018] The aperture unit 114 is equipped with aperture blades 114a and 114b. The state (position) of the aperture blades 114a and 114b is detected by a Hall element 115. The output from the Hall element 115 is input to the lens microcontroller 111 via an amplification circuit 122 and an A / D conversion circuit 123. The lens microcontroller 111 outputs a drive signal to the aperture drive circuit 121 based on the input signal from the A / D conversion circuit 123 to drive the aperture actuator 113. This controls the light intensity adjustment operation by the aperture unit 114.

[0019] Furthermore, the lens microcontroller 111 drives the vibration damping actuator (voice coil motor, etc.) 126 via the vibration damping drive circuit 125 in response to camera shake detected by a shake sensor (not shown), such as a vibration gyroscope, located inside the interchangeable lens 100. This performs vibration damping processing that controls the shift operation (vibration damping operation) of the vibration damping lens 103.

[0020] The interchangeable lens 100 also has a manual operation ring (hereinafter simply referred to as the operation ring) 130 and a ring rotation detector 131. The ring rotation detector 131 is composed of, for example, a photointerrupter that outputs a two-phase signal in response to the rotation of the operation ring 130. The lens microcontroller 111 can use this two-phase signal to detect the amount of rotation of the operation ring 130. The lens microcontroller 111 can also notify the camera microcontroller 205 of the amount of rotation of the operation ring 130 via the lens communication unit 112.

[0021] The adapter 300 is, for example, an extender for changing the focal length, and includes a variable magnification lens 301 and an adapter microcomputer (hereinafter referred to as the adapter microcontroller) 302. The adapter microcontroller 302 is an adapter control unit (accessory control unit) that controls the operation of each part within the adapter 300. The adapter microcontroller 302 also receives control commands and transmission request commands transmitted from the camera 200 via an adapter communication unit (accessory communication unit) 303, which includes a communication interface circuit. The adapter microcontroller 302 performs adapter control corresponding to the control commands and transmits adapter data corresponding to the transmission request commands to the camera 200 via the adapter communication unit 303. The camera 200 includes an image sensor 201 such as a CCD sensor or a CMOS sensor, an A / D conversion circuit 202, a signal processing circuit 203, a recording unit 204, a camera microcomputer (hereinafter referred to as camera microcontroller) 205, and a display unit 206.

[0022] The image sensor 201 converts the subject image formed by the imaging optical system in the interchangeable lens 100 into an electrical signal (analog signal) via photoelectric conversion and outputs an electrical signal. The A / D conversion circuit 202 converts the analog signal from the image sensor 201 into a digital signal. The signal processing circuit 203 performs various image processing on the digital signal from the A / D conversion circuit 202 to generate a video signal. The signal processing circuit 203 also generates focus information, which indicates the contrast state of the subject image (focus state of the imaging optical system), and brightness information, which indicates the exposure state, from the video signal. The signal processing circuit 203 outputs the video signal to the display unit 206, which displays the video signal as a live view image used for checking composition, focus, etc.

[0023] The camera microcontroller 205, acting as the camera control unit, controls the camera 200 in response to inputs from camera operating components such as an imaging instruction switch (not shown) and various setting switches. The camera microcontroller 205 also transmits control commands related to the zoom lens 102's magnification operation to the lens microcontroller 111 via the camera communication unit 208, which includes a communication interface circuit, in response to the operation of a zoom switch (not shown). Furthermore, the camera microcontroller 205 transmits control commands related to the light intensity adjustment operation of the aperture unit 114 according to brightness information and the focus adjustment operation of the focus lens 104 according to focus information to the lens microcontroller 111 via the camera communication unit 208. The camera microcontroller 205 also transmits a transmission request command to the lens microcontroller 111 to acquire control information and status information of the interchangeable lens 100 as needed. Furthermore, the camera microcontroller 205 transmits a transmission request command to the adapter microcontroller 302 to acquire control information and status information of the adapter 300.

[0024] Next, the communication circuit configured between the camera 200 (camera microcontroller 205), the interchangeable lens 100 (lens microcontroller 111), and the adapter 300 (adapter microcontroller 302) will be explained using Figure 2. The camera microcontroller 205, the lens microcontroller 111, and the adapter microcontroller 302 communicate using signal lines (channels) connected via the communication terminals provided on the mounts 400 and 401 mentioned above.

[0025] The signal lines include a signal line (first signal line: corresponding to the signal transmission channel) CS for transmitting signals for communication control, and a signal line (second signal line: corresponding to the data communication channel) DATA for communicating data.

[0026] The signal line CS is connected to the camera microcontroller 205, the adapter microcontroller 302, and the lens microcontroller 111. Therefore, the camera microcontroller 205, the adapter microcontroller 302, and the lens microcontroller 111 can detect the state of the signal line CS as Hi (High) or Low. The signal line CS is also pulled up to a power supply (not shown) within the camera 200. Furthermore, the signal line CS can be connected to ground GND (open drain connection) via the ground switch 1121 in the interchangeable lens 100, the ground switch 2081 in the camera 200, and the ground switch 3031 in the adapter 300.

[0027] With this configuration, the camera microcontroller 205, adapter microcontroller 302, and lens microcontroller 111 can each set the signal line CS to Low by turning on (connecting) the ground switches 2081, 1121, and 3031, respectively. Conversely, the camera microcontroller 205, adapter microcontroller 302, and lens microcontroller 111 can each set the signal line CS to High by turning off (disconnecting) the ground switches 2081, 1121, and 3031, respectively.

[0028] Furthermore, a CS switch (channel switch) 3033 is provided inside the adapter 300. The adapter microcontroller 302 can connect and disconnect the signal line CS by switching the CS switch 3033 between connected and disconnected states. When the CS switch 3033 is disconnected, the signal output status from the camera side (camera 200 in this embodiment) to the signal line CS and the signal output status from the adapter 300 to the signal line CS are not transmitted to the interchangeable lens side (interchangeable lens 100 in this embodiment). In other words, broadcast communication, which will be described later, cannot be performed from the adapter 300 to the communication slave on the interchangeable lens side. Details of the communication control signals (instructions and notifications) transmitted through the signal line CS and their output processing will be described later.

[0029] The signal line DATA is a single-wire bidirectional data communication line that can be used while switching the direction of data transmission. The signal line DATA can be connected to the lens microcontroller 111 via the input / output selector switch 1122 in the interchangeable lens 100, and can be connected to the camera microcontroller 205 via the input / output selector switch 2082 in the camera 200. In addition, the signal line DATA can be connected to the adapter microcontroller 302 via the input / output selector switch 3032 in the adapter 300. Each microcontroller is equipped with a CMOS-type data output unit for transmitting data and a CMOS-type data input unit for receiving data (neither of which are shown). Each microcontroller can select whether to connect the signal line DATA to the data output unit or the data input unit by switching the input / output selector switch.

[0030] The camera microcontroller 205, adapter microcontroller 302, and lens microcontroller 111 each set their input / output switches to connect the signal line DATA to the data output section when transmitting data. Similarly, when receiving data, the camera microcontroller 205, adapter microcontroller 302, and lens microcontroller 111 each set their input / output switches to connect the signal line DATA to the data input section. Details of the input / output switching process for the signal line DATA will be described later.

[0031] Figure 2 shows an example of a communication circuit, but other communication circuits may also be used. For example, the signal line CS may be pulled down to GND within the camera 200 and connected to a power supply (not shown) via the ground switch 1121 of the interchangeable lens 100, the ground switch 2081 of the camera 200, and the ground switch 3031 of the adapter 300. Alternatively, the signal line DATA may be always connected to the data input section in the interchangeable lens 100, camera 200, and adapter 300, and the connection / disconnection of the signal line DATA to the data output section may be switched using a switch. [Communication data format] Next, using Figure 3, we will explain the format of the communication data exchanged between the camera 200 (camera microcontroller 205), the interchangeable lens 100 (lens microcontroller 111), and the adapter 300 (adapter microcontroller 302). This communication data format is common to both the first type of communication, broadcast communication, and the second type of communication, P2P communication, which will be described later. Here, we will explain the communication data format when performing so-called asynchronous communication, in which the communication speed to be used for communication is predetermined between the microcontrollers, and transmission and reception are performed at the communication bitrate according to this agreement.

[0032] First, in the non-transmission state, when no data is being transmitted, the signal level is maintained at Hi. Next, to notify the data receiver of the start of data transmission, the signal level is set to Low for a 1-bit period. This 1-bit period is called the start bit ST. Subsequently, one byte of data is transmitted in an 8-bit period from the 2nd bit to the 9th bit. The data bit arrangement is in MSB-first format, starting with the most significant data D7, followed by D6, D5, ..., D1, and ending with the least significant data D0. One bit of parity information PA is added as the 10th bit, and finally, the signal level is set to Hi for the period of the stop bit SP, which indicates the end of the transmitted data, thus ending the 1 frame period that started with the start bit ST.

[0033] Figure 3 shows an example of a communication data format, but other communication data formats may be used. For example, the data bit array may be LSB-first or 9 bits long, and parity PA information may not be added. Also, the communication data format may be switched between broadcast communication and P2P communication. [Broadcast communication] Next, broadcast communication (the first communication mode) will be explained. Broadcast communication is a one-to-many communication mode in which one of the camera microcontroller 205, lens microcontroller 111, and adapter microcontroller 302 simultaneously transmits data to the other two (i.e., simultaneous transmission). This broadcast communication is performed using signal lines CS and DATA. The communication mode in which broadcast communication is performed is also called the broadcast communication mode (the first communication mode).

[0034] Figure 4 shows the signal waveforms during broadcast communication between the camera microcontroller 205, the lens microcontroller 111, and the adapter microcontroller 302. As an example, we will describe the case where the adapter microcontroller 302 broadcasts to the camera microcontroller 205 and the lens microcontroller 111 in response to broadcast communication from the camera microcontroller 205 to the lens microcontroller 111 and the adapter microcontroller 302.

[0035] First, the camera microcontroller 205, which is the communication master, starts outputting a Low signal to the signal line CS to notify the lens microcontroller 111 and adapter microcontroller 302, which are the communication slaves, that it is starting broadcast communication. Next, the camera microcontroller 205 outputs the data to be transmitted to the signal line DATA. Meanwhile, the lens microcontroller 111 and adapter microcontroller 302 start outputting a Low signal to the signal line CS when they detect the start bit ST input from the signal line DATA. At this point, the camera microcontroller 205 has already started outputting a Low signal to the signal line CS, so the signal level of the signal line CS does not change.

[0036] Subsequently, the camera microcontroller 205 releases its Low output to signal line CS after completing the output of stop bit SP. Meanwhile, the lens microcontroller 111 and adapter microcontroller 302 receive data up to stop bit SP input from signal line DATA, then analyze the received data and perform internal processing associated with the received data. When they are ready to receive the next data, they release their Low output to signal line CS. As mentioned above, the signal level of signal line CS becomes High when the camera microcontroller 205, lens microcontroller 111, and adapter microcontroller 302 all release their Low output to signal line CS. Therefore, the camera microcontroller 205, lens microcontroller 111, and adapter microcontroller 302 can each confirm that the signal level of signal line CS becomes High after releasing their Low output to signal line CS. By confirming that the signal level of signal line CS has become High, the camera microcontroller 205, lens microcontroller 111, and adapter microcontroller 302 can each determine that they have completed the current communication process and are ready to perform the next communication.

[0037] Next, once the adapter microcontroller 302 confirms that the signal level on signal line CS has returned to high, it starts outputting a low signal to signal line CS to notify the camera microcontroller 205 and lens microcontroller 111 that it is starting broadcast communication.

[0038] Next, the adapter microcontroller 302 outputs the data to be transmitted to the signal line DATA. The camera microcontroller 205 and lens microcontroller 111 begin outputting a Low signal to the signal line CS when they detect the start bit ST input from the signal line DATA. At this point, the adapter microcontroller 302 has already started outputting a Low signal to the signal line CS, so the signal level propagated on the signal line CS does not change. After the adapter microcontroller 302 has finished outputting the stop bit SP, it releases the Low signal output to the signal line CS. Meanwhile, the camera microcontroller 205 and lens microcontroller 111, after receiving the data up to the stop bit SP input from the signal line DATA, analyze the received data and perform internal processing associated with the received data. Then, after they are ready to receive the next data, they release the Low signal output to the signal line CS.

[0039] As described above, in broadcast communication, the signals transmitted on the signal line CS function as signals indicating the start (execution) and ongoing execution of broadcast communication.

[0040] Figure 4 shows an example of broadcast communication, but other types of broadcast communication may be used. For example, the data transmitted in a single broadcast communication may be 1 byte as shown in Figure 4, but it may also be 2 or 3 bytes. Furthermore, the broadcast communication may be a one-way communication from the camera microcontroller 205, which is the communication master, to the lens microcontroller 111 and adapter microcontroller 302, which are the communication slaves. [P2P communication] Next, we will explain the P2P communication that takes place between the camera 200 (camera microcontroller 205), the interchangeable lens 100 (lens microcontroller 111), and the adapter 300 (adapter microcontroller 302). In P2P communication, the camera 200, which is the communication master, designates (selects) one communication partner (specific accessory device) from the interchangeable lens 100 and the adapter 300, which are the communication slaves, and sends and receives data only between the camera 200 and the designated communication slave. This P2P communication also takes place using signal lines CS and DATA. The communication mode in which P2P communication takes place is also called the P2P communication mode (second communication mode).

[0041] Figure 5 shows, as an example, the signal waveforms of P2P communication exchanged between the camera microcontroller 205 and the lens microcontroller (specific accessory device) 111, which is designated as the communication partner. In response to the camera microcontroller 205 sending 1 byte of data, the lens microcontroller 111 sends 2 bytes of data to the camera microcontroller 205. The switching process of the communication mode (broadcast communication mode and P2P communication mode) and the process of specifying the communication partner in P2P communication will be described later.

[0042] First, the camera microcontroller 205, which is the communication master, outputs the data to be sent to the lens microcontroller 111 to the signal line DATA. After the camera microcontroller 205 has finished outputting the stop bit SP, it starts outputting a Low (waiting request) to the signal line CS. The camera microcontroller 205 releases the Low output to the signal line CS after it is ready to receive the next data. Meanwhile, the lens microcontroller 111 detects the Low signal input from the signal line CS and then analyzes the received data input from the signal line DATA and performs internal processing associated with the received data. After that, when the lens microcontroller 111 confirms that the signal level of the signal line CS has returned to High, it outputs two bytes of data to be sent consecutively to the signal line DATA.

[0043] The lens microcontroller 111 starts outputting a Low signal to the signal line CS after it has finished outputting the stop bit SP of the second byte. The lens microcontroller 111 then stops outputting a Low signal to the signal line CS when it is ready to receive the next data. The adapter microcontroller 302, which is not designated as a communication partner for P2P communication, does not output signals to the signal line CS and the signal line DATA.

[0044] As described above, in P2P communication, the signals transmitted on the signal line CS function as notification signals indicating the end of data transmission and a request to wait for the next data transmission.

[0045] Although Figure 5 shows an example of P2P communication, other P2P communication methods may be used. For example, data may be sent one byte at a time via the DATA signal line, or three or more bytes of data may be sent. [Communication mode switching process and communication partner specification process] Next, the process of switching communication modes and specifying communication partners in P2P communication will be explained using Figure 6. Figure 6 shows the signal waveforms exchanged between the camera microcontroller 205, the lens microcontroller 111, and the adapter microcontroller 302 during communication mode switching and communication partner specification. The communication partner for P2P communication is specified by broadcast communication. Here, as an example, we will explain the case where the adapter microcontroller 302 is specified as the P2P communication partner from the camera microcontroller 205, and a 1-byte P2P communication from the camera microcontroller 205 and a 1-byte P2P communication from the adapter microcontroller 302 are executed. Subsequently, the lens microcontroller 111 is specified as the P2P communication partner from the camera microcontroller 205, and a 2-byte P2P communication from the camera microcontroller 205 and a 3-byte P2P communication from the lens microcontroller 111 are executed.

[0046] First, the camera microcontroller 205, which is the communication master, performs broadcast communication according to the procedure described in Figure 4. The notification in this broadcast communication is slave designation data that specifies the partner with whom the camera microcontroller 205 will communicate in the next P2P communication. At this time, the lens microcontroller 111 and adapter microcontroller 302, which are communication slaves, determine whether or not they have been designated as communication partners for P2P communication based on the slave designation data received in the broadcast communication. Based on this determination result, the communication mode between the camera microcontroller 205 and the designated communication slave (specific accessory device) switches from broadcast communication mode to P2P communication mode. Here, the adapter microcontroller 302 is designated as the communication partner, so in the next P2P communication, data is sent and received between the camera microcontroller 205 and the adapter microcontroller 302 according to the procedure described in Figure 5. Here, the camera microcontroller 205 sends 1 byte of data to the adapter microcontroller 302, and then the adapter microcontroller 302 sends 1 byte of data to the camera microcontroller 205.

[0047] Once P2P communication between the camera microcontroller 205 and the adapter microcontroller 302 ends, the camera microcontroller 205 can again specify a communication partner for P2P communication via broadcast communication. Here, in order to specify the lens microcontroller 111 as the communication partner for the next P2P communication, the lens microcontroller 111 is set as the slave designation data, and broadcast communication is executed according to the procedure described in Figure 4. In response to this broadcast communication, the adapter microcontroller 302 terminates P2P communication, and at the same time, the communication mode of the camera microcontroller 205 and the lens microcontroller 111 is switched to P2P communication mode. If broadcast communication is not executed at this point, P2P communication between the camera microcontroller 205 and the adapter microcontroller 302 continues.

[0048] In the following P2P communication, data is sent and received between the camera microcontroller 205 and the lens microcontroller 111 according to the procedure described in Figure 5. Here, the camera microcontroller 205 sends 2 bytes of data to the lens microcontroller 111, and then the lens microcontroller 111 sends 3 bytes of data to the camera microcontroller 205.

[0049] As described above, it is possible to specify the communication partner for P2P communication via broadcast communication, and to switch between broadcast communication and P2P communication simultaneously. [Communication control processing] Next, we will describe the communication control process performed between the camera microcontroller 205, the lens microcontroller 111, and the adapter microcontroller 302. First, we will explain the process in broadcast communication mode using the flowcharts in Figures 7A and 7B. Figure 7A shows the process performed by the camera microcontroller 205, and Figure 7B shows the process performed by the lens microcontroller 111 and the adapter microcontroller 302. The camera microcontroller 205, lens microcontroller 111, and adapter microcontroller 302, which are computers respectively, execute this process and other processes described later according to the communication control program, which is a computer program.

[0050] When an event occurs in step S100 to initiate broadcast communication, the camera microcontroller 205 turns on (connects) the ground switch 2081 in step S101, setting the signal line CS low. This notifies the lens microcontroller 111 and the adapter microcontroller 302 of the start of broadcast communication. Upon detecting the low signal line CS in step S200, the lens microcontroller 111 and the adapter microcontroller 302 permit data reception from the signal line DATA in step S201.

[0051] Next, in step S102, the camera microcontroller 205 operates the input / output selector switch 2082 to connect the signal line DATA to the data output unit, and in step S103, it transmits data. When the lens microcontroller 111 and adapter microcontroller 302 detect the start bit of the signal line DATA in step S202, they turn on (connect) the ground switch 1121 and ground switch 3031 in step S205 to indicate that communication processing is in progress. This initiates a Low output to the signal line CS. Subsequently, when the lens microcontroller 111 and adapter microcontroller 302 determine in step S206 that all data has been received, they prohibit data reception from the signal line DATA in step S207. Furthermore, in step S208, they turn off (disconnect) the ground switch 1121 and ground switch 3031 to indicate that communication processing has ended, and release the Low output to the signal line CS. There is no limit to the number of bytes of data sent and received here; it is sufficient that the camera microcontroller 205, lens microcontroller 111, and adapter microcontroller 302 recognize each other correctly.

[0052] Next, in step S104, the camera microcontroller 205 determines whether the data transmitted in step S103 is a bidirectional command that also includes transmissions from the lens microcontroller 111 or the adapter microcontroller 302. If it is not a bidirectional command, the camera microcontroller 205 turns off (disconnects) the ground switch 2081 in step S105 to release the Low output to the signal line CS and proceeds to step S116. If it is a bidirectional command, the camera microcontroller 205 operates the input / output selector switch 2082 in step S106 to connect the signal line DATA to the data input section. Then, in step S107, it turns off (disconnects) the ground switch 2081 to release the Low output to the signal line CS and waits in step S108 until the signal line CS goes Hi.

[0053] Meanwhile, in step S209, the lens microcontroller 111 and the adapter microcontroller 302 determine whether the data received in step S206 is a bidirectional command that includes a transmission from themselves. If it is not a bidirectional command, the lens microcontroller 111 and the adapter microcontroller 302 proceed to step S215. If it is a bidirectional command, they wait in step S210 until the signal line CS goes high. When the signal line CS goes high, the lens microcontroller 111 and the adapter microcontroller 302 turn on (connect) the ground switches 1121 and 3031 in step S211 to bring the signal line CS low, thereby notifying the start of broadcast communication. When the camera microcontroller 205 detects that the signal line CS is low in step S109, it permits data reception from the signal line DATA in step S110.

[0054] Next, in step S212, the lens microcontroller 111 and adapter microcontroller 302 operate the input / output selector switches 1122 and 3032 to connect the signal line DATA to the data output unit, and in step S213, they transmit data. When the camera microcontroller 205 detects the start bit of the signal line DATA in step S111, it turns on (connects) the ground switch 2081 in step S112 to indicate that communication processing is in progress. This starts the Low output to the signal line CS. After all data transmission is complete, the lens microcontroller 111 and adapter microcontroller 302 turn off (disconnect) the ground switches 1121 and 3031 in step S214 to release the Low output to the signal line CS. When the camera microcontroller 205 determines in step S113 that all data has been received, it prohibits data reception from the signal line DATA in step S114. Then, in step S115, the camera microcontroller 205 turns off (disconnects) the ground switch 2081 to indicate that the communication process is complete, and releases the Low output to the signal line CS. There is no limit to the number of bytes of data transmitted or received at this stage; it is sufficient that the camera microcontroller 205, lens microcontroller 111, and adapter microcontroller 302 have a shared understanding of each other.

[0055] Next, the camera microcontroller 205 waits in step S116 until the signal line CS goes high. When the signal line CS goes high, in step S117 the camera microcontroller 205 determines whether it has designated the lens microcontroller 111 or the adapter microcontroller 302 as the communication partner for P2P communication based on the data transmitted in step S103. If the camera microcontroller 205 has not designated the lens microcontroller 111 or the adapter microcontroller 302 as the communication partner, it terminates the process. If it has designated either of them, it transitions to P2P communication mode in step S118.

[0056] Meanwhile, the lens microcontroller 111 and the adapter microcontroller 302 wait until the signal line CS goes high in step S215. When the signal line CS goes high, the lens microcontroller 111 and the adapter microcontroller 302 determine in step S216 whether they have been designated as communication partners for P2P communication by the camera microcontroller 205 based on the data received in step S206. If they have not been designated as communication partners, the lens microcontroller 111 and the adapter microcontroller 302 terminate processing. If they have been designated as communication partners, the designated microcontroller among the lens microcontroller 111 and the adapter microcontroller 302 permits data reception from the signal line DATA in step S217 and transitions to P2P communication mode in step S218.

[0057] If the lens microcontroller 111 and adapter microcontroller 302 have not detected the start bit in step S202, they check in step S203 whether the signal line CS has gone high. If the signal line CS has gone high (returned to high), the lens microcontroller 111 and adapter microcontroller 302 disable data reception from the signal line DATA in step S204 and terminate processing. This is a process to accommodate a low output to the signal line CS due to P2P communication between the camera microcontroller 205 and other communication slaves, when a communication slave that has not been designated as a communication partner for P2P communication is not specified.

[0058] Next, the processing in P2P communication mode will be explained using the flowcharts in Figures 8A and 8B. Figure 8A shows the processing performed by the camera microcontroller 205, and Figure 8B shows the processing performed by the microcontroller designated as the P2P communication partner (hereinafter referred to as the "specific microcontroller") among the lens microcontroller 111 and the adapter microcontroller 302.

[0059] When an event occurs in step S300 to initiate P2P communication, the camera microcontroller 205 operates the input / output switch 2082 in step S301 to connect the signal line DATA to the data output unit, and transmits data in step S302. After all data transmission is complete, the camera microcontroller 205 turns on (connects) the ground switch 2081 in step S303 to begin outputting a Low to the signal line CS. Meanwhile, the specific microcontroller, upon detecting the Low signal on the signal line CS in step S400, determines that data transmission from the camera microcontroller 205 has ended, and analyzes the data received from the signal line DATA in step S401.

[0060] Next, in step S304, the camera microcontroller 205 determines whether the data transmitted in step S302 is a bidirectional command, including transmissions from a specific microcontroller. If it is not a bidirectional command, the camera microcontroller 205 turns off (cuts off) the ground switch 2081 in step S305 to release the Low output to signal line CS. Then, in step S306, it waits until signal line CS goes Hi before proceeding to step S311. If it is a bidirectional command, the camera microcontroller 205 operates the input / output selector switch 2082 in step S307 to connect signal line DATA to the data input section. Then, in step S308, it turns off (cuts off) the ground switch 2081 to release the Low output to signal line CS.

[0061] Meanwhile, in step S402, the specific microcontroller waits until the signal line CS goes high, and then in step S403, it determines whether the data received in step S401 is a bidirectional command, including one transmitted from itself. If it is not a bidirectional command, the specific microcontroller turns the ground switch (1121 or 3031) on (connects) and off (disconnects) in steps S404 and S405. This starts and stops the low output to the signal line CS, and the process proceeds to step S411. If it is a bidirectional command, in step S406, the specific microcontroller operates the input / output selector switch (1122 or 3032) to connect the signal line DATA to the data output unit, and transmits the data in step S407. After all data transmission is complete, in step S408, the specific microcontroller turns the ground switch (1121 or 3031) on (connects) to start the low output to the signal line CS.

[0062] Next, in step S609, the camera microcontroller 205 detects a Low on the signal line CS, determines in step S310 that data transmission from the specific microcontroller has ended, and analyzes the data received from the signal line DATA. Meanwhile, in step S409, the specific microcontroller operates the input / output selector switch (1122 or 3032) to connect the signal line DATA to the data input section. After that, in step S410, the specific microcontroller turns off (disconnects) the ground switch (1121 or 3031) to release the Low output to the signal line CS.

[0063] Next, the camera microcontroller 205 waits in step S311 until the signal line CS goes high. Then, when an event occurs in step S312 that initiates broadcast communication, the camera microcontroller 205 switches to broadcast communication mode in step S313. Meanwhile, the specific microcontroller waits in step S411 until the signal line CS goes high and then terminates its processing.

[0064] In this embodiment, the meaning (function) of the signals transmitted on the signal line CS is appropriately switched between broadcast communication and P2P communication. This makes it possible to achieve communication between the camera microcontroller 205, the lens microcontroller 111, and the adapter microcontroller 302 with a small number of signal lines (channels). [Authentication communication processing] Next, the authentication communication process in this embodiment will be explained using Figures 9 and 10. Figure 9 shows the signal waveforms during the authentication communication process between the camera microcontroller 205, the lens microcontroller 111, and the adapter microcontroller 302.

[0065] The top of the diagram shows the data communicated via the signal line DATA. "Camera" indicates the data output by the camera microcontroller 205, "Adapter" indicates the data output by the adapter microcontroller 302, and "Lens" indicates the data output by the lens microcontroller 111. "CS signal (camera)" indicates the signal output state of the signal line CS detected by the camera microcontroller 205 (hereinafter referred to as the CS signal state), and "CS output (camera)" indicates the signal that the camera microcontroller 205 outputs to the signal line CS. "CS signal (adapter)" indicates the CS signal state detected by the adapter microcontroller 302, and "CS output (adapter)" indicates the signal that the adapter microcontroller 302 outputs to the signal line CS. "CSSW" indicates the state of the CS switch 3033 controlled by the adapter microcontroller 302, with Low indicating the connection state. "CS signal (lens)" indicates the CS signal state detected by the lens microcontroller 111, and "CS output (lens)" indicates the signal that the lens microcontroller 111 outputs to the signal line CS.

[0066] The flowchart in Figure 10 shows the flow of the authentication communication process. This authentication communication process is performed when the camera 200 detects the connection of the interchangeable lens 100 using a detection switch (1123) provided on the camera 200, and power is supplied from the camera 200 to the interchangeable lens 100 and the adapter 300. At the start of the authentication communication process, the camera microcontroller 205 sends an authentication start request command via broadcast communication through the signal line DATA in step S500. That is, it performs authentication start communication. This process is performed as pre-processing for authentication communication by the camera microcontroller 205. At this time, the CS switch 3033 is set to the connected state. The broadcast communication and the subsequent P2P communication processes are as explained using Figures 7A, 7B and 8A, 8B. In addition, as explained earlier, the adapter microcontroller 302 and the lens microcontroller 111 output different signals (Low and Hi) to the signal line CS during broadcast communication and P2P communication when communicating with the camera microcontroller 205 (from start to end of communication) and when waiting for communication.

[0067] Upon receiving the authentication start request command, the adapter microcontroller 302 and the lens microcontroller 111 perform broadcast communication reception processing in steps S506 and S513, respectively. If the received result is an authentication start request command, the adapter microcontroller 302 switches the CS switch 3033 to the disconnected state in step S507. Here, the timing of this switch is after the adapter microcontroller 302 releases the Low output to the signal line CS (after step S208 in Figure 7), but it may also be immediately before or simultaneously with the release of the Low output.

[0068] Next, in response to the adapter microcontroller 302 releasing the Low output to signal line CS and the communication circuit entering a communication standby state, the camera microcontroller 205 sends an authentication request command via broadcast communication over the communication line DATA in step S501. In other words, it performs authentication request communication. In subsequent processing, the camera microcontroller 205 performs authentication communication. The authentication request command becomes slave designation data for designating the communication slave that received it via broadcast communication as a designated slave (specific accessory device). In step S507, the communication line CS is disconnected by the CS switch 3033, so the Low output to communication line CS in step S501 is not detected by the lens microcontroller 111. On the other hand, since the communication line DATA is connected, the authentication request command is sent to the lens microcontroller 111. However, the authentication request command is a command that relies on broadcast communication, which can only receive data when communication line CS is Low. Therefore, the lens microcontroller 111, which receives the authentication request command while communication line CS is Hi, ignores it.

[0069] Meanwhile, in step S508, the adapter microcontroller 302 receives an authentication request command via broadcast communication through the communication line DATA. Upon receiving the authentication request command, the adapter microcontroller 302 interprets it as the first authentication request command it has received, and that the next P2P communication will be addressed to it.

[0070] Next, in step S502, the camera microcontroller 205 sends an ID communication request command via the communication line DATA using P2P communication. In other words, it performs authentication information communication. At this time, the camera microcontroller 205 does not recognize that the P2P communication partner is the adapter microcontroller 302. This is because it does not yet know what kind of accessories are connected to the camera 200 and how many of them are connected. The camera microcontroller 205 only knows that one of the connected communication slaves will respond to P2P communication by specifying a designated slave with the authentication request command sent in step S501.

[0071] The adapter microcontroller 302, designated as the specified slave, receives an ID communication request command via P2P communication in step S509 and, in response, transmits its own ID information (authentication information) to the camera microcontroller 205 via P2P communication through the signal line DATA. Subsequently, in step S510, the adapter microcontroller 302 switches the CS switch 3033 to the connected state. Here, the timing of this switch is after the adapter microcontroller 302 releases the Low output to the signal line CS (after step S410 in Figure 8), but it may also be immediately before or simultaneously with the release of the Low output.

[0072] Furthermore, the P2P communication in steps S502 and S509 may be performed only once between the camera microcontroller 205 and the adapter microcontroller 302, or it may be performed two or more times, as shown in Figure 9.

[0073] Furthermore, although this flowchart shows the timing for switching the CS switch 3033 to the connected state as after step S509, it may also be done before step 509 (after receiving the authentication request command in step S508). This is because the adapter microcontroller 302, which receives the authentication request command via broadcast communication, recognizes it as slave designation data for itself, while the lens microcontroller 111, which has not received the authentication request command, does not recognize it as slave designation data for itself. For this reason, even if the CS switch 3033 is switched to the connected state after step S508, only the adapter microcontroller 302 will respond to the ID communication request command in step S509.

[0074] Next, in response to the Low output to the signal line CS by the adapter microcontroller 302 being released and the communication circuit entering a communication standby state, the camera microcontroller 205 again sends an authentication request command via broadcast communication over the communication line DATA in step S503. Here, since the communication line CS is connected, the adapter microcontroller 302 receives the authentication request command in step S511, and the lens microcontroller 111 also receives it in step S514. However, since the adapter microcontroller 302 has already completed communication (i.e., authentication) in response to the authentication request command and the ID communication request command once, it ignores the authentication request command here. On the other hand, since this is the first time the lens microcontroller 111 has received an authentication request command, it interprets it as slave designation data for itself and prepares for P2P communication.

[0075] Subsequently, in step S504, the camera microcontroller 205 sends an ID communication request command via P2P communication over the communication line DATA. Here again, the camera microcontroller 205 does not recognize that the P2P communication partner is the lens microcontroller 111. This is for the same reason as with the adapter microcontroller 302. In step S515, the lens microcontroller 111 sends its own ID information (authentication information) to the camera microcontroller 205 via P2P communication over the signal line DATA in response to the ID communication request command. Once the camera microcontroller 205 confirms that the received ID information belongs to the interchangeable lens 100, it determines that there are no more communication slaves that need to be authenticated. Then, in step S505, the camera microcontroller 205 sends an authentication termination request command via broadcast communication over the signal line DATA to terminate the authentication communication process. In other words, it performs authentication termination communication. In steps S512 and S516, the adapter microcontroller 302 and the lens microcontroller 111 receive the authentication termination request command. This terminates the authentication communication process.

[0076] Thus, in this embodiment, the camera microcontroller 205 sequentially designates a specified slave using broadcast communication each time the CS output status indicates that communication is pending, and performs authentication communication to the designated slave using broadcast communication and P2P communication. [Differentiation] The ID information, which the adapter microcontroller 302 and lens microcontroller 111 transmit to the camera microcontroller 205 in response to an ID communication request command, may be a serial number for each type of accessory device (for example, 00 for interchangeable lenses and 01 for extenders). It may also be information with a meaning assigned to each bit. Furthermore, it may be multi-byte information. The ID information may be any information that indicates the type or function of the accessory device.

[0077] The authentication communication process described above explains the case where the camera microcontroller 205 confirms that the ID information belongs to the interchangeable lens 100 and determines the termination of the authentication communication. Alternatively, the ID information may include information indicating the interchangeable lens along with information instructing the termination of the authentication communication, and the camera microcontroller 205 may determine the termination of the authentication communication by detecting this information. In addition, separate confirmation communication may be performed via P2P communication before or after the ID communication to confirm with the communication slave whether or not the authentication communication can be terminated.

[0078] In this embodiment, the case where one adapter 300 is connected between the camera 200 and the interchangeable lens 100 has been described, but multiple adapters may be connected in a chain. Even when multiple adapters are connected, it is possible to authenticate each adapter and the interchangeable lens 100 in a short time using the same procedure as described above. In this case, since the multiple adapters that simultaneously receive the authentication start request command via broadcast communication will turn off their CS switches almost simultaneously, subsequent authentication will always be performed sequentially, starting with the adapter closest to the camera 200. Then, just as in the case where one adapter is connected, the interchangeable lens 100 is authenticated last, and the series of authentication communication processes is completed.

[0079] Furthermore, if the adapter 300 is not connected and the interchangeable lens 100 is directly connected to the camera 200, the authentication communication portion for the adapter 300 in the authentication communication process shown in Figures 9 and 10 will not be performed, and authentication communication will be performed for the interchangeable lens 100 instead.

[0080] Furthermore, the adapter 300 in this embodiment may be an extender as described above, or it may be an adapter including a drivable optical element (focus lens, aperture, image stabilization lens, etc.), or an adapter including various sensors (phase difference sensor, angular velocity sensor, etc.). The same modifications described above apply to Embodiment 2, which will be described later.

[0081] According to this embodiment, in a camera system that communicates using two lines (two channels), signal line CS and signal line DATA, authentication communication can be performed sequentially starting with the accessory device closest to the camera 200 by switching the CS switch 3033 provided on the adapter 300. Finally, authentication communication can be performed for the interchangeable lens. As a result, authentication communication can be performed in a short time even if multiple accessory devices are connected to the camera 200. [Examples]

[0082] Next, Embodiment 2 of the present invention will be described. In Embodiment 1, the case in which the communication line CS is connected and disconnected with the CS switch 3033 was described, but in this embodiment, the communication line DATA is connected and disconnected with a switch. The configuration of the camera system in this embodiment is the same as in Embodiment 1 (Figure 1), so the description will be omitted.

[0083] Figure 11 shows the communication circuit configured between the camera microcontroller 205, the adapter microcontroller 302, and the lens microcontroller 111. This communication circuit differs from Embodiment 1 (Figure 2), in that the adapter 300' is equipped with a DATA switch (channel switch) 3034 for connecting and disconnecting the communication line DATA, while the adapter 300' is equipped with a CS switch 3033 for connecting and disconnecting the communication line CS.

[0084] The adapter microcontroller 302' can connect and disconnect the signal line DATA by switching the DATA switch 3034 between connected and disconnected states. When the DATA switch 3034 is disconnected, the data output status from the camera side (camera 200 in this embodiment) to the signal line DATA from the adapter 300' is not transmitted to the interchangeable lens side (interchangeable lens 100 in this embodiment). Similarly, the data output status from the adapter 300' to the signal line DATA is not transmitted to the interchangeable lens side. In other words, data communication using the signal line DATA becomes impossible from the adapter 300' to the communication slave on the interchangeable lens side.

[0085] The authentication communication process in this embodiment will be explained using Figures 12 and 13. Figure 12 shows the signal waveforms in the authentication communication process between the camera microcontroller 205, the lens microcontroller 111, and the adapter microcontroller 302. At the top of the figure is the signal output state (CS signal state) of the signal line CS. Below that, "DATA (camera)" shows the data that the camera microcontroller 205 outputs to the signal line DATA, and "DATA (adapter)" shows the data that the adapter microcontroller 302 outputs to the signal line DATA. "DATA (lens)" shows the data that the lens microcontroller 111 outputs to the signal line DATA. "CS output (camera)" shows the signal that the camera microcontroller 205 outputs to the signal line CS, and "CS output (adapter)" shows the signal that the adapter microcontroller 302 outputs to the signal line CS. "CS output (lens)" shows the signal that the lens microcontroller 205 outputs to the signal line CS. "DATASW" shows the state of the DATA switch 3034 controlled by the adapter microcontroller 302, where Low represents the connection state.

[0086] The flowchart in Figure 13 shows the flow of the authentication communication process. This authentication communication process is performed when a detection switch (not shown) on the camera 200 detects the connection of the interchangeable lens 100, and in response, power is supplied from the camera 200 to the interchangeable lens 100 and the adapter 300'.

[0087] At the start of the authentication communication process, the camera microcontroller 205 sends an authentication start request command via broadcast communication over the signal line DATA in step S600. In other words, it performs authentication start communication. This process is performed as pre-processing for authentication communication by the camera microcontroller 205. At this time, the DATA switch 3034 is set to the connected state. The broadcast communication and the subsequent P2P communication processes are as described using Figures 7A, 7B and 8A, 8B. In this embodiment as well, the adapter microcontroller 302 and the lens microcontroller 111 output different signals (Low and Hi) to the signal line CS during broadcast communication and P2P communication, depending on whether they are communicating with the camera microcontroller 205 (from start to end of communication) or waiting for communication.

[0088] Upon receiving the authentication start request command, the adapter microcontroller 302 and the lens microcontroller 111 perform broadcast communication reception processing in steps S606 and S613, respectively. If the received result is an authentication start request command, the adapter microcontroller 302 switches the DATA switch 3034 to the disconnected state in step S607. Here, the timing of this switch is after the adapter microcontroller 302 releases the Low output to signal line CS (after step S208 in Figure 7), but it may also be immediately before or simultaneously with the release of the Low output.

[0089] Next, in response to the Low output to signal line CS by the adapter microcontroller 302 being released and the communication circuit entering a communication standby state, the camera microcontroller 205 sends an authentication request command via broadcast communication over the communication line DATA in step S601. In other words, it performs authentication request communication. In the subsequent processing, the camera microcontroller 205 performs authentication communication. The authentication request command, as in Embodiment 1, becomes slave designation data for designating the communication slave that received it via broadcast communication as a designated slave (specific accessory device). In step S607, the communication line DATA is disconnected by the DATA switch 3034, so the authentication request command via communication line DATA in step S601 is not detected by the lens microcontroller 111. On the other hand, since the communication line CS is connected, the lens microcontroller 111 also detects that the communication line CS goes Low and then Hi. However, since no data is sent via communication line DATA, the lens microcontroller 111 terminates processing as if there was no communication.

[0090] Meanwhile, in step S608, the adapter microcontroller 302 receives an authentication request command via broadcast communication. Upon receiving the authentication request command, the adapter microcontroller 302 interprets it as the first authentication request command it has received, and that the next P2P communication will be addressed to it.

[0091] Next, in step S602, the camera microcontroller 205 sends an ID communication request command via the signal line DATA using P2P communication. In other words, it performs authentication information communication. At this time, the camera microcontroller 205 does not recognize that the P2P communication partner is the adapter microcontroller 302. This is because it does not yet know what kind of accessories are connected to the camera 200 and how many of them are connected. The camera microcontroller 205 only knows that one of the connected communication slaves will respond to P2P communication by specifying a designated slave with the authentication request command sent in step S601.

[0092] The adapter microcontroller 302, designated as the specified slave, receives an ID communication request command via P2P communication in step S609 and, in response, transmits its own ID information (authentication information) to the camera microcontroller 205 via P2P communication through the signal line DATA. Subsequently, in step S610, the adapter microcontroller 302 switches the DATA connection switch 3034 to the connected state. Here, this switching timing occurs after the adapter microcontroller 302 releases the Low output to the signal line CS (after step S410 in Figure 8), but it may also occur immediately before or simultaneously with the release of the Low output.

[0093] Furthermore, the P2P communication in steps S602 and S609 may be performed only once between the camera microcontroller 205 and the adapter microcontroller 302, or it may be performed two or more times, as shown in Figure 12.

[0094] Furthermore, although this flowchart shows the timing for switching the DATA switch 3034 to the connected state as after step S609, it may also be done before step 609 (after receiving the authentication request command in step S608). This is because the adapter microcontroller 302, which receives the authentication request command via broadcast communication, recognizes it as slave designation data for itself, while the lens microcontroller 111, which has not received the authentication request command, does not recognize it as slave designation data for itself. For this reason, even if the DATA switch 3034 is switched to the connected state after step S608, only the adapter microcontroller 302 will respond to the ID communication request command in step S609.

[0095] Next, in response to the adapter microcontroller 302 releasing the Low output to signal line CS and the communication circuit entering a communication standby state, the camera microcontroller 205 again sends an authentication request command via broadcast communication over signal line DATA in step S603. Here, since communication line DATA is connected, the adapter microcontroller 302 receives the authentication request command in step S611, and the lens microcontroller 111 also receives it in step S614. However, since the adapter microcontroller 302 has already completed communication (i.e., authentication) in response to the authentication request command and ID communication request command once, it ignores the authentication request command here. On the other hand, since this is the first time the lens microcontroller 111 has received an authentication request command, it interprets it as slave designation data for itself and prepares for P2P communication.

[0096] Subsequently, in step S604, the camera microcontroller 205 sends an ID communication request command via P2P communication through the signal line DATA. Here again, the camera microcontroller 205 does not recognize that the P2P communication partner is the lens microcontroller 111. This is for the same reason as with the adapter microcontroller 302. In step S615, the lens microcontroller 111 sends its own ID information (authentication information) to the camera microcontroller 205 via P2P communication through the signal line DATA in response to the ID communication request command. When the camera microcontroller 205 confirms that the received ID information belongs to the interchangeable lens 100, it determines that there are no more communication slaves that need to be authenticated. Then, in step S605, the camera microcontroller 205 sends an authentication termination request command via broadcast communication through the signal line DATA to terminate the authentication communication process. In other words, it performs authentication termination communication. In steps S612 and S616, the adapter microcontroller 302 and the lens microcontroller 111 receive the authentication termination request command. This terminates the authentication communication process.

[0097] Thus, in this embodiment as well, the camera microcontroller 205 sequentially designates a specified slave using broadcast communication each time the CS output status indicates that communication is pending, and performs authentication communication to the designated slave using broadcast communication and P2P communication.

[0098] According to this embodiment, in a camera system that communicates using two lines (two channels), signal line CS and signal line DATA, authentication communication can be performed sequentially starting with the accessory device closest to the camera 200 by switching the DATA switch 3034 provided on the adapter 300'. Finally, authentication communication can be performed for the interchangeable lens. As a result, authentication communication can be performed in a short time even if multiple accessory devices are connected to the camera 200.

[0099] The embodiment described above can be used in conjunction with other communication channels, in addition to the communication channels including the notification channel CS and the data communication channel DATA.

[0100] An example of this will be explained using Figure 14. In Figure 14, the same reference numerals are used for components identical to those in Figure 1, and redundant explanations are omitted. Also, in Figure 14, some of the components shown in Figure 1 are not shown. The aforementioned notification channel CS and data communication channel DATA are communication lines for a third type of communication. In the third type of communication, when the operating component 304 is operated by the user, the adapter microcontroller 302 and the camera microcontroller 205 communicate that an operation has occurred and the amount of operation, etc. If the operating component 130 is operated by the user, communication may also be made between the lens microcontroller 111 and the camera microcontroller 205 using the communication line for the third type of communication.

[0101] The lens microcontroller 111 controls the communication unit 112, as well as the communication unit 131 for first communication and the communication unit 132 for second communication. The camera microcontroller 205 controls the communication unit 112, as well as the communication unit 209 for first communication and the communication unit 210 for second communication.

[0102] First, let's explain the first communication. The first communication is conducted via communication unit 131 and communication unit 209. Communication unit 131 communicates via notification channel CS1, data communication channel DCL, and data communication channel DLC based on instructions from lens microcontroller 111, and communication unit 209 communicates via notification channel CS1, data communication channel DCL, and data communication channel DLC based on instructions from camera microcontroller 205. Communication unit 131 and communication unit 209 set the voltage level of notification channel CS1, the communication rate (amount of data per unit time) and communication voltage during asynchronous communication. Furthermore, they send and receive data via data communication channel DCL and data communication channel DLC based on instructions from lens microcontroller 111 and camera microcontroller 205.

[0103] Notification channel CS1 is a signal line used for notifying the camera 200 of communication requests to the interchangeable lens 100, etc. Data communication channel DCL is a channel used when transmitting data from the camera 200 to the interchangeable lens 100, and data communication channel DLC is a channel used when transmitting data from the interchangeable lens 100 to the camera 200.

[0104] In the first communication, the camera microcontroller 205 and the lens microcontroller 111 communicate using either clock-synchronous communication or asynchronous communication. Initial communication, which occurs when the interchangeable lens 100 is connected to the camera 200, is also initially performed using the first communication method. The camera microcontroller 205 and the lens microcontroller 111 communicate identification information of the interchangeable lens 100, and when it is determined that the interchangeable lens 100 mounted on the camera 200 is compatible with asynchronous communication, the communication method is switched from clock-synchronous communication to asynchronous communication. In addition, as a result of the communication of identification information, the camera microcontroller 205 may determine whether the interchangeable lens 100 is compatible with a third communication, which includes communication with the adapter 300. If the camera microcontroller 205 determines that the interchangeable lens 100 is compatible with the third communication, it may perform authentication communication via P2P communication to recognize the interchangeable lens 100 and the intermediate adapter 300.

[0105] Next, the second communication will be described. The second communication is a one-way communication from the interchangeable lens 100 to the camera 200. The second communication is conducted via the communication unit 132 and the communication unit 210. The communication unit 132 communicates via the notification channel CS2 and the data communication channel DLC2 based on instructions from the lens microcontroller 111, and the communication unit 210 communicates via the notification channel CS2 and the data communication channel DLC2 based on instructions from the camera microcontroller 205. The camera communication unit 208 and the lens communication unit 118 send and receive data using clock-synchronous communication or asynchronous communication. By using the data communication channel DLC2 of the second communication channel together with the data communication channel DLC of the first communication, it becomes possible to send a large amount of data from the interchangeable lens 100 to the camera 200 in a short amount of time. (Other examples) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0106] The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention. [Explanation of Symbols]

[0107] 100 interchangeable lenses 200 Camera body 300 adapter 111 Lens Microcomputer 205 Camera Microcomputer 302 Adapter Microcomputer 112 Lens Communication Unit 208 Camera Communications Department 303 Adapter Communication Unit

Claims

1. An accessory device that can be attached to and detached from a camera, When the accessory device is attached to the camera together with other accessory devices, the receiving unit includes a receiving unit that receives an instruction signal different from a clock signal transmitted from the camera using a first communication channel that includes a communication channel between the other accessory devices and the camera. The instruction signal includes identification information assigned to an accessory device attached to the camera and instructions from the camera. An accessory device characterized in that, in the state described above, if the other accessory device is not identified by the camera, it does not perform individual communication with the camera using the first communication channel.

2. The accessory device according to claim 1, characterized in that the identification information is information for identifying an accessory device attached to the camera.

3. An accessory device that can be attached to or removed from a camera, When the accessory device is attached to the camera together with other accessory devices, the receiving unit includes a receiving unit that receives an instruction signal different from a clock signal transmitted from the camera using a first communication channel that includes a communication channel between the other accessory devices and the camera. The instruction signal includes identification information for identifying an accessory device attached to the camera. An accessory device characterized in that, in the state described above, if the other accessory device is not identified by the camera, it does not perform individual communication with the camera using the first communication channel.

4. The accessory device according to any one of claims 1 to 3, characterized in that, after the other accessory device is identified by the camera, it performs individual communication with the camera using the first communication channel.

5. The accessory device according to any one of claims 1 to 4, characterized in that it transmits signals to the camera using a second communication channel different from the first communication channel.

6. The accessory device according to claim 5, characterized in that the second communication channel includes a communication channel between the other accessory device and the camera.

7. The accessory device according to any one of claims 1 to 6, characterized in that the identification information is information that identifies the accessory device that performs the instruction.

8. The accessory device according to any one of claims 1 to 7, characterized in that the identification information is information that specifies a communication partner with whom to communicate with the camera.

9. The accessory device according to claim 8, characterized in that the identification information is information for identifying one communication partner from among a plurality of accessory devices attached to the camera.

10. The accessory device according to any one of claims 1 to 9, characterized in that the identification information is information indicating the order in which the camera is attached.

11. The accessory device according to any one of claims 1 to 10, characterized in that the instructions from the camera include at least one of instructions relating to the control of the accessory device and instructions relating to a request for data transmission to the accessory device.

12. The accessory device according to any one of claims 1 to 11, characterized by comprising an optical system into which light from a subject is incident.

13. The accessory device according to any one of claims 1 to 12, characterized in that the other accessory device is detachably attached between the camera and the accessory device.

14. An accessory device that can be attached to or detached from a camera, When the accessory device is attached to the camera together with other accessory devices, the receiving unit includes a receiving unit that receives an instruction signal different from a clock signal transmitted from the camera using a first communication channel included in the communication channel between the other accessory devices and the camera. The instruction signal includes identification information assigned to an accessory device attached to the camera and instructions from the camera. An accessory device characterized by blocking individual communication between the camera and other accessory devices when the accessory device is not identified by the camera in the aforementioned state.

15. An accessory device that can be attached to or detached from a camera, When the accessory device is attached to the camera together with other accessory devices, the receiving unit includes a receiving unit that receives an instruction signal different from a clock signal transmitted from the camera using a first communication channel included in the communication channel between the other accessory devices and the camera. The instruction signal includes identification information for identifying an accessory device attached to the camera. An accessory device characterized by blocking individual communication between the camera and other accessory devices when the accessory device is not identified by the camera in the aforementioned state.

16. The accessory device according to claim 14 or 15, characterized in that, when the accessory device is not identified by the camera, it blocks communication between the camera and other accessory devices while it is communicating with the camera using the first communication channel.

17. The accessory device according to any one of claims 14 to 16, further comprising a switch for switching whether or not communication is possible between the camera and the other accessory device.

18. The accessory device according to claim 17, wherein the switch switches whether or not communication between the camera and the other accessory device using the first communication channel is enabled.

19. The accessory device according to claim 17, characterized in that the switch switches whether or not communication between the camera and the other accessory device is enabled using a second communication channel different from the first communication channel.

20. The accessory device according to any one of claims 14 to 19, characterized in that, after the accessory device is identified by the camera, individual communication between the camera and the other accessory device is permitted.

21. The accessory device according to any one of claims 14 to 20, characterized in that it is detachable between the camera and the other accessory device.

22. A camera with detachable accessory devices, When the accessory device is attached to the camera together with other accessory devices, the device includes a transmitting unit that transmits an instruction signal different from a clock signal to the accessory device using a first communication channel that includes a communication channel between the other accessory devices and the camera. The instruction signal includes identification information assigned to an accessory device attached to the camera and instructions from the camera. A camera characterized in that, if the other accessory device is not identified in the aforementioned state, it does not perform individual communication with the accessory device using the first communication channel.

23. A camera with detachable accessory devices, When the accessory device is attached to the camera together with other accessory devices, the device includes a transmitting unit that transmits an instruction signal different from a clock signal to the accessory device using a first communication channel that includes a communication channel between the other accessory devices and the camera. The instruction signal includes identification information for identifying an accessory device attached to the camera. A camera characterized in that, if the other accessory device is not identified in the aforementioned state, it does not perform individual communication with the accessory device using the first communication channel.

24. The camera according to claim 22 or 23, characterized in that the instructions from the camera include at least one of instructions relating to the control of the accessory device and instructions relating to a request for data transmission to the accessory device.

25. The camera according to any one of claims 22 to 24, characterized in that after identifying the other accessory device, it performs individual communication with the accessory device using the first communication channel.

26. The camera according to any one of claims 22 to 25, characterized in that it transmits signals to the accessory device using a second communication channel different from the first communication channel.

27. ​​The camera according to claim 26, characterized in that the second communication channel includes a communication channel between the other accessory device and the camera.

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