JP2020166203A - Adapter device, camera system, control method and program - Google Patents

Abstract

To achieve an adapter device that makes it possible to perform high-speed transmission/reception of data without inducing a failure of communication, not adding a new channel.SOLUTION: An adapter device 200 has a control unit 205 that controls communication with a lens device 100, using a notification channel to be used for notification from the adapter device 200 to the lens device 100, a lens data communication channel to be used for data transmission from the lens device 100 to the adapter device 200, and an adapter data communication channel to be used for data transmission from the adapter device 200 to the lens device 100. The control unit 205 is configured to: transmit a transmission request signal requesting the data transmission from the lens device 100 to the adapter device 200 via the notification channel; and responding to a reception start of first data transmitted from the lens device in responce to the transmission request signal, transmit second data to the lens device via the adapter data communication channel.SELECTED DRAWING: Figure 4

Description

The present invention relates to adapter devices, camera systems, control methods and programs.

As an interchangeable lens type camera system, there is known a system in which a camera performs image pickup processing and lens control, and a lens device as an interchangeable lens drives a lens in accordance with a control command from the camera. In such a camera system, the transmission of control commands from the camera to the interchangeable lens and the transmission of lens information from the interchangeable lens to the camera are performed via a communication channel for exchanging information with each other.

Among interchangeable lens camera systems, especially in digital camera systems, smooth lens control is required according to the imaging cycle during movie shooting and live view shooting. For this purpose, it is necessary to synchronize the imaging timing of the camera with the control timing of the interchangeable lens, and the camera acquires the lens information necessary for lens control and transmits the control command to the interchangeable lens within the imaging cycle. Need to be completed.

On the other hand, with the advancement of imaging technology, the amount of lens information data acquired by the camera from the interchangeable lens is increasing, and the frame rate is increasing. As a result, it is necessary to communicate a large amount of data in a shorter time than before.

Patent Document 1 discloses a clock-synchronized communication system including a clock channel, a data transmission channel from a camera to an interchangeable lens, and a data transmission channel from an interchangeable lens to a camera. In this communication system, the camera first generates a clock signal as a communication master, and outputs a clock signal of one frame to the interchangeable lens via the clock channel. After that, the input and output of the clock channel are switched, and the interchangeable lens that became the communication master instead of the camera outputs the standby request signal to the same channel. This makes it possible for the interchangeable lens to notify the camera that it is in a processing waiting state after communication.

JP-A-9-304804

There is known an adapter device that is mounted between an interchangeable lens and a camera and that appropriately establishes communication between a lens device in one camera system and a camera in another camera system. This adapter device attempts to appropriately establish communication in a combination of a lens device and an imaging device that are not supposed to be directly connected. Consider the case where the interchangeable lens is connected to the image pickup device via such an adapter device.

When the communication system disclosed in Patent Document 1 is applied between an adapter device and an interchangeable lens, communication is performed between the adapter device that outputs a clock signal and the interchangeable lens that outputs a standby request signal on the same channel. It is necessary to switch the master by time management. Therefore, for the purpose of preventing communication collisions, it is necessary to provide a time for switching the communication master, that is, a communication invalid time during which communication cannot be performed, and as a result, there is a risk of delay in communication or control.

If the output of the standby request signal to the clock channel by the interchangeable lens is stopped in order to solve such a problem, the communication standby request from the interchangeable lens to the camera cannot be made at all. If there is no means for the interchangeable lens side to control the timing at which data can be received, such as a standby request signal, a large amount of data can be communicated from the adapter device to the interchangeable lens at any time. As a result, if the interchangeable lens that is the communication slave overflows the receive buffer or the data to be transmitted to the adapter device is not generated in time, the communication may be disrupted. Further, if a new channel is provided to output the standby request signal, the power consumption increases, and the miniaturization of the adapter device and the interchangeable lens is hindered.

An object of the present invention is to realize an adapter device capable of transmitting and receiving data at high speed without adding a new channel and without causing a communication failure.

The adapter device according to the embodiment of the present invention is an adapter device that can be attached and detached between the camera and the lens device, and includes a notification channel used for notification from the adapter device to the lens device and the lens device to the lens device. It has a control unit that controls communication with the lens device using the lens data communication channel used for data transmission to the adapter device and the adapter data communication channel used for data transmission from the adapter device to the lens device. Then, the control unit transmits a transmission request signal requesting data transmission from the lens device to the adapter device via the notification channel, and the first unit transmitted from the lens device in response to the transmission request signal. The second data is transmitted to the lens device via the adapter data communication channel in response to the start of data reception.

The adapter device according to the embodiment of the present invention is an adapter device that can be attached and detached between the camera and the lens device, and is used for transmitting a transmission request signal requesting data transmission from the adapter device to the lens device. It has a control unit that controls communication with the lens device using a channel including a notification channel and a lens data communication channel used for data transmission from the lens device to the adapter device, and the transmission request signal is transmitted. The control unit does not transmit the transmission request signal to the lens device while the standby request signal is received from the lens device.

The program of one embodiment of the present invention is used for a notification channel used for notification from an adapter device detachable between a camera and a lens device to the lens device, and for data transmission from the lens device to the adapter device. A program to be executed by a computer of an adapter device capable of communicating with the lens device via the lens data communication channel to be used and an adapter data communication channel used for data transmission from the adapter device to the lens device. A step of transmitting a transmission request signal requesting data transmission from the adapter device to the lens device via the notification channel, and reception of first data transmitted from the lens device in response to the transmission request signal. It is characterized in that the step of transmitting the second data to the lens device via the adapter data communication channel is executed according to the start.

The program of one embodiment of the present invention is used for a notification channel used for notification from an adapter device detachable between a camera and a lens device to the lens device, and for data transmission from the lens device to the adapter device. A program to be executed by a computer of an adapter device capable of communicating with the lens device via a lens data communication channel, so that a transmission request signal requesting data transmission from the lens device to the adapter device is not transmitted. It is characterized by having a step of starting to receive the standby request signal from the lens device and a step of not transmitting the transmission request signal to the lens device while the standby request signal is being performed.

The camera system of one embodiment of the present invention is a camera system including a lens device that can be attached to and detached from a camera and an adapter device that can be attached and detached between the camera and the lens device. For the notification channel used for notification from the adapter device to the lens device, the lens data communication channel used for data transmission from the lens device to the adapter device, and data transmission from the adapter device to the lens device. It has a first control unit that controls communication with the lens device using the adapter data communication channel used, and the lens device includes the notification channel, the lens data communication channel, and the adapter data communication channel. The first control unit has a second control unit that controls communication with the adapter device using the above, and the first control unit sends a transmission request signal requesting data transmission from the lens device to the adapter device in the notification channel. The second control unit transmits the first data to the adapter device via the lens data communication channel in response to receiving the transmission request signal. The first control unit is characterized in that the second data is transmitted to the lens device via the adapter data communication channel in response to the start of reception of the first data.

The camera system of one embodiment of the present invention is a camera system including a lens device that can be attached to and detached from a camera and an adapter device that can be attached and detached between the camera and the lens device. 1. A notification channel used for notification from the adapter device to the lens device and a lens data communication channel used for data transmission from the lens device to the adapter device are used to control communication with the lens device. The lens device has one control unit, and the lens device has a second control unit that controls communication with the adapter device using a channel including the notification channel and the lens data communication channel, and the first control unit. The unit transmits a transmission request signal requesting data transmission from the lens device to the adapter device via the notification channel to the lens device, and the second control unit receives the transmission request signal. Data is transmitted to the adapter device via the lens data communication channel, and the second control unit prevents the adapter device from transmitting the transmission request signal to the lens device. It is characterized in that a standby request signal for the purpose is transmitted to the first control unit.

According to the adapter device of the present invention, it is possible to transmit and receive data to and from the interchangeable lens at high speed without adding a new channel and without causing a communication failure.

It is a figure which shows the structure of the camera system including the adapter device which concerns on embodiment. It is the schematic which shows the communication circuit between an adapter device and an interchangeable lens. It is the schematic which shows the communication waveform in the communication mode M1. It is the schematic which shows the communication waveform in the communication mode M2. It is the schematic which shows the communication waveform in communication mode M3. It is a flowchart explaining the flow of determining a communication format in an interchangeable lens and an adapter device. It is a flowchart explaining the data communication flow in a communication mode M2. It is the schematic which shows the communication waveform at the time of switching a communication method. It is a flowchart explaining the communication flow at the time of switching a communication method.

The present embodiment relates to a camera system including a camera, an interchangeable lens (lens device) detachable from the camera, and an adapter device. The adapter device is removable between the camera and the interchangeable lens, and communication between the camera and the interchangeable lens is also possible via the adapter device.

Prior to the description of this embodiment, the definitions of terms used in the present specification will be described.

"Communication format" refers to the overall communication arrangement between the adapter device and the interchangeable lens. The "communication method" means a clock synchronization type and a pace synchronization type, and the clock synchronization type is the communication method A and the pace synchronization type is the communication method B. The "data format" indicates whether or not the standby request signal (BUSY signal) can be added. The data format that allows the addition of the BUSY signal is "format F1", and the data format that prohibits the addition of the BUSY signal is "format F2". To do.

The “communication mode” means a combination of a communication method and a data format, and the following three communication modes will be described in the present embodiment. "Communication mode M1" is a communication mode of communication method A and format F1, and "communication mode M2" is a communication mode of communication method B and format F1. Further, the "communication mode M3" is a communication mode of the communication method B and the format F2.

The present embodiment specifically relates to communication control between the adapter device and the interchangeable lens in the communication mode M2. In the following embodiment, an adapter device system having an adapter device capable of switching a plurality of communication modes including the communication mode M2 and communicating with an interchangeable lens is shown. By appropriately switching the communication mode in this way and performing communication, an appropriate communication mode can be selected according to the combination of the adapter device and the interchangeable lens and the shooting mode.

For example, when the adapter device and the interchangeable lens are compatible with the communication mode M3 and a large amount of data is transmitted / received, the addition of the BUSY signal is prohibited after switching each communication mode to the communication mode M3. Data communication is executed. If it takes a certain amount of time to process the data in the interchangeable lens, the communication mode of the adapter device and the interchangeable lens is switched to the communication mode M2, and then the data communication in which the BUSY signal is permitted is performed. As a result, data communication is performed between the adapter device and the interchangeable lens without causing communication failure.

Next, the camera system having the adapter device according to the embodiment will be described with reference to the attached drawings. In the following description, the same components will be designated by the same reference numerals, and duplicate description will be omitted.

FIG. 1 is a diagram showing a configuration of a camera system 1 including an adapter device 200 according to an embodiment of the present invention. The adapter device 200 is detachably mounted between the interchangeable lens 100 and the camera 300.

The interchangeable lens 100 and the adapter device 200 are mechanically and electrically connected via a mount 150, which is a coupling mechanism. Further, the adapter device 200 and the camera 300 are mechanically and electrically connected via a mount 250 which is a coupling mechanism.

The interchangeable lens 100 has a communication unit 112, the adapter device has a communication unit 208, and the camera 300 has a communication unit 308, and control commands and internal information are communicated via these communication units.

However, the interchangeable lens 100 and the camera 300 are not supposed to be directly connected to each other, and the communication protocol of the interchangeable lens 100 and the communication protocol of the camera 300 are different. A communication protocol is a procedure for exchanging data.

That is, the adapter device 200 has a function of appropriately establishing signal exchange between the interchangeable lens 100 and the camera 300. In order to execute the function, the communication unit 208 communicates with the communication unit 308 using the first communication protocol (hereinafter referred to as a camera-side protocol) and a communication protocol with the communication unit 112. Communication using (hereinafter referred to as the lens-side protocol) is possible.

In this embodiment, the lens-side protocol is configured to support a plurality of communication methods. When communication is started in the lens-side protocol, initial communication is performed in which the interchangeable lens 100 transmits information about the communication method supported by the interchangeable lens 100 to the adapter device 200. The timing at which communication using the lens-side protocol is started is the timing at which the connection between the interchangeable lens 100, the adapter device 200, and the camera 300 is completed, the timing at which the power of the camera 300 is turned on, and the like. After that, the adapter device 200 and the interchangeable lens 100 select the optimum communication method from the communication methods supported by the adapter device 200 and the interchangeable lens 100 according to the type of communication data, the communication purpose, and the timing, and perform communication.

First, a specific configuration of the interchangeable lens 100 and the adapter device 200 will be described. The interchangeable lens 100 and the adapter device 200 are mechanically and electrically connected via a mount 150, which is a coupling mechanism. The interchangeable lens 100 receives power from the adapter device 200 via a power supply terminal (not shown) provided on the mount 150, and controls various actuators and a lens microcomputer (hereinafter referred to as a lens microcomputer) 111, which will be described later. Further, the interchangeable lens 100 and the adapter device 200 communicate with each other via a communication terminal (shown in FIG. 2) provided on the mount 150.

The interchangeable lens 100 has an imaging optical system. The imaging optical system includes a field lens 101, a variable magnification lens 102 that performs magnification change, an aperture unit 114 that adjusts the amount of light, an image shake correction lens 103, and a focus lens 104 that adjusts focus, in order from the subject OBJ side. including.

The variable magnification lens 102 and the focus lens 104 are held by the lens holding frames 105 and 106, respectively. The lens holding frames 105 and 106 are movably guided in the optical axis direction shown by a broken line in the drawing by a guide shaft (not shown), and are driven in the optical axis direction by stepping motors 107 and 108, respectively. The stepping motors 107 and 108 move the variable magnification lens 102 and the focus lens 104 in synchronization with the drive pulse, respectively.

The image shake correction lens 103 moves in a direction orthogonal to the optical axis of the image pickup optical system to reduce image shake caused by camera shake or the like.

The lens microcomputer 111 is a lens control unit (second control unit) that controls the operation of each unit in the interchangeable lens 100. The lens microcomputer 111 has a communication unit 112 including a lens data transmission / reception unit 112b for transmitting / receiving data via an interface (I / F) circuit 112a (shown in FIG. 2). The lens microcomputer 111 performs lens control corresponding to a control command received from the adapter device 200, and transmits lens data corresponding to a data transmission request from the adapter device 200 to the adapter device 200. The lens data includes optical information of the interchangeable lens 100, characteristic information (lens ID) unique to the interchangeable lens 100, and the like.

The lens microcomputer 111 is a lens control unit that controls the operation of each part in the interchangeable lens 100. The lens microcomputer 111 receives a control command transmitted from the adapter device 200 via the communication unit 112, and receives a lens data transmission request. Further, the lens microcomputer 111 controls the lens corresponding to the control command, and transmits the lens data corresponding to the transmission request to the adapter device 200 via the communication unit 112.

Further, the lens microcomputer 111 outputs a drive signal to the zoom drive circuit 119 and the focus drive circuit 120 in response to commands related to scaling and focusing among control commands to drive the stepping motors 107 and 108. As a result, a zoom process for controlling the variable magnification operation by the variable magnification lens 102 and an autofocus process for controlling the focus adjustment operation by the focus lens 104 are performed.

The diaphragm unit 114 has diaphragm blades 114a and 114b. The states of the diaphragm blades 114a and 114b are detected by the Hall element 115 and input to the lens microcomputer 111 via the amplifier circuit 122 and the A / D conversion circuit 123. The lens microcomputer 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. Thereby, the light amount adjustment operation by the diaphragm unit 114 is controlled.

Further, the lens microcomputer 111 drives the vibration isolation actuator 126 via the vibration isolation drive circuit 125 in response to the vibration detected by a vibration sensor (not shown) such as a vibration gyro provided in the interchangeable lens 100. As a result, vibration isolation processing is performed to control the shift operation of the image shake correction lens 103.

The adapter device 200 includes an adapter microcomputer (hereinafter referred to as an adapter microcomputer) 205. The adapter microcomputer 205 functions as an adapter control unit (first control unit) that controls the operation of each unit in the adapter device 200.

The adapter microcomputer 205 has a communication unit 208 including an adapter data transmission / reception unit 208b for transmitting / receiving data via a communication interface (I / F) circuit 208a (shown in FIG. 2). The adapter data transmission / reception unit 208b and the lens data transmission / reception unit 112b are connected. The communication unit 208 transmits a control command to the lens microcomputer 111 using the lens-side protocol, and receives data transmitted from the lens microcomputer 111.

The adapter data transmission / reception unit 208b is also connected to the communication unit 308, which will be described later. The communication unit 208 receives a control command transmitted from the communication unit 308 by the camera-side protocol, and transmits data to the communication unit 308.

Further, the communication unit 208 converts the first signal transmitted from the camera 300 into a second signal in the communication by the lens-side protocol performed between the adapter device 200 and the interchangeable lens 100 to the interchangeable lens 100. It has a function to transmit. Further, the communication unit 208 converts the third signal transmitted from the interchangeable lens 100 into a fourth signal in the communication by the camera-side protocol performed between the adapter device 200 and the camera 300 and transmits it to the camera 300. Has the function of

Next, the configuration of the camera 300 will be described. The camera 300 includes an image sensor 301 such as a CCD sensor or a CMOS sensor, an A / D conversion circuit 302, a signal processing circuit 303, a recording unit 304, a camera microcomputer (hereinafter referred to as a camera microcomputer) 305, and a display unit. It has 306 and.

The image pickup element 301 photoelectrically converts the subject image formed by the image pickup optical system in the interchangeable lens 100 and outputs an electric signal (analog signal). The A / D conversion circuit 302 converts the analog signal from the image sensor 301 into a digital signal. The signal processing circuit 303 performs various image processing on the digital signal from the A / D conversion circuit 302 to generate a video signal.

The signal processing circuit 303 also generates contrast state of the subject image, that is, focus information indicating the focus state of the imaging optical system and luminance information indicating the exposure state from the video signal. The signal processing circuit 303 outputs a video signal to the display unit 306, and the display unit 306 displays the video signal as a live view image used for confirming a composition, a focus state, or the like.

The camera microcomputer 305 controls the camera 300 in response to inputs from camera operating members such as an imaging instruction switch (not shown) and various setting switches. Further, the camera microcomputer 305 transmits a control command related to the variable magnification operation of the variable magnification lens 102 to the adapter microcomputer 205 via the communication unit 208. Further, the camera microcomputer 305 transmits a control command regarding the light amount adjusting operation of the aperture unit 114 according to the luminance information and the focus adjusting operation of the focus lens 104 according to the focus information to the adapter microcomputer 205 via the communication unit 308.

Next, the communication circuit configured between the adapter device 200 and the interchangeable lens 100 and the communication control performed between them will be described with reference to FIG. The adapter microcomputer 205 has a function of managing a communication format with the lens microcomputer 111 and a function of notifying the lens microcomputer 111 of a transmission request or the like. Further, the lens microcomputer 111 has a function of generating lens data and a function of transmitting the lens data.

The adapter microcomputer 205 and the lens microcomputer 111 communicate with each other via the interface circuits 208a and 112a. Here, the interface circuit 208a and the adapter data transmission / reception unit 208b are collectively referred to as a communication unit 208, and the interface circuit 112a and the lens data transmission / reception unit 112b are collectively referred to as a communication unit 112.

In the present embodiment, the adapter microcomputer 205 and the lens microcomputer 111 perform serial communication by the three-wire communication method A and the communication method B using three channels.

One of the above three channels is a clock channel in the communication method A, and is a notification channel used for notification from the adapter microcomputer 205 to the lens microcomputer 111 in the communication method B. One of the other two channels is a first data communication channel (lens data communication channel) used for transmitting lens data from the lens microcomputer 111 to the adapter microcomputer 205. The other channel is a second data communication channel (adapter data communication channel) used for transmitting adapter data from the adapter microcomputer 205 to the lens microcomputer 111.

The content indicated by the adapter data transmitted from the adapter microcomputer 205 may be a command to the lens microcomputer 111 output from the camera microcomputer 305, or dummy data that must be transmitted in order to communicate with the lens microcomputer 111. ..

The content indicated by the lens data transmitted from the lens microcomputer 111 may be a response to a request from the camera microcomputer 305, or various values to be periodically transmitted to the camera microcomputer 305. Alternatively, it may be dummy data that must be transmitted in order to communicate with the adapter microcomputer 205. When the adapter microcomputer 205 determines that the content indicated by the lens data received from the lens microcomputer 111 should be transmitted to the camera microcomputer 305, the adapter microcomputer 205 converts the data according to the camera side protocol into the data according to the camera microcomputer 305. Communicate the contents to. At this time, the adapter microcomputer 205 appropriately converts the lens data received from the lens microcomputer 111 into a data format that can be transmitted to the camera microcomputer 305, and then transmits the lens data to the camera microcomputer 305.

The lens data transmitted as a signal from the lens microcomputer 111 to the adapter microcomputer 205 via the first data communication channel is called a lens data signal DLC. Further, the adapter data transmitted as a signal from the adapter microcomputer 205 to the lens microcomputer 111 via the second data communication channel is referred to as an adapter data signal DCL.

First, communication using the communication method A will be described. In the communication method A, the clock signal LCLK is output from the adapter microcomputer 205 as the communication master to the lens microcomputer 111 as the communication slave via the clock channel. The adapter data signal DCL includes a control command, a transmission request command, and the like from the adapter microcomputer 205 to the lens microcomputer 111. On the other hand, the lens data signal DLC includes various data transmitted from the lens microcomputer 111 to the adapter microcomputer 205 in synchronization with the clock signal LCLK. The adapter microcomputer 205 and the lens microcomputer 111 can communicate with each other by a full duplex communication method (full duplex method) in which transmission and reception are performed simultaneously and simultaneously in synchronization with the common clock signal LCLK.

3 (A) to 3 (C) show waveforms of signals exchanged between the adapter microcomputer 205 and the lens microcomputer 111.

FIG. 3A shows a signal waveform of one frame, which is the minimum communication unit. First, the adapter microcomputer 205 outputs a clock signal LCLK having a set of clock pulses of 8 cycles, and transmits an adapter data signal DCL to the lens microcomputer 111 in synchronization with the clock signal LCLK. At the same time, the adapter microcomputer 205 receives the lens data signal DLC output from the lens microcomputer 111 in synchronization with the clock signal LCLK.

In this way, 1 byte (8 bits) of data is transmitted and received between the lens microcomputer 111 and the adapter microcomputer 205 in synchronization with a set of clock signals LCLK. This 1-byte data transmission / reception period is called a data frame. After transmitting and receiving the 1-byte data, the lens microcomputer 111 transmits a signal for notifying the standby request BUSY to the adapter microcomputer 205 (hereinafter referred to as a BUSY signal), whereby a communication standby period is inserted. This communication standby period is called a BUSY frame, and the adapter microcomputer 205 is in the communication standby state while receiving the BUSY frame. Then, the communication unit in which the data frame period and the BUSY frame period are a set is one frame. Depending on the communication status, the BUSY frame may not be added, but in this case, one frame is configured only by the data frame period.

FIG. 3B shows a signal waveform when the adapter microcomputer 205 transmits the request command CMD1 to the lens microcomputer 111 and receives the corresponding 2-byte lens data DT1 (DT1a, DT1b) from the lens microcomputer 111. ing. FIG. 3B shows an example in which data communication is executed according to “communication CMD1”.

Between the adapter microcomputer 205 and the lens microcomputer 111, the type and the number of bytes of the lens data DT corresponding to each of the plurality of types of command CMDs are determined in advance. When the adapter microcomputer 205, which is a communication master, transmits a specific command CMD to the lens microcomputer 111, the lens microcomputer 111 transmits the required number of clocks to the adapter microcomputer 205 based on the information on the number of lens data bytes corresponding to the command CMD. To do. Further, the processing of the lens microcomputer 111 with respect to the command CMD1 includes superimposing a BUSY signal on the clock signal LCLK of each frame, and the above-mentioned BUSY frame is inserted between the data frames.

In the communication CMD1, the adapter microcomputer 205 transmits the clock signal LCLK to the lens microcomputer 111, and further transmits the request command CMD1 requesting the transmission of the lens data DT1 to the lens microcomputer 111 as the adapter data signal DCL. The lens data signal DLC in this frame is treated as invalid data.

Subsequently, the adapter microcomputer 205 switches the clock channel on the camera microcomputer side (camera side) from the output setting to the input setting after outputting the clock signal LCLK for eight cycles on the clock channel. When the switching of the clock channel on the camera microcomputer side is completed, the lens microcomputer 111 switches the clock channel on the lens microcomputer 111 side (interchangeable lens side) from the input setting to the output setting. Then, the lens microcomputer 111 sets the voltage level of the clock channel to Low in order to notify the adapter microcomputer 205 of the standby request BUSY. As a result, the BUSY signal is superimposed on the clock channel. The adapter microcomputer 205 maintains the clock channel input setting during the period when the standby request BUSY is notified, and stops the communication to the lens microcomputer 111.

The lens microcomputer 111 generates the lens data DT1 corresponding to the transmission request command CMD1 during the notification period of the standby request BUSY. Then, when the preparation for transmitting the lens data DT1 as the lens data signal DLC of the next frame is completed, the signal level of the clock channel on the lens microcomputer side is switched to High, and the standby request BUSY is released.

Upon recognizing the cancellation of the standby request BUSY, the adapter microcomputer 205 receives the lens data DT1a from the lens microcomputer 111 by transmitting the clock signal LCLK of one frame to the lens microcomputer 111. In the next frame, the adapter microcomputer 205 and the lens microcomputer 111, which output the clock signal LCLK again for eight cycles, repeat the same operation as described above. As a result, the adapter microcomputer 205 receives the lens data DT1b from the lens microcomputer 111.

FIG. 3C shows a signal waveform when the adapter microcomputer 205 transmits the request command CMD2 to the lens microcomputer 111 and receives the corresponding 3-byte lens data DT2 (DT2a to DT2c) from the lens microcomputer 111. ing. FIG. 3C shows an example in which data communication is executed according to the communication CMD2. The processing of the lens microcomputer 111 with respect to the request command CMD2 in the communication CMD2 includes superimposing the BUSY signal on the clock channel only in the first frame. That is, the lens microcomputer 111 does not superimpose the BUSY signal on the following second to fourth frames.

As a result, the BUSY frame is not inserted between the frames from the second frame to the fourth frame, and the waiting period between the frames can be shortened. However, during the period when the BUSY frame is not inserted, the lens microcomputer 111 cannot send the communication standby request to the adapter microcomputer 205. Therefore, it is necessary to determine the number of data to be transmitted, the transmission interval, the priority of communication processing in the lens microcomputer 111, and the like so as not to cause communication failure due to this.

Next, communication in the communication method B will be described. Here, the communication mode M2 in which communication is performed in the format F1 using the communication method B will also be described. FIG. 4 shows the waveform of the communication signal exchanged between the adapter microcomputer 205 and the lens microcomputer 111 in the communication mode M2. As described above, in the format F1, the BUSY frame is selectively added to the lens data signal DLC.

In the communication method B, the notification channel is used for notification of a lens data transmission request or the like from the adapter microcomputer 205, which is the communication master, to the lens microcomputer 111, which is the communication slave. Notification on the notification channel is performed by switching the signal level (voltage level) of the notification channel between High (first level) and Low (second level). In the following description, the signal supplied to the notification channel in the communication method B is referred to as a transmission request signal RTS.

The first data communication channel is used for transmitting the lens data signal DLC including various data from the lens microcomputer 111 to the adapter microcomputer 205, as in the communication method A. Similar to the communication method A, the second data communication channel is also used for transmitting the adapter data signal DCL including the control command, the transmission request command, and the like from the adapter microcomputer 205 to the lens microcomputer 111.

In the communication method B, unlike the communication method A, the adapter microcomputer 205 and the lens microcomputer 111 do not transmit / receive data in synchronization with a common clock signal, but set a communication speed in advance and communicate based on this setting. Send and receive at bit rate. The communication bit rate indicates the amount of data that can be transferred per second, and the unit is represented by bps (bit per second).

In the present embodiment, also in the communication method B, the adapter microcomputer 205 and the lens microcomputer 111 communicate with each other by the full duplex communication method (full duplex method) in which the adapter microcomputer 205 and the lens microcomputer 111 transmit and receive each other, as in the communication method A.

FIG. 4 shows a signal waveform of one frame, which is the minimum communication unit. The breakdown of the data format of one frame is partially different between the adapter data signal DCL and the lens data signal DLC.

First, the data format of the lens data signal DLC will be described. When there is a BUSY frame, the lens data signal DLC of one frame is composed of a first half data frame and a subsequent BUSY frame. The signal level of the lens data signal DLC is maintained at Low while data is being transmitted.

In order to notify the adapter microcomputer 205 of the start of transmission of one frame of the lens data signal DLC, the lens microcomputer 111 sets the voltage level of the lens data signal DLC to Low for a 1-bit period. This 1-bit period is called a start bit ST, and a data frame is started from the start bit ST. Subsequently, the lens microcomputer 111 transmits 1-byte lens data in an 8-bit period from the 2nd bit to the 9th bit following the start bit ST.

The bit array of data is an MSB (Most Signal Bit) first format, starting from the highest data D7, continuing with data D6 and data D5 in that order, and ending with the lowest data D0. Then, the lens microcomputer 111 adds 1-bit parity information (PA) to the 10th bit, and sets the voltage level of the lens data signal DLC to HIGH during the period of the stop bit SP indicating the end of one frame. As a result, the data frame period started from the start bit ST ends. The parity information does not have to be one bit, and the parity information of a plurality of bits may be added. Further, the parity information is not indispensable, and the format may be such that the parity information is not added.

Subsequently, as shown in "DLC (with BUSY)" in the figure, the lens microcomputer 111 adds a BUSY frame after the stop bit SP. The BUSY frame represents the period of the standby request BUSY notified from the lens microcomputer 111 to the adapter microcomputer 205, as in the communication method A. The lens microcomputer 111 indicates the start of the standby request BUSY by changing the signal level of the lens data signal DLC from High (first level) to Low (second level), and the lens data signal DLC until the standby request BUSY is released. Hold the signal level at Low.

On the other hand, it may not be necessary to notify the standby request BUSY from the lens microcomputer 111 to the adapter microcomputer 205. For this case, as shown in "DLC (without BUSY)" in FIG. 4, a data format that constitutes one frame without adding a BUSY frame (hereinafter, also referred to as BUSY notification) is also provided. That is, the lens microcomputer 111 can select a data format of the lens data signal DLC with or without the BUSY notification according to the processing status on the lens microcomputer side.

A method of identifying the presence / absence of BUSY notification performed by the adapter microcomputer 205 will be described. The signal waveform shown in “DLC (without BUSY)” in FIG. 4 and the signal waveform shown in “DLC (with BUSY)” in FIG. 4 include bit positions B1 and B2. The adapter microcomputer 205 selects one of the bit positions of B1 and B2 as the BUSY identification position P for identifying the presence or absence of the BUSY notification. As described above, in this embodiment, the data format in which the BUSY identification position P is selected from the bit positions of B1 and B2 is adopted. This makes it possible to deal with the problem that the processing time from the transmission of the data frame of the lens data signal DLC to the confirmation of the BUSY notification (Low of the DLC) differs depending on the processing performance of the lens microcomputer 111.

Whether the BUSY identification position P is the bit position of B1 or the bit position of B2 is determined by communication between the adapter microcomputer 205 and the lens microcomputer 111 before the communication in the communication method B is performed. It is not necessary to fix the BUSY identification position P to either the bit position of B1 or B2, and it may be changed according to the processing capacity of the adapter microcomputer 205 and the lens microcomputer 111. The BUSY identification position P is not limited to B1 and B2, and may be set to a predetermined position after the stop bit SP.

Here, the reason why the BUSY frame added to the clock signal LCLK in the communication method A is used as the data format added to the lens data signal DLC in the communication method B will be described.

In the communication method A, it is necessary to exchange the clock signal LCLK output by the adapter microcomputer 205, which is the communication master, and the BUSY signal output by the lens microcomputer 111, which is the communication slave, on the same clock channel. Therefore, the collision between the outputs of the adapter microcomputer 205 and the lens microcomputer 111 is prevented by the time division method. That is, the output possible periods of the adapter microcomputer 205 and the lens microcomputer 111 in the clock channel are appropriately allocated to prevent collisions between the outputs.

However, in this time division method, it is necessary to reliably prevent collisions between the outputs of the adapter microcomputer 205 and the lens microcomputer 111. Therefore, a certain output prohibition period is inserted between the time when the adapter microcomputer 205 completes the output of the 8-pulse clock signal LCLK and the time when the lens microcomputer 111 allows the output of the BUSY signal. During this output prohibition period, output from the adapter microcomputer 205 and the lens microcomputer 111 is prohibited. Since the output prohibition period is a communication invalid period during which the adapter microcomputer 205 and the lens microcomputer 111 cannot communicate with each other, it causes a decrease in the effective communication speed.

In order to solve such a problem, the communication method B adopts a data format in which a BUSY frame from the lens microcomputer 111 is added to the lens data signal DLC in the first data communication channel which is the output channel of the lens microcomputer 111. are doing.

Next, the data format of the adapter data signal DCL will be described. The specifications of the one-frame data frame are the same as those of the lens data signal DLC. However, unlike the lens data signal DLC, the adapter data signal DCL is prohibited from adding a BUSY frame.

Next, the procedure of communication in the communication method B between the adapter microcomputer 205 and the lens microcomputer 111 will be described. First, the adapter microcomputer 205 sets the voltage level of the transmission request signal RTS to Low when an event for starting communication with the lens microcomputer 111 occurs (hereinafter, also referred to as asserting the transmission request signal RTS). By setting the voltage level to Low, the lens microcomputer 111 is notified of the communication request.

When the lens microcomputer 111 detects a communication request due to a change in the voltage level of the transmission request signal RTS to Low, the lens microcomputer 111 generates a lens data signal DLC to be transmitted to the adapter microcomputer 205. Then, when the lens data signal DLC is ready to be transmitted, the transmission of one frame of the lens data signal DLC is started via the first data communication channel. Here, the lens microcomputer 111 starts transmitting the lens data signal DLC within a set time set mutually between the adapter microcomputer 205 and the lens microcomputer 111 from the time when the voltage level of the transmission request signal RTS becomes Low. To do.

That is, in the communication method B, the lens data to be transmitted may be determined between the time when the voltage level of the transmission request signal RTS becomes Low and the time when the transmission of the lens data signal DLC is started. Unlike the communication method A, there is no strict restriction that the lens data to be transmitted must be fixed by the time when the first clock pulse is input, so there is a degree of freedom in the timing of starting the transmission of the lens data signal DLC. Can be given.

Next, the adapter microcomputer 205 returns the voltage level of the transmission request signal RTS to High in response to the detection of the start bit ST added to the head of the data frame of the lens data signal DLC received from the lens microcomputer 111. Hereinafter, changing the voltage level of the transmission request signal RTS from Low to High is also referred to as negating the transmission request signal RTS. Further, in response to the detection of the start bit ST, the transmission of the adapter data signal DCL on the second data communication channel is started. It does not matter which of the negate of the transmission request signal RTS and the start of transmission of the adapter data signal DCL comes first. It is preferable that at least a part of the reception period of the data frame of the lens data signal DLC and the transmission period of the adapter data signal DCL overlap. That is, it is preferable that the transmission request signal RTS negate and the adapter data signal DCL transmission be started by the time the reception of the data frame of the lens data signal DLC is completed. As a result, one round-trip exchange between the lens data signal DLC and the adapter data signal DCL can be performed in a short time.

The lens microcomputer 111 that has transmitted the data frame of the lens data signal DLC adds the BUSY frame to the lens data signal DLC when it is necessary to notify the adapter microcomputer 205 of the standby request BUSY. The adapter microcomputer 205 monitors the presence or absence of notification of the standby request BUSY, and while the standby request BUSY is notified, it is prohibited to assert the transmission request signal RTS for the next transmission request.

The lens microcomputer 111 executes necessary processing during the period in which the communication from the adapter microcomputer 205 is made to wait by the standby request BUSY, and releases the standby request BUSY after the next communication preparation is completed. The adapter microcomputer 205 is permitted to assert the transmission request signal RTS for the next transmission request, provided that the standby request BUSY is released and the transmission of the data frame of the adapter data signal DCL is completed.

As described above, in the present embodiment, the adapter microcomputer 205 asserts the transmission request signal RTS triggered by the communication start event. The assertion of the transmission request signal RTS is, for example, a signal that the adapter microcomputer 205 wants to transmit data to the interchangeable lens 100 when the adapter microcomputer 205 receives a control command for the interchangeable lens 100 from the camera microcomputer 305. Become.

The lens microcomputer 111 starts transmitting the data frame (first data) of the lens data signal DLC to the adapter microcomputer 205. This is a signal for the adapter microcomputer 205 that the lens microcomputer 111 is in a state where it can receive the adapter data.

Then, the adapter microcomputer 205 transmits a data frame (second data) of the adapter data signal DCL to the lens microcomputer 111 in response to detecting the start bit ST of the lens data signal DLC. The adapter data signal DCL transmitted here is a signal obtained by converting the control command received by the adapter device 200 from the camera microcomputer 305 into data suitable for the lens-side protocol.

If the adapter data signal DCL transmitted at this time requests the lens microcomputer 111 for data to be transmitted to the camera microcomputer 305, the lens microcomputer 111 generates a lens data signal DLC that is a response to the request. To do. Then, in response to the assertion of the transmission request signal RTS, the generated lens data signal DLC is transmitted to the adapter microcomputer 205. The adapter microcomputer 205 transmits the adapter data signal DCL to the lens microcomputer 111 in response to the start of reception of the lens data signal DLC. At this time, the adapter data signal DCL is merely a signal indicating the start of reception of the lens data DLC.

As described above, the lens data signal DLC may be a signal indicating that the data can be received at one time, or may be contentally meaningful data such as a response to a data request at another time.

Like the lens data signal DLC, the adapter data signal DCL may be a mere signal indicating data reception at one time, or may be content-significant data such as a control command at another time.

Here, the lens microcomputer 111 adds a BUSY frame after the data frame of the lens data signal DLC for the standby request BUSY as needed, and then cancels the standby request BUSY to complete the communication processing of one frame. .. By this communication process, 1 byte of communication data is transmitted and received between the adapter microcomputer 205 and the lens microcomputer 111.

Next, the communication mode M3 that communicates in the format F2 using the communication method B will be described. FIG. 5A shows the waveform of the communication signal exchanged between the adapter microcomputer 205 and the lens microcomputer 111 in the communication mode M3. FIG. 5A shows the waveform of the communication signal when three frames of data are continuously transmitted. As described above, in the format F2, it is prohibited to add the standby request BUSY to the lens data signal DLC.

In the data format of the lens data signal DLC in the communication mode M3, one frame is composed of only the data frame, and the BUSY frame does not exist. Therefore, in the communication mode M3, the standby request BUSY cannot be notified from the lens microcomputer 111 to the adapter microcomputer 205.

Such a format F2 is used when transferring a relatively large amount of data between the adapter microcomputer 205 and the lens microcomputer 111. In the format F2, continuous communication with a short interval between frames can be performed by not sandwiching the standby request BUSY, and high-speed communication of a large amount of data becomes possible.

Next, the communication control process between the adapter microcomputer 205 and the lens microcomputer 111, which is characterized by this embodiment, will be described. FIG. 5B shows the waveforms of communication signals when the adapter microcomputer 205 and the lens microcomputer 111 continuously transmit and receive the n-frame adapter data signal DCL and the lens data signal DLC, respectively. The adapter microcomputer 205 asserts the transmission request signal RTS when an event for starting communication with the lens microcomputer 111 occurs. In the format F2, unlike the format F1, the adapter microcomputer 205 does not need to negate the transmission request signal RTS for each frame. Therefore, while the data can be continuously transmitted / received, the asserted state of the transmission request signal RTS is maintained during and after the data reception of the lens data signal DLC of the first frame.

When the lens microcomputer 111 detects a communication request by asserting the transmission request signal RTS, the lens microcomputer 111 generates a lens data signal DLC to be transmitted to the adapter microcomputer 205. Then, when the lens data signal DLC is ready to be transmitted, the transmission of the lens data signal DLC (DL1) (first data) of the first frame on the first data communication channel is started.

The lens microcomputer 111 that has transmitted the data frame of the lens data signal DLC of the first frame confirms the transmission request signal RTS again. At this time, when the transmission request signal RTS is in the asserted state, the lens microcomputer 111 transmits the lens data signal DLC (DL2) (third data) of the next second frame following the first frame in which transmission is completed. Send to the adapter microcomputer 205. In this way, the lens data signals DLC (DL1 to DLn) from the lens microcomputer 111 are continuously transmitted to the adapter microcomputer 205 while the asserted state of the transmission request signal RTS is maintained. Then, when the transmission of the predetermined number of frames n is completed, the transmission of the lens data signal DLC is stopped.

From the adapter microcomputer 205, the start bit ST for each frame of the lens data signal DCL from the lens microcomputer 111 is detected, and the second data communication channel of the adapter data signal DCL (DC1 to DCn) of n frames is used. Is started to be transmitted.

FIG. 5C shows the waveform of the communication signal when a temporary communication standby is instructed by the adapter microcomputer 205 or the lens microcomputer 111 during the continuous data transmission / reception communication shown in FIG. 5B. There is. Here, too, the lens microcomputer 111 starts transmitting the lens data signal DLC when the transmission request signal RTS is asserted from the adapter microcomputer 205, and the adapter microcomputer 205 transmits the adapter data signal DCL in response to the detection of the start bit ST. To start.

The communication standby period T2w1 is a period in which the adapter microcomputer 205 instructs the lens microcomputer 111 to wait for communication. The instruction is notified to the lens microcomputer 111 by temporarily negating the transmission request signal RTS. When the lens microcomputer 111 detects that the transmission request signal RTS has been negated, it transmits after completing the transmission of the lens data signal DLC frame (DL6: hereinafter referred to as pause frame in the figure) being transmitted at the time of the detection. To pause.

In response to the suspension of transmission of the lens data signal DLC, the adapter microcomputer 205 also suspends the transmission of the adapter data signal DCL after transmitting the frame (DC6) corresponding to the pause frame among the adapter data signal DCL. With such communication control, it is possible to manage the number of transmitted frames of the lens data signal DLC and the adapter data signal DCL to be the same even when a communication standby instruction is generated during continuous data transmission / reception communication.

When the request event for communication standby disappears, the adapter microcomputer 205 can instruct the lens microcomputer 111 to resume communication by asserting the transmission request signal RTS again. In response to the communication restart instruction, the lens microcomputer 111 restarts the transmission of the lens data signal DLC from the frame next to the pause frame (DL7: hereinafter referred to as the restart frame). Then, in response to the detection of the start bit ST of the restart frame, the adapter microcomputer 205 restarts the transmission of the adapter data signal DCL from the frame (DC7) corresponding to the restart frame.

On the other hand, the communication standby period T2w2 is a period in which the lens microcomputer 111 instructs the adapter microcomputer 205 to wait for communication. In FIG. 5C, after the end of the communication standby period T2w1, neither the adapter microcomputer 205 nor the lens microcomputer 111 is instructed to wait for communication, and the frames DL7, DC7 and the subsequent frames DL8, DC8 to DL9, and DC9 are in that order. Continuous data transmission / reception is performed.

Then, when the transmission of the frame DL9 (reception of the frame DC9 by the adapter microcomputer 205) is completed in the lens microcomputer 111, the communication standby request event occurs, so that the lens microcomputer 111 instructs the adapter microcomputer 205 to wait for communication. Notify.

When the transmission request signal RTS is in the asserted state, the lens microcomputer 111 does not transmit the lens data signal DLC, so that the lens microcomputer 111 notifies the adapter microcomputer 205 that communication is suspended.

The adapter microcomputer 205 constantly monitors the start bit ST for each frame of the lens data signal DLC, and if the start bit ST is not detected, it is arranged to stop the transmission of the frame of the next adapter data signal DCL. .. If the adapter microcomputer 205 does not receive the lens data signal DLC (DL10 in the figure) from the lens microcomputer 111 even if the transmission request signal RTS is asserted, the adapter microcomputer 205 suspends communication without transmitting the adapter data signal DCL (DC10). To do. The adapter microcomputer 205 maintains the transmission request signal RTS in the asserted state during the communication standby period T2w2.

After that, the communication standby request event disappears in the lens microcomputer 111, and the lens microcomputer 111 restarts the transmission of the resume frame DL10 of the lens data signal DLC. The adapter microcomputer 205 restarts the transmission of the corresponding frame DC10 in the adapter data signal DCL in response to detecting the start bit ST of the restart frame DL10.

Next, the procedure for determining the communication format performed between the adapter microcomputer 205 and the lens microcomputer 111 will be described with reference to FIG. The adapter microcomputer 205 and the lens microcomputer 111 perform the communication control shown in the flowcharts of FIGS. 6 and 7 according to a program which is a computer program. In FIGS. 6 and 7, "S" means a step.

First, when the adapter device 200 and the interchangeable lens 100 are attached to the camera 300, steps S100 and S200 are started. In step S100 and step S200, the adapter microcomputer 205 and the lens microcomputer 111 set the communication format to the initial communication format in which the establishment of communication is guaranteed. Here, the initial communication format may be a combination of the communication method and the data format disclosed in the present embodiment, or may be another communication format. When a pace-synchronized communication format is selected as the initial communication format, it is preferable to set the BUSY identification position P so that communication can be executed regardless of the combination of the camera and the interchangeable lens.

Subsequently, in step S101, the adapter microcomputer 205 transmits the camera identification information to the lens microcomputer 111. The camera identification information is originally information transmitted from a camera to which the interchangeable lens 100 can be directly attached to the interchangeable lens 100, and is information representing a communication format compatible with the camera. Here, since the adapter device 200 is pretending to be a camera, the adapter microcomputer 205 transmits camera identification information to the interchangeable lens 100 instead of the camera. The camera identification information is also information representing a communication format compatible with the adapter device 200. Further, in step S202, the lens microcomputer 111 transmits the lens identification information representing the communication format supported by the interchangeable lens 100 to the adapter microcomputer 205.

Here, the "identification information" includes information indicating which communication method of the clock synchronization type and the pace synchronization type is supported, and information indicating a range of communication bit rates that can be supported. Information indicating the BUSY identification position P is also included in the identification information.

The adapter microcomputer 205 receives the lens identification information in step S102. The lens microcomputer 111 receives the camera identification information in step S201. Here, in the flowchart of FIG. 6, the lens identification information is transmitted after the camera identification information is transmitted, but the transmission of the camera identification information and the transmission of the lens identification information may be performed at the same time. Further, the camera identification information may be transmitted after the lens identification information is transmitted.

In steps S103 and S203, the communication format for subsequent communication is set. Specifically, the adapter microcomputer 205 and the lens microcomputer 111 determine the fastest rate among the communication bit rates that can correspond to each other as the communication bit rate. Further, among the BUSY identification positions that can correspond to each other, the position closest to the stop bit SP is set as the BUSY identification position P.

Next, the data communication flow in the pace-synchronized communication method will be described with reference to FIG. 7. FIG. 7 describes a communication flow in a data format in which the addition of a BUSY signal is permitted.

The adapter microcomputer 205 monitors whether or not a communication event for starting communication with the lens microcomputer 111 has occurred, and proceeds to step S111 when the communication event occurs in step S110. In step S111, as described above, the transmission request signal RTS is asserted to make a communication request to the lens microcomputer 111.

The lens microcomputer 111 monitors whether or not the transmission request signal RTS has been asserted, and when it recognizes that the transmission request signal RTS has been asserted in step S210, the process proceeds to step S211. In step S211 the lens microcomputer 111 transmits the lens data signal DLC to the adapter microcomputer 205 via the first data communication channel.

When the adapter microcomputer 205 receives the lens data signal DLC from the lens microcomputer 111 (YES in step S112), the adapter microcomputer 205 proceeds to step S113 and negates the transmission request signal RTS. Then, the process proceeds to step S114, and the adapter data signal DCL is transmitted to the lens microcomputer 111 via the second data communication channel.

When the lens microcomputer 111 detects the start of reception of the adapter data signal DCL in step S212, the lens microcomputer 111 proceeds to step S213 and performs reception processing of the adapter data signal DCL. In parallel with the process of step S213, the lens microcomputer 111 determines in step S214 whether or not it is necessary to notify the adapter microcomputer 205 of the standby request BUSY. If it is not necessary to notify the standby request BUSY, the process proceeds to step S218 and waits until the reception of the adapter data signal DCL is completed.

On the other hand, when it is necessary for the lens microcomputer 111 to notify the adapter microcomputer 205 of the standby request BUSY, the process proceeds to step S215 to add a BUSY frame to the lens data signal DLC. The lens microcomputer 111 executes necessary processing while notifying the standby request BUSY, and releases the standby request BUSY after the next communication preparation is ready (Yes in step S216) (step S217). After canceling the standby request BUSY, the process proceeds to step S218 and waits until the reception of the adapter data signal DCL is completed. When the reception of the adapter data signal DCL is completed (Yes in step S218), the process returns to step S210 and continues monitoring whether or not the transmission request signal RTS has been asserted.

Upon receiving the notification of the standby request BUSY in step S115, the adapter microcomputer 205 waits until the standby request BUSY is released. When the standby request BUSY is released (YES in step S116), the process proceeds to step S117, and it is determined whether or not the transmission of the adapter data signal DCL is completed. Further, even when the notification of the standby request BUSY is not received in step S115, the process proceeds to step S117 to determine whether or not the transmission of the adapter data signal DCL is completed. When it is determined in step S117 that the transmission of the adapter data signal DCL is completed, the process returns to step S110 to continue monitoring whether or not a communication event has occurred.

As described above, one embodiment of the present invention relates to communication control in a pace synchronous type (communication method B) communication composed of three channels. A standby request BUSY is transmitted from the lens microcomputer 111 to the adapter microcomputer 205 via the first data communication channel which is the output channel of the lens microcomputer 111. On the other hand, the transmission request signal RTS from the adapter microcomputer 205 is transmitted from the adapter microcomputer 205 to the lens microcomputer 111 via the notification channel as the output channel of the adapter microcomputer 205.

In this way, the standby request BUSY from the lens microcomputer 111 is transmitted and received via the output channel of the lens microcomputer 111, and the transmission request signal RTS from the adapter microcomputer 205 is transmitted and received via the output channel of the adapter microcomputer 205. As a result, the communication invalid period between the adapter microcomputer 205 and the lens microcomputer 111 can be shortened, and as a result, the effective communication speed can be increased.

Regarding the communication start timing, first, the adapter microcomputer 205 transmits a transmission request signal RTS requesting data transmission from the lens microcomputer 111 to the adapter microcomputer 205. Then, in response to the reception of the transmission request signal RTS, data transmission of the lens data signal DLC is started from the lens microcomputer 111 to the adapter microcomputer 205. The adapter microcomputer 205 starts transmitting the adapter data signal DCL to the lens microcomputer 111 in response to the start of reception of the lens data signal DLC. Specifically, the adapter microcomputer 205 starts data transmission of the adapter data signal DCL in response to detecting the start bit ST of the data frame transmitted from the lens microcomputer 111. By setting the communication start timing in this way, it is possible to give a degree of freedom to the timing at which the lens microcomputer 111 that has received the transmission request signal RTS starts data transmission to the adapter microcomputer 205.

For example, the start timing of data transmission of the lens data signal DLC can be changed according to the information processing capability of the lens microcomputer 111. Thereby, the timing at which the adapter data signal DCL is transmitted from the adapter microcomputer 205 can be adjusted. Therefore, the communication speed between the adapter device 200 and the interchangeable lens 100 can be improved without causing communication failure. Then, through the adapter device 200, the user can take a picture without communication failure even when the camera 300 and the interchangeable lens 100 having different communication protocols are used.

The method of asserting the transmission request signal RTS and notifying the standby request BUSY described above is an example, and may be other than this. For example, the assertion of the transmission request signal RTS and the standby request BUSY may be represented by switching the voltage level from Low to High.

Subsequently, the procedure for switching from the communication method A to the communication method B will be described with reference to FIG. FIG. 8 shows waveforms of communication signals exchanged between the adapter microcomputer 205 and the lens microcomputer 111 before and after switching from the communication method A to the communication method B. When switching from the communication method A to the communication method B, the adapter microcomputer 205 changes the communication setting of the communication unit 208 from the setting corresponding to the communication method A to the setting corresponding to the communication method B. Similarly, the lens microcomputer 111 changes the communication setting of the lens communication unit 112 from the first setting corresponding to the communication method A to the second setting corresponding to the communication method B.

At the switching timing X shown in FIG. 8, the switching of the communication settings between the adapter microcomputer 205 and the lens microcomputer 111 is completed, and thereafter, communication by the communication method B is performed. As described above, the notification channel functions as a clock channel in the communication method A, and is used for notification from the adapter microcomputer 205 to the lens microcomputer 111 in the communication method B.

In the present embodiment, the lens microcomputer 111, which is a communication slave in the communication method A, changes to the second setting before the adapter microcomputer 205, which is the communication master.

FIG. 9 is a flowchart showing the contents of processing in switching the communication method. The communication method is switched according to an instruction from the adapter microcomputer 205.

The adapter microcomputer 205 monitors in S120 whether or not a communication method switching event has occurred. If it is determined that it has not occurred (No), the process returns to S120. When the adapter microcomputer 205 determines that the communication method switching event has occurred (Yes), the adapter microcomputer 205 proceeds to S121. Then, by communicating in the communication method A, the notification of switching from the communication method A to the communication method B is transmitted to the lens microcomputer 111 via the adapter data communication channel. This switching notification is included in the data frame.

The lens microcomputer 111 monitors in S220 whether or not a switching notification has been received. If it is determined that the item has not been received (No), the process returns to S220. When the lens microcomputer 111 determines that the switching notification has been received (Yes), the lens microcomputer 111 superimposes the BUSY signal on the notification channel in S221. As a result, the communication standby request BUSY is notified to the adapter microcomputer 205.

Then, the lens microcomputer 111 changes the communication setting of the communication unit 112 from the first setting to the second setting in S222 while notifying the adapter microcomputer 205 of the communication standby request BUSY.

When the switching of the communication method in the lens microcomputer 111 is completed, the lens microcomputer 111 cancels the communication standby request BUSY in S223. By canceling BUSY, the adapter microcomputer 205 is notified that the switching of the communication method is completed. After that, the lens microcomputer 111 proceeds to the step of S210 described above, and monitors the presence or absence of notification of the transmission request signal RTS in the communication method B.

When the communication standby request BUSY is canceled in S122, the adapter microcomputer 205 changes the communication setting of the communication unit 208 from the first setting corresponding to the communication method A to the second setting corresponding to the communication method B. After that, the adapter microcomputer 205 proceeds to S110 and monitors whether or not a communication event has occurred in the communication method B. The timing at which the switching to the communication method B in the adapter microcomputer 205 is completed is the switching timing X shown in FIG. After the switching timing X, the data communication in the communication method B is executed.

As described above, in the present embodiment, the lens microcomputer 111 as the communication slave is configured to change from the first setting to the second setting before the adapter microcomputer 205 as the communication master. Since it is unclear whether the lens microcomputer 111 can immediately execute the change to the second setting, the adapter microcomputer 205 confirms the change to the second setting in the lens microcomputer 111, and then makes the first setting. Execute the change from the setting of to the second setting.

If the change to the second setting is executed in the adapter microcomputer 205 without confirming that the change to the second setting is executed in the lens microcomputer 111, the communication method between the interchangeable lens 100 and the adapter device 200 is changed. Differently, communication between the two may break down. In the present embodiment, after confirming the change to the second setting in the lens microcomputer 111, the adapter microcomputer 205 executes the change from the first setting to the second setting, so that the above-mentioned situation occurs. Can be prevented.

Further, the lens microcomputer 111 changes the communication setting of the lens microcomputer 111 from the first setting to the second setting while notifying the adapter microcomputer 205 of the communication standby request BUSY. As a result, the communication setting can be changed without the clock signal CLK being output from the adapter microcomputer 205, and a situation in which a communication collision occurs between the adapter microcomputer 205 and the lens microcomputer 111 can be avoided. Can be done.

The lens microcomputer 111 does not necessarily have to switch the communication method in response to the notification of switching from the communication method A to the communication method B, and may refuse to switch the communication method. For example, after receiving the switching notification from the adapter microcomputer 205, a notification indicating that the switching of the communication method is rejected is transmitted via the lens data communication channel. Upon receiving this, the adapter microcomputer 205 can continue communication with the lens microcomputer 111 in the communication method A without changing the communication setting. As a result, when the lens microcomputer 111 cannot immediately execute the change to the second setting, the adapter microcomputer 205 returns to the first setting immediately after executing the change from the first setting to the second setting. You can avoid having to make changes to. This is the end of the explanation of switching the communication method.

In each of the above-described embodiments, a channel in which three channels are set is formed, and a case where the adapter device 200 and the interchangeable lens 100 communicate with each other in the first communication protocol has been described, but still another communication. Communication may be possible depending on the protocol. For example, another channel, which is a set of two channels, is formed between the adapter device 200 and the interchangeable lens 100, and communication may be possible using a second communication protocol different from the first communication protocol. Of these two channels, one may be a notification channel used for notification of communication timing, and the other may be a data communication channel capable of transmitting and receiving data between the adapter device 200 and the interchangeable lens 100.

The embodiments described above are merely typical examples, and various modifications and changes can be made to each embodiment in carrying out the present invention.

100 Interchangeable Lens 111 Lens Microcomputer (2nd Control Unit)
200 Adapter device 205 Adapter microcomputer (1st control unit)
208 Communication unit 300 Camera

Claims (28)

It is an adapter device that can be attached and detached between the camera and the lens device.
A notification channel used for notification from the adapter device to the lens device, a lens data communication channel used for data transmission from the lens device to the adapter device, and data transmission from the adapter device to the lens device. It has a control unit that controls communication with the lens device using the adapter data communication channel.
The control unit transmits a transmission request signal requesting data transmission from the lens device to the adapter device via the notification channel, and the first data transmitted from the lens device in response to the transmission request signal. An adapter device characterized in that second data is transmitted to the lens device via the adapter data communication channel in response to the start of reception. The adapter device according to claim 1, wherein at least a part of the period for receiving the first data and the period for transmitting the second data overlap. The adapter device according to claim 1 or 2, wherein the control unit starts transmission of the second data in response to receiving the start bit included in the first data. The adapter device according to any one of claims 1 to 3, wherein the control unit transmits the transmission request signal to the lens device by changing the voltage level of the notification channel. The control unit transmits the transmission request signal by changing the voltage level of the notification channel from the first level to a second level different from the first level, and the first level via the lens data communication channel. The adapter device according to claim 4, wherein when the third data is received following the data, the voltage level of the notification channel is maintained at the second level during and after the reception of the first data. .. The claim is characterized in that the control unit does not transmit the transmission request signal to the lens device while the standby request signal for preventing the transmission request signal from being transmitted is received from the lens device. The adapter device according to any one of 1 to 5. The adapter device according to claim 6, wherein the standby request signal is represented by changing the voltage level of the lens data communication channel. The control unit starts a communication standby state in which the transmission request signal is not transmitted in response to the change in the voltage level of the lens data communication channel from the first level to the second level lower than the first level. The adapter device according to claim 7. The control unit is characterized in that the communication standby state in which the transmission request signal is not transmitted is released in response to the change in the voltage level of the lens data communication channel from the second level to the first level. The adapter device according to claim 8. The adapter device according to any one of claims 6 to 9, wherein the standby request signal is added to a data frame received from the lens device via the lens data communication channel. The adapter device according to claim 10, wherein the standby request signal is added to a predetermined position after the stop bit included in the data frame. It is an adapter device that can be attached and detached between the camera and the lens device.
A channel including a notification channel used for transmitting a transmission request signal requesting data transmission from the adapter device to the lens device and a lens data communication channel used for data transmission from the lens device to the adapter device is used. It has a control unit that controls communication with the lens device.
The adapter device is characterized in that the control unit does not transmit the transmission request signal to the lens device while the standby request signal for preventing the transmission request signal from being transmitted is received from the lens device. .. The adapter device according to claim 12, wherein the standby request signal is represented by changing the voltage level of the lens data communication channel. The control unit starts a communication standby state in which the transmission request signal is not transmitted in response to the change in the voltage level of the lens data communication channel from the first level to the second level lower than the first level. 13. The adapter device according to claim 13. The control unit is characterized in that the communication standby state in which the transmission request signal is not transmitted is released in response to the change in the voltage level of the lens data communication channel from the second level to the first level. The adapter device according to claim 14. The adapter device according to any one of claims 12 to 15, wherein the standby request signal is added to a data frame received from the lens device via the lens data communication channel. The adapter device according to claim 16, wherein the standby request signal is added to a predetermined position after the stop bit included in the data frame. The channel provided between the adapter device and the lens device includes the notification channel, the lens data communication channel, and an adapter data communication channel used for data transmission from the adapter device to the lens device. The adapter device according to any one of claims 12 to 17, characterized in that. Any one of claims 1 to 18, wherein the communication protocol for communication between the adapter device and the lens device is different from the communication protocol for communication between the adapter device and the camera. The adapter device described in the section. The control unit converts the first signal received from the camera into a second signal corresponding to the communication protocol of the communication performed between the adapter device and the lens device and transmits the second signal to the lens device. The adapter device according to any one of claims 1 to 19, wherein the adapter device is characterized by the above. The adapter device according to any one of claims 1 to 20, wherein the control unit performs pace-synchronous communication with the lens device. The adapter device can communicate with the lens device by switching the communication method between a clock synchronization type communication method synchronized with a clock signal and a pace synchronization type communication method.
In the clock-synchronous communication, the control unit transmits the clock signal to the lens device via the notification channel, and in the pace-synchronous communication, the transmission request signal is transmitted via the notification channel. The adapter device according to claim 21, wherein the adapter device transmits to a lens device. Each of the adapter device and the lens device can switch between a first setting corresponding to a clock-synchronized communication method synchronized with a clock signal and a second setting corresponding to a pace-synchronized communication method. ,
After transmitting a notification instructing the switching from the first setting to the second setting to the lens device, the control unit uses the lens device with the first setting, the adapter device, and the like. A standby request signal for preventing data communication to the lens device is received via the notification channel.
The adapter device according to any one of claims 1 to 22, wherein data communication is not performed with the lens device while the standby request signal is being received via the notification channel. The control unit receives the notification indicating that the switching from the first setting to the second setting in the lens device is completed via the notification channel, and the first setting. The adapter device according to claim 23, wherein the second setting is switched from the first to the second setting. A notification channel used for notification from an adapter device detachable between a camera and a lens device to the lens device, a lens data communication channel used for data transmission from the lens device to the adapter device, and the adapter device. A program to be executed by a computer of an adapter device capable of communicating with the lens device via an adapter data communication channel used for transmitting data from the lens device to the lens device.
A step of transmitting a transmission request signal requesting data transmission from the lens device to the adapter device to the lens device via the notification channel.
In response to the start of reception of the first data transmitted from the lens device in response to the transmission request signal, the step of transmitting the second data to the lens device via the adapter data communication channel is executed. Characterized program. Through a notification channel used for notification from the adapter device detachable between the camera and the lens device to the lens device, and a lens data communication channel used for data transmission from the lens device to the adapter device, A program to be executed by a computer of an adapter device capable of communicating with the lens device.
A step of starting reception from the lens device of a standby request signal for preventing transmission of a transmission request signal requesting data transmission from the lens device to the adapter device, and
A program characterized in that while receiving the standby request signal, the step of not transmitting the transmission request signal to the lens device is executed. A camera system including a lens device that can be attached to and detached from a camera and an adapter device that can be attached and detached between the camera and the lens device.
The adapter device includes a notification channel used for notification from the adapter device to the lens device, a lens data communication channel used for data transmission from the lens device to the adapter device, and the adapter device to the lens device. It has a first control unit that controls communication with the lens device using an adapter data communication channel used for data transmission of the lens device.
The lens device has a notification channel, a lens data communication channel, and a second control unit that controls communication with the adapter device using the adapter data communication channel.
The first control unit transmits a transmission request signal requesting data transmission from the lens device to the adapter device to the lens device via the notification channel.
In response to receiving the transmission request signal, the second control unit transmits the first data to the adapter device via the lens data communication channel.
The camera system is characterized in that the first control unit transmits second data to the lens device via the adapter data communication channel in response to the start of reception of the first data. A camera system including a lens device that can be attached to and detached from a camera and an adapter device that can be attached and detached between the camera and the lens device.
The adapter device communicates with the lens device using a notification channel used for notification from the adapter device to the lens device and a lens data communication channel used for data transmission from the lens device to the adapter device. Has a first control unit that controls
The lens device has a second control unit that controls communication with the adapter device using a channel including the notification channel and the lens data communication channel.
The first control unit transmits a transmission request signal requesting data transmission from the lens device to the adapter device to the lens device via the notification channel.
In response to receiving the transmission request signal, the second control unit transmits data to the adapter device via the lens data communication channel.
The camera system is characterized in that the second control unit transmits a standby request signal for preventing the transmission request signal from being transmitted from the adapter device to the lens device to the first control unit.

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