Imaging device, illumination device, and control method thereof

Abstract

To make it possible to suppress the speed limit of continuous shooting caused by a light adjustment process while performing, every time imaging is performed, the light adjustment process of the amount of main light emission by causing a strobe device to emit light during continuous shooting of an imaging device.SOLUTION: A control unit 101 of an imaging device 100 communicates with a strobe device 500 used for imaging, obtains information on a preliminary light emission result of the strobe device 500, and based on the obtained information on the preliminary light emission result, performs a light adjustment process of determining an amount of main light emission of the strobe device 500 in main imaging. When an imaging frequency to repeat imaging is high enough to exceed a threshold value, the control unit 101 obtains information used for setting at the time of preliminary light emission or at the time of the main light emission, which is different from information on the main light emission amount, by dividing a first communication process before the preliminary light emission and a second communication process after the preliminary light emission.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an imaging device, a lighting device, and control methods therefor.

Background Art

[0002] In an imaging device, an external strobe device as a lighting device can be attached as in Patent Document 1 and made to emit light during imaging. Also, in this case, the imaging device may perform a light adjustment process of pre-emitting light from the strobe device before the main imaging to determine the light emission amount at the main light emission. For such a light adjustment process, the imaging device needs to pre-emit light from the strobe device before the main light emission in the main imaging, communicate with the strobe device to receive information on the pre-emission result from the strobe device, and calculate the light emission amount at the main light emission based on the acquired information.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, some imaging devices have a continuous shooting function that allows for repeated image capture. When continuous shooting, the imaging device may fire the strobe device each time an image is captured. Even in such cases of continuous shooting, it is desirable for the imaging device to pre-fire the strobe device and perform the main flash amount adjustment process. However, if the strobe device is fired and the main flash amount adjustment process is performed each time an image is captured during continuous shooting, it takes time for the process to complete. The speed of continuous shooting is limited by the main flash amount adjustment process performed each time an image is captured, and it cannot be increased beyond that limit. As a countermeasure, similar to how the strobe zoom drive of the strobe device is fixed and prohibited during continuous shooting in Patent Document 1, it is conceivable to fix and prohibit the main flash amount adjustment process during continuous shooting. However, in this case, it is not possible to adjust the main flash amount to match changes in the imaging environment during continuous shooting.

[0005] Therefore, the present invention aims to enable the strobe device to emit light and perform light emission adjustment processing for each image taken during continuous shooting, while suppressing the limitation on the continuous shooting speed caused by this processing. [Means for solving the problem]

[0006] The imaging device according to the present invention includes an imaging communication unit that communicates with an illumination device to acquire information on the pre-flash result of the illumination device, a dimming means that performs a dimming process to determine the amount of main light emitted by the illumination device during main imaging based on the pre-flash result information acquired by the imaging communication unit, and a setting acquisition means that acquires information on the continuous shooting setting during imaging. The imaging communication unit acquires information different from the main light emission amount information in two separate communication processes: a first communication process before pre-flash and a second communication process after pre-flash, when the continuous shooting frame rate for repeating imaging based on the continuous shooting setting exceeds a predetermined threshold. [Effects of the Invention]

[0007] In this invention, the flash device is activated and the amount of light emitted is controlled for each image taken during continuous shooting, while suppressing the limitation on the continuous shooting speed caused by this process. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram of an imaging device according to the first embodiment of the present invention. [Figure 2] Figure 1 is a flowchart of the automatic exposure control during continuous shooting by the camera's MPU. [Figure 3] This is an explanatory diagram showing the relationship between the continuous shooting frame rate and the threshold for switching the communication of pre-flash result information of a strobe device during continuous shooting. [Figure 4] Figure 1 shows the timing chart of the automatic flash control during continuous shooting of the imaging device. [Figure 5] This is a block diagram of a strobe device according to a second embodiment of the present invention. [Figure 6] Figure 4 is a flowchart of the automatic flash control during continuous shooting by the strobe MPU. [Figure 7] Figure 4 is a flowchart showing a modified example of automatic flash control during continuous shooting using the strobe MPU. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the configurations described in the following embodiments are merely illustrative, and the scope of the present invention is not limited to the configurations described in the embodiments.

[0010] [First Embodiment] Figure 1 is a block diagram of an imaging device 100 according to a first embodiment of the present invention. Figure 1 also shows an external strobe device 500, which is an illumination device attached to the imaging device 100. The strobe device 500 may be the same as that shown in Figure 5, which will be described later. The imaging device 100 in Figure 1 has a lens unit 102 and an image sensor 103 as an optical system for imaging a subject. It also has a timing signal generation circuit 104, an A / D converter 105, a memory controller 106, and a buffer memory 107 as a processing system for the image captured by the image sensor 103. The lens unit 102 includes, for example, an aperture adjustment mechanism and a focus adjustment mechanism, and forms an image of the light beam containing the light of the incident subject on the image sensor 103. The timing signal generation circuit 104 generates the timing signals necessary to operate the image sensor 103 and outputs them to the image sensor 103. The image sensor 103 may be a CCD or CMOS having a plurality of photoelectric conversion elements arranged on the light-receiving surface. The photoelectric conversion element accumulates charge according to the amount of light received. The image sensor 103 converts the light in the imaging range, including the subject, into an electrical signal using multiple photoelectric conversion elements to generate analog image data. The image sensor 103 can also be used as a photometer to measure the amount of light received. The A / D converter 105 converts the analog image data output from the image sensor 103 into digital image data. The memory controller 106 controls the refresh operation of the buffer memory 107 and records the digital image data in the buffer memory 107.

[0011] The imaging device 100 in Figure 1 includes a storage unit 119, a shutter control unit 111, a photometering unit 112, a lens control unit 113, a focus detection unit 114, a posture detection unit 115, an operation unit 116, a camera communication unit 117, and a camera MPU 101 to which these are connected. A system bus 120 is further connected to the camera MPU 101. A memory controller 106, an image display unit 108, and an interface 109 for the recording medium 110 are connected to the system bus 120. The storage unit 119 is a non-volatile memory such as ROM or HDD, and records the program executed by the camera MPU 101, design parameters, setting data, etc. The camera MPU 101 may be a microcontroller. The microcontroller may also have a built-in storage unit 119 and a timer. The camera MPU 101 reads and executes the program recorded in the storage unit 119. As a result, the camera MPU 101 functions as a control unit that controls the overall operation of the imaging device 100. The image display unit 108 displays, for example, image data stored in the buffer memory 107 as a live view image. In addition, the image display unit 108 may also display various settings such as the current imaging mode and exposure parameters using icons. The recording medium 110 may be a non-volatile memory such as a memory card or hard disk. The recording medium 110 may be removable from the imaging device 100. The interface 109 stores and records image data stored in the buffer memory 107 and processed image data on the recording medium 110. The interface 109 may also be an interface 109 for connection with a wireless communication unit (not shown). The shutter control unit 111 controls the opening and closing of a shutter (not shown) that is positioned in front of the image sensor 103 and switches the image sensor 103 between a light-shielding state and an imaging state, according to a signal from the camera MPU 101. The photometering unit 112 outputs photometric values, which are the photometric results for each area, to the camera MPU 101 based on the output of the image sensor 103, which divides the imaging screen into multiple areas. Based on the photometric values ​​for each area, the camera MPU 101 performs exposure calculations to determine exposure parameters such as AV (aperture value), TV (shutter speed), and ISO (sensitivity) during imaging.Furthermore, when the strobe device 500 pre-flashes (preliminary flash) towards the subject, the camera MPU 101 can calculate the amount of light emitted by the strobe device 500 during the main flash based on the photometric value measured by the photometric unit 112 during the pre-flash. The lens control unit 113 controls a lens drive motor and an aperture drive motor (not shown) according to signals from the camera MPU 101. This adjusts the focus and aperture of the lens unit 102. The lens control unit 113 also acquires lens information from the lens unit 102 according to signals from the camera MPU 101 and outputs it to the camera MPU 101. The camera MPU 101 can acquire lens information during the pre-flash or lens information during the main flash as imaging information. The focus detection unit 114 outputs the amount of defocus for each autofocus point to the camera MPU 101 based on the output of a focus detection sensor equipped with multiple autofocus points within the imaging screen. This allows the camera MPU 101 to adjust the focus it instructs the focus detection unit 114 to focus based on the amount of defocus. The attitude detection unit 115 is, for example, an acceleration sensor and detects the attitude of the imaging device 100 with respect to the direction of gravity. The attitude detection unit 115 outputs the detected attitude information of the imaging device 100 to the camera MPU 101. The operation unit 116 has a release button operated by the user for imaging, other buttons, a touch panel superimposed on the image display unit 108, etc. When the release button is operated with a first stroke (half-press) and SW1 is turned ON, it outputs an ON signal for SW1 to the camera MPU 101. This causes the camera MPU 101 to start imaging preparation operations such as focus detection and metering. When the release button is operated with a second stroke (full-press) and SW2 is turned ON, it outputs an ON signal for SW2 to the camera MPU 101. This causes the camera MPU 101 to start the imaging operation. If there is insufficient light during imaging, the camera communication unit 117 pre-flashes the strobe device 500 before firing the main flash during imaging, according to the strobe usage settings. The camera communication unit 117 controls the flash pattern and amount during the pre-flash, calculates the flash pattern and amount during the main flash through dimming processing based on the pre-flash result, and then fires the strobe device 500 during imaging based on the calculation result.If an external strobe device 500 is attached for imaging, the camera MPU 101 controls communication with the strobe device 500.

[0012] The camera communication unit 117 communicates with the strobe device 500. The strobe device 500 is mounted on the main body of the imaging device 100 for use in imaging. The strobe device 500 is mounted on the imaging device 100 such that the strobe connection unit 502 is connected to the camera connection unit 118 of the imaging device 100. The camera communication unit 117 and the strobe device 500 perform data communication through the strobe connection unit 502 and the camera connection unit 118 under the communication control of the camera MPU 101. The camera MPU 101 uses the camera communication unit 117 to receive and acquire various types of information from the strobe device 500, such as charge completion information indicating the charging status of the strobe device 500. When the strobe device 500 is in a charged state where it can emit light, the camera MPU 101 uses the camera communication unit 117 to transmit instructions to the strobe device 500 regarding the flash pattern and amount of light emitted during pre-flash and instructions regarding the flash pattern and amount of light emitted during main flash. The camera MPU 101 may periodically communicate with the strobe device 500 using the camera communication unit 117. For example, the camera MPU 101 may pre-flash the strobe device 500 before each image (main flash) during continuous shooting to obtain information on the pre-flash result and perform exposure control processing for the main flash for each image. However, in this case, before each image (main flash) during continuous shooting, the camera MPU 101 must communicate with the strobe device 500 regarding pre-flash, perform calculations for exposure control processing, and communicate with the strobe device 500 regarding the main flash. This series of processes requires a predetermined amount of time. When continuous shooting is performed using the strobe device 500, the time from pre-flash to exposure control processing may prevent the imaging frequency at which images can be repeated from being higher than a predetermined frequency (preventing the imaging interval from being shorter than a predetermined interval).

[0013] Figure 2 is a flowchart of the automatic exposure control during continuous shooting by the camera MPU 101 in Figure 1. The camera MPU 101 of the imaging device 100 may repeatedly execute the automatic exposure control in Figure 2 each time it starts continuous shooting. In step S201, the camera MPU 101 communicates with the external strobe device 500, which is attached to the main body of the device for use in imaging, through periodic strobe communication using the camera communication unit 117, which is performed while the camera is running. The camera MPU 101 and the strobe device 500 exchange information such as information on when the strobe is fully charged, strobe settings, camera settings, and lens focal length. Based on this information, the camera MPU 101 can determine whether or not it is possible to take images using the strobe device 500. Then, while the periodic strobe communication is being repeated, if the user operates the release button on the operation unit 116 with a second stroke (full press) and SW2 turns ON, the camera MPU 101 proceeds to step S202 based on the settings at the time of the operation. In step S202, the camera MPU 101 determines the flashing conditions, such as the flashing method and flash amount (peak value), based on the information communicated in step S201, and pre-flashes the strobe device 500. At the same time as the pre-flash, the camera MPU 101 also takes an image with the image sensor 103. The photometering unit 112 measures the subject under pre-flash conditions. Based on the photometering results, the camera MPU 101 measures the degree of influence of the pre-flash on the subject. At this time, if the subject is measured under conditions where the strobe device is not flashing, and the photometering results (non-flash metering results) are compared with the pre-flash metering results, the degree of influence of the pre-flash on the subject can be measured with greater accuracy. Here, the camera MPU 101 performs the strobe communication in step S201 before the pre-flash in step S202. Even when repeated imaging, the camera MPU101, as the imaging communication unit, acquires information used for setting pre-flash or main flash that differs from the main flash amount information of the initial strobe device 500 only through the first communication processing before pre-flash.Here, the information used for setting pre-flash or main flash, which differs from the main flash output information, may include, in addition to the charging completion information of the strobe device 500, at least one of the strobe setting information of the strobe device 500, the camera setting information of the imaging device 100, or the lens focal length information.

[0014] In step S203, the camera MPU 101 determines the amount of main flash during still image capture by dimming calculation (also called dimming process) based on the pre-flash result information from step S202. The camera MPU 101 may also receive and acquire the pre-flash result information from the strobe device 500 by communicating with the strobe device 500 using the camera communication unit 117. The camera MPU 101 may also acquire the pre-flash result information from the strobe device 500 as an imaging communication unit. In this case, the camera MPU 101 can perform dimming processing as an automatic dimming means to determine the amount of main flash for main image capture by the strobe device 500 based on the photometric result of the subject under pre-flash. In step S204, the camera MPU 101 performs still image capture with main flash. Before image capture, the camera MPU 101 communicates the flash setting values, such as the amount of main flash determined in step S203, with the strobe device 500 using the camera communication unit 117. The strobe device 500 performs the main flash at the timing of the image capture. The camera MPU 101 captures an image with the image sensor 103 at the same time as the main flash. The camera MPU 101 transfers and records the digital image data from the first image captured in continuous shooting to the recording medium 110 via the interface 109.

[0015] In step S205, the camera MPU 101 acquires the continuous shooting setting. The camera MPU 101 may acquire the continuous shooting setting from a non-volatile memory such as the storage unit 119. In step S206, the camera MPU 101 calculates the continuous shooting frame rate corresponding to the actual imaging frequency from the continuous shooting setting acquired in step S205. Then, the camera MPU 101 compares the calculated frame rate with a predetermined threshold. As a result, the camera MPU 101, as an imaging communication unit, can determine whether the imaging frequency for repeating imaging is high enough to exceed the threshold by determining whether the continuous shooting frame rate based on the continuous shooting setting of the imaging device 100 exceeds the threshold. Here, the threshold may be the upper limit of the continuous shooting frame rate that can be executed even if communication similar to the strobe communication performed in step S201 is performed after imaging. In this case, a frame rate exceeding the threshold will be difficult to actually execute when normal strobe communication is performed. If the calculated frame rate is below the threshold, the camera MPU 101 proceeds to step S207. If the calculated frame rate exceeds the threshold, the camera MPU 101 proceeds to step S209.

[0016] In step S207, the camera MPU 101 performs the same strobe communication as in step S201 because the frame rate at which continuous shooting is to be performed based on the settings is below the threshold, and performing normal strobe communication will not affect continuous shooting. If the frame rate for repeating image capture is below the threshold, the camera MPU 101 can obtain information used for setting pre-flash or main flash, which is different from the main flash output information of the strobe device 500, by only the first communication processing before pre-flash. In step S208, the camera MPU 101 determines whether the user has released the second stroke operation of the release button on the operation unit 116. If it is determined that the operation of the second stroke on the release button is not continuing, the camera MPU 101 terminates the automatic flash control during continuous shooting as shown in Figure 2. If the operation of the second stroke on the release button is continuing, the camera MPU 101 returns the process to step S202. In this case, the camera MPU 101 repeats the process from steps S202 to S208 during the period when the second stroke operation of the release button is continuing. Here, the camera MPU 101 performs the strobe communication in step S207 before the pre-flash in step S202. Based on the strobe communication in step S207 before the pre-flash, the camera MPU 101 pre-flashes the strobe device 500. Also, if the camera MPU 101 determines in step S208 that the second stroke operation of the release button is no longer continuing, it terminates the automatic flash control during continuous shooting as shown in Figure 2.

[0017] In step S209, unlike in step S201 or step S207, the camera MPU 101 performs stroboscopic communication in which only some information is transmitted and received to reduce the communication volume. When the frame rate for repeating imaging exceeds the threshold, the camera MPU 101 cannot secure in one lump the time for communication with the same communication volume as normal stroboscopic communication. Therefore, before pre-flash, a first communication process is executed in which only some of the information used for the settings at the time of pre-flash or main flash, which is different from the main light emission amount information of the strobe device 500, is transmitted and received. The information transmitted and received by the first communication process before pre-flash is, for example, the charging completion information of the strobe device 500. Since the imaging device 100 cannot send a pre-flash instruction assuming that the strobe device 500 cannot perform pre-flash if it does not receive the charging completion information of the strobe device 500, the charging completion information of the strobe device 500 is transmitted and received by the first communication process. Other information may be transmitted and received before pre-flash, but if the communication volume becomes too large, the time required for communication becomes long, so the information transmitted and received may be changed according to the frame rate. Thereby, the time for stroboscopic communication before pre-flash can be shortened. In step S210, the camera MPU 101 determines whether or not the user has released the operation of the second stroke, similarly to step S208. When the operation in the second stroke is not continuing, the camera MPU 101 ends the automatic light control during continuous shooting in FIG. 2. When the operation in the second stroke is continuing, the camera MPU 101 advances the process to step S211.

[0018] In step S211, the camera MPU 101 uses the information communicated in step S209 to determine the flashing conditions, such as the flashing method and flashing amount (peak value) for the pre-flash. If the information communicated in step S209 was only charge completion information, the camera MPU 101 may substitute the information not communicated in step S209 with previously acquired information, such as the information communicated in step S201. For example, the camera MPU 101 may substitute the strobe setting information of the strobe device 500. The camera MPU 101 pre-flashes the strobe device 500 according to the determined flashing conditions. The camera MPU 101 also takes an image with the image sensor 103 at the same time as the pre-flash. The photometering unit 112 measures the light of the subject under pre-flash conditions. Based on the photometering results, the camera MPU 101 measures the degree of influence of the pre-flash on the subject.

[0019] In step S212, the camera MPU 101 performs strobe communication to send and receive any remaining information not received in step S209. Simultaneously with the strobe communication, the camera MPU 101 determines the amount of main flash used for still image capture by dimming calculations based on the acquired information used for setting the main flash and the measurement results from step S212. The camera MPU 101 may determine the amount of main flash used for still image capture by dimming calculations using the same calculation process as in step S203. In this case, information that was not communicated in the first communication process in step S209 and is communicated after the pre-flash but cannot be reflected in the dimming calculations in time may be substituted with information acquired previously (for example, one frame earlier). For example, if the lens focal length information is substituted with information acquired one frame earlier to control the light distribution of the strobe device 500 during the main flash, a difference will occur between the substituted information and the current lens focal length, but the effect of the difference is small because the frame rate is fast enough to exceed the threshold.

[0020] As described above, when the frame rate for repeating imaging by the camera MPU 101 exceeds the threshold value, the camera MPU 101 communicates the information used for the pre-emission or main emission settings different from the main emission amount information separately through the first communication process before the pre-emission and the second communication process after the pre-emission. Note that the sum of the communication amount of the first communication process in step S209 and the communication amount of the second communication process in step S212 does not have to match the stroboscopic communication and the communication amount in step S201 or step S207. Instead of communicating all the information used for the pre-emission or main emission settings different from the main emission amount information before the pre-emission, by communicating a part of the information simultaneously and in parallel with the dimming calculation after the pre-emission, communication can be efficiently performed within the limited time during continuous shooting.

[0021] After that, the camera MPU 101 proceeds to step S204. When the frame rate for repeating imaging exceeds the threshold value and may be bottlenecked in this way, the camera MPU 101 repeats the processes from step S209 to step S212 and the processes from step S204 to step S206. The camera MPU 101 repeats a series of processes until it determines that the operation in the second stroke in step S208 is not continued. The camera MPU 101 will repeatedly execute the first communication process before the pre-emission and the second communication process after the pre-emission in each imaging of continuous shooting. Also, when the camera MPU 101 determines that the operation in the second stroke regarding the release button is not continued in step S208, it ends the automatic dimming control during continuous shooting in FIG. 2.

[0022] Figure 3 is an explanatory diagram showing the relationship between the frame rate of continuous shooting and thresholds for switching the communication of pre-flash result information of the strobe device 500. The horizontal axis of Figure 3 is the frame rate of continuous shooting. The vertical axis is the amount of information communicated in each image taken during continuous shooting. The amount of information communicated includes the charging completion information of the strobe device 500. In Figure 3, the first threshold speed V1, the second threshold speed V2, and the third threshold speed V3 are set as thresholds for the frame rate. This information in Figure 3 may be recorded in the storage unit 119. In step S206, the camera MPU 101 may refer to the storage unit 119 and compare the frame rate of continuous shooting based on the continuous shooting setting of the imaging device 100 with these three threshold speeds: the first threshold speed V1, the second threshold speed V2, and the third threshold speed V3. If the frame rate of continuous shooting based on the continuous shooting setting of the imaging device 100 is less than or equal to the first threshold speed V1, the camera MPU 101 communicates information used for pre-flash or main flash settings that differ from the main flash amount information only in the first communication process before pre-flash. If the frame rate of continuous shooting based on the continuous shooting setting of the imaging device 100 exceeds the first threshold speed V1 and is less than or equal to the second threshold speed V2, the camera MPU 101 communicates more than half of the information used for pre-flash or main flash settings that differ from the main flash amount information in the first communication process before pre-flash. The camera MPU 101 communicates the remaining information in the second communication process after pre-flash, which is executed simultaneously and in parallel with the exposure control process. If the frame rate of continuous shooting based on the continuous shooting setting of the imaging device 100 exceeds the second threshold speed V2 and is less than or equal to the third threshold speed V3, the camera MPU 101 communicates less than half of the information used for pre-flash or main flash settings that differ from the main flash amount information before pre-flash. The camera MPU 101 communicates the remaining information in a second communication process after pre-flash, which is performed simultaneously and in parallel with the exposure control process. If the frame rate of continuous shooting based on the continuous shooting setting of the imaging device 100 exceeds the third threshold speed V3, the camera MPU 101 communicates only the charge completion information, which is information used for pre-flash or main flash settings that differs from the main flash amount information, in the first communication process before pre-flash. The camera MPU 101 communicates the remaining information in a second communication process after pre-flash, which is performed simultaneously and in parallel with the exposure control process.

[0023] By performing switching control that distributes the amount of communication in this way, the amount of communication and communication time of the first communication process before pre-flash can be increased or decreased without affecting the frame rate of continuous shooting. The camera MPU 101, as the imaging communication unit, reduces the amount of information acquired by the first communication process before pre-flash and increases the amount of information acquired by the second communication process after pre-flash, depending on the extent to which the frame rate of continuous shooting exceeds a threshold. The time of strobe communication does not affect the frame rate, and it is possible to achieve a frame rate that exceeds the limit when communicating only with the first communication process before pre-flash. In addition, the camera MPU 101 can acquire at least the charging completion information of the strobe device 500 during the first communication process before pre-flash.

[0024] Figure 4 is a timing chart of the automatic flash control during continuous shooting of the imaging device 100 in Figure 1. Figure 4(a) is a timing chart when only the first communication process before pre-flash is performed for each image taken during continuous shooting. When the processes from step S202 to step S208 in Figure 2 are repeated to perform the strobe communication in step S207, the timing chart is as shown in Figure 4(a). In Figure 4(a), after the image of the previous still image is taken, live view imaging is performed along with the strobe communication at the start of imaging, and pre-flash is performed. After that, the flash calculation is performed, and the image of the next still image is taken. If strobe communication continues to be performed even after the live view imaging is completed, as shown in Figure 4(a), the duration of this communication becomes a waiting time, and the timing of the pre-flash is delayed. The period from the previous image to the next image becomes longer, and this limits the frame rate of continuous shooting.

[0025] Figure 4(b) is a timing chart for when the first communication process before pre-flash and the second communication process after pre-flash are executed for each image during continuous shooting. When the processes from steps S209 to S212 and steps S204 to S206 in Figure 2 are repeated to execute the strobe communication in steps S209 and S212, the timing chart is as shown in Figure 4(b). In Figure 4(b), after capturing the previous still image, live view imaging is performed along with a short strobe communication at the start of imaging before pre-flash, and pre-flash is executed. Subsequently, the flash metering calculation is performed along with the strobe communication after pre-flash, and the next still image is captured. In Figure 4(b), the strobe communication before pre-flash is completed before live view imaging is completed. In this case, pre-flash can be executed at an earlier timing without the waiting time shown in Figure 4(a). The period from the previous image to the next image is shortened, and the frame rate of continuous shooting is less likely to be limited. A decrease in frame rate can be avoided.

[0026] As described above, in this embodiment, the imaging communication unit communicates with the strobe device 500, which is attached to the main body of the device for use in imaging, and communicates information used for setting pre-flash or main flash, which is different from the main flash amount information. When the imaging frequency for repeating imaging is high enough to exceed a threshold, the imaging communication unit acquires the pre-flash result information of the strobe device 500 in two parts: a first communication process before pre-flash and a second communication process after pre-flash. At the time of each continuous shot, the automatic flash control means performs a flash control process to determine the main flash amount of the strobe device 500 based on the latest pre-flash result information of the strobe device 500 acquired by the imaging communication unit. At this time, the automatic flash control means can perform a flash control process to determine the main flash amount of the strobe device 500 for main imaging, based on the information from the first communication process before pre-flash, simultaneously with the second communication process after pre-flash by the imaging communication unit. As a result, in this embodiment, the second communication process after pre-flash by the imaging communication unit and the flash control process to determine the main flash amount of the strobe device 500 for main imaging are executed simultaneously and in parallel. As a result, in this embodiment, the time required from pre-flash to main flash of the strobe device 500 is reduced, enabling support for high imaging frequencies. In this embodiment, the time required from pre-flash to main flash can be reduced compared to the case where all information of the flash result is acquired after pre-flash and dimming processing is performed.

[0027] In this embodiment, the acquisition of pre-flash result information and the dimming process are performed simultaneously and in parallel, making it possible to increase the continuous shooting speed. Even if the imaging device 100 drives and controls the image sensor 103 with high readout speed using an electronic shutter method, the frame rate of continuous strobe imaging can be improved without being affected by communication time with the strobe device 500. The imaging device 100 can continue imaging at a high frame rate in continuous shooting with synchronized flashing of the strobe device 500. The imaging device 100 can continue imaging at a high frame rate in continuous shooting with synchronized flashing of the strobe device 500, while performing, for example, strobe zoom control linked to the lens focal length without restriction.

[0028] [Second Embodiment] Next, a second embodiment of the present invention will be described. In the second embodiment, the strobe device 500, rather than the imaging device 100, determines the switching of strobe communication.

[0029] Figure 5 is a block diagram of a strobe device 500 according to a second embodiment of the present invention. Figure 5 also shows an imaging device 100 to which the strobe device 500 is mounted. The imaging device 100 may be the same as that in Figure 1. The strobe device 500 in Figure 5 has a strobe MPU 501. The strobe MPU 501 is connected to a light-emitting unit 503, a charging unit 504, a strobe operation unit 505, a strobe display unit 506, and a strobe memory unit 507. The strobe memory unit 507 is a semiconductor memory such as ROM, and records the program executed by the strobe MPU 501, design parameters, setting information of the strobe operation unit 505, etc. The strobe MPU 501 may be a microcontroller. The microcontroller may have a built-in strobe memory unit 507 and timer. The strobe MPU 501 reads and executes the program recorded in the strobe memory unit 507. As a result, the strobe MPU 501 functions as a control unit that controls the overall operation of the strobe device 500. The strobe connection unit 502 is connected to the camera connection unit 118 of the imaging device 100 and performs strobe communication with the imaging device 100. The light-emitting unit 503 includes, for example, a light-emitting circuit, a light-emitting capacitor, and a discharge tube. The light-emitting unit 503 drives the light-emitting circuit according to the instructions of the strobe MPU 501 and releases the energy charged in the light-emitting capacitor to the discharge tube, causing the discharge tube to emit light. The light from the discharge tube is shone onto the subject. The charging unit 504 charges the light-emitting capacitor of the light-emitting unit 503 using the power of a battery (not shown) mounted on the strobe device 500. The strobe operation unit 505 includes, for example, buttons and dials that are operated by the user. The strobe operation unit 505 outputs signals based on the user's operation to the camera communication unit 117. The strobe control unit 505 outputs, for example, setting information for the strobe's flash mode to the camera communication unit 117. The strobe flash modes include, for example, a "continuous shooting speed priority mode" that prioritizes the continuous shooting speed of the image. The strobe display unit 506 displays, for example, the flash mode according to the instructions of the camera communication unit 117. The strobe MPU 501, in the strobe device 500 used for imaging by the imaging device 100, controls the flash emission of the flash unit 503 as a flash control unit and controls strobe communication with the imaging device 100 as a strobe communication unit 508.In strobe communication, for example, setting information for pre-flashing the light-emitting unit 503 before taking an image may be acquired based on the setting operation of the strobe control unit 505.

[0030] Figure 6 is a flowchart of the automatic flash control during continuous shooting by the strobe MPU 501 shown in Figure 4. The strobe MPU 501 may repeatedly execute the automatic flash control shown in Figure 6 each time continuous shooting is started. In step S601, the strobe MPU 501 communicates with the imaging device 100, which is attached for use in imaging, through periodic strobe communication using the strobe communication unit 508, which is performed while the camera is running. The strobe MPU 501 exchanges information with the imaging device 100 that is used for pre-flash or main flash settings, which is different from the main flash output information, such as strobe charge completion information, strobe setting information, camera setting information, and lens focal length. Then, while periodic strobe communication is being repeated, when the user operates the release button on the control unit 116 with a second stroke (full press) and SW2 turns ON, the strobe MPU 501 proceeds to step S602 based on the settings at the time of the operation. In step S602, the strobe MPU 501 determines the flashing conditions, such as the flashing method and flash amount (peak value), based on the information communicated in step S601, and pre-flashes the strobe device 500. Simultaneously with the pre-flash, the imaging device 100 takes an image with the image sensor 103. The photometering unit 112 of the imaging device 100 measures the subject under pre-flash conditions. The strobe MPU 501 instructs the imaging device 100 to measure the degree of influence of the pre-flash on the subject based on the photometering results. Here, the strobe MPU 501 performs the strobe communication in step S601 before the pre-flash in step S602. Even when imaging is repeated, the strobe MPU 501, as the strobe communication unit 508, acquires the image only through the first communication process before the pre-flash.

[0031] In step S603, the strobe MPU 501 determines the amount of main flash for still image capture by dimming calculation based on the pre-flash result information from step S602. The strobe MPU 501 may also communicate with the imaging device 100 using the strobe communication unit 508 to receive and acquire the pre-flash result information from the imaging device 100. The strobe MPU 501 may acquire the pre-flash result information as the strobe communication unit 508. In this case, the strobe MPU 501, as an automatic dimming means, can perform dimming processing to determine the amount of main flash for main image capture by the strobe device 500 based on the photometric result of the subject under pre-flash. In step S604, the strobe MPU 501 performs the main flash at the timing when the imaging device 100 captures a still image. The imaging device 100 transfers and records the digital image data from the first image in continuous shooting to the recording medium 110 via the interface 109.

[0032] In step S605, the strobe MPU 501 acquires the setting information for the flash mode during continuous shooting. The camera MPU 101 may acquire the setting information for the flash mode set in the flash control unit 505 from the flash memory unit 507. In step S606, the strobe MPU 501 determines whether the flash mode acquired in step S605 is set to "continuous shooting speed priority mode". This allows the strobe MPU 501 to determine whether to repeat imaging at a high imaging frequency. If the flash mode is "continuous shooting speed priority mode", the strobe MPU 501 proceeds to step S609. If the flash mode is not "continuous shooting speed priority mode", the strobe MPU 501 proceeds to step S607.

[0033] In step S607, the strobe MPU 501 performs the same strobe communication as in step S601. If the flash mode is not "continuous shooting speed priority mode", the strobe MPU 501 can obtain information used for pre-flash or main flash settings that differ from the main flash output information by only the first communication process before pre-flash. In step S608, the strobe MPU 501 determines whether the user has released the second stroke of the release button on the control unit 116. If it is determined that the second stroke operation on the release button is not continuing, the strobe MPU 501 terminates the automatic flash control during continuous shooting as shown in Figure 6. If the second stroke operation on the release button is continuing, the strobe MPU 501 returns to step S602. In this case, the strobe MPU 501 repeats the processes from step S602 to step S608 for the period during which the second stroke operation on the release button is continuing. Here, the strobe MPU 501 performs the strobe communication in step S607 before the pre-flash in step S602. Based on the strobe communication in step S607 before the pre-flash, the strobe MPU 501 pre-flashes the strobe device 500. Also, if the camera MPU 101 determines in step S608 that the operation of the release button in the second stroke has not continued, it terminates the automatic flash control during continuous shooting as shown in Figure 2.

[0034] In step S609, unlike in steps S601 and S607, the strobe MPU 501 performs strobe communication that sends and receives only some of the information to reduce the amount of communication. When the flash mode is "continuous shooting speed priority mode", the camera MPU 101 performs a first communication process that sends and receives only some of the information used for setting pre-flash or main flash, which is different from the main flash amount information, before the pre-flash. This shortens the time of strobe communication before the pre-flash. In addition, the camera MPU 101 communicates at least the information that the strobe device 500 has finished charging during the first communication process before the pre-flash. In step S610, the strobe MPU 501 determines whether the user has released the second stroke operation, similar to step S608. If the operation in the second stroke is not continuing, the camera MPU 101 terminates the automatic flash control during continuous shooting as shown in Figure 2. If the operation in the second stroke is continuing, the camera MPU 101 proceeds to step S611.

[0035] In step S611, the strobe MPU 501 uses the information communicated in step S609 (for example, only the charging completion information) to determine the flashing conditions such as the pre-flash method and pulse height. At this time, any missing information other than the charging completion information, such as flash settings, lens focal length, and camera control values, may be substituted with the information communicated in step S601. The strobe MPU 501 pre-flashes the strobe device 500 with the determined flashing conditions. Simultaneously with the pre-flash, the imaging device 100 takes an image with the image sensor 103 and measures the photometering unit 112 to measure the subject under pre-flash conditions. Based on the photometering results, the strobe MPU 501 measures the degree of influence of the pre-flash on the subject. Here, the strobe MPU 501 performs the strobe communication in step S609 before the pre-flash in step S611.

[0036] In step S612, the strobe MPU 501 performs strobe communication to send and receive any remaining information not sent or received in step S609. When the flash mode is "continuous shooting speed priority mode", the strobe MPU 501 communicates information used for pre-flash or main flash settings that differ from the main flash output information in two separate communication processes: a first communication process before pre-flash and a second communication process after pre-flash. Note that the sum of the communication volume of the first communication process in step S609 and the communication volume of the second communication process in step S612 does not have to match the communication volume of the strobe communication in step S601 or step S267. In this way, the strobe MPU 501 can send and receive information used for pre-flash or main flash settings that differ from the main flash output information in two separate communication processes: a first communication process before pre-flash and a second communication process after pre-flash, when there is a possibility that the imaging frequency will exceed a threshold. Furthermore, the strobe MPU 501, simultaneously and in parallel with the second communication processing after pre-flash, determines the main flash amount for still image capture by dimming calculations based on the pre-flash result information of the strobe device 500 that has already been acquired. The strobe MPU 501 may determine the main flash amount for still image capture by dimming calculations similar to those in step S603. In this case, any information that is insufficient in the first communication processing in step S609 may be substituted with previous information already acquired by the second communication processing after pre-flash.

[0037] Subsequently, the strobe MPU501 proceeds to step S604. When the flash mode during repeated imaging is "continuous shooting speed priority mode," the strobe MPU501 repeats the processes from steps S609 to S612 and from steps S604 to S606. The strobe MPU501 repeats this series of processes until it determines in step S608 that the flash mode is not "continuous shooting speed priority mode." The strobe MPU501 repeatedly performs the first communication process before pre-flash and the second communication process after pre-flash for each image in continuous shooting. Also, if the strobe MPU501 determines in step S608 that the operation of the release button in the second stroke has not continued, it terminates the automatic flash control during continuous shooting as shown in Figure 6.

[0038] As described above, in this embodiment, when the flash mode of the strobe device 500 is set to "continuous shooting speed priority mode", the amount of communication before pre-flash is reduced so that strobe communication does not affect the upper limit of the frame rate.

[0039] Although the present invention has been described in detail above based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various forms that do not depart from the spirit of the invention are also included in the present invention.

[0040] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. Furthermore, the present invention can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0041] In the second embodiment described above, the strobe MPU 501 of the strobe device 500 determines the mode as the setting information to be acquired and switches the transmission of pre-flash result information according to the mode setting. In addition, the strobe MPU 501 of the strobe device 500 may also determine other information, such as the communication rate, and switch the transmission of pre-flash result information according to the communication rate. Figure 7 is a flowchart of a modified example of the automatic flash control during continuous shooting by the strobe MPU 501 of Figure 4. The strobe MPU 501 may repeatedly execute the automatic flash control of Figure 7 instead of the automatic flash control of Figure 6 each time imaging by continuous shooting is started. Steps S601 to S612 in Figure 7 are the same as in Figure 6, and their explanation is omitted.

[0042] In step S706, the strobe MPU 501 compares the communication rate in flash mode acquired in step S605 with a threshold. This allows the camera MPU 101, as the imaging communication unit, to determine whether the communication rate during continuous shooting based on the continuous shooting setting of the imaging device 100 exceeds the threshold, thereby determining whether the imaging frequency for repeating images is high enough to exceed the threshold. Here, the threshold may be the upper limit of the frame rate for continuous shooting that is feasible even if the same communication as the strobe communication performed in step S601 is performed after imaging. In this case, frame rates exceeding the threshold will be difficult to actually implement. If the communication rate in flash mode is below the threshold, the camera MPU 101 proceeds to step S609. If the communication rate in flash mode exceeds the threshold, the camera MPU 101 proceeds to step S607. This allows the strobe MPU 501 to function as the strobe communication unit 508. For example, if the setting information to be acquired by the strobe MPU 501 has a communication rate below the threshold for communication with the imaging device 100, it can transmit information used for pre-flash or main flash settings that differ from the main flash output information, separately before and after the pre-flash. Also, if the setting information to be acquired by the strobe MPU 501 has a communication rate higher than the threshold for communication with the imaging device 100, it can transmit the pre-flash result information of the strobe device 500 in only the first communication process before the pre-flash. [Explanation of symbols]

[0043] 100 Imaging device 101 Camera MPU 103 Image sensor 117 Camera Communications Department 118 Camera connection section 119 Memory section 500 Strobe Device 501 Strobe MPU 502 Strobe connection 507 Strobe memory unit 508 Strobe Communications Department

Claims

1. An imaging communication unit that communicates with a lighting device and acquires information on the pre-light emission result of the lighting device, A dimming means that performs dimming processing to determine the amount of light emitted during main imaging of the illumination device based on the pre-light emission result information acquired by the imaging communication unit, A setting acquisition method for acquiring information on continuous shooting settings during image capture, It has, The aforementioned imaging communication unit is If the continuous shooting frame rate, which repeats imaging based on the aforementioned continuous shooting setting, exceeds a predetermined threshold, information different from this light emission amount information is acquired separately in a first communication process before pre-flash and a second communication process after pre-flash. An imaging device characterized by the following features.

2. The aforementioned imaging communication unit is The imaging device according to claim 1, characterized in that, if the continuous shooting frame rate at which images are repeatedly taken based on the continuous shooting setting does not exceed a predetermined threshold, information different from the light emission amount information is acquired in the first communication processing before pre-flash.

3. The aforementioned imaging communication unit is The imaging device according to claim 1, characterized in that the amount of information acquired by the first communication processing before pre-flash decreases in proportion to the extent to which the frame rate of continuous shooting exceeds a threshold.

4. The dimming means is Based on the latest pre-light emission result information of the illumination device acquired by the imaging communication unit, a dimming process is performed to determine the main light emission amount of the illumination device. When the imaging communication unit acquires information different from the main light emission amount information separately in the first communication process before pre-flash and the second communication process after pre-flash, it performs a dimming process to determine the main light emission amount for the main imaging of the illumination device, based on the information obtained from the first communication process before pre-flash, simultaneously with the second communication process after pre-flash performed by the imaging communication unit. The imaging apparatus according to feature 1.

5. The dimming means is When the imaging communication unit performs a dimming process to determine the amount of light emitted during the main imaging of the illumination device, simultaneously with the second communication process after pre-light emission, based on the information obtained by the first communication process before pre-light emission, any missing information is substituted with information obtained before the second communication process after pre-light emission. The imaging apparatus according to feature 4.

6. The aforementioned imaging communication unit is At least the information regarding the completion of charging of the lighting device is obtained in the first communication process before pre-light emission. The imaging apparatus according to any one of claims 1 to 5.

7. The aforementioned imaging communication unit is Even when imaging is repeated, any information that differs from the initial emission amount information is acquired only by the first communication processing before pre-emission. The imaging apparatus according to any one of claims 1 to 6.

8. An imaging communication step involves communicating with a lighting device to obtain information on the pre-light emission result of the lighting device, A dimming step is performed to execute a dimming process that determines the amount of light emitted by the illumination device during main imaging based on the pre-light emission result information acquired in the imaging communication step, A setting acquisition step to obtain information on the continuous shooting setting at the time of imaging, It has, The aforementioned imaging communication step includes: When the continuous shooting frame rate, which repeats imaging based on the continuous shooting setting, exceeds a predetermined threshold, the system includes a first communication processing step before pre-flash and a second communication processing step after pre-flash, for acquiring information different from the light emission amount information separately in a first communication processing step before pre-flash and a second communication processing step after pre-flash. A control method for an imaging device, characterized by the following:

9. A lighting device, A light emission control unit that controls the emission of light from the light-emitting part, A communication unit that communicates with the imaging device to acquire imaging setting information for pre-emitting the light-emitting unit before imaging, It has, The aforementioned communications unit is If the acquired setting information is in a mode that prioritizes continuous shooting speed for imaging, information different from this light emission amount information is transmitted separately in a first communication process before pre-flash and a second communication process after pre-flash. If the acquired setting information is not in a mode that prioritizes the continuous shooting speed of the image capture, information different from the main light emission amount information is transmitted in the first communication processing before pre-flash. A lighting device characterized by the following features.

10. The aforementioned communications unit is If the setting information to be acquired has a communication rate below a threshold for communication with the imaging device, information different from the main light emission amount information is transmitted in two separate communication processes: a first communication process before pre-flash and a second communication process after pre-flash. The lighting device according to feature 9.

11. The aforementioned communications unit is At least the information regarding the completion of charging of the lighting device is transmitted in the first communication process before pre-light emission. The lighting device according to claim 9 or 10.

12. The aforementioned communications unit is Even when imaging is repeated, any information that differs from the initial emission amount information is transmitted only during the first communication processing before pre-emission. The lighting device according to any one of claims 9 to 11, characterized by the features described herein.

13. A method for controlling a lighting device, A light emission control step that controls the emission of light from the light-emitting section, A communication step to obtain imaging setting information by communicating with the imaging device to pre-illuminate the light-emitting unit before imaging, It has, The aforementioned communication step is, If the acquired setting information is in a mode that prioritizes continuous shooting speed for imaging, information different from this light emission amount information is transmitted separately in a first communication processing step before pre-flash and a second communication processing step after pre-flash. If the acquired setting information is not in a mode that prioritizes the continuous shooting speed of the image capture, information different from the main light emission amount information is transmitted in the first communication processing step before the pre-flash. A method for controlling a lighting device, characterized by the following features.

Images