JP2011158712A - Image pickup apparatus, light emitting apparatus, and camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To synchronize the operation of an image pickup apparatus with light emission of a light emitting apparatus without depending on use environment and a communication rate even when performing wireless communication by radio waves between the image pickup apparatus and the light emitting apparatus. <P>SOLUTION: A flash apparatus 300, which is a slave apparatus wirelessly connected to a camera 200 which is a master apparatus, performs ACK light emission that is light emission for confirmation to a light emission start signal transmitted from the camera 200 by light emission of an electric discharge tube. The camera 200 starts photographing and the flash apparatus 300 starts flashing after the lapse of the predetermined time set in advance, while making the ACK light emission reference timing of the camera 200 and the flash apparatus 300. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an imaging device, a light emitting device, and a camera system in which an imaging device and a light emitting device perform wireless communication using radio waves.

  In recent years, a camera system for connecting a camera and a light-emitting device by wireless communication using radio waves has been developed. In this camera system, the imaging device transmits a light emission start command to the light emitting device by radio waves, and the light emitting device receives the command and starts light emission.

  However, in the above system, it may be difficult to match the timing of the operation of the imaging device and the light emission of the wirelessly connected light emitting device depending on the usage environment due to the influence of obstacles and interference with other radio waves.

  Therefore, in Patent Document 1, for example, a packet transmitted from the master of the wireless lighting system is included in timing data, and the transmission state of the packet is changed at the start timing of the processing related to photographing, thereby instructing the start of light emission of the remote flash device. A method has been proposed.

JP 2008-102337 A

  However, in the above system, a delay time including a modulation / demodulation period of a digital signal and a radio wave occurs. However, in Patent Document 1, transmission varies depending on a modulation period on a radio wave transmission side, a demodulation period on a radio wave reception side, and a communication rate It does not consider the radio wave delivery period from the receiver to the receiver. Therefore, it is impossible to accurately synchronize the operation of the camera and the light emission of the remote flash device.

  The present invention has been made in view of the above problems, and even when wireless communication is performed between an imaging device and a light emitting device using radio waves, the operation of the imaging device and the light emitting device are independent of the use environment and the communication rate. The purpose is to synchronize the light emission.

  In order to solve the above-described problem, an imaging apparatus according to the present invention is an imaging apparatus that performs radio communication with a light emitting device via radio waves via a communication unit, the imaging unit imaging an object, and detection of light emission by the light emitting device. A light emission detecting means for performing the first light emission to the light emitting device and outputting a light emission start signal for instructing the second light emission when a predetermined time elapses, and the light emission detection. Control means for starting an operation corresponding to the second light emission when a waiting time set based on the predetermined time has elapsed after detecting the first light emission based on the light emission start signal by the light emitting device. It is characterized by having.

  In order to solve the above problems, a light-emitting device according to the present invention includes a light-emission detecting unit that detects light emitted from the light-emitting device, and performs a first light emission to the light-emitting device and emits a second light after a predetermined time has elapsed. A signal output means for outputting a light emission start signal instructing to perform, and a standby time set based on the predetermined time after detecting the first light emission based on the light emission start signal by the light emission device by the light emission detection means A light-emitting device that performs radio communication using radio waves via a communication unit and a communication unit, the control unit configured to start an operation corresponding to the second light emission, and transmitted from the imaging device When a light emission start signal is received via the communication means, the first light emission is performed, and the second light emission is performed when the predetermined time has elapsed.

  In order to solve the above problems, a camera system according to the present invention is a camera system in which an imaging device and a light emitting device perform wireless communication using radio waves via communication means, and detects light emitted by the light emitting device. Based on the detection means, a signal output means for outputting a light emission start signal to the light emitting device, and the light emission start signal received via the communication means, the first light emission is performed and the second light emission is performed after a predetermined time has elapsed. A light emission control means for performing light emission control so as to perform light emission, and a standby time set based on the predetermined time after the first light emission based on the light emission start signal by the light emitting device is detected by the light emission detection means. Then, it has a control means which starts operation | movement of the said imaging device corresponding to said 2nd light emission, It is characterized by the above-mentioned.

  According to the present invention, even when wireless communication using radio waves is performed between the imaging device and the light emitting device, the operation of the imaging device and the light emission of the light emitting device can be synchronized regardless of the use environment and the communication rate. .

It is a schematic diagram which shows the camera system which performs the radio | wireless communication using an electromagnetic wave. It is a block diagram which shows a part of structure of the camera which is a master apparatus in 1st Embodiment. It is a block diagram which shows a part of structure of the flash device which is a slave apparatus in 1st Embodiment. It is a flowchart which shows the imaging | photography operation | movement of the camera in 1st Embodiment. It is a flowchart which shows the light emission sequence of the flash device in 1st Embodiment. It is a timing chart which shows the operation timing of the camera and flash device at the time of photography in a 1st embodiment. It is a flowchart which shows the imaging | photography operation | movement of the camera in 2nd Embodiment. It is a flowchart which shows the light emission sequence of the flash device in 2nd Embodiment. It is a timing chart which shows the operation timing of the camera and flash device at the time of photography in a 2nd embodiment. It is a flowchart which shows the imaging | photography operation | movement of the camera in 3rd Embodiment. It is a timing chart which shows the operation timing of the camera and flash device at the time of photography in a 3rd embodiment.

[First Embodiment]
FIG. 1 is a schematic diagram illustrating a camera system that performs wireless communication using radio waves between an imaging device and a light-emitting device according to the first embodiment of the present invention. In the camera system 100, a camera 200 as an imaging device and a flash device 300 as a light emitting device are wirelessly communicated using radio waves typified by a wireless LAN or Bluetooth via antennas 201 and 309 incorporated or connected to the respective devices. Connected with. Hereinafter, in the camera system 100, the camera 200 is a master device and the flash device 300 is a slave device.

  FIG. 2 is a block diagram showing a part of the configuration of the camera which is the master device in the present embodiment. The configuration of the camera 200 will be described with reference to FIG.

  In FIG. 2, 201 is a radio communication antenna, 202 is a radio wave communication unit that performs radio wave communication control, and 203 is a microcomputer (hereinafter referred to as camera microcomputer) that controls the operation of each part of the camera 200. Reference numeral 204 denotes a photometric unit that measures the luminance of the subject by photometry, including a photometric sensor, and 205 denotes an imaging unit that captures the subject, including an image sensor.

  In addition, the camera 200 includes a PGA (Programmable Gain Amplifier) circuit (not shown) that attenuates or amplifies the level of the image data with respect to the image data read from the image sensor. By attenuating / amplifying the image data by this PGA circuit, that is, by changing the sensitivity, the exposure of the image data can be changed in a pseudo manner. It is possible to attenuate / amplify the output of the photometric sensor of the photometric unit 204, that is, to change the sensitivity of the photometric unit 204, as well as to the image data read from the image sensor. The camera microcomputer 203 transmits the amplification level to the PGA circuit, thereby controlling the amplification amount and setting the sensitivity.

  Reference numeral 206 denotes an operation unit, which includes a power switch for switching on / off the power of the camera 200, a release switch for instructing start of a shooting preparation operation, and a start instruction of a shooting operation.

  FIG. 3 is a block diagram illustrating a part of the configuration of the flash device 300 that is a slave device. The configuration of the flash device 300 will be described with reference to FIG. 3.

  In FIG. 3, 301 is a battery as a power source, 302 is a booster circuit that boosts the voltage of the battery 301 by several hundred volts, and 303 is a main capacitor that stores (charges) electrical energy boosted by the booster circuit 302. Reference numeral 304 denotes an existing trigger circuit for applying a high voltage of several KV to the discharge tube 305 to excite it, and the discharge tube 305 converts electrical energy stored in the main capacitor 303 into light energy. Reference numeral 306 denotes a light emission control unit that performs light emission control of the discharge tube 305, and reference numeral 307 denotes a microcomputer (hereinafter referred to as “flash device microcomputer”) that controls the operation of each part of the flash device 300. Reference numeral 309 denotes a wireless communication antenna, and reference numeral 308 denotes a radio wave communication unit that controls radio wave communication with a connected camera and other light emitting devices.

  In the flash device 300 having the above configuration, when a power switch (not shown) is turned on, the flash device microcomputer 307 starts its operation and starts the operation of the booster circuit 302. The electric energy boosted by the booster circuit 302 is stored in the main capacitor 303, and the electric energy is stored in the main capacitor 303 until the discharge tube 305 reaches a charging voltage at which light can be emitted. When the radio wave communication unit 308 receives a light emission start signal from the camera 200, the discharge tube 305 is caused to emit light using the electrical energy stored in the main capacitor 303.

  Next, the photographing operation of the camera 200 will be described using the flowchart of FIG. 4 and the timing chart of FIG. In FIG. 6, the upper horizontal axis indicates the time axis of the camera, and the lower horizontal axis indicates the time axis of the flash device.

  When the release switch of the operation unit 206 is turned on to instruct the start of the shooting operation, the camera 200 starts a routine for performing the shooting operation (step S1001).

  In step S1002, the camera microcomputer 203 starts the photometry operation of the photometry unit 204 and proceeds to step S1003. In step S1003, the camera microcomputer 203 outputs a light emission start signal to the radio wave communication unit 202, and proceeds to step S1004. T1201 in FIG. 6 corresponds to the signal output timing.

  In step S <b> 1004, the radio wave communication unit 202 modulates communication data with the light emission start signal output from the camera microcomputer 203 and starts transmission of communication data from the antenna 201. T1202 in FIG. 6 corresponds to this transmission start timing. At this time, information related to a predetermined time T used for standby processing described later is also transmitted. In this embodiment, the information about the predetermined time T is included in the light emission start signal output from the camera microcomputer 203, but is output from the camera microcomputer 203 as a signal different from the light emission start signal. Also good. Even when the light emission start signal and the information signal related to the predetermined time T are output separately, the light emission start signal and the information signal related to the predetermined time T are combined to form the light emission start signal. That is, as described later, the light emission start signal is a signal instructing to perform desired light emission (second light emission) after a predetermined time T has elapsed after ACK light emission (first light emission).

  In step S1005, after transmitting the light emission start signal via the radio wave communication unit 202 and the antenna 201, the camera microcomputer 203 determines whether or not the light emission detection signal from the photometry unit 204 is detected, and the light emission detection signal is detected. Then, the process proceeds to step S1006. The timing at which the light emission detection signal is detected by the photometry unit 204 here corresponds to T1203 in FIG. It is assumed that the photometry unit 204 outputs a light emission detection signal to the camera microcomputer 203 when detecting a luminance change of a predetermined value or more within a predetermined time.

  In step S1006, the camera microcomputer 203 operates an internal timer to perform a standby process according to a predetermined time T. The standby process performed here is for synchronizing the main exposure performed below with the main light emission of the flash device 300. In this embodiment, the case where the standby time of the camera 200 and the standby time of the flash device 300 are set to be equal to each other will be described. However, not only the predetermined time T but also the setting of the light emission timing is taken into consideration. Time may be set. For example, in the case of performing so-called front curtain sync shooting in which main flash is performed immediately after the start of exposure, it is determined that the main flash will be performed after a predetermined time T when ACK flash is detected, which is equal to the standby time of the flash device 300. The time may be set as the standby time of the camera 200. Further, when performing so-called trailing curtain sync shooting, which performs main flash just before the end of exposure, it is determined that the main flash will be performed after a predetermined time T when the ACK flash is detected, and the standby time of the flash device 300 is set. The waiting time of the camera 200 may be set based on the exposure time. Note that the exposure start here is the time when the entire imaging region of the image sensor starts exposure due to travel of a shutter (not shown), and the end of exposure is the image sensor due to travel of a shutter (not shown). This is the time when at least a part of the imaging region ends the exposure.

  When the standby process is completed, the process advances to step S1007, and the camera microcomputer 203 controls the imaging unit 205 to perform main exposure (photographing). T1204 in FIG. 6 corresponds to this timing. Thereafter, in step S1008, the photographing operation routine is terminated.

  In the present embodiment, the predetermined time T is set as a fixed time, but the predetermined time T may be set every time a light emission start signal is output to the flash device 300. At this time, information regarding the predetermined time T may be transmitted from the camera 200 to the flash device 300 together with the light emission start signal.

  Next, processing of the flash device microcomputer 307 when a light emission start signal is received via the antenna 309 and the radio communication unit 308 of the flash device 300 will be described with reference to the flowchart of FIG. 5 and the timing chart of FIG.

  When the radio wave transmission / reception unit 308 of the flash device receives communication data obtained by modulating the light emission start signal from the camera 200 from the antenna 309, the radio communication unit 308 demodulates the received communication data and sends a light emission start signal to the flash device microcomputer 307. The timing of receiving communication data from the camera 200 corresponds to the timing of T1205 in FIG. At this time, information on a predetermined time T used for standby processing described later is also received and sent to the flash device microcomputer 307.

  Upon receiving the main light emission start signal from the radio wave communication unit 308, the flash device microcomputer 307 starts the main light emission process in accordance with the received main light emission start signal (S1101).

  In step S1102, the flash device microcomputer 307 outputs an H signal to the light emission control unit 306, whereby the light emission control unit 306 enters a conductive state, and the anode-discharge tube 305 of the main capacitor 303, the light emission control unit 306, and the cathode of the main capacitor 303. The discharge loop is formed.

  In step S1103, the flash device microcomputer 307 outputs an H signal to the trigger circuit 304 for a predetermined time, whereby the trigger circuit 304 applies a high voltage to the discharge tube 305, whereby the discharge tube 305 starts ACK emission. The ACK light emission is a confirmation light emission for indicating that the light emission start signal has been received, and the camera 200 detects the ACK light emission, which is the confirmation light emission, so that the communication of the light emission start signal is normally performed. I can recognize that.

  Then, the flash device microcomputer 307 outputs an L signal to the light emission control unit 306 after a predetermined time, and stops ACK light emission. The timing of this ACK light emission corresponds to T1206 in FIG. 6, and there is almost no delay in the time it takes for the camera 200 to detect the light after the flash device 300 performs ACK light emission. T1203 and T1206 can have the same timing.

  In step S1104, the flash device microcomputer 307 operates an internal timer to perform standby processing according to a predetermined time T transmitted from the camera. The standby process performed here is for synchronizing the main light emission performed below with the main exposure of the camera 200. In this embodiment, the standby time in the standby process of the flash device 300 is set to a time equal to the predetermined time T. It shall be.

  In step S1104, the flash device microcomputer 307 outputs an H signal to the light emission control unit 306 during the standby process. As a result, the light emission control unit 306 enters a conductive state, and forms a discharge loop of the anode-discharge tube 305 of the main capacitor 303, the light emission control unit 306, and the cathode of the main capacitor 303.

  When the standby process is completed, the process proceeds to step S1105, where the flash device microcomputer 307 outputs an H signal to the trigger circuit 304 for a predetermined time, whereby the trigger circuit 304 applies a high voltage to the discharge tube 305, thereby Start flashing. The timing of this main light emission corresponds to T1207 in FIG. Note that the light emission amount in the main light emission is determined by the camera microcomputer 203 and transmitted to the flash device microcomputer 307 by the light emission start signal.

  In step S 1106, the flash device microcomputer 307 outputs an L signal to the light emission control unit 306, thereby causing the light emission control unit 306 to be cut off, and the anode of the main capacitor 303 -discharge tube 305 -light emission control unit 306 -cathode of the main capacitor 303. Interrupts the discharge loop. As a result, the discharge tube 305 stops the main light emission, and the main light emission process is terminated in the subsequent S1107.

  As described above, the flash device 300 performs ACK light emission before the main light emission based on the main light emission start signal, and performs the main light emission after a predetermined time T has elapsed since the ACK light emission, whereby the camera 200 performs the main light emission. It is possible to know the start timing accurately. In addition, the camera 200 starts the main exposure when the standby time set based on the predetermined time T has elapsed after detecting the ACK light emission of the flash device 300, thereby accurately synchronizing the main exposure and the main light emission. Can do. That is, the camera 200 can determine that the main light emission is performed after the elapse of the predetermined time T from the detection of the ACK light emission of the flash device 300, and can accurately synchronize the main exposure and the main light emission.

[Second Embodiment]
Since the configuration of the camera and the flash device in the second embodiment of the present invention is the same as that in FIGS. 2 and 3 of the first embodiment, the description thereof is omitted.

  In the second embodiment, the ACK light emission indicates that the flash device 300 has received the light emission start signal, and the confirmation signal indicates that the light emission start signal has been received via the antenna 309 and the radio wave communication unit 308. The ACK signal is transmitted. The camera 200 is configured to determine that the ACK light emission from the flash device 300 is detected by detecting the light emission and receiving the ACK signal from the flash device 300. With these configurations, it is possible to reduce false detections that detect light from a light source different from the target flash device and determine ACK emission, and to properly perform wireless communication using radio waves due to the occurrence of communication errors. It is possible to detect that the state is not possible.

  The shooting operation of the camera 200 in the second embodiment will be described with reference to the flowchart of FIG. 7 and the timing chart of FIG. In FIG. 9, the upper horizontal axis indicates the time axis of the camera, and the lower horizontal axis indicates the time axis of the flash device. Further, since steps S2001 to S2006 in FIG. 7 perform the same processes as steps S1001 to S1006 in FIG. 4 described in the first embodiment, detailed description thereof will be omitted below.

  In step S2007, the camera microcomputer 203 determines whether an ACK signal is received from the flash device 300 via the antenna 201 and the radio wave communication unit 202 during the standby process in step S2006. If the ACK signal is received, the camera microcomputer 203 determines that the light emission detected in step S2005 is the ACK light emission by the flash device 300, and proceeds to step S2008 to start shooting. Note that the reception timing of this ACK signal corresponds to the timing of T2204 in FIG. 9, and the start timing of imaging corresponds to the timing of T2205 in FIG.

  On the other hand, if the ACK signal has not been received, the camera microcomputer 203 determines that the light emission detected in step S2005 is not the ACK light emission by the flash device 300, and proceeds to step S2009 to perform error processing. In the error processing in step S2009, an error flag may be set, an error notification may be issued to a control IC (not shown) different from the camera microcomputer 203, or a sequence may be returned to step S2002 or S2003 again. Moreover, you may alert | report to a user that the ACK signal was not able to be received by the alerting | reporting means not shown.

  Next, processing of the flash device microcomputer 307 when a light emission start signal is received via the flash device antenna 309 and the radio wave communication unit 308 will be described with reference to the flowchart of FIG. 8 and the timing chart of FIG. Since steps other than step S2103 perform the same processing as the step of FIG. 6 described in the first embodiment, detailed description thereof will be omitted below.

  After turning on the light emission control unit 306 in step S2102, in step S2103, the flash device microcomputer 307 receives an ACK signal indicating that the main light emission start signal has been received via the antenna 309 and the radio wave communication unit 308. Send to. The transmission timing of this ACK signal corresponds to T2208 in FIG. When the ACK signal is transmitted, the process proceeds to step S2104 to perform ACK light emission.

  As described above, the camera 200 receives the ACK signal transmitted from the flash device 300 within a predetermined time after the light emission is detected by the photometry unit 204, so that the light emission is the ACK light emission by the flash device 300. Judgment can be made. For this reason, it is possible to reduce erroneous detection that detects light from a light source different from the target flash device and determines ACK light emission, and it is possible to more accurately synchronize the photographing operation and the main light emission. Further, when the ACK signal cannot be received during the standby process before the photographing operation, it can be detected that wireless communication using radio waves cannot be normally performed due to a communication error or the like. Note that the timing at which the flash device 300 transmits the ACK signal may not be the timing shown in the flowchart of FIG. 8, but may be before step S2102 or after step S2104.

  In step S2007, it is determined whether or not an ACK signal has been received during the standby process. However, the determination time set after the detection of light emission is set as a determination time that is shorter than the standby time. It may be determined whether or not an ACK signal has been received before the elapse. Alternatively, a predetermined period before and after the time point at which light emission is detected may be set as the determination period, and it may be determined whether or not the timing at which the ACK signal is received is within the set determination period (within the predetermined period). That is, regardless of the order of the light emission detection timing and the reception timing of the ACK signal, it may be determined whether or not the time difference between the time when the light emission is detected and the time when the ACK signal is detected is within a predetermined value. In this way, it is determined whether or not the time difference between the time point when the light emission is detected and the time point when the ACK signal is detected is within a predetermined value, and the light emission detected when the time difference is within the predetermined value is the ACK light emission of the flash device 300. By determining that there is, it is possible to further reduce false detection of ACK emission.

[Third Embodiment]
Since the configuration of the camera and the flash device in the third embodiment of the present invention is the same as that in FIGS. 2 and 3 of the first embodiment, the description thereof is omitted.

  In the third embodiment, the light emission detection limit period is set to limit the period during which the camera 200 detects ACK light emission. With such a configuration, it is possible to reduce erroneous detection in which light from a light source different from the target flash device is detected and ACK emission is determined. Further, when the light emission cannot be detected within the light emission detection limit period, it is possible to detect that the flash device cannot emit light even if the light emission start signal is transmitted due to the occurrence of a communication error or the like.

  The shooting operation of the camera 200 according to the third embodiment will be described with reference to the flowchart of FIG. 10 and the timing chart of FIG.

  In FIG. 11, the upper horizontal axis indicates the time axis of the camera, and the lower horizontal axis indicates the time axis of the flash device. Further, Steps S3001 to S3003 and Steps S3009 to S3013 in FIG. 10 perform the same processes as Steps S2001 to S2003 and Steps S2006 to S2010 in FIG. 7 described in the second embodiment, respectively. Therefore, detailed description is omitted below.

  When a light emission start signal is output in step S3003, in step S3004, the camera microcomputer 203 starts an elapsed time by operating an internal timer. The timing for operating this timer corresponds to T3212 in FIG.

  In step S3005, a light emission start signal is transmitted to the flash device 300 via the antenna 201 and the radio wave communication unit 202. In step S3006, whether or not the predetermined time T2 has elapsed since the camera microcomputer 203 activated the timer. Determine whether. Specifically, it is determined whether or not a timer count t, which is an elapsed time since the timer is operated, is equal to or greater than a predetermined time T2. If the predetermined time T2 has not elapsed, the process proceeds to step S3007. If the predetermined time T2 has elapsed, the process proceeds to step S3012 to perform error processing.

  As described above, when the light emission is not detected even after the predetermined time T2 elapses, it can be determined that the flash device cannot emit light even if the light emission start signal is transmitted due to the occurrence of a communication error or the like. As an error process in step S3012, an error flag may be set, an error notification may be sent to a control IC (not shown) different from the camera microcomputer 203, or a sequence of returning to step S3002 or S3003 again. Good. Moreover, you may alert | report to a user that the error generate | occur | produced by the alerting | reporting means not shown.

  In step S3007, the camera microcomputer 203 determines whether or not light emission is detected by the photometry unit 204. If light emission is detected, the process proceeds to step S3008. If no light emission is detected, the process returns to step S3006.

  In step S3008, the camera microcomputer 203 determines whether or not a predetermined time T1 has elapsed since the timer was activated. If the predetermined time T1 has elapsed, the process proceeds to step S3009. If the predetermined time T1 has not elapsed, it is determined that the photometry unit 204 has detected an error, and the process returns to step S3006.

  As described above, when the photometry unit 204 detects the light emission earlier than the ACK light emission start time assumed in advance, it is determined that the light detection by another light source is detected and waits for the ACK light emission to be performed again. Thus, it is possible to accurately detect ACK emission. As shown in FIG. 11, the relationship between the predetermined time T1 and the predetermined time T2 is T1 <T2, and the light emission is detected when the elapsed time from the activation of the timer is not less than the predetermined time T1 and less than the predetermined time T2. It is a limited period.

  Since the processing of the flash device microcomputer 307 when receiving the light emission start signal by the antenna 309 and the radio wave communication unit 308 of the flash device 300 in this embodiment is the same as that of the second embodiment, description thereof will be omitted.

  As described above, by setting the light emission detection restriction period in which the light emission detection by the photometry unit 204 is valid, the light emission detected outside the light emission detection restriction period is generated by a light source different from the target flash device. It is possible to reduce erroneous detection of ACK light emission by determining light. Therefore, ACK light emission can be detected more accurately, and the exposure of the imaging device and the light emission of the light emitting device can be accurately synchronized.

  If the light emission is not detected within the light emission detection limit period, it can be detected that the flash device cannot emit ACK even if a light emission start signal is transmitted due to the occurrence of a communication error or the like.

  Also, even if the light emission is detected within the light emission detection limit period, if the camera 200 cannot receive an ACK signal during the standby process, it is determined that the light is from a light source other than the target flash device. False detection of ACK emission can be further reduced. Further, when the ACK signal cannot be received during the standby process before the photographing operation, it can be detected that wireless communication using radio waves cannot be normally performed due to a communication error or the like.

  As in the second embodiment, the timing at which the flash device 300 transmits the ACK signal does not have to be the timing shown in the flowchart of FIG. 8, but before step S2102 or after step S2104. It doesn't matter.

  In step S3010, it is determined whether or not an ACK signal has been received during the standby process. However, the determination time set after the light emission is detected is set as a determination time that is shorter than the standby time. It may be determined whether or not an ACK signal has been received before the elapse. Alternatively, a predetermined period before and after the time point at which light emission is detected may be set as the determination period, and it may be determined whether or not the timing at which the ACK signal is received is within the set determination period. That is, regardless of the order of the light emission detection timing and the reception timing of the ACK signal, it may be determined whether or not the time difference between the time when the light emission is detected and the time when the ACK signal is detected is within a predetermined value. In this way, it is determined whether or not the time difference between the time point at which the light emission is detected and the time point at which the ACK signal is detected is within a predetermined value. By determining that there is, it is possible to further reduce false detection of ACK emission. Alternatively, the light emission detection limit period may be set as a determination period for determining whether or not an ACK signal has been received.

  Further, the timing for operating the timer may not be the timing shown in the flowchart of FIG. 10, and may be before step S3002 or after step S3005.

  Further, since the predetermined time T1 and the predetermined time T2 are set in advance assuming a period during which ACK light emission is highly likely to start, the predetermined time T1 and the predetermined time T2 are changed according to the communication method, the communication rate, and the like. You may do it.

  In addition, by using an ACK signal by radio waves, false detection of ACK light emission can be further reduced, but even if the ACK signal is not detected as in the first embodiment, a light emission detection limit period is set. By doing so, erroneous detection of ACK emission can be reduced.

  In the three embodiments described above, by using the ACK light emission as the pre-light emission performed to determine the main light emission amount, a decrease in the charging voltage of the main capacitor 303 can be suppressed before the main light emission. It is possible to suppress the charging voltage from becoming insufficient at times. Further, since the light is emitted only once before the main light emission, the release time lag can be suppressed.

  In the above three embodiments, the configuration in which ACK light emission is performed before the main light emission has been described. However, ACK light emission may be performed before the pre-light emission. When the flash device 300 receives the pre-flash start signal from the camera 200, the flash device 300 performs ACK flash indicating that the pre-flash start signal has been received. By detecting this ACK light emission, the camera 200 can determine that the pre-light emission is performed after a predetermined time T has elapsed since the ACK light emission was detected. At this time, the sensitivity of the photometry unit 204 at the time of pre-emission or the light emission amount of pre-emission may be set based on the photometry result when the flash device 300 performs ACK emission. In this way, by setting the sensitivity or pre-emission amount of the photometry unit 204 at the time of pre-emission based on the photometry result at the time of ACK emission, it is possible to accurately perform photometry at the time of pre-emission, and more appropriate main emission The amount can be determined.

  In the three embodiments described above, the configuration in which ACK light emission is performed before the main light emission has been described. However, a configuration in which ACK light emission, pre-light emission, and main light emission are sequentially performed by one light emission start signal may be used. In that case, for each of the camera 200 and the flash device 300, a first standby time from the ACK light emission to the pre-light emission and a second standby time from the pre-light emission to the main light emission or a third time from the ACK light emission to the main light emission. The waiting time may be set individually.

  In the above three embodiments, the case where the flash device using the discharge tube as the light emitting means is used as the light emitting device has been described, but the present invention can also be applied to a light emitting device using other light emitting means such as an LED.

  In the three embodiments described above, the configuration in which the light emission detection is performed using the photometry unit has been described. However, the configuration in which the light emission detection is performed using an image photographed by the image sensor may be used. For example, after sending a light emission start signal to the flash device, perform continuous shooting at high speed, select an image that appears to have emitted light from among the continuously shot images, and based on the point in time when the image was shot A waiting time may be set.

  In the above three embodiments, the configuration in which the imaging device includes the radio wave communication unit and the antenna has been described. However, the imaging device can also be applied to an imaging device equipped with a communication device capable of radio communication with the light emitting device. it can. Similarly, the present invention can also be applied to a case where the light emitting device does not include a radio wave communication unit and an antenna, and the light emitting device is equipped with a communication device capable of radio communication with the imaging device using radio waves.

  Further, the predetermined time used for the standby process of the slave device may be set not by the imaging device but by the light emitting device or the communication device attached to the imaging device. For example, the microcomputer of the light emitting device attached to the imaging device may set a predetermined time used for the standby process of the slave device and transmit it to both the imaging device and the slave device.

100 camera system 200 camera 201 antenna (camera side)
202 Radio communication unit (camera side)
DESCRIPTION OF SYMBOLS 203 Camera microcomputer 204 Photometry part 205 Image pick-up part 300 Flash apparatus 307 Flash apparatus microcomputer 308 Radio wave communication part (flash apparatus side)
309 Antenna (flash device side)

Claims (12)

An imaging device that performs radio communication with a light emitting device via radio waves via a communication means,
Imaging means for imaging a subject;
A light emission detecting means for detecting light emission by the light emitting device;
A signal output means for outputting to the communication means a light emission start signal instructing the light emitting device to perform the first light emission and perform the second light emission when a predetermined time has elapsed;
After the first light emission based on the light emission start signal from the light emitting device is detected by the light emission detection means, when a standby time set based on the predetermined time has elapsed, an operation corresponding to the second light emission is started. And an imaging device.   The imaging apparatus according to claim 1, wherein the first light emission is a confirmation light emission indicating that the light emission start signal has been received. Photometric means for measuring the brightness of the subject;
3. A determining unit that determines a light emission amount of the second light emission based on a photometric result obtained by the photometric unit when the first light emission is performed. The imaging device described. Photometric means for measuring the brightness of the subject;
Setting means for setting a sensitivity of the photometry means when performing the second light emission based on a photometry result obtained by the photometry means when performing the first light emission. The imaging device according to claim 1 or 2.   When the second light emission is a main light emission, the control means detects a first light emission based on the light emission start signal from the light-emitting device by the light emission detection means and is set based on the predetermined time. 5. The imaging apparatus according to claim 1, wherein the main exposure by the imaging unit is started after elapse of time.   6. The imaging apparatus according to claim 1, further comprising a determination unit that determines whether or not the light emission detected by the light emission detection unit is light emission by the light emitting device.   The determination means determines that the light emission detected by the light emission detection means within a predetermined period based on a time point when the light emission start signal is output by the signal output means is light emission by the light emitting device. The imaging device according to claim 6.   The determination means has received a confirmation signal via the communication means indicating that the light emission start signal transmitted from the light emitting device has been received within a predetermined time after the light emission is detected by the light emission detection means. The imaging apparatus according to claim 6, wherein the light emission is determined to be light emission by the light emitting device.   The determination means has a time difference between a time point when the light emission detection means detects the light emission and a time point when the confirmation signal indicating that the light emission start signal transmitted from the light emitting device is received is received via the communication means. The imaging apparatus according to claim 6 or 7, wherein when the light emission is within a predetermined value, the light emission is determined as light emission by the light-emitting device. A light emission detecting means for detecting light emission by the light emitting device; a signal output means for outputting a light emission start signal for instructing the light emitting device to perform the first light emission and perform the second light emission after a predetermined time; Control for starting an operation corresponding to the second light emission when a waiting time set based on the predetermined time has elapsed after detecting the first light emission based on the light emission start signal by the light emitting device by the light emission detecting means. A light-emitting device that performs radio communication by radio waves via a communication means and an imaging device comprising:
A light emitting device characterized in that when the light emission start signal transmitted from the imaging device is received via the communication means, the first light emission is performed and the second light emission is performed when the predetermined time has elapsed.   11. The confirmation signal indicating that the light emission start signal has been received is transmitted to the imaging apparatus via the communication unit after the light emission start signal is received via the communication unit. Light-emitting device. A camera system in which an imaging device and a light emitting device perform wireless communication using radio waves via a communication means,
A light emission detecting means for detecting light emission by the light emitting device;
A signal output means for outputting a light emission start signal for the light emitting device;
Based on the light emission start signal received via the communication means, light emission control means for performing light emission control so that the first light emission is performed and the second light emission is performed when a predetermined time has elapsed,
After the first light emission based on the light emission start signal from the light emitting device is detected by the light emission detecting means, the imaging device corresponding to the second light emission when a standby time set based on the predetermined time has elapsed. And a control means for starting the operation of the camera system.

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