JP5520214B2 - Camera system - Google Patents

Description

  The present invention relates to a camera system, and more particularly to a camera system including an interchangeable lens and a camera body.

  Patent Document 1 discloses a camera system including a camera body and an interchangeable lens. This camera system performs autofocus control when capturing a still image by notifying the interchangeable lens with a command for controlling the drive of the interchangeable lens while synchronizing the camera body and the interchangeable lens. .

JP 2007-322922 A

  As described above, the drive of the interchangeable lens is controlled while synchronizing the camera body and the interchangeable lens. However, the processing executed in each of the camera body and the interchangeable lens does not necessarily need to be executed while synchronizing the camera body and the interchangeable lens. Processing that does not need to be synchronized can be processed more efficiently in the camera body or the interchangeable lens without being synchronized.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a camera system that can perform synchronization control only when synchronization between the camera body and the interchangeable lens is necessary. is there.

In a first aspect, a camera system including a camera body and an interchangeable lens is provided. The camera body includes an imaging unit, a synchronization signal generation unit that generates a synchronization signal, a body control unit that generates a command for controlling the camera body and the interchangeable lens, and a transmission unit that transmits the synchronization signal and the command. With. The transmission unit transmits the synchronization signal at a timing correlated with the exposure timing of the imaging unit. The body control means exchanges a command for setting the interchangeable lens in a synchronous mode in which the operation of the interchangeable lens is controlled in synchronization with a synchronization signal and a command for setting the interchangeable lens in an asynchronous mode other than the synchronous mode. Control to transmit to the lens. The body control means controls switching between the synchronous mode and the asynchronous mode according to the control state of the camera body. The interchangeable lens includes a receiving unit that receives a synchronization signal and a command from the camera body, and a lens control unit that controls the operation of the interchangeable lens. The lens control means controls the operation of the interchangeable lens in a synchronous mode or an asynchronous mode according to a command received from the camera body.

  With the above configuration, it is possible to switch between the synchronous mode and asynchronous mode of the interchangeable lens at an arbitrary timing, and synchronous control can be performed only when synchronization between the camera body and the interchangeable lens is necessary. Therefore, in the asynchronous mode, the camera controller can concentrate on controlling the camera body, and the lens controller is not subject to restrictions more than necessary to synchronize with the camera body.

In a second aspect, a camera body to which an interchangeable lens can be attached is provided. The camera body includes an imaging unit, a synchronization signal generation unit that generates a synchronization signal, a body control unit that generates a command for controlling the camera body and the interchangeable lens, and a transmission unit that transmits the synchronization signal and the command. With. The transmission unit transmits the synchronization signal at a timing correlated with the exposure timing of the imaging unit. The body control means includes a command for setting the interchangeable lens in a synchronous mode in which the operation of the interchangeable lens is controlled in synchronization with the synchronization signal, and a command for setting the interchangeable lens in an asynchronous mode other than the synchronous mode. Control to transmit to the interchangeable lens. The body control means controls switching between the synchronous mode and the asynchronous mode according to the control state of the camera body.

  According to the configuration of the above aspect, it is possible to provide a camera system that can switch between the synchronous mode / asynchronous mode of the interchangeable lens at an arbitrary timing and can perform the synchronization control only when synchronization between the camera body and the interchangeable lens is necessary. .

Block diagram of the camera system in the first and second embodiments The figure explaining the switching sequence of the synchronous mode and asynchronous mode in Embodiment 1 Flow chart of switching operation between synchronous mode and asynchronous mode The figure explaining the switching sequence of the synchronous mode and asynchronous mode in Embodiment 2 Diagram explaining problems when switching from synchronous mode to asynchronous mode The figure explaining switching of the control cycle at the time of switching from the synchronous mode to the asynchronous mode in the second embodiment

  Hereinafter, preferred embodiments will be described with reference to the accompanying drawings.

Embodiment 1
1. Configuration 1-1. Overview FIG. 1 is a block diagram illustrating a configuration of a camera system according to a first embodiment. The camera system 1 includes a camera body 100 and an interchangeable lens 200 that can be attached to and detached from the camera body 100. The camera system 1 can perform a contrast autofocus operation based on image data generated by the CCD image sensor 110.

1-2. Configuration of Camera Body The camera body 100 includes a CCD image sensor 110, a liquid crystal monitor 120, a camera controller 140, a body mount 150, a power source 160, and a card slot 170.

  The camera controller 140 controls the overall operation of the camera system 1 by controlling components such as the CCD image sensor 110 in accordance with an instruction from an operation member such as the release button 130. The camera controller 140 transmits a vertical synchronization signal to the timing generator 112. In parallel with this, the camera controller 140 generates an exposure synchronization signal. The camera controller 140 periodically transmits the generated exposure synchronization signal to the lens controller 240 via the body mount 150 and the lens mount 250. The camera controller 140 uses the DRAM 141 as a work memory during control operations and image processing operations.

  The CCD image sensor 110 captures a subject image incident through the interchangeable lens 200 and generates image data. The generated image data is digitized by the AD converter 111. The image data digitized by the AD converter 111 is subjected to predetermined image processing by the camera controller 140. The predetermined image processing includes, for example, gamma correction processing, white balance correction processing, scratch correction processing, YC conversion processing, electronic zoom processing, and JPEG compression processing.

  The CCD image sensor 110 operates at a timing controlled by the timing generator 112. The operation of the CCD image sensor 110 includes a still image capturing operation, a through image capturing operation, and the like. The through image is mainly a moving image, and is displayed on the liquid crystal monitor 120 in order for the user to determine a composition for capturing a still image.

  The liquid crystal monitor 120 displays an image indicated by the display image data image-processed by the camera controller 140. The liquid crystal monitor 120 can selectively display both moving images and still images.

  The card slot 170 can be loaded with a memory card 171 and controls the memory card 171 based on the control from the camera controller 140. The memory card 171 can store image data generated by image processing of the camera controller 140. For example, the memory card 171 can store a JPEG image file. The image data or image file stored in the memory card 171 can be read, and the image data or image file read from the memory card 171 is subjected to image processing by the camera controller 140. For example, the camera controller 140 decompresses the image data or image file acquired from the memory card 171 and generates display image data.

  The power supply 160 supplies power for consumption by the camera system 1. The power source 160 may be, for example, a dry battery or a rechargeable battery. Alternatively, the power source 160 may supply power to the camera system 1 from the outside via a power cord.

  The body mount 150 can be mechanically and electrically connected to the lens mount 250 of the interchangeable lens 200. The body mount 150 can transmit and receive data to and from the interchangeable lens 200 via the lens mount 250. The body mount 150 transmits the exposure synchronization signal received from the camera controller 140 to the lens controller 240 via the lens mount 250. Further, other control signals received from the camera controller 140 are transmitted to the lens controller 240 via the lens mount 250. For example, information related to driving of the focus lens 230 received from the camera controller 140 is transmitted to the lens controller 240 via the lens mount 250. The body mount 150 transmits a signal received from the lens controller 240 via the lens mount 250 to the camera controller 140. Further, the body mount 150 supplies the power received from the power supply 160 to the entire interchangeable lens 200 via the lens mount 250.

1-3. Configuration of Interchangeable Lens The interchangeable lens 200 includes an optical system, a lens controller 240, and a lens mount 250. The optical system includes a zoom lens 210, an OIS lens 220, an aperture 260, and a focus lens 230.

  The zoom lens 210 is a lens for changing the magnification of a subject image formed by the optical system. The zoom lens 210 is composed of one or a plurality of lenses. The drive mechanism 211 includes a zoom ring or the like that can be operated by the user, transmits the operation by the user to the zoom lens 210, and moves the zoom lens 210 along the optical axis direction of the optical system. The detector 212 detects the drive amount in the drive mechanism 211. The lens controller 240 can grasp the zoom magnification in the optical system by acquiring the detection result in the detector 212.

  The OIS lens 220 is a lens for correcting blurring of a subject image formed by the optical system of the interchangeable lens 200. The OIS lens 220 moves in a direction that cancels out the blur of the camera system 1, thereby reducing the blur of the subject image on the CCD image sensor 110. The OIS lens 220 is composed of one or a plurality of lenses. The actuator 221 drives the OIS lens 220 in a plane perpendicular to the optical axis of the optical system under the control of the OIS IC 223. The actuator 221 can be realized by a magnet and a flat coil, for example. The position detection sensor 222 is a sensor that detects the position of the OIS lens 220 in a plane perpendicular to the optical axis of the optical system. The position detection sensor 222 can be realized by a magnet and a Hall element, for example. The OIS IC 223 controls the actuator 221 based on the detection result of the position detection sensor 222 and the detection result of a shake detector such as a gyro sensor. The OIS IC 223 obtains the detection result of the shake detector from the lens controller 240. Further, the OIS IC 223 transmits a signal indicating the state of the optical image blur correction process to the lens controller 240.

  The diaphragm 260 is a member for adjusting the amount of light passing through the optical system. The diaphragm 260 includes, for example, a plurality of diaphragm blades, and the amount of light can be adjusted by opening and closing an opening formed by the blades. The diaphragm motor 261 is a driving unit for opening and closing the opening of the diaphragm 260.

  The focus lens 230 is a lens for changing the focus state of the subject image formed on the CCD image sensor 110 by the optical system. The focus lens 230 is composed of one or a plurality of lenses.

  The focus motor 233 drives the focus lens 230 to advance and retract along the optical axis of the optical system based on the control of the lens controller 240. Thereby, the focus state of the subject image formed on the CCD image sensor 110 via the optical system can be changed. In this embodiment, a stepping motor can be used as the focus motor 233. However, the motor is not limited to this, and can be realized by a DC motor, a servo motor, an ultrasonic motor, or the like.

  The lens controller 240 controls the entire interchangeable lens 200 by controlling the OIS IC 223, the focus motor 233, and the like based on a control signal from the camera controller 140. For example, the lens controller 240 controls the focus motor 233 based on a control signal from the camera controller 140 so that the focus lens 230 is advanced and retracted along the optical axis by a predetermined driving method. Further, the lens controller 240 can perform wobbling control of the focus lens 230 in synchronization with the exposure synchronization signal from the camera controller 140. Here, the wobbling control of the focus lens 230 is to drive the focus lens 230 minutely forward and backward on the optical axis. This minute advance / retreat drive is performed in a predetermined cycle. By performing the wobbling operation of the focus lens 230, the subject can be continuously focused. Further, the lens controller 240 receives signals from the detector 212, the OIS IC 223, and the like, and transmits them to the camera controller 140. Data transmission / reception between the lens controller 240 and the camera controller 140 is performed via the lens mount 250 and the body mount 150.

  The lens controller 240 uses the DRAM 241 as a work memory at the time of control. The flash memory 242 stores programs and parameters used when the lens controller 240 is controlled.

  The camera controller 140 is an example of a synchronization signal generation unit. The body mount 150 is an example of a transmission unit. The camera controller 140 is an example of body control means. The lens mount 250 is an example of a receiving unit. The lens controller 240 is an example of a lens control unit. The CCD image sensor 110 is an example of an imaging unit.

2. Operation The operation of the camera system configured as described above will be described with reference to FIGS.

2-1. Example of Operation of Camera System In the camera system of the present embodiment, the interchangeable lens 200 operates in synchronization with a synchronization signal (exposure synchronization signal) received from the camera body 100, and synchronization transmitted from the camera body 100. And an asynchronous mode that operates in synchronization with a synchronization signal generated inside the interchangeable lens 200, not a signal. In the synchronous mode, the camera body 100 outputs a synchronization signal to the interchangeable lens 200, and in the asynchronous mode, the camera body 100 stops outputting the synchronization signal to the interchangeable lens 200. Switching between the synchronous mode / asynchronous mode of the interchangeable lens 200 is controlled by the camera controller 140 according to the control state of the camera body 100. For example, the interchangeable lens 200 is controlled to the synchronous mode at the time of through image display operation and moving image shooting, and is controlled to the asynchronous mode at the time of starting the camera system, during image reproduction, and during still image shooting.

  Switching between synchronous mode / asynchronous mode in the interchangeable lens 200 will be described with reference to FIG.

  First, an operation for starting synchronization will be described. The camera body 100 transmits a synchronization start command for setting the interchangeable lens 200 to the synchronization mode to the interchangeable lens 200 (A1). The interchangeable lens 200 receives the synchronization start command and executes synchronization start processing (A2). The synchronization start process includes a process of notifying each processing unit in order to adjust the drive frequency of the interchangeable lens 200 by the lens controller 240 to the frequency instructed by the camera controller 140. The synchronization start processing includes processing for notifying each processing unit to complete the remaining processing that had to be driven in the asynchronous state, and processing for notifying each processing unit so as to correspond to the changed frequency. . When the interchangeable lens 200 detects that such a notification has been executed, the interchangeable lens 200 ends the asynchronous state (A3). Thereafter, the interchangeable lens 200 enters a mode switching waiting state. This mode switching waiting state is provided for each processing unit of the interchangeable lens 200 to perform processing for completing the remaining processing and processing for dealing with a new frequency (frequency after change). When the interchangeable lens 200 ends the asynchronous state, the interchangeable lens 200 transmits a start command response to the camera body 100 (A4). Upon receiving this start command response, the camera body 100 starts communication in the synchronous mode (A5). Specifically, the camera body 100 transmits a command requesting status information of the interchangeable lens 200 to the interchangeable lens 200 (A5), and the interchangeable lens 200 transmits status information of the interchangeable lens 200 to the camera body 100. In addition, the camera body 100 transmits an operation setting command for instructing control to be executed in the synchronous mode to the interchangeable lens 200. The camera body 100 transmits a synchronization signal after transmitting the operation setting command (A6). The interchangeable lens 200 starts a synchronization operation after a predetermined delay time has elapsed (A7). At this time, the interchangeable lens 200 executes focus driving (for example, wobbling) instructed by the operation setting command from the camera body 100 (A8).

  Next, an operation for ending the synchronization will be described. The camera body 100 transmits a synchronization end command for ending the synchronization mode to the interchangeable lens 200 (B1). The interchangeable lens 200 receives the synchronization end command and executes the synchronization end process (B2). The synchronization end process includes a process of notifying each processing unit in order to adjust the driving frequency of the lens controller 240 to a convenient frequency of the interchangeable lens 200. For example, if it is predetermined that the control frequency of the interchangeable lens 200 by the lens controller 240 is 120 Hz, the synchronization end processing is notified to each processing unit in order to adjust the driving frequency of the lens controller 240 to 120 Hz. Processing will be included. The synchronization end process is the same operation as the above-described synchronization start process. When the interchangeable lens 200 confirms the completion of the synchronization end process, it ends the synchronization mode (B3). The interchangeable lens 200 transmits an end command response to the camera body 100 (B4). Thereafter, the interchangeable lens 200 enters a mode switching waiting state. In this mode switching waiting state, the lens controller 240 adjusts the driving frequency to a convenient frequency for the interchangeable lens 200. In addition, the camera body 100 stops outputting the synchronization signal (B5), and the interchangeable lens 200 shifts to the asynchronous mode.

As described above, the synchronous mode / asynchronous mode between the camera body 100 and the interchangeable lens 200 is switched by the synchronization start command and the synchronization end command.
It should be noted that the camera system 1 according to the present embodiment only “notifies” the instruction of each process from the camera body 100 to the interchangeable lens 200 in the start process and the end process. We decided to do it during the "waiting time". However, such a configuration is not necessarily required. In the start process and the end process, “notification” and “process” of instructions of each process may be performed, and “mode switching waiting time” may not be provided.

  FIG. 3 is a flowchart illustrating an operation example of the camera system regarding the above-described switching operation of the synchronous mode / asynchronous mode. The operations of the camera controller 140 and the lens controller 240 in the switching operation of the synchronous mode / asynchronous mode will be described with reference to the flowchart of FIG.

  When the camera system is turned off and is switched on by a user operation or the like (S11), the camera controller 140 starts an initialization operation in the camera body 100 (S12) and the interchangeable lens 200. Is instructed to start the initialization operation (S13).

  In response to the instruction from the camera controller 140, the lens controller 240 performs an initialization operation in the interchangeable lens 200 (S14). The initialization operation in the interchangeable lens 200 includes various operations. For example, the origin measurement of the operation of the focus motor 233, the confirmation of the value of the counter 243, the loading of the program stored in the flash memory 242 to the DRAM 241 and the like. Can be mentioned. When the initialization operation in the interchangeable lens 200 is completed, the lens controller 240 notifies the camera controller 140 to that effect (S15).

  When the initialization operation of the camera body 100 is completed and the initialization operation completion notification is received from the lens controller 240, the camera controller 140 shifts from the asynchronous mode to the synchronous mode (S16). When the camera controller 140 shifts from the asynchronous mode to the synchronous mode, the camera controller 140 transmits a synchronization start command to the lens controller 240. Upon receiving the synchronization start command, the lens controller 240 shifts from the asynchronous mode to the synchronous mode, and performs a control operation in synchronization with the synchronization signal received from the camera controller 140 (S16B). For example, the lens controller 240 grasps the driving state of the focus motor 233 and the aperture motor 261 in synchronization with the synchronization signal, and transmits the result to the camera controller 140.

  Thereafter, the camera controller 140 proceeds to a through image generation and display operation (S17). In this way, by shifting to the synchronous mode and performing the through image generation and display operation, the camera controller 140 accurately grasps the position information of the focus lens 230, the aperture value of the aperture 260, and the like at a predetermined timing. can do. As a result, the camera system 1 can perform AF control and AE control with higher accuracy. The details of the through image and display operation will be described later.

  During the period in which the generated through image is displayed on the liquid crystal monitor 120, the camera controller 140 monitors whether the release button 130 has been pressed halfway (S18). When the release button 130 is pressed halfway, the camera controller 140 performs an autofocus operation and an automatic exposure control operation (S19). When these operations are completed, the release button 130 monitors whether or not a full-press operation has been performed (S20).

  When the release button 130 is fully pressed, the camera controller 140 shifts from the synchronous mode to the asynchronous mode (S21). When the camera controller 140 shifts from the synchronous mode to the asynchronous mode, the camera controller 140 transmits a synchronization end command to the lens controller 240. When receiving the synchronization end command, the lens controller 240 shifts to the asynchronous mode (S21B).

  Thereafter, the CCD image sensor 110 performs exposure (S22). The camera controller 140 reads image data generated by exposure from the CCD image sensor 110 and performs image processing (S23). When the reading of the image data is completed and the generated image data is stored in the memory card 171, the process returns to step S16, and the camera controller 140 shifts to the synchronous mode. The reason why the camera controller 140 shifts to the asynchronous mode at the start of image capturing (when the release button 130 is fully pressed) is that the camera controller 140 does not capture the image data until it is recorded on the memory card 171. This is because each processing unit in the camera body 100 may be controlled (processing of captured image data or recording to the memory card 171), and it is not necessary to synchronize with the lens controller 240. Thereby, the camera controller 140 can concentrate on the processing in the camera body 100.

  Note that when the image data stored in the memory card 171 is reproduced and displayed on the liquid crystal monitor 120, the camera controller 140 and the lens controller 240 are driven in an asynchronous mode. During the reproduction operation, the camera controller 140 only needs to control each processing unit provided in the camera body 100 and does not need to control the processing unit in the lens controller 240. Because there is no need to take. By not synchronizing with the lens controller 240 during reproduction, the camera controller 140 can concentrate on reproducing the image data. As a result, the camera controller 140 can perform image data reproduction processing at high speed. Further, by driving in the asynchronous mode during reproduction, the power of the CCD image sensor 110 can be turned off during reproduction. This is because the camera controller 140 and the lens controller 240 are driven in an asynchronous mode, so that the camera controller 140 does not need to transmit a synchronization signal to the lens controller 240. As a result, the power of the CCD image sensor 110 is turned off during the reproduction of the image data, thereby realizing power saving.

  Thus, in the camera system according to the present embodiment, when the release button 130 is fully pressed, the camera controller 140 shifts from the synchronous mode to the asynchronous mode. As a result, when the camera controller 140 performs processing of captured image data or recording to the memory card 171, the camera body 100 and the interchangeable lens 200 are not particularly synchronized. It is possible to concentrate on processing and recording of image data on the memory card 171. As a result, the camera controller 140 can perform image data processing and image data recording on the memory card 171 at high speed.

  In the camera system according to the present embodiment, when reproducing the image data recorded on the memory card 171, the camera controller 140 operates in the asynchronous mode. Thereby, the camera controller 140 can concentrate on reproduction | regeneration of image data. As a result, the camera controller 140 can perform image data reproduction processing at high speed.

As described above, in the camera system of the present embodiment, the camera controller 140 notifies the lens controller 240 of a command to switch between the synchronous mode and the asynchronous mode. As a result, when it is not necessary to synchronize, control is performed in the asynchronous mode, and the control of the camera system can be simplified.
2-2. Operation in Synchronous Mode In the synchronous mode, the interchangeable lens 200 performs various operations in synchronization with a synchronization signal acquired from the camera body 100. For example, the interchangeable lens 200 performs drive control of the focus lens 230, the diaphragm 260, and the zoom lens 210 in synchronization with a synchronization signal indicating the exposure period of the CCD image sensor 110. Hereinafter, these operations will be described.

  In the camera system of the present embodiment, the camera controller 140 transmits a synchronization signal to the lens controller 240 at a frequency of 60 (Hz).

  The lens controller 240 acquires the F value in response to acquiring the synchronization signal. The lens controller 240 can perform drive control of the diaphragm 260 according to the acquired F value.

  In addition, the lens controller 240 acquires position information of the zoom lens 210 in response to acquiring the synchronization signal.

  In addition, the lens controller 240 notifies the camera controller 140 of information indicating a camera shake state in response to acquiring the synchronization signal. The camera controller 140 can perform various controls in consideration of the camera shake state based on the acquired information indicating the camera shake state.

  As described above, in the synchronization mode, the lens controller 240 controls the diaphragm 260, the zoom lens 210, the OIS lens 220, and the like, while synchronizing with the synchronization signal frequency acquired by the lens controller 240 from the camera controller 140. The same frequency is 60 (Hz).

3. Summary The camera system according to the present embodiment is a camera system including a camera body 100 and an interchangeable lens 200. The camera body 100 corresponds to a camera controller 140 that generates a synchronization signal, a body mount 150 that transmits the generated synchronization signal to the interchangeable lens 200, a camera controller 140 that controls the camera body 100, and a control mode by the camera controller 140. Thus, a command for controlling the interchangeable lens 200 in a synchronous mode (the interchangeable lens 200 is controlled in synchronization with the synchronization signal) and an asynchronous mode (the interchangeable lens 200 is controlled in synchronization with the synchronization signal) is generated. A camera controller 140. The interchangeable lens 200 includes a lens mount 250 that receives a synchronization signal and a command transmitted from the camera body 100, and a lens controller 240 that controls the interchangeable lens 200 in a synchronous mode or an asynchronous mode according to the received command.

  With the above configuration, when synchronization is unnecessary, control can be performed in the asynchronous mode. Therefore, the camera controller 140 can concentrate on controlling the camera body 100 without considering synchronization with the interchangeable lens 200. In addition, the lens controller 240 is not subject to excessive restrictions in order to synchronize with the camera body 100.

  In the present embodiment, the camera controller 140 transmits a command for operating the interchangeable lens 200 in the synchronous mode during moving image capture, while operating the interchangeable lens 200 in the asynchronous mode during still image capture. You may make it instruct | indicate the command for making it. At the time of moving image capturing, it is necessary to perform walling control for autofocus operation, and the interchangeable lens 200 must be operated in a synchronous mode. On the other hand, when a full-press operation is performed to capture a still image, it is not necessary to perform walling control for autofocus operation, and therefore it is not necessary to operate the interchangeable lens 200 in the synchronous mode. Therefore, when the still image is captured, the camera controller 140 can concentrate on the control in the camera body 100 by operating the interchangeable lens 200 in the asynchronous mode.

  In the present embodiment, the camera controller 140 controls the camera controller 140 not to capture the image data generated by the CCD image sensor 110 into the processing unit subsequent to the CCD image sensor 110 (for example, a through image). The interchangeable lens 200 may be controlled asynchronously when it is not necessary to generate or during image reproduction.

  When the camera controller 140 does not capture image data, it is not necessary to synchronize the CCD image sensor 110 and the interchangeable lens 200. In such a case, the interchangeable lens 200 is controlled asynchronously, thereby reducing the load on the camera controller 140. Can be reduced.

(Embodiment 2)
In the first embodiment, as shown in FIG. 2, a “mode switching waiting time” is provided between the synchronous mode and the asynchronous mode. In the present embodiment, as shown in FIG. 4, control for realizing smooth switching from the synchronous mode to the asynchronous mode when no “mode switching waiting time” is provided between the synchronous mode and the asynchronous mode will be described. . In the present embodiment, the process executed during the mode switching waiting time in the first embodiment is executed in the “start process” or “end process”. The configuration and operation of the camera system 1 are basically the same as those of the first embodiment. Hereinafter, the operation of the camera system 1 unique to the present embodiment will be described.

  In the interchangeable lens 200, in the synchronous mode, control is performed based on a synchronization signal from the camera body 100, and in the asynchronous mode, control is performed based on a timing signal generated in the interchangeable lens 200. Therefore, when the mode is switched from the synchronous mode to the asynchronous mode, the reference signal for giving the control timing is switched, so that the control cycle is also switched. There is a possibility that a problem occurs due to the switching of the reference signal that gives such control timing.

  For example, as shown in FIG. 5, when switching from the synchronous mode to the asynchronous mode without providing a switching waiting time as in this embodiment, a period of the control cycle t smaller than the control cycle T1 of the synchronous mode occurs. In this case, it is necessary to complete the processing set for the control cycle T1 before switching in a shorter control cycle t. For this reason, it is necessary to increase the operating speed of an actuator (for example, a motor). However, if the operating speed of the actuator is set high, the actuator may not be able to cope with the high speed and may step out.

  Therefore, in the present embodiment, when switching from the synchronous mode to the asynchronous mode, the control cycle is not switched immediately, and the control cycle T1 in the interchangeable lens 200 is switched to after the control cycle T1 before switching has elapsed. Adjust the period. This operation will be described in detail with reference to FIG.

  In the synchronous mode, the lens controller 240 counts the length (T1) of the control cycle for each control cycle and stores it in the DRAM 241. When switching from the synchronous mode to the asynchronous mode, the lens controller 240 changes the length of the control cycle to the interchangeable lens in the asynchronous mode when the previous control cycle length (T1) has elapsed since the mode switching. Switching to 200 control cycles T2. That is, at the time of switching from the synchronous mode to the asynchronous mode, the length of the control cycle including the switching time is set so that the length of the control cycle including the switching time becomes the same length (T1) as the control cycle of the synchronous mode. Set

  Thereby, the control cycle immediately after the mode change becomes the same as the control cycle in the synchronous mode. For this reason, immediately after the mode is switched, the process to be executed in the last cycle of the synchronous mode can be completed.

(Other embodiments)
In the camera system 1 of the above-described embodiment, the camera controller 140 notifies the lens controller 240 of a synchronization signal at a frequency of 60 (Hz). However, the configuration is not necessarily limited thereto. The camera controller 140 may notify the lens controller 240 of a synchronization signal at a frequency of 30 (Hz), or may notify the synchronization signal at a frequency of 15 (Hz). That is, any frequency synchronization signal may be notified.

  In the camera system 1 of the above embodiment, the lens controller 240 controls each processing unit at 120 Hz in the asynchronous mode. However, such a configuration is not necessarily required. For example, the lens controller 240 may control each processing unit at 60 Hz in the asynchronous mode, or may control each processing unit at 30 Hz. Further, the lens controller 240 does not need to uniformly control each processing unit at 120 Hz, and may perform control at different frequencies depending on each processing unit and processing content.

  In the camera system 1 of the above embodiment, the camera controller 140 transmits a synchronization signal to the lens controller 240 in the synchronous mode and does not transmit a synchronization signal to the lens controller 240 in the asynchronous mode. However, such a configuration is not necessarily required. For example, the camera controller 140 transmits a synchronization signal to the lens controller 240 in both the synchronous mode and the asynchronous mode, and the lens controller 240 synchronizes with the synchronization signal in the synchronous mode, but is synchronized in the asynchronous mode. A configuration that does not synchronize with the signal may be employed.

  In the above-described embodiment, the configuration having the zoom lens 210 and the OIS lens 220 has been exemplified, but these are not essential configurations for the present invention. In other words, the present invention can be applied to a camera system equipped with a single focus lens that does not have a zoom function, and can also be applied to a camera system equipped with an interchangeable lens that does not have a camera shake correction function. It is.

  In the above-described embodiment, the camera body that does not include the movable mirror is illustrated, but the present invention is not limited to this. For example, a movable mirror may be provided in the camera body, or a prism for separating the subject image may be provided. Moreover, the structure provided with a movable mirror not in a camera body but in an adapter may be sufficient.

  In the above embodiment, the CCD image sensor 110 is exemplified as the image pickup device, but the present invention is not limited to this. For example, the image sensor may be constituted by a CMOS image sensor or an NMOS image sensor.

  The present invention is applicable to an interchangeable lens camera system (specifically, a digital still camera, a movie, or the like) in which an interchangeable lens and a camera body communicate with each other.

  Although the above description has been described with reference to specific embodiments, many other variations, modifications, and other uses will be apparent to those skilled in the art. Accordingly, the embodiments are not limited to the specific disclosure herein, but can be limited only by the scope of the appended claims. This application includes Japanese patent application, Japanese Patent Application No. 2008-141929 (submitted on May 30, 2008) and Japanese Patent Application No. 2008-145687 (submitted on June 3, 2008), and US Provisional Application No. 61/053815. (Submitted on May 16, 2008), the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 100 Camera body 110 CCD image sensor 111 AD converter 112 Timing generator 120 Liquid crystal monitor 130 Release button 140 Camera controller 141 DRAM
150 Body Mount 160 Power Supply 170 Card Slot 171 Memory Card 200 Interchangeable Lens 210 Zoom Lens 211 Drive Mechanism 212 Detector 220 OIS Lens 221 Actuator 222 Position Detection Sensor 223 OIS IC
230 Focus lens 233 Focus motor 240 Lens controller 241 DRAM
242 Flash memory 243 Counter 250 Lens mount 260 Aperture 261 Aperture motor

Claims (10)

A camera system comprising a camera body and an interchangeable lens,
The camera body is
Imaging means;
Synchronization signal generating means for generating a synchronization signal;
Body control means for controlling the camera body and generating a command for controlling the interchangeable lens;
Transmission means for transmitting the synchronization signal and the command,
The transmission means transmits the synchronization signal at a timing correlated with the exposure timing of the imaging means,
The body control means sets a command for setting the interchangeable lens in a synchronous mode in which an operation of the interchangeable lens is controlled in synchronization with the synchronization signal, and sets the interchangeable lens in an asynchronous mode other than the synchronous mode. And a command to transmit to the interchangeable lens,
The body control means controls switching between the synchronous mode and the asynchronous mode according to a control state of the camera body,
The interchangeable lens is
Receiving means for receiving a synchronization signal and a command transmitted from the camera body;
Lens control means for controlling the operation of the interchangeable lens,
The lens control means controls the operation of the interchangeable lens in the synchronous mode or the asynchronous mode according to a command received from the camera body.
Camera system. The asynchronous mode is a mode in which the operation of the interchangeable lens is controlled in synchronization with a synchronization signal generated in the interchangeable lens.
The camera system according to claim 1. The body control means controls the interchangeable lens to the synchronous mode during moving image capturing.
The camera system according to claim 1. The body control means controls the interchangeable lens to the asynchronous mode when taking a still image.
The camera system according to claim 3. The camera body further includes an imaging unit that captures an image of a subject formed by the interchangeable lens and generates image data.
The body control means controls the interchangeable lens to an asynchronous mode when the image data generated by the imaging means is not taken into the subsequent processing unit.
The camera system according to claim 1. The synchronous mode has a first control period, the asynchronous mode has a second control period,
When the lens control means switches from the synchronous mode to the asynchronous mode, the length of the control cycle including the switching time point is such that the length of the control cycle including the switching time point is the same as the first control cycle. Set
The camera system according to claim 1. A camera body to which an interchangeable lens can be attached,
Imaging means;
Synchronization signal generating means for generating a synchronization signal;
Body control means for controlling the camera body and generating a command for controlling the interchangeable lens;
Transmission means for transmitting the synchronization signal and the command,
The transmission means transmits the synchronization signal at a timing correlated with the exposure timing of the imaging means,
The body control means sets a command for setting the interchangeable lens in a synchronous mode in which an operation of the interchangeable lens is controlled in synchronization with the synchronization signal, and sets the interchangeable lens in an asynchronous mode other than the synchronous mode. And a command to transmit to the interchangeable lens ,
The body control means controls switching between the synchronous mode and the asynchronous mode according to a control state of the camera body.
Camera body. The camera body records image data based on the image data generated by the imaging unit on a predetermined recording medium,
  The camera system according to claim 1, wherein the body control unit transmits a command for setting the interchangeable lens to the asynchronous mode when recording the image data captured by the imaging unit onto the recording medium. The camera body records image data based on the image data generated by the imaging unit on a predetermined recording medium,
  The camera system according to claim 1, wherein the body control unit transmits a command for setting the interchangeable lens to the asynchronous mode when reproducing the image data recorded on the recording medium. The camera body transmits a command for setting the interchangeable lens to the synchronous mode during moving image capturing, and transmits a command for setting the interchangeable lens to the asynchronous mode during still image capturing. The camera system according to claim 1.

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