JPH05165084A - Electronic flash device - Google Patents

Abstract

PURPOSE:To enhance the workmanship of flash photographing by making judgement on the basis of the set output of an external operating member, comparing the response time of a light quantity control means with the time from the camera put in the prepared condition for photograph till the photographing starting, and judging whether the emitted light quantity control is conducted acceptably according to the type of camera in use. CONSTITUTION:On the basis of set output of an external operating member 103, a judging means 102A judges whether the emitted light quantity control of flash light can be made with a light quantity control means 101, while another judging means 102B makes judgement through comparison of the response time of the light quantity control means 101 with the time from the camera put in the condition for photograph till the photographing starting. Meantime a judging means 102C makes judgement according to the type of camera on which electronic flash device is mounted. Therein a light emitting means 100A makes preliminary light emission and a regular process of light emitting and is equipped with a light measuring means 104 to measure the reflected light from the object at the time of preliminary light emission, while a light quantity control means 101A controls the emitted light quantity on the basis of the result from measurement made by the light measuring means 104 at the time of regular process of light emitting, and further a light measuring means 104A measures light upon dividing the field of object photographed, and a light quantity control means 101B makes control for each light emission region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic flash device that changes the light distribution when a flash is emitted according to the distribution of subjects in the field.

[0002]

2. Description of the Related Art Conventionally, when a plurality of subjects having different photographing distances as shown in FIG. 14 are flash-photographed, the subject in front is an exposure over and the subject in the back is underexposure. It was difficult to properly expose the subject. In order to solve this problem, the applicant of the present invention divides the object field into a plurality of irradiation regions, adjusts the amount of light emitted from the light emitting unit for each irradiation region, and irradiates the electronic flash device of the camera. Is proposed. In this type of electronic flash device, a liquid crystal or electrochromic display (hereinafter,
An irradiation light amount adjusting member such as ECD) is provided in front of the light emitting unit, and the amount of light passing through each irradiation region is adjusted according to the spatial distribution state of a plurality of subjects so that all the subjects have proper exposure. Illuminate.

[0003]

However, depending on the shooting scene, it may not be desirable to shoot all subjects with flash exposure. For example, there is a case where only the main subject is properly exposed, and a subject farther than the main subject is underexposed, and flash photography is performed so that the main subject floats up from the background. Also, liquid crystal and ECD
Has a long response time from the application of a voltage to the actual state of adjusting the irradiation light quantity, and the irradiation light quantity may not be sufficiently adjusted when flash photography is performed at a high shutter speed.

It is an object of the present invention to provide an electronic flash device which makes it possible to select whether or not to adjust the irradiation light amount and which controls the irradiation light amount in consideration of the response time of the irradiation light amount adjusting member.

[0005]

The present invention will be described with reference to FIG. 1, which is a diagram corresponding to claims, and the invention of claim 1 is applied to an electronic flash device provided with a light emitting means 100 for emitting a flash light. A light amount control means 101 for controlling the light emission amount of the flash light to the outside of the flash device, and a judgment means 1 for judging whether or not the light amount control means 101 controls the light emission amount of the flash light.
02, and thereby achieve the above object. The determination means 102A of the electronic flash device according to the second aspect is configured to make a determination based on the set output of the external operation member 103 that sets whether or not the light amount control means 101 controls the emission light amount of the flash light. The determination means 102B of the electronic flash device according to claim 3 makes a determination by comparing the response time of the light amount control means 101 with the time from the shooting preparation state of the camera to the start of shooting. The determination means 102C of the electronic flash device according to claim 4,
The determination is made based on the type of camera to which the electronic flash device is attached. The light emitting means 100A of the electronic flash device according to claim 5 performs preliminary light emission and main light emission, and measures light reflected from a subject during preliminary light emission.
4, the light amount control means 101A controls the amount of flash light emitted to the outside of the electronic flash device on the basis of the photometric result of the photometric means 104 during main light emission. Claim 6
The photometric means 104A of the electronic flash device performs photometry for each photometric area obtained by dividing the object field into a plurality of areas, and the light quantity control means 101B has a plurality of emission areas corresponding to the plurality of photometric areas of the photometric means 104A. However, the amount of flash light emitted is controlled for each corresponding emission region based on the photometric result of each photometric region. An electronic flash device according to a seventh aspect of the present invention comprises a temperature detecting means 105 for detecting the temperature, and a correcting means 106 for correcting the control characteristic of the light quantity control means 101 according to the temperature detected by the temperature detecting means 105.

[0006]

According to the first aspect, the judging means 102 judges whether or not the light quantity control means 101 controls the emitted light quantity of the flash light,
The light quantity control means 101 controls the quantity of light emitted from the electronic flash device. In claim 5, the photometric means 104 measures the reflected light from the subject during the preliminary light emission, and the light amount control means 101A emits the amount of flash light to the outside of the electronic flash device based on the photometric result of the photometric means 104 during the main flash. To control.
In claim 7, the correction unit 106 includes the temperature detection unit 105.
The control characteristic of the light amount control means 101 is corrected according to the detected temperature of.

[0007]

FIG. 2 is a block diagram showing the structure of an embodiment. A selection unit 1 selects whether or not to adjust the irradiation light amount for each of a plurality of irradiation regions of the object scene. This choice is
It is determined based on the result that the photographer selects the irradiation light amount adjustment mode and the normal irradiation mode by a selection member described later, or whether or not the camera 3 to which the split irradiation type flash device 2 is attached is a camera compatible with the split irradiation type flash device 2. Will be done. An automatic selection unit 4 includes a measurement unit 5 and a determination unit 6. The measuring unit 5 measures the time from when the shutter release button (not shown) is half-pressed to when it is fully pressed. When the measurement time of the measurement unit 5 is longer than a preset time, the determination unit 6 sends a signal for permitting the adjustment of the irradiation light amount to the selection unit 1, and when the measurement time is shorter than the set time, the photographer Sends a signal to the selection unit 1 indicating that the irradiation light amount adjustment is not permitted even when the irradiation light amount adjustment mode is selected.

7 is a microcomputer (hereinafter, CPU)
X), which performs the preliminary light emission control of the split irradiation type flash device 2, the photometric control during the preliminary light emission, the main light emission control, the irradiation light amount calculation control, and the like, and the shutter drive timing and the X contact signal for starting the main light emission. The output timing is sent to the CPU 8 on the camera side. Reference numeral 9 is a light emission drive circuit for driving the light emitting tube 10, 11 is a photometric unit for measuring the exposure amount of flash light during preliminary light emission, and 12 is a power source of the split irradiation flash device 2. Further, reference numeral 13 denotes a divided irradiation light amount calculation unit, which has a memory 13a for temporarily storing the exposure amount measured by the photometry unit 11, and each irradiation at the time of main light emission based on the photometry result at the time of preliminary light emission. The amount of irradiation light for each area is calculated.
Reference numeral 14 denotes an emission light amount adjusting unit, which has a plurality of emission regions corresponding to a plurality of irradiation regions of the object field, and according to the irradiation light amount for each irradiation region calculated by the divided irradiation light amount calculation unit 13,
Emitting light amount adjusting member 14 composed of liquid crystal or ECD
By controlling a, the amount of light emitted from the arc tube 10 is adjusted for each emission region. Reference numeral 15 is a temperature detecting unit that detects the ambient temperature, and 16 is a voltage changing circuit that changes the voltage applied to the emitted light amount adjusting unit 14 according to the ambient temperature detected by the temperature detecting unit 15.

When a light emission command is received from the CPU 8 on the camera side, the selection unit 1 transmits to the CPU 7 of the divided irradiation type flash device 2 whether or not to adjust the irradiation light amount. Since the light emission command from the camera side must be transmitted at the moment of release, the contact point for transmitting and receiving a signal between the split irradiation type flash device 2 and the camera 3 is different from the conventional contact point. Is. When the CPU 7 of the split irradiation type flash device 2 receives the selection signal from the selection unit 1 and adjusts the irradiation light amount,
Timings of shutter drive and X-contact signal output at the time of main light emission are transmitted to the CPU 8 of the camera 3, and a preliminary light emission command is sent to the light emission drive circuit 9. Further, the CPU 7 sends a photometry command to the photometry unit 11, and sends a calculation command of the operation start timing of the emission light amount adjustment unit 14 to the divided irradiation light amount calculation unit 13. As a result, the light emission drive circuit 9 performs the preliminary light emission of the flash tube 10, and the photometric unit 11 measures the reflected light from the object field accompanying the preliminary light emission. The divided irradiation light amount calculation unit 13 includes the photometry unit 1
The photometric data of No. 1 is temporarily stored in the memory 13a, and the CPU 7
When the calculation command is issued from, the photometric data of the memory 13a is called, and the irradiation light amount for each irradiation region at the time of main light emission (that is, when the X contact signal is turned on) and the operation start timing of the emission light amount adjusting unit 14 are calculated, At that timing, the emitted light quantity adjusting unit 14 is activated. When the irradiation light amount is not adjusted, only the main light emission is performed according to the X contact signal as in the conventional flash device.

The emitted light quantity adjusting unit 14 controls the emitted light quantity adjusting member 14a such as liquid crystal or ECD according to the irradiation light quantity calculated by the divided irradiation light quantity calculation unit 13 for each irradiation area. The emitted light amount adjusting member 14a is driven by applying a voltage, but the operating characteristics such as the response time change depending on the ambient temperature. Therefore, the voltage changing circuit 16 includes the temperature detecting unit 15
The applied voltage is changed according to the ambient temperature detected in step S6, and the emitted light amount adjustment member 14a is controlled so as to maintain a constant operating characteristic.

In this embodiment, the discriminating section 6, the measuring section 11 and the temperature detecting section 15 are provided in the split irradiation type flash device 2, but they may be provided in the camera 3, or the temperature detecting section 15 may be provided. You may use the temperature detection means normally provided in the camera 3.

FIG. 3 is a sectional view of a split irradiation type flash device according to the present invention. The light emitting tube 10 is composed of a light emitting tube 10a for preliminary light emission and a light emitting tube 10b for main light emission. A part of flash light emitted from these light emitting tubes 10a, 10b is reflected by a reflecting mirror 21. The light passes through the emission light amount adjusting member 14a and the Fresnel lens 22 and is emitted to the outside. The emission light amount adjusting member 14a is divided into nine emission regions F1 to F9 as shown in the drawing, and controls the amount of light passing through the arc tubes 10a and 10b for each emission region F1 to F9. The reflected light of the flash from the field is the lens 1
The light is guided to the photometric element 11b made of silicon photodiode (SPD) via 1a. These lenses 11a
The photometric element 11b constitutes the photometric unit 11. The photometric element 11b includes nine photometric areas f1 to f9 as shown in the figure.
The photometry is performed for each of the photometry areas f1 to f9. It should be noted that these divided photometric areas f1 to f9 correspond to the divided emission areas F1 to F9 of the emitted light amount adjusting member 14a.

FIG. 4 is a flow chart showing the adjusting operation of the irradiation light amount. The operation of the embodiment will be described with reference to this flowchart. The operation is started by the release operation of the camera 3, and the selection processing of the selection unit 1 described above is performed in steps S2 to S4. First, in step S2, it is determined whether or not the camera 3 to which the split irradiation type flash device 2 is attached is a camera compatible with irradiation light amount adjustment. In the case of a camera capable of adjusting the irradiation light amount, the CPU 8 of the camera 3 issues a light emission command to the divided irradiation type flash device 2 at the time of shutter release. At this time,
If the light emission command is not received by the split irradiation type flash device 2, it is determined that the camera does not support the conventional irradiation light amount adjustment, and step S
In step 21, the X-contact signal of the camera is output to the flash device 2 to perform main light emission as in the conventional case. In the case of a camera capable of adjusting the irradiation light amount, it is determined in step S3 whether or not the irradiation light amount adjustment mode is selected by the selection member, and if the normal irradiation mode in which the irradiation light amount adjustment is not performed is selected, the process proceeds to step S31. Then, the X-contact signal of the camera is output to the flash device 2 to perform main light emission. When the irradiation light amount adjustment mode is selected, in step S4, as a result of the determination by the determination unit 6 described above, the time from the half-pressing to the full-pressing the shutter release button is predetermined even if the irradiation light amount adjustment mode is selected. If it is determined that the shooting is shorter than the time and this shooting is an urgent shooting, and it is determined that the divided irradiation that takes some time before the shooting starts is unnecessary, the process proceeds to step S41, and the X contact signal of the camera is output to the flash device 2. Main light emission.

As a result of the selection by the selection unit 1, step S
When all of 2 to S4 are affirmed, in step S5,
The irradiation light amount adjustment command is sent from the selection unit 1 to the CPU 7, and the CPU 7 having received the irradiation light amount adjustment command sends the control signals of the shutter drive timing and the X contact signal output timing to the CPU 8 of the camera 3. Here, the time when the control signal is output is set to T0, and the shutter drive is started from time T0 to T0.
It is assumed that after 3 hours, the X contact signal is output from T0 to T4 hours later. Then in step S6,
After the time T0 to T1, the preliminary light emission command is output to the light emission drive circuit 9 to start the preliminary light emission, and in the subsequent step S7, the light measurement command is output to the photometry unit 11 to measure the reflected light by the preliminary light emission. This photometric data is used for the divided irradiation light amount calculation unit 1
3 and is stored in the memory 13a. Step S
8, the divided irradiation light amount calculation unit 1 after the time T2 from the time T0
A calculation command is output to 3, and the irradiation light amount for each irradiation region is calculated based on the photometric data of the memory 13a. further,
Based on the irradiation light amount for each irradiation region, the light amount adjustment operation start timing of each emission region F1 to F9 of the emission light amount adjustment unit 14 is calculated. And at the calculated timing,
An operation start command is output from the divided irradiation light amount calculation unit 13 to the emission light amount adjustment unit 14, and thereby the emission light amount adjustment unit 14 is output.
Starts the light amount adjustment operation.

On the other hand, in step S11, the CPU 8 of the camera 3, which has received the control command from the split-illumination type flash device 2,
The shutter drive is started in step S12 after T3 time, and the X contact signal is output in step S13 after T4 time. The output timing of the X contact signal is shutter-
For a type of camera that is determined by the start of driving, the shutter driving time may be set so that the X contact signal is output after T4 from time T0. Further, when the irradiation light amount adjustment is performed by the above procedure, the irradiation light amount adjustment execution lamp provided in the divided irradiation type flash device 2 is turned on for several seconds to confirm that the photographer has completely adjusted the irradiation light amount. Make them recognize. The display device in the finder may display execution of the irradiation light amount adjustment.

FIG. 5 is a time chart showing the timings of preliminary light emission, main light emission, and irradiation light amount adjustment control. First, at time T0, a control signal, that is, a timing signal for shutter drive and X-contact signal output is output from the CPU 7 of the split-illumination flash device 2 to the CP 8 of the camera 3.
Now, let this time T0 be the origin time. From time T0 to T1
After a lapse of time, the preliminary light emission and the photometric command are output. Also,
After T2, a calculation command of the divided irradiation light amount is output.
On the other hand, shutter driving is started from time T0 to time T3, and an X contact signal is output after time T4. Further, the origin time of the irradiation light amount adjustment control is set after the time Ts0 from the time T0. The origin time TS0 is set to the emission light amount adjusting member 14 by activating the emission light amount adjusting unit 14 at this time.
It is the time when a responds completely and the amount of passing light can be almost blocked. The start time TS1 of the irradiation light amount adjustment is determined based on this time TS0. It should be noted that the start time of the irradiation light amount adjustment TS1
Corresponds to the irradiation light amount for each irradiation region calculated by the divided irradiation light amount calculation unit 13, and is different for each emission region F1 to F9 of the emission light amount adjustment member 14a. In this way, liquid crystal and E
Even with an emission light amount adjusting member having a long response time such as a CD, the irradiation light amount can be adjusted accurately.

FIG. 6 is a circuit diagram of the irradiation light amount adjustment controller. Electric power for driving the emitted light quantity adjusting unit 14 is supplied from the power source 12 to the voltage changing circuit 16, the emission areas F1 to F9 of the emitted light quantity adjusting member 14a, and the thyristor 1 provided for each area.
4b to 14j and the reset switch 23. As described above, the photometry unit 11 measures the light in each of the nine photometry areas f1 to f9 during the preliminary light emission, and each photometry area f
The photometric data of 1 to f9 are stored in the memory 13a. The divided irradiation light amount calculation unit 13 reads out these photometric data at the time of preliminary light emission from the memory 13a, and each emission of the light amount adjustment member 14a is performed so that the amount of passing light is completely controlled in each emission region F1 to F9 at the time of main light emission. The operation time for each of the regions F1 to F9, that is, the light amount adjustment start time is calculated.

As described above, the response time of the emitted light quantity adjusting member 14a such as liquid crystal or ECD may be longer than the flash light emission time. In front of the light amount adjusting member 14
It is necessary to start the operation of a. The divided irradiation light amount calculation unit 13 sets each emission region F at the calculated light amount adjustment start time of each emission region F1 to F9 of the emission light amount adjustment member 14a.
A positive voltage pulse signal is applied to the gates of the thyristors 14b to 14j corresponding to 1 to F9, and the thyristors 14b to 1
4j is made conductive. As a result, the emitted light amount adjusting member 1
A voltage is applied to each of the emission regions F1 to F9 of 4a. When the emitted light amount adjusting member 14a is a liquid crystal, it is driven even if a DC voltage is applied, but it is desirable to convert it into a square wave and apply it in order to shorten the life of the liquid crystal. When the irradiation light amount adjustment control is completed, the reset switch 23 is turned off to turn off all the thyristors 14b to 14j. As a result, the emitted light amount adjusting member 14a returns to the initial state, and the transmittances of the emission regions F1 to F9 become uniform.

FIG. 7 is an external view of a split irradiation type flash device according to the present invention mounted on a camera. In order to exchange signals such as a light emission command, a timing signal for shutter drive and X-contact signal output, and a time from the half-pressing of the shutter release button to the full-pressing, between the split irradiation type flash device 2 and the camera 3. , Many connection contacts are required.
Therefore, a dedicated cable 30 is provided from the side surface of the split irradiation type flash device 2 to the left front surface of the camera 3. Of course, any method may be used as long as it completely exchanges all signals. Reference numeral 31 is a selection member for selecting the irradiation light amount adjustment mode and the normal irradiation mode described above. Again 3
Reference numeral 2 denotes the irradiation light amount adjustment execution lamp described above.

FIG. 8 is a circuit diagram of the light emitting section. Power 12
Is boosted by the boosting circuit 33 and applied to the preliminary light emission capacitor 34 and the main light emission capacitor 35. When the preliminary light emission command signal is supplied from the CPU 7 of the split irradiation type flash device 2 to the preliminary light emission drive circuit 37 via the terminal 36, the preliminary light emission tube 10a emits light. Also, camera 3
When an X contact signal is supplied from the terminal to the main light emission drive circuit 39 through the terminal 38, the main light emission tube 10b emits light. Also, 4
Reference numeral 0 denotes a TTL dimming terminal, which can stop the main light emission by the TTL dimming of the camera 3.

FIG. 9 is a view showing the emitted light amount adjusting member 14a. The emission light amount adjusting member 14a is divided into the nine emission regions F1 to F9 as described above, and each of the regions F1 to F9.
F9 starts the light amount adjustment control at the time calculated by the divided irradiation light amount calculation unit 13 based on the light measurement data of the corresponding light measurement regions f1 to f9 of the light measurement unit 11. Emitting light amount adjusting member 1
Each of the emission regions F1 to F9 of 4a is provided with a polarizing plate 4 from the light emitting unit side.
1, transparent electrode 42, liquid crystal 43, transparent electrode 44, analyzer plate 4
It is configured in the order of 5. In the figure, nine injection regions F1 to
Only one of F9 is shown, but the same applies to the other emission areas.

FIG. 10 is a view for explaining the principle of light quantity adjustment when a twisted nematic liquid crystal is used for the outgoing light quantity adjusting member 14a. Twisted nematic liquid crystals have the property of rotating the plane of polarization. As shown in FIG.
When the nematic liquid crystal is twisted by 90 degrees, the transparent electrode 53,
When no voltage is applied between 54, the incident light that is linearly polarized light that has passed through the polarizing plate 51 is rotated and output as linearly polarized light in a direction perpendicular to the incident light. Therefore, it becomes possible to pass through the light analysis plate 52. However, the transparent electrode 5
When a voltage is applied between 3 and 54, the liquid crystal is oriented in a direction perpendicular to the polarizing plate 51 and the light analyzing plate 52 by the electric field, so that the liquid crystal cannot rotate and cannot pass through the light analyzing plate 52. In this embodiment, the twisted nematic liquid crystal is used as the emitted light amount adjusting member 14a, but if the liquid crystal of other types can pass or block the light by applying or releasing the voltage, the emitted light amount adjusting member 14a. Can be used as

FIG. 11 is a view for explaining the principle of light amount adjustment when a guest-host type liquid crystal is used for the emitted light amount adjusting member 14a. A dichroic dye 55 having anisotropy in absorption of visible light is dissolved in a liquid crystal of a certain arrangement in the long side direction and the short side direction of the photographing screen, and the dichroic dye 55 is arranged in parallel with the liquid crystal molecules 56. .. When the arrangement of the liquid crystal molecules 56 is changed by applying a voltage in this state, the arrangement of the molecules of the dichroic dye 55 can be changed. In this embodiment, a nematic liquid crystal is used which is composed of liquid crystals having a negative dielectric anisotropy and is arranged in the optical axis direction when a voltage is not applied, and is arranged in a direction perpendicular to the optical axis when a voltage is applied. Using. Note that, in reality, it is necessary to direct the light in one direction when a voltage is applied, so when the voltage is not applied, it is slightly tilted from the optical axis. In this embodiment, the color of the dichroic dye 55 is black, and the irradiation light amount is adjusted by applying and releasing the voltage. That is, when the voltage is not applied, the dichroic dye 55 is arranged in the optical axis direction, so that the light passing therethrough passes through without being colored. However, when the voltage mark is applied, the dichroic dye 55 is arranged in the direction perpendicular to the optical axis, so that the flash light passing therethrough is colored black, whereby the light amount is extremely reduced. Since this method does not use a polarizing plate, it is possible to prevent a reduction in the amount of flash light passing through the emitted light amount adjusting member 14a when the light amount adjusting control is not performed.

FIG. 12 shows an EC for the light quantity adjusting member 14a.
It is sectional drawing when D is used. The ECD is, for example, as disclosed in Japanese Utility Model Laid-Open No. 2-138719.
It has a property of being colored when a voltage is applied, and this property is used for light amount adjustment control. The transparent electrodes 61, EC from the light emitting portion side are provided in the respective emission regions F1 to F9 of the emission light amount adjusting member 14a.
The layer 62, the solid electrolyte layers 63 and 64, and the transparent electrode 65 are arranged. In addition, in this figure, one of the nine emission regions F1 to F9 is shown, but the other emission regions have the same configuration.
When a voltage is applied between the transparent electrodes 61 and 65, the transparent electrodes 61 and 65 are colored by an oxidation-reduction reaction, whereby the amount of passing light can be adjusted. In this example, WO ₃ is used for the EC layer 62, Ta ₂ O ₅ and Ir ₂ O ₃ / SnO ₂ are used for the solid electrolyte layers 63 and 64, and the WO ₃ layer and Ta are used from the incident light side.
It is arranged with a ₂ O ₅ layer and an Ir ₂ O ₃ / SnO ₂ layer. For the solid electrolyte layer 63, SiO ₂ , Cr ₂ O ₃ or the like can be used in addition to the above.

In the case of this ECD, the light amount adjustment control is performed by the circuit shown in FIG. 13 because the initial state cannot be restored unless a reverse voltage is applied. The switch 71 is always turned on to the A side, and is turned on to the B side at the time of resetting to apply a reverse voltage to each of the emission regions F1 to F9 of the emission light amount adjusting member 14a to decolorize.

As described above, the mounted camera is an irradiation light amount adjustment compatible camera, the irradiation light amount adjustment mode is set by the selection member 31, and the discriminating unit 6 further sets a predetermined time from half-pressing to full-pressing the shutter release button. When it is determined that the irradiation light amount can be adjusted for longer than the time, the irradiation light amount for each irradiation region is calculated based on the photometry data of each photometry region measured by the photometry unit 11 during the preliminary light emission, and thus the emission light amount adjustment is performed. Since the light quantity adjustment is started for each emission area of the unit 14, flash photography can be performed without adjusting the irradiation light quantity, and the flash photography intended by the photographer can be performed according to the photography scene. Further, even if the irradiation light amount adjusting member 14a such as liquid crystal or ECD having a long response time is used, flash photography can be performed at a high shutter speed. Further, when the camera is accidentally attached to a camera that does not support the light amount adjustment control, it is possible to prevent an erroneous operation such as flash photography.

In the above embodiment, the example in which the present invention is applied to the single-lens reflex camera which does not have the split-illumination type flash device is shown, but the same applies to the single-lens reflex camera and the compact camera which incorporate the split-illumination type flash device. Applied to the same effect.

In the structure of the above embodiment, the light emission drive circuit 9 and the light emission tube 10 serve as the light emitting means, and the emitted light quantity adjusting section 1 is provided.
4 and the emitted light amount adjusting member 14a serve as a light amount controlling means, the selecting portion 1 and the automatic selecting portion 4 serve as a judging portion, the selecting member 31 serves as an external operating member, the light measuring portion 11 serves as a light measuring means, and the temperature detecting portion 15 serves to detect a temperature. The voltage changing circuit 16 constitutes a correcting means.

[0029]

As described above, according to the present invention, it is determined whether to control the amount of flash light emitted to the outside of the electronic flash device based on the set output of the external operation member. The flash photography can be performed without adjusting the irradiation light amount, and the flash photography intended by the photographer can be performed according to the shooting scene. Further, by comparing the response time of the light amount control means and the time from the shooting preparation state of the camera to the start of shooting, it is determined whether or not to control the emission light amount of the flash light to the outside of the electronic flash device. Even if a light amount control means such as a liquid crystal or ECD having a long response time is used, flash photography can be performed at a high shutter speed. Furthermore, based on the type of camera to which the electronic flash device is attached, it is determined whether or not to control the emitted light amount of the flash light to the outside of the electronic flash device. It is possible to prevent an erroneous operation such as performing flash photography as it is when mounted.

[Brief description of drawings]

FIG. 1 is a diagram for responding to a complaint.

FIG. 2 is a block diagram showing the configuration of an embodiment.

FIG. 3 is a sectional view of a split irradiation type flash device according to the present invention.

FIG. 4 is a flow chart showing an irradiation light amount adjusting operation.

FIG. 5 is a time chart showing timings of preliminary light emission, main light emission, and irradiation light amount adjustment control.

FIG. 6 is a circuit diagram of an irradiation light amount adjustment control unit.

FIG. 7 is an external view of a split irradiation type flash device mounted on a camera.

FIG. 8 is a circuit diagram of a light emitting unit.

FIG. 9 is a view showing an emitted light amount adjusting member.

FIG. 10 is a diagram illustrating a light amount adjustment principle when a twisted nematic liquid crystal is used for an emission light amount adjustment member.

FIG. 11 is a diagram illustrating a light amount adjustment principle when a guest-host type liquid crystal is used as an emission light amount adjustment member.

FIG. 12 is a cross-sectional view when an ECD is used as an emission light amount adjustment member.

FIG. 13 is a diagram showing a control circuit when an ECD is used.

FIG. 14 is a diagram showing a case where a plurality of subjects having different distances are present on the shooting screen.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 selection unit 2 split irradiation type flash device 3 camera 4 automatic selection unit 5 measurement unit 6 discrimination unit 7,8 microcomputer (CPU) 9 light emission drive circuit 10 light emission tube 10a preliminary light emission tube 10b main light emission tube 11 light measurement unit 12 power supply 13 Divided irradiation light amount calculation unit 13a Memory 14 Emission light amount adjustment unit 14a Emission light amount adjustment member 14b to 14j Thyristor 15 Temperature detection unit 16 Voltage change circuit 21 Reflector 22 Fresnel lens 23, 71 Switch 30 Cable 31 Selection member 32 Irradiation light amount adjustment execution lamp 33 Booster circuit 34, 35 Condenser 36, 38, 40 Terminal 37 Preliminary light emission drive circuit 39 Main light emission drive circuit 41, 51 Deflection plate 42, 44, 53, 54, 61, 65 Transparent electrode 43 Liquid crystal 45, 52 Light detection plate 55 2 Color dye 56 Liquid crystal molecule 62 EC layer 63, 64 Solid electrolyte layer 100, 100A Light emitting means 101, 101A, 101B Light intensity control means 102, 102A-102C Judging means 103 External operating member 104, 104A Photometric means 105 Temperature detecting means 106 Correcting means

Claims (7)

[Claims] 1. An electronic flash device provided with a light emitting means for emitting flash light, and a light quantity control means for controlling the quantity of light emitted from the electronic flash apparatus, and the quantity of light emitted from the flash light is controlled by the light quantity control means. An electronic flash device, comprising: a determination unit that determines whether or not to perform. 2. The electronic flash device according to claim 1, wherein the determination means makes a determination based on a set output of an external operation member that sets whether or not the light amount control means controls the emission light amount of the flash light. An electronic flash device characterized by: 3. The electronic flash device according to claim 1, wherein the determination unit makes a determination by comparing a response time of the light amount control unit with a time from a shooting preparation state of the camera to a shooting start. And electronic flash device. 4. The electronic flash device according to claim 1, wherein the determination unit makes a determination based on a type of a camera in which the electronic flash device is mounted. 5. The electronic flash device according to claim 1, wherein the light emitting means performs preliminary light emission and main light emission, and photometers reflected light from a subject during the preliminary light emission. An electronic flash device comprising: means for controlling the amount of light emitted from the flash device to the outside of the electronic flash device based on a photometric result of the photometric device during the main flash. 6. The electronic flash device according to claim 5, wherein the photometric means performs photometry for each photometric area obtained by dividing the object field into a plurality of areas, and the light amount control means is provided for the plurality of photometric means. The electronic flash device is characterized in that it has a plurality of emission areas corresponding to the respective photometric areas, and controls the emission light quantity of the flash light for each corresponding emission area based on the photometric results of the respective photometric areas. 7. The electronic flash device according to any one of claims 1 to 6, wherein temperature control means for detecting a temperature and control characteristics of the light quantity control means in accordance with the temperature detected by the temperature detection means are set. An electronic flash device, comprising: a correction means for correcting.