JP2005128246A - Electronic flash device, camera and camera system equipped with the device and the camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new transmission system related to an exposure sequence period between a camera and an electronic flash device in order to reduce electric energy consumed for the switching control of an X contact. <P>SOLUTION: The electronic flash device electrically connected through the X contact of the camera is equipped with an X contact judgement part, an information receiving part and an exposure sequence judgement part. The X contact judgement part judges the conduction/non-conduction of the X contact. The information receiving part receives non-exposure information showing the finishing time of exposure sequence from the camera. The exposure sequence judgement part detects a period until the finishing time of the exposure sequence shown by the non-exposure information after the X contact judgement part detects the conduction of the X contact as the exposure sequence period of the camera. Then, the exposure sequence judgement part generates timing information showing the detected exposure sequence period. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for determining the timing of an exposure sequence period of a camera on the electronic flash device side.

At the beginning of the development of an electronic flash device using a xenon tube, etc., it was first practical to turn on and off the light emitting circuit on the electronic flash device side using a mechanical contact (mechanical contact) built into the shutter on the camera side. It became.
This mechanical contact begins to conduct as the shutter opens. While the shutter is open (i.e., the period during which the governor or the like in the shutter is operating), the mechanical contact continues to be in contact and the conduction state continues. Thereafter, the mechanical contact returns to the non-conductive state with the closing operation of the shutter.

When the light emitting circuit is closed by the conduction of the mechanical contact, the electronic flash device emits flash light. Such a mechanical contact of light emission timing is generally called an X contact.
Such an early period was an era in which a mechanical shutter was mounted on a camera, and a mechanical contact X contact was used for a long time. Thereafter, as electric control is introduced into the shutter of the camera, an electrical switching element is also used for the X contact (for example, Patent Document 1 below).

  By the way, some large strobes apply a high voltage exceeding 300 V to the X contact on the camera side. Some of these types of large strobes apply a negative high voltage to the X contact. In consideration of such severe conditions of applied voltage, a switching element (triac or the like) that can withstand a high current and can flow a large current in both directions is used for the current X contact.

Conventionally, a large control current (for example, a gate current) must be supplied to this type of switching element so that the conduction state can be maintained with a margin even when a large current flows from the electronic flash device side to the X contact. It was.
JP 2002-82372 A (paragraph 0046 and the like)

Incidentally, some conventional electronic flash devices determine the duration of the exposure sequence of a camera by detecting the duration of conduction of the X contact.
Using such a determination result, the electronic flash device performs an operation such as displaying a display corresponding to the exposure sequence period on the rear display unit or prohibiting a user operation during the exposure sequence of the camera.

  Since the conventional camera cooperates with the timing determination of such an electronic flash device, it is necessary to maintain the conduction state of the X contact during the exposure sequence. Therefore, in the case of long-time exposure such as slow sync, a large control current has to be continuously supplied to the switching element over a long time, and there is a problem that the current consumption on the camera side is large.

  When the electronic flash device is not connected to the camera, it is not necessary to connect the X contact on the camera side. However, a case where an electronic flash device of a type that cannot be detected by the camera is used is also assumed. For this reason, conventionally, it has been necessary to always maintain the conduction state of the X contact during the exposure sequence regardless of whether or not the electronic flash device is connected.

For the reasons described above, the current consumption required for controlling the switching element at the X contact is extremely large, which has been a major obstacle in achieving power saving of the camera.
Accordingly, an object of the present invention is to provide a new transmission method of an exposure sequence period between a camera and an electronic flash device in order to reduce the amount of power consumed for switching control of the X contact.

<Claim 1>
The invention of claim 1 is an electronic flash device that is electrically connected via an X contact of a camera, and includes an X contact determination unit, an information reception unit, and an exposure sequence determination unit.
The X contact determination unit determines conduction / non-conduction of the X contact.
The information receiving unit receives non-exposure information indicating the end point of the exposure sequence from the camera.
The exposure sequence determination unit detects a period from when the X contact determination unit detects conduction of the X contact until the end of the exposure sequence indicated by the non-exposure information as an exposure sequence period of the camera.
Then, the exposure sequence determination unit generates timing information indicating the detected exposure sequence period.

<Claim 2>
According to a second aspect of the present invention, in the electronic flash device according to the first aspect, the exposure sequence determination unit prohibits a change in the state of the electronic flash device performed by a user operation during the exposure sequence period of the camera determined by the timing information. .

<Claim 3>
According to a third aspect of the present invention, in the electronic flash device according to the first or second aspect, when the information receiving unit receives start information indicating the start time of the exposure sequence from the camera, the exposure sequence determining unit Regardless of conduction / non-conduction, a period from the start time indicated by the start information to the end time indicated by the non-exposure information is preferentially detected as the exposure sequence period of the camera. The exposure sequence determination unit generates timing information based on the exposure sequence period detected in this way.

<Claim 4>
According to a fourth aspect of the present invention, in the electronic flash device according to any one of the first to third aspects, a connection test unit that tests a connection state with the camera is provided. When the connection test unit detects that communication with the camera is impossible during the detection of the exposure sequence period, the exposure sequence determination unit ends timing determination regarding the exposure sequence period.

<Claim 5>
According to a fifth aspect of the present invention, in the electronic flash device according to any one of the first to fourth aspects, the camera determines whether or not the camera transmits non-exposure information based on communication with the camera. A determination unit is provided. When the camera determination unit determines that “the camera does not transmit non-exposure information”, the exposure sequence determination unit detects the conduction continuation period of the X contact as the exposure sequence period of the camera. The exposure sequence determination unit generates timing information indicating the exposure sequence period.

<Claim 6>
The invention according to claim 6 is a camera that realizes an X contact connected to the electronic flash device by an electrical switching element, and includes an X contact control unit and an information transmission unit.
The X contact control unit conducts the X contact for a time interval that is less than the end of the exposure sequence period of the camera from the point of time when the electronic flash device starts to emit light.
The information transmission unit transmits non-exposure information indicating the end point of the exposure sequence of the camera to the electronic flash device.
With such a configuration, the period from the conduction of the X contact to the end of the exposure sequence indicated by the non-exposure information is transmitted to the electronic flash device as the exposure sequence period of the camera.

<Claim 7>
According to a seventh aspect of the present invention, in the camera according to the sixth aspect, the electronic flash unit determines whether or not the electronic flash unit can detect the end point of the exposure sequence from the non-exposure information based on the communication with the electronic flash unit. A determination unit is provided.
When the flash device determination unit determines that “the electronic flash device cannot detect the end point of the exposure sequence from the non-exposure information”, the X contact control unit switches to an operation of continuing the X contact during the exposure sequence.

<Claim 8>
According to an eighth aspect of the present invention, there is provided a camera system comprising the electronic flash device according to any one of the first to fifth aspects and the camera according to any one of the sixth to seventh aspects. Configure.

<Claim 1>
The electronic flash device according to the first aspect of the present invention determines that the exposure sequence period starts when the conduction of the X contact is started. On the other hand, the end of the exposure sequence period is determined based on the non-exposure information received from the camera side.

  Therefore, it is not particularly necessary to continue the conduction of the X contact during the exposure sequence on the camera side constituting the electronic flash device and the camera system. That is, if the conduction of the X contact is only a signal for starting the light emission, it is sufficient to make the X contact conductive for a moment regardless of the shutter time of the camera. In this case, on the camera side, the conduction time of the X contact can be remarkably shortened. As a result, the amount of power consumed for switching control of the X contact can be drastically reduced, and the battery usable time of the camera can be significantly increased.

<Claim 2>
The electronic flash device according to claim 2 prohibits a state change by a user operation during the determined exposure sequence of the camera. Therefore, even if the user performs an erroneous operation during the exposure sequence period, the electronic flash device does not react to the erroneous operation. As a result, an electronic flash device with high operational reliability is realized.

<Claim 3>
When the electronic flash device according to claim 3 receives the start information indicating the start time of the exposure sequence from the camera, it preferentially determines the start of the exposure sequence period from the start information regardless of the conduction / non-conduction of the X contact. .
Therefore, in the system configuration with the camera having the function of transmitting the start information, it is possible to freely set the start point of the exposure sequence period as well as the X contact conduction start (when the focal plane shutter is fully opened). Become.

Accordingly, it is possible to flexibly set the start time of the exposure sequence period (for example, the release full press time or the in-focus time) that is more appropriate for the camera system.
On the other hand, when the above start information is not received, the start of conduction of the X contact can be determined as the start time of the exposure sequence. Therefore, the electronic flash device can support any of these cameras, and the user can easily select the model of the camera system.

<Claim 4>
According to the fourth aspect of the present invention, when it is detected that communication with the camera is disabled during the detection of the exposure sequence period, the timing determination relating to the exposure sequence period ends.
Usually, it is assumed that the connection to the camera side is cut off or the camera side is powered off (including battery exhaustion and failure) during the period until the non-exposure information is received. In this case, since the non-exposure information from the camera side cannot be received, the electronic flash device always determines that the exposure sequence is in progress. In this case, in particular, in the invention of claim 2, the electronic flash device cannot accept the user operation indefinitely, and the user misunderstands that the electronic flash device has failed.
Therefore, a camera connection test is performed, and the timing determination relating to the exposure sequence period is completed according to the determination of the situation where communication is impossible. As a result, it is possible to properly determine the timing of the exposure sequence period by appropriately determining the situation where the connection with the camera is disconnected or the camera is powered off.

<Claim 5>
The invention of claim 5 determines whether or not the camera is a new model capable of outputting non-exposure information through communication with the camera. At this time, if it is determined that “the camera does not transmit non-exposure information”, the conventional exposure sequence period is determined. That is, the conduction continuation period of the X contact is detected as the exposure sequence period.
Therefore, an electronic flash device that automatically corresponds to a conventional camera is realized.

<Claim 6>
According to a sixth aspect of the present invention, there is provided a camera that enables the above-described new determination method for the exposure sequence period by constituting a system configuration with the electronic flash device according to the first to fifth aspects.
That is, the camera makes the X contact conduct for a time interval that is less than the end of the exposure sequence period of the camera from the point of time when the electronic flash device starts to emit light. On the other hand, this camera separately transmits the end point of the exposure sequence period by non-exposure information.

Therefore, the system configuration with the electronic flash device according to claims 1 to 5 does not hinder the information transmission during the exposure sequence period.
In addition, the conduction time of the X contact is significantly shortened. As a result, the amount of power on the camera side consumed for switching control of the X contact can be dramatically reduced. As a result, significant power saving, which has been impossible in the past, is realized, and the battery usable time of the camera can be significantly increased.

<Claim 7>
According to the seventh aspect of the invention, the state of correspondence on the electronic flash device side with respect to the non-exposure state is determined through communication with the electronic flash device. At this time, if it is determined that “the electronic flash device cannot detect the end point of the exposure sequence from the non-exposure information”, the camera switches to the conventional method of transmitting the exposure sequence period according to the conduction period of the X contact.
Therefore, an electronic flash device that automatically corresponds to the conventional electronic flash device is realized.

<Claim 8>
The invention of claim 8 is a camera system in which the electronic flash device according to any one of claims 1 to 5 and the camera according to any one of claims 6 to 7 are combined. is there. With this combination of camera systems, the conduction time of the X contact can be remarkably shortened regardless of the duration of the exposure sequence period. As a result, it is possible to significantly reduce power consumption due to switching control of the X contact.

FIG. 1 is a block diagram showing a camera system 11 of the present embodiment.
This camera system 11 is configured by mounting an electronic flash device 13 on a hot shoe 27 of a camera 12.

[Description of Configuration of Camera 12]
The camera 12 is configured with the following configuration requirements.
(1) An imaging unit 21... Includes a shutter and captures a subject image formed by a photographing lens.
(2) Camera MPU 22... A system control microprocessor for the camera 12, and implements functions such as the X contact control unit 23, the flash device determination unit 24, and the information transmission unit 25.
(3) The switching element 26 is composed of an electrical element such as a triac, and switches the X contact 28 between conduction and non-conduction.
(4) Hot shoe 27.. An adapter to which the electronic flash device 13 and the like can be attached, and includes terminals such as an X contact 28 and an information contact 29. Note that the GND potential is connected through a guide portion of the hot shoe 27 or the like.

[Description of Configuration of Electronic Flash Device 13]
On the other hand, the electronic flash device 13 is configured with the following configuration requirements.
(5) Microprocessor for system control of the flash unit MPU31... The electronic flash unit 13, an exposure sequence determination unit 35, an exposure sequence flag 35a, an X contact determination unit 36, a camera determination unit 37, a connection test unit 38, Functions such as the information receiving unit 39 are realized.
(6) Flash light emitting tube 32... A light emitting tube that emits flash light such as a xenon tube.
(7) Light emitting circuit 33... Drive circuit for driving light emission of the flash light emitting tube 32 (8) Operation member 34.. Operation member group provided on the back side of the electronic flash device 13, such as a test light emission button including.

[Explanation of operation on the camera 12 side]
FIG. 2 is a diagram for explaining the operation related to the present invention on the camera 12 side. Hereinafter, the camera operation will be described along the step numbers shown in FIG.

Step S1: The flash device determination unit 24 on the camera 12 side attempts a new communication protocol that is not compatible with the electronic flash device 13 via the information contact 29.

Step S2: The flash device determination unit 24 determines whether or not the electronic flash device 13 returns a normal response to the new communication protocol.
Here, when a normal response is returned from the electronic flash device 13, the flash device determination unit 24 determines that the electronic flash device 13 is compatible with the new method, and proceeds to the operations of steps S6 to S7.
On the other hand, when a normal response is not returned from the electronic flash device 13, it can be determined that the electronic flash device is a conventional type (a type in which the end point of the exposure sequence period cannot be detected from non-exposure information (described later)). In this case, the flash device determination unit 24 proceeds to a conventional compatible operation in steps S3 to S5.

Step S3: First, the flash device determination unit 24 changes the communication setting of the camera MPU 22 and switches the communication protocol of the camera 12 to the communication protocol of the conventional system.

Step S4: In synchronization with the timing when the shutter of the imaging unit 21 is fully opened, the X contact control unit 23 supplies a gate current to the switching element 26 to switch the X contact 28 to a conductive state.

Step S5: The X contact control unit 23 continues the conduction state of the X contact 28 over the exposure sequence period.
During this duration of continuity, the camera MPU 22 transmits a light emission stop signal to the electronic flash device 13 via a light emission stop contact (not shown) in the hot shoe 27 as necessary. The electronic flash device 13 stops the flash emission according to the light emission stop signal, thereby realizing the light control.
Thereafter, at the end of the exposure sequence period (for example, when the travel of the shutter rear curtain of the imaging unit 21 is completed), the X contact control unit 23 switches the X contact 28 to non-conduction. With this operation (steps S3 to S5), the conventional compatible operation is completed.

Step S6: The X contact control unit 23 supplies the gate current to the switching element 26 in synchronization with the shutter fully open timing to make the X contact 28 conductive for a moment.
For example, in the case of a small electronic flash device, a conduction time of about 50 to 100 μs is sufficient. In the case of a medium-sized to large-sized electronic flash device for studios, a conduction time of about 10 to 100 milliseconds is sufficient. When such a momentary conduction period elapses, the X contact control unit 23 quickly returns the X contact 28 to the non-conduction state.
Thereafter, if necessary, the camera MPU 22 transmits a light emission stop signal to the electronic flash device 13 via a light emission stop contact (not shown) in the hot shoe 27, thereby controlling the light control of the electronic flash device 13. To do.

Step S7: Thereafter, in synchronization with the end point of the exposure sequence period (for example, when the travel of the shutter rear curtain of the image pickup unit 21 is completed), the information transmission unit 25 electronically transmits the non-exposure information via the information contact 29. Transmit to flash device 13.
With this operation (steps S6 to S7), the transmission of the exposure sequence period of the new method is completed.

[Description of operation on the electronic flash unit 13 side]
FIG. 3 is a diagram for explaining the operation related to the present invention on the electronic flash unit 13 side. Hereinafter, the camera operation will be described along the step numbers shown in FIG.

Step S21: The camera determination unit 37 in the electronic flash device 13 accepts communication transmitted from the camera 12 via the information contact 29, and returns a response corresponding to the communication protocol.

Step S22: The camera determination unit 37 determines whether or not the communication received from the camera 12 side is a new communication protocol.
Here, in the case of a new communication protocol, the camera determination unit 37 proceeds to the operations of steps S29 to S36.
On the other hand, if it is a conventional communication protocol, it can be determined that the electronic flash device is a conventional type (a type in which the end point of the exposure sequence period cannot be detected from non-exposure information (described later)). In this case, the camera determination unit 37 proceeds to the conventional compatible operation in steps S23 to S28.

Step S23: First, the camera determination unit 37 changes the communication setting of the flash device MPU31 and switches the communication protocol of the electronic flash device 13 to the communication protocol of the conventional system.

Step S24: The light emitting circuit 33 causes the flash light emitting tube 32 to start flashing in synchronization with the timing of starting the conduction of the X contact 28.

Step S25: The X contact determination unit 36 detects the start of conduction of the X contact 28 and transmits it to the exposure sequence determination unit 35. The exposure sequence determination unit 35 sets an exposure sequence flag 35a (corresponding to the timing information described in the claims) at the timing of starting the conduction. During the set period of the exposure sequence flag 35a, the exposure sequence determination unit 35 determines that “the camera 12 is in the exposure sequence period” and does not accept the user operation of the operation member 34. As a result, even if the user performs an incorrect operation (for example, pressing operation of the test light emission button) during this exposure sequence period, the electronic flash device 13 does not react and the normal operation during the exposure sequence is maintained safely. .

Step S <b> 26: When the light emission stop signal is transmitted from the camera 12, the light emitting circuit 33 stops the flash light emission of the flash light emitting tube 32.

Step S27: Subsequently, the X contact determination unit 36 stands by until the X contact 28 changes to non-conduction, and shifts the operation to step S28 when the X contact 28 changes to non-conduction.

Step S28: The X contact determination unit 36 notifies the exposure sequence determination unit 35 that the conduction state of the X contact 28 has ended.
The exposure sequence determination unit 35 determines that the exposure sequence period of the camera 12 has ended with the end of this conduction continuation state, and resets the exposure sequence flag 35a. The reset of the exposure sequence flag 35a cancels the prohibition of accepting user operations.
With such an operation (steps S23 to S28), the conventionally compatible exposure sequence determination is completed.

Step S29: Here, the information receiving unit 39 determines whether or not the start information (information indicating the start time of the exposure sequence period) is transmitted via the information contact 29. For example, the camera 12 can transmit this start information at the timing of step S6 shown in FIG.
If such start information is received, the information receiving unit 39 preferentially shifts the operation to step S31 regardless of the conduction / non-conduction of the X contact 28.
On the other hand, when the start information is not received, the information receiving unit 39 shifts the operation to Step S30.

Step S30: The X contact determination unit 36 determines conduction / non-conduction of the X contact 28.
Here, when the conduction start of the X contact 28 is detected, the information receiving unit 39 shifts the operation to step S31.
On the other hand, when the X contact 28 is in the non-conductive state, the information receiving unit 39 returns the operation to step S29.

Step S31: The exposure sequence determination unit 35 sets the exposure sequence flag 35a at the timing of “the conduction start time of the X contact 28” or “the start time of the exposure sequence indicated by the start information”. During the set period of the exposure sequence flag 35a, the exposure sequence determination unit 35 determines that “the camera 12 is in the exposure sequence period” and does not accept the user operation of the operation member 34. As a result, even if the user performs an incorrect operation (for example, pressing operation of the test light emission button) during this exposure sequence period, the electronic flash device 13 does not react and the normal operation during the exposure sequence is maintained safely. .

Step S32: When the light emitting circuit 33 detects the start of conduction of the X contact 28, the light emitting circuit 33 causes the flash light emitting tube 32 to start flashing.
Note that the light emitting circuit 33 may cause the flash light emitting tube 32 to start flash emission at the shutter fully open timing indicated by the start information described above.

Step S33: When the light emission stop signal is transmitted from the camera 12, the light emitting circuit 33 stops the flash light emission of the flash light emitting tube 32. Or flash emission stops spontaneously by full emission.

Step S34: During the set period of the exposure sequence flag 35a (except for the flash emission period), the connection test unit 38 performs a connection test (communication trial or the like) with the camera 12 via the information contact 29. . By this connection test, the communication connection state with the camera 12 is determined. In addition, it is more preferable to perform this connection test also about the period from start information to X contact conduction.

  If the connection test unit 38 determines that “communication with the camera 12 is not possible”, the exposure sequence determination unit 35 moves the operation to step S36 in order to end the timing determination of the exposure sequence period. For example, the communication disabled state may be a power off or failure of the camera 12 or a disconnected state in which the electronic flash device 13 is disconnected from the hot shoe 27.

  On the other hand, when the connection test unit 38 determines that “communication with the camera 12 is possible”, the exposure sequence determination unit 35 moves the operation to step S35.

Step S35: Here, the information receiving unit 39 determines whether or not the non-exposure information (see Step S7) transmitted by the camera 12 has been received.
When the non-exposure information is received, the information receiving unit 39 moves the operation to step S36.
On the other hand, when the non-exposure information is not received, the information receiving unit 39 returns the operation to step S34.

Step S36: The exposure sequence determination unit 35 resets the exposure sequence flag 35a. The reset of the exposure sequence flag 35a cancels the prohibition of accepting user operations.
With such an operation (steps S29 to S36), the new exposure sequence determination is completed.

[Effects of this embodiment, etc.]
FIG. 4 is a diagram showing exposure sequence determination compatible with the prior art in the present embodiment. If it is determined in step S2 or S22 described above that either the camera 12 or the electronic flash device 13 does not support the new method, the conventional compatible timing determination shown in FIG. 4 is performed. By maintaining the conventional compatibility in this way, the camera 12 and the electronic flash device 13 can freely select a partner device to be combined regardless of the old and new systems.

  FIG. 5 is a diagram showing a first exposure sequence determination in the present embodiment. Here, the period from the momentary conduction of the X contact 28 to the time point indicated by the non-exposure information is determined as the exposure sequence period. In such an operation, since the conduction time of the X contact 28 is shortened to a negligible level, the amount of current consumed for the switching control of the X contact 28 can be greatly reduced. As a result, it becomes possible to further reduce the power consumption of the camera 12, and the battery usable time of the camera 12 can be significantly extended.

  Furthermore, since the X contact 28 (that is, the switching element 26) conducts only for a moment, the total amount of current flowing from the electronic flash device 13 to the switching element 26 is also reduced. Therefore, it contributes to power saving of the electronic flash device 13, and an effect such as shortening the light emission charge time of the electronic flash device 13 is obtained.

  In addition, since the time during which current flows from the electronic flash device 13 to the switching element 26 is instantaneous, the heat generation of the switching element 26 becomes very small, and the maximum rating of the switching element 26 can be greatly reduced. As a result, the component size of the switching element 26 is reduced, and an effect such as downsizing the camera 12 is obtained.

  In the first exposure sequence determination, as shown in FIG. 5, the time when the shutter of the imaging unit 21 is completely closed is set as the end time of the exposure sequence period. Therefore, even if the user mistakenly presses the light emission test button before the shutter is completely closed, the electronic flash device 13 does not perform test light emission, and it is possible to appropriately avoid a photographing error due to excessive light emission.

  FIG. 6 is a diagram showing a second exposure sequence determination possible in the present embodiment. Here, the timing of the exposure sequence period is determined based on the start information and the non-exposure information. Also in this case, the amount of current required for the switching control of the X contact 28 can be greatly reduced, so that power saving similar to the above can be achieved.

  Furthermore, on the camera 12 side, using the start information, the start point of the exposure sequence period can be freely transmitted regardless of the conduction / non-conduction of the X contact 28. Therefore, as shown in FIG. 6, it is possible to transmit the travel start time of the shutter front curtain of the imaging unit 21 to the electronic flash device 13 side as the start time of the exposure sequence period. In this case, the exposure sequence period can be determined including a period in which the shutter of the imaging unit 21 is slightly open. Therefore, even when the shutter is slightly open, even if the user accidentally presses the light emission test button, the electronic flash device 13 never emits a test light, so that it is possible to more reliably avoid a photographing error due to excessive light emission.

  Further, FIG. 7 is a diagram showing exposure sequence determination when it is determined that communication connection is impossible in the connection test on the electronic flash device 13 side (see step S34). Normally, when the communication connection between the camera 12 and the electronic flash device 13 is cut off, the electronic flash device 13 cannot receive the non-exposure information and cannot determine the end of the exposure sequence period. In this state, the electronic flash device 13 is worried about various adverse effects, such as no longer accepting user operations. However, in the present embodiment, when it is detected that communication connection is impossible by the connection test, the timing determination of the exposure sequence period is ended. Therefore, it is possible to reliably avoid a situation in which it is impossible to determine the end of the exposure sequence period.

[Supplementary items of the embodiment]
In the above-described embodiment, the case where only the main light emission is performed has been described. However, the present invention is not limited to this. The present invention may be applied to a case where preliminary light emission is performed prior to main light emission. In this case, the conduction start of the X contact 28 at the time of preliminary light emission may be set as the start time of the exposure sequence period. Further, the start of conduction of the X contact during the main light emission may be set as the start time of the exposure sequence period.

  In the embodiment described above, non-exposure information and start information are communicated via the information contact point 29. However, the present invention is not limited to this. For example, non-exposure information and / or start information may be exchanged via a data terminal other than the hot shoe 27. Further, non-exposure information and / or start information may be exchanged by radio or optical communication. Further, non-exposure information and / or start information can be exchanged via the signal line of the non-conductive X contact 28.

  In the above-described embodiment, the end time of the exposure sequence period is the time when the shutter of the imaging unit 21 is completely closed. However, the present invention is not limited to this. For example, the time when the imaging unit 21 completes the mirror down, the time when the shutter charging of the imaging unit 21 is completed, or the like may be set as the end point of the exposure sequence period.

  In the above-described embodiment, the camera 12 may be either an electronic camera or a silver salt camera. Furthermore, although the above-described embodiment is premised on a focal plane shutter, the present invention is not limited to this. For example, the shutter of the present embodiment may be any one of a focal plane shutter, a lens shutter, an electronic shutter based on drive control of an image sensor, and the like.

  In the embodiment described above, the start time and end time of the exposure sequence period are transmitted in real time using the transmission timing of start information and non-exposure information. However, the present invention is not limited to this. For example, it is also possible to transmit information after the elapse of a predetermined time from the transmission point of start information or non-exposure information as the start point or end point of the exposure sequence period. In addition, by including information on absolute time (or relative time such as several milliseconds after the transmission time) in the start information and non-exposure information, it is also possible to transmit information on the start time and end time of the exposure sequence period.

  In the above-described embodiment, the electronic flash device 13 is attached to the hot shoe 27 of the camera 12. However, the present invention is not limited to such usage. For example, by connecting a communication adapter or a connection cord to the hot shoe 27 of the camera 12, it is possible to transmit information on the exposure sequence period to the electronic flash device 13 at a spatially separated position.

  As described above, the present invention is a technique that can be used for information transmission during an exposure sequence period between a camera and an electronic flash device.

It is a block diagram which shows the camera system 11 of this embodiment. It is a figure explaining the operation | movement by the side of the camera. It is a figure explaining the operation | movement by the side of the electronic flash apparatus. It is a figure which shows the exposure sequence determination compatible with the prior art in this embodiment. It is a figure which shows the 1st exposure sequence determination in this embodiment. It is a figure which shows the 2nd exposure sequence determination in this embodiment. It is a figure which shows the exposure sequence determination in the case where communication connection is impossible.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Camera system 12 Camera 13 Electronic flash device 21 Imaging part 22 Camera MPU
23 X contact control unit 24 Flash device determination unit 25 Information transmission unit 26 Switching element 27 Hot shoe 28 X contact 29 Information contact 31 Flash device MPU
32 Flash emission tube 33 Light emitting circuit 34 Operation member 35 Exposure sequence determination unit 35a Exposure sequence flag 36 X contact determination unit 37 Camera determination unit 38 Connection test unit 39 Information reception unit

Claims (8)

An electronic flash device electrically connected via the X contact of the camera,
An X contact determination unit for determining conduction / non-conduction of the X contact;
An information receiving unit for receiving non-exposure information indicating an end point of an exposure sequence from the camera;
The timing from which the X contact determination unit detects the conduction of the X contact until the end of the exposure sequence indicated by the non-exposure information is detected as the exposure sequence period of the camera, and indicates the exposure sequence period An electronic flash device comprising: an exposure sequence determination unit that generates information. The electronic flash device according to claim 1,
The exposure sequence determination unit
The electronic flash device is characterized by prohibiting a state change of the electronic flash device performed by a user operation during the exposure sequence period of the camera determined by the timing information. The electronic flash device according to claim 1 or 2,
The exposure sequence determination unit
When the information receiving unit receives start information indicating the start time of the exposure sequence from the camera, the non-exposure information indicates from the start time indicated by the start information regardless of whether the X contact is conductive or not. An electronic flash device, wherein a period until the end point is preferentially detected as the exposure sequence period of the camera, and the timing information indicating the exposure sequence period is generated. The electronic flash device according to any one of claims 1 to 3,
A connection test unit for testing a connection state with the camera;
The exposure sequence determination unit
If the connection test unit detects that communication with the camera is not possible during detection of the exposure sequence period, the timing determination regarding the exposure sequence period is terminated. The electronic flash device according to any one of claims 1 to 4,
A camera determination unit that determines whether the camera transmits the non-exposure information based on communication with the camera;
The exposure sequence determination unit
When the camera determination unit determines that “the camera does not transmit the non-exposure information”, the conduction sequence period of the X contact is detected as the exposure sequence period of the camera, and indicates the exposure sequence period. An electronic flash device characterized by generating timing information. A camera that realizes the X contact connected to the electronic flash device by an electrical switching element,
An X contact control unit that conducts the X contact for a time interval that is less than the end of the exposure sequence period of the camera from an instruction to start light emission to the electronic flash device;
An information transmission unit that transmits non-exposure information indicating an end point of the exposure sequence of the camera to the electronic flash device;
The camera transmits information to the electronic flash unit as a period from the conduction of the X contact to the end of the exposure sequence indicated by the non-exposure information as the exposure sequence period of the camera. The camera according to claim 6, wherein
A flash device determination unit that determines whether the electronic flash device can detect the end point of the exposure sequence from the non-exposure information based on communication with the electronic flash device;
The X contact controller is
When it is determined that the electronic flash device cannot detect the end time of the exposure sequence from the non-exposure information in the flash device determination unit, the operation of continuing the conduction of the X contact during the exposure sequence is performed. A camera characterized by switching. An electronic flash device according to any one of claims 1 to 5,
A camera system comprising: the camera according to claim 6.

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