JP7071151B2 - Light emission control device, light emission device, control method, and program - Google Patents

Description

The present invention relates to a light emission control device, a light emission device, an image pickup device, a control method, and a program.

In a conventional radio wave wireless system that includes an image pickup device such as a camera and a light emitting device such as a strobe, the exposure of the camera and the light emission of the strobe are synchronized by transmitting a light emission instruction including the light emission timing information of the strobe from the camera to the strobe. I'm letting you. For example, Patent Document 1 discloses that a camera transmits a light emission command including information indicating a light emission timing to a strobe in order to synchronize the exposure of the camera with the light emission of the strobe. In addition, when shooting with a multi-flash wireless system using multiple strobes, the flash timing of each strobe should be synchronized by broadcasting a flash command from a relay terminal such as a master strobe connected to the camera. Is disclosed.

Further, with the progress of radio wave technology in recent years, high-speed and low power consumption wireless communication methods such as Bluetooth (registered trademark) have been developed. Further, terminals having power restrictions such as cameras and mobile phones are increasingly equipped with a wireless communication function corresponding to such a wireless communication method. As a result, it has become possible to construct a multi-flash wireless system that directly communicates wirelessly between the camera and each strobe.

Japanese Unexamined Patent Publication No. 2010-185961

However, the Bluetooth® standard does not allow wireless communication by multicast. Therefore, in a multi-flash wireless system in which direct wireless communication is performed between the camera and each strobe, the camera needs to sequentially transmit a light emission instruction to each strobe by a single cast, which is inefficient.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a technique for realizing an efficient multi-lamp wireless system for an image pickup device that transmits a light emission instruction by a single cast. ..

In order to solve the above problems, the present invention comprises a first receiving means for receiving a first light emitting instruction indicating a first light emitting timing from an image pickup apparatus by one-to-one wireless communication, and the first light emitting instruction. A transmission means for simultaneously transmitting a second light emission instruction indicating the first light emission timing to a plurality of light emission control devices by one-to-many wireless communication, and reception of the first light emission instruction. A control means for controlling the light emitting means so as to emit light at the first light emission timing is provided , and the one-to-one wireless communication is faster than the one-to-many wireless communication. Provided is a light emission control device characterized by being present.

According to the present invention, it is possible to realize an efficient multi-lamp wireless system for an image pickup device that transmits a light emission instruction by a single cast.

In addition, other features and advantages of the present invention will be further clarified by the accompanying drawings and the description in the following embodiments for carrying out the invention.

The block diagram of the camera 100 (imaging device), the lens unit 200, and the strobe 300 (light emitting device). The figure which shows an example of a strobe photography system (multi-flash wireless system). The figure which shows the synchronized photography sequence in the strobe photography system which concerns on 1st Embodiment. The figure which shows the synchronized photography sequence in the strobe photography system which concerns on 2nd Embodiment. The figure which shows the synchronized photography sequence in the strobe photography system which concerns on 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Throughout the accompanying drawings, elements with the same reference numeral represent the same or similar elements. The technical scope of the present invention is determined by the scope of claims, and is not limited by the following individual embodiments. Also, not all combinations of features described in the embodiments are essential to the present invention. It is also possible to appropriately combine the features described in the separate embodiments.

[First Embodiment]
FIG. 1 is a block diagram of a camera 100 (imaging device), a lens unit 200, and a strobe 300 (light emitting device). The main mirror 101 is rotatable according to the operating state of the camera 100. When the user observes the subject with the finder, the main mirror 101 is inserted obliquely with respect to the photographing optical path (the alternate long and short dash line in FIG. 1), and guides the light flux from the lens unit 200 toward the focus plate 109. Further, at the time of photographing, the main mirror 101 is retracted from the photographing optical path, and the light flux from the lens unit 200 is guided to the image pickup element 103 described later. In FIG. 1, the main mirror 101 represents a state of being arranged on the photographing optical path, and the main mirror 101'represents a state of being retracted from the photographing optical path.

The shutter 102 is provided to control the incident light flux from the lens unit 200 on the image pickup device 103, and is normally closed and driven so as to be open at the time of shooting. The shutter 102 is controlled by the camera control unit 105 via the shutter control unit 115. The image sensor 103 takes an image of the subject. For example, the image pickup device 103 is a CMOS sensor or a CCD sensor, is driven based on a timing signal output from the timing generator 116, and photoelectrically converts an optical image of a subject to generate an analog signal. The analog signal processing unit 104 holds a sample of the analog signal from the image pickup element 103, adds an analog gain, converts it into a digital signal by A / D conversion, and outputs it.

The camera control unit 105 performs various processes on the digital signal output from the analog signal processing unit 104 using the digital gain unit 106 and the image processing unit 107, which will be described later, and stores the digital signal in the memory 121 via the memory control unit 120. do. The digital gain unit 106 adds a digital gain to the digital signal and outputs it to the image processing unit 107. The image processing unit 107 performs various digital signal processing (for example, pixel interpolation processing and color conversion processing).

The image display unit 119 is a rear monitor for displaying images and shooting information, and includes, for example, an LCD and the like. The operation unit 122 includes various operation members as an input unit for receiving an operation from the user. The operation unit 122 has various operation buttons such as an AF instruction button, a shooting instruction button, and an AE instruction button, and outputs an input operation by the user to the camera control unit 105.

The focus plate 109 is arranged on the primary image plane of the lens unit 200, has a Fresnel lens (condensing lens) on the incident surface, and forms an optical image (finder image) of the subject on the ejection surface. The pentaprism 110 changes the finder optical path, and corrects the subject image formed on the ejection surface of the focus plate 109 to an upright orthodox image. The eyepiece 111 is configured to be able to adjust the diopter according to the user's eyes when the user looks through the viewfinder. The photometric sensor 112 is composed of photodiodes corresponding to each region divided in the imaging region, and outputs the luminance of the subject image formed on the ejection surface of the focus plate 109 to the photometric processing unit 113.

The AF sensor 117 outputs the defocus amount to the camera control unit 105. The camera control unit 105 determines the lens drive amount based on the defocus amount from the AF sensor 117, and drives the lens unit 200 via the communication terminal 118. The camera control unit 105 is a microcomputer including a CPU, a ROM, and a RAM, and executes a program stored in the ROM. The camera control unit 105 controls each unit included in the camera 100.

Further, the camera 100 has a wireless communication unit 123. The wireless communication unit 123 is configured to perform single cast wireless communication (one-to-one wireless communication), and conforms to a communication standard such as Bluetooth (registered trademark). The wireless communication unit 123 includes an antenna 123a, a wireless control unit 123b, and an oscillation circuit 123c. The oscillation circuit 123c generates a clock signal corresponding to the oscillation frequency of the crystal oscillator (not shown) and gives the clock signal to the radio control unit 123b. The wireless control unit 123b operates in response to a clock signal and transmits / receives data by radio waves via the antenna 123a. Further, the camera 100 has a strobe connection unit 114 which is a connection terminal for serial communication with the strobe 300, and can communicate with the strobe 300 via the strobe connection unit 114.

The lens unit 200 is a lens unit equipped with an interchangeable photographing lens. The lens 201 is, for example, a lens group having a focusing lens and a zoom lens, and captures the reflected light incoming from the subject into the camera 100. The aperture 202 adjusts the amount of light at the time of shooting by adjusting the aperture diameter thereof. The aperture diameter of the aperture 202 is controlled by the lens control unit 205 via the aperture drive unit 204. The focus drive unit 203 focuses by shifting the position of the lens 201 in response to a command from the lens control unit 205.

The lens control unit 205 controls each unit included in the lens unit 200. Further, the lens control unit 205 can obtain the zoom position (focal length information) of the lens 201 and the distance information to the focal plane based on the position information of the lens 201 from the lens position acquisition unit 207. The communication terminal 206 is a communication terminal for the lens unit 200 to communicate with the camera 100. The communication terminal 118 is a communication terminal for the camera 100 to communicate with the lens unit 200. The lens unit 200 communicates with the camera control unit 105 inside the camera 100 via the communication terminals 206 and 118.

The strobe 300 is removable from the camera 100 and has a main body (light emission control device) and a head. The strobe control unit 301 performs flash control, communication control, and the like. The light emitting unit 302 emits light according to a light emitting instruction from the strobe control unit 301. The operation unit 303 includes various operation members as an input unit that receives an operation from the user. The operation unit 303 has various operation buttons such as a flash mode setting button, and outputs an input operation by the user to the strobe control unit 301. Further, the strobe 300 has a wireless communication unit 304 and a wireless communication unit 305. The wireless communication unit 304 is configured to perform single cast wireless communication (one-to-one wireless communication), conforms to a communication standard such as Bluetooth (registered trademark), and is a wireless communication unit 123 of the camera 100. And single cast wireless communication. The wireless communication unit 305 is configured to perform one-to-many wireless communication such as multicast or broadcast, and conforms to a communication standard such as Zigbee®. The wireless communication unit 305 performs multicast or broadcast wireless communication with the wireless communication unit of another strobe having the same configuration as the strobe 300.

The wireless communication unit 304 includes an antenna 304a, a wireless control unit 304b, and an oscillation circuit 304c. The oscillation circuit 304c generates a clock signal corresponding to the oscillation frequency of the crystal oscillator (not shown) and gives the clock signal to the radio control unit 304b. The wireless control unit 304b operates in response to a clock signal and transmits / receives data by radio waves via the antenna 304a. The wireless communication unit 305 includes an antenna 305a, a wireless control unit 305b, and an oscillation circuit 305c. The oscillation circuit 305c generates a clock signal corresponding to the oscillation frequency of the crystal oscillator (not shown) and gives the clock signal to the radio control unit 305b. The wireless control unit 305b operates in response to a clock signal and transmits / receives data by radio waves via the antenna 305a.

Further, the strobe 300 has a camera connection unit 306 which is a connection terminal for serial communication with the camera 100, and can communicate with the camera 100 via the camera connection unit 306.

FIG. 2 is a diagram showing an example of a strobe photography system (multi-flash wireless system). The strobe 400 and the strobe 500 have the same configuration as the strobe 300. The strobe 300 may or may not be attached to the camera 100. Further, instead of the strobe 300, the strobe 400 or the strobe 500 may be attached to the camera 100.

FIG. 3 is a diagram showing a synchronized shooting sequence in the strobe shooting system according to the first embodiment.

In S700, the camera control unit 105 detects that the SW2 button included in the operation unit 122 is pressed (fully pressed the shutter button), and starts a shooting operation.

In S701, the camera control unit 105 selects the strobe 300 as the master strobe, and transmits a flash preparation instruction instructing the strobe flash preparation to the strobe 300. The light emission preparation instruction includes light emission information such as a light emission amount and a light emission mode. The flash preparation instruction reaches the strobe control unit 301 via wireless communication between the wireless communication unit 123 of the camera 100 and the wireless communication unit 304 of the strobe 300. In Bluetooth®, communication is performed periodically according to a predetermined communication cycle. Therefore, wireless communication such as a light emission preparation instruction and a light emission timer information described later is performed at the communication timing for each communication cycle T1 shown in FIG. Further, this wireless communication is performed by a single cast. Subsequent communication between the camera 100 and the strobe 300 is similarly performed by single-cast wireless communication (one-to-one wireless communication) via the wireless communication unit 123 and the wireless communication unit 304.

The camera control unit 105 may select the strobe 400 or the strobe 500 as the master strobe instead of the strobe 300. Strobes other than the master strobe operate as slave strobes. That is, the strobe 300, the strobe 400, and the strobe 500 can operate as a master strobe and also as a slave strobe.

In S702, the strobe control unit 301 of the strobe 300 prepares for flash according to the flash preparation instruction. When the flash preparation is completed, the strobe control unit 301 transmits data indicating the flash preparation completion to the camera 100.

In S703, the camera control unit 105 starts a process (exposure preparation process) for performing an exposure operation. Specifically, the camera control unit 105 performs drive control of the main mirror 101, aperture control for photographing the lens unit 200, and the like. However, some of these controls may be performed in advance by the camera control unit 105 at the timing of S700. Further, in S703, the camera control unit 105 transmits the light emission timer information including the exposure prediction time T4 to the strobe 300. The exposure prediction time T4 is a time calculated by subtracting the communication delay time due to the wireless communication being performed in the communication cycle T1 from the time until the exposure is started (exposure start time T2). Specifically, the exposure prediction time T4 is calculated by the following formula.
Expected exposure time T4 = exposure start time T2-communication delay time
= Exposure start time T2- (Communication cycle T1-Exposure preparation time T3)
Here, the exposure start time T2 is the time from the timing when the camera control unit 105 outputs the light emission timer information to the wireless communication unit 123 to the timing when the exposure starts (the time from the determination timing of the light emission timing to the light emission timing). .. The communication cycle T1 is a cycle in which the wireless communication unit 123 communicates with the wireless communication unit 304. The exposure preparation time T3 is the time from when the camera control unit 105 receives the data indicating that the light emission preparation is completed to when the light emission timer information is output to the wireless communication unit 123.

In S704, the strobe control unit 301 performs flash control based on the exposure prediction time T4 included in the flash timer information (flash instruction indicating the flash timing). Further, the strobe control unit 301 simultaneously transmits the light emission timer information (light emission instruction indicating the light emission timing) including the exposure prediction time T4 to the strobe 400 and the strobe 500, which are slave strobes, by one-to-many wireless communication. .. The light emission timer information reaches the strobe control unit 301 of the strobe 400 and the strobe 500 via the wireless communication unit 305 of the strobe 300 and the wireless communication unit 305 of the strobe 400 and the strobe 500. The strobe control unit 301 of the strobe 300 repeatedly transmits the flash timer information to the strobe 400 and the strobe 500 in the communication cycle T5 while updating the exposure prediction time. That is, the light emission timer information is transmitted a plurality of times, and each light emission timer information includes information (time information) indicating the time from the transmission timing to the light emission timing. Therefore, even if the communication environment is poor and the transmission of some light emission timer information fails, the slave strobe can be fired stably.

In S705, the camera control unit 105 exposes the image sensor 103 (imaging control). At the same time, in S706, the strobe 300, the strobe 400, and the strobe 500 emit light. That is, the exposure of the image pickup device 103 is performed at the light emission timing of the strobe 300, the strobe 400, and the strobe 500.

As described above, according to the first embodiment, the strobe 300, which is a master strobe, receives light emission timer information from the camera 100 by one-to-one wireless communication, and is one-to-many with respect to a plurality of slave strobes. The flash timer information is transmitted at the same time by wireless communication. Therefore, it is not necessary for the camera 100 to sequentially transmit the light emission timer information to each strobe by one-to-one wireless communication. That is, according to the present embodiment, it is possible to realize an efficient multi-lamp wireless system for an image pickup device that transmits a light emission instruction by a single cast.

Further, the camera 100 transmits the light emission timer information indicating the time from the predetermined communication timing to the light emission timing to the strobe 300 at the predetermined communication timing of the periodic wireless communication. Therefore, even when a communication standard such as Bluetooth (registered trademark) capable of executing one-to-one periodic wireless communication is used, it is possible to make the light emitting device emit light at an accurate timing.

When the strobe 300 is connected to the strobe connection portion 114 of the camera 100, the wireless communication performed in S701 to S703 in FIG. 3 may be replaced with serial communication via the strobe connection portion 114 and the camera connection portion 306. good. Further, in the above description, the wireless communication unit 305 is assumed to comply with a communication standard such as Zigbee (registered trademark), but the wireless communication unit 305 is configured to perform wireless communication using an optical pulse. You may be. In this case, the communication between the master strobe and the slave strobe in S704 of FIG. 3 is performed by using an optical pulse.

[Second Embodiment]
In the second embodiment, the processing when the transmission of the light emission timer information from the camera 100 to the strobe 300 fails due to the influence of disturbance or the like will be described. In the present embodiment, the basic configuration of the camera 100, the lens unit 200, the strobe 300, and the strobe photographing system is the same as that of the first embodiment (see FIGS. 1 and 2). Hereinafter, the points different from the first embodiment will be mainly described.

FIG. 4 is a diagram showing a synchronized shooting sequence in the strobe shooting system according to the second embodiment.

In S707, the wireless communication unit 304 of the strobe 300 detects that an error has occurred in the light emission timer information received from the camera 100. Then, the wireless communication unit 304 transmits data indicating a communication failure to the camera 100. By receiving this data, the camera control unit 105 of the camera 100 detects a communication failure of the light emission timer information. If the light emission timer information of S703 does not reach the wireless communication unit 304, the wireless communication unit 304 cannot transmit the data indicating the communication failure of the light emission timer information to the camera 100. In this case, the camera control unit 105 detects a communication failure of the flash timer information based on the fact that the flash data indicating that the flash is ready is not received from the strobe 300 within a predetermined time.

In S708, the camera control unit 105 performs the exposure readjustment process and calculates the exposure start time T7. Further, the camera control unit 105 transmits the light emission timer information including the exposure prediction time T6 to the strobe 300. The exposure prediction time T6 is a time calculated by subtracting the communication delay time due to the wireless communication being performed in the communication cycle T1 from the time until the exposure is started (exposure start time T7). Specifically, the exposure prediction time T6 is calculated by the following formula.
Expected exposure time T6 = exposure start time T7-communication delay time
= Exposure start time T7- (communication cycle T1-exposure readjustment time T8)
Here, the exposure readjustment time T8 is the time from when the camera control unit 105 receives the data indicating the communication failure until the light emission timer information is output to the wireless communication unit 123.

As described above, according to the second embodiment, when the camera control unit 105 detects a communication failure of the light emission timer information, the camera control unit 105 retransmits the light emission timer information. This makes it possible to perform more reliable multi-flash photography.

[Third Embodiment]
In the third embodiment, a process of taking a picture without a strobe when the transmission of the light emission timer information from the camera 100 to the strobe 300 fails due to the influence of disturbance or the like will be described. In the present embodiment, the basic configurations of the camera 100, the lens unit 200, the strobe 300, and the strobe photographing system are the same as those of the first and second embodiments (see FIGS. 1 and 2). Hereinafter, the differences from the first and second embodiments will be mainly described.

FIG. 5 is a diagram showing a synchronized shooting sequence in the strobe shooting system according to the third embodiment.

When the camera control unit 105 detects a communication failure of the light emission timer information in S707, the camera control unit 105 performs a strobe-less shooting preparation process in S709. Specifically, the camera control unit 105 calculates the shutter speed (TV), aperture value (AV), and sensitivity (ISO) for strobe non-flash, and performs aperture drive control for the lens unit 200. After that, in S705, the camera control unit 105 performs exposure with the sensitivity and shutter speed calculated in S709.

As described above, according to the third embodiment, even when the communication of the light emission timer information fails and the strobe 300 or the like does not emit light, appropriate exposure can be performed.

[Other embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100 ... camera, 105 ... camera control unit, 123 ... wireless communication unit, 300 ... strobe, 301 ... strobe control unit, 304 ... wireless communication unit, 305 ... wireless communication unit, 400 ... strobe, 500 ... strobe

Claims (7)

A first receiving means for receiving a first light emitting instruction indicating a first light emitting timing by one-to-one wireless communication from an image pickup apparatus, and a first receiving means.
A transmission means for simultaneously transmitting a second light emission instruction indicating the first light emission timing to a plurality of light emission control devices by one-to-many wireless communication in response to the reception of the first light emission instruction.
A control means for controlling the light emitting means so as to emit light at the first light emission timing in response to the reception of the first light emission instruction.
Equipped with
The one-to-one wireless communication is a light emission control device characterized by being faster than the one-to-many wireless communication . The light emission control device according to claim 1, wherein the transmission means transmits the second light emission instruction to the plurality of light emission control devices a plurality of times. 2. The control means is characterized in that each of the plurality of second light emission instructions corresponding to the plurality of transmissions includes time information indicating the time from the transmission timing to the first light emission timing. The light emission control device according to the above. One of the plurality of light emission control devices further comprises a second receiving means for receiving a third light emission instruction indicating the second light emission timing transmitted by the one-to-many wireless communication.
The control means according to any one of claims 1 to 3 , wherein the control means controls the light emitting means so as to emit light at the second light emitting timing in response to the reception of the third light emitting instruction. The light emission control device according to the description. The light emission control device according to any one of claims 1 to 4 .
With the light emitting means
A light emitting device characterized by being provided with. It is a control method executed by the light emission control device.
The first receiving step of receiving the first light emitting instruction indicating the first light emitting timing from the image pickup apparatus by one-to-one wireless communication, and the first receiving step.
A transmission step of simultaneously transmitting a second light emission instruction indicating the first light emission timing to a plurality of light emission control devices by one-to-many wireless communication in response to the reception of the first light emission instruction.
A control step of controlling the light emitting means so as to emit light at the first light emission timing in response to the reception of the first light emission instruction.
Equipped with
The control method , wherein the one-to-one wireless communication is a wireless communication having a higher speed than the one-to-many wireless communication . A program for causing a computer to function as each means of the light emission control device according to any one of claims 1 to 4 .

Images