JP2599835Y2 - Electronic flash device - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to an electronic flash device,
More particularly, the present invention relates to an electronic flash device having a function of continuously emitting light over the entire opening time of a shutter of a camera, that is, a so-called FP (focal plane) light emitting function.

[0002]

2. Description of the Related Art Conventionally, in an electronic flash device or a strobe device, in a well-known operation mode such as TTL light control, external automatic light control, and manual light control, a front curtain of a shutter is fully opened and a rear curtain runs. Single light emission is performed in a state where the shutter has not been started, that is, in a state where the shutter is fully opened, and the amount of light emission is adjusted by changing the duration of light emission during such a fully open time.

However, recently, so-called FP light emission has been introduced so that tuning can be performed even when the shutter speed is higher. In this FP emission, the electronic flash device repeatedly emits light at high speed and continuously during the so-called slit sync, in which the front curtain of the shutter starts running and the rear curtain subsequently runs thereafter.

FIG. 5 shows the relationship between the movement of the front curtain and the rear curtain of the shutter and the light emission waveform when performing the above-described single emission. In FIG. 5, for example, in a 35 mm vertically running camera, the front curtain and the rear curtain move 24 mm between A and B. Then, the shutter button (not shown) of the camera
When is pressed, the leading curtain starts running at time t0,
When the operation reaches B, that is, at time t2, the shutter curtain is fully opened. In this state, the X contact is closed, and at time t2
Then, the electronic flash device starts emitting light. The second curtain is fully open (t
Starting from time t3 according to the settings of (2) to (t4) and reaching B at time t5, the shutter curtain closes and the exposure of the film surface ends. As described above, in the single light emission, light emission is performed only once, for example, with the shutter curtain fully opened.

FIG. 6 shows the movement of the front curtain and the rear curtain at the time of high-speed shutter, and the emission waveform of FP emission. That is, when the shutter button of the camera (not shown) is first pressed, at time t0, the front curtain starts running, the X contact is closed in synchronization with the opening of the shutter curtain, and light emission starts. Immediately after the leading curtain starts moving, at time t1, the trailing curtain also starts moving. In this state, the slit formed by the front curtain and the rear curtain moves on the film surface at high speed. When the leading curtain reaches B at time t4 and the trailing curtain also reaches B at time t5, the shutter curtain closes. As described above, while the shutter is running in the slit, the electronic flash device continuously emits light at high speed at least until time t5. The operation of the FP light emission makes it possible to use the electronic flash device even at the time of high-speed shutter.

[0006]

However, in the FP light emission operation as described above, if the light emission of the electronic flash device is terminated while the shutter curtain is performing slit synchronization, there is a disadvantage that exposure unevenness occurs. is there. For example, as shown in FIG. 7, if the emission of the electronic flash device is stopped around the time t4, for example, while the leading curtain and the trailing curtain are running synchronously, the electronic flash is emitted between the times t4 and t5. Since a bright image illuminated by the device is not exposed on the film surface, exposure unevenness occurs.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional device, and in the electronic flash device using the slit synchro and the continuous light emission, the light emission is stopped during the slit synchro. If
Alternatively, a warning may be displayed when there is a possibility that light emission may stop during slit synchronization due to setting of a shutter speed, and appropriate shooting may be performed using an electronic flash device even during a high-speed shutter. .

[0008]

According to the present invention, there is provided, in accordance with the present invention, an electronic flash device having a function of continuously emitting light over the entire shutter opening time of a camera. Comparing means for comparing the shutter open time at the set shutter speed with the time during which the electronic flash device can continuously emit light, and wherein the comparing means compares the shutter open time with the time during which the electronic flash device can continuously emit light. Warning display means for displaying a warning in advance when the event is detected.

[0009]

In the electronic flash device having the FP light emission function according to the above configuration, if the shutter opening time at the shutter speed of the camera set by the photographer is longer than the time during which the electronic flash device can continuously emit light, a warning is issued in advance. Is performed,
The photographer can set the shutter speed and the like again to perform shooting, and can perform shooting without failure using FP emission even during high-speed shutter.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of a camera system including an electronic flash device as a reference example of the present invention. The system of FIG.
The camera includes a camera 1 and an electronic flash device 2 connected to the camera 1. It is clear that the camera 1 and the electronic flash device 2 may be integrated or may be separate units.

The camera 1 has functions necessary for photographing, including a shutter button (not shown), and has a function of giving a trigger timing for FP emission to the electronic flash device 2 in response to pressing of the shutter button. It is assumed that Further, the camera 1 has a trailing curtain end detecting means 3 for detecting that the trailing curtain of the shutter has finished traveling, and a camera interface 4 for connecting to the electronic flash device 2 of the camera 1.
And

The electronic flash device 2 comprises a control means 6 constituted by a microprocessor, for example, and a camera 1
An electronic flash device interface 5 for connecting the electronic flash device 2 to the electronic flash device 2, a light emission mode setting means 7, a light emission detection means 8, a warning display means 9, and a light emission means 10 are provided. The control means 6 receives the information on the end of the second curtain from the camera 1 and the information from the light emission mode setting means 7 and the light emission detection means 8 via the lines L3, L4 and L5, respectively. 9 through a line L6.

The light emission mode setting means 7 sets FP light emission for performing continuous light emission over the entire opening time of the shutter, or sets normal single light emission, and is constituted by, for example, a push button switch or the like. When the FP light emission mode is set by the light emission mode setting means 7, the light emission detection means 8 emits light when the rear curtain end detection means 3 of the camera 1 detects that the rear curtain has ended. This is for detecting whether or not the power supply is turned on, and is constituted by, for example, a photodiode. The warning display means 1
A warning is displayed when the light emission detecting means 8 does not emit light when the second curtain is completed, and may be constituted by, for example, a light emitting diode, a buzzer or the like. When the single light emission is set by the light emission mode setting means 7, no warning is issued by the warning display means 9.

Next, the operation of the camera system of FIG. 1 will be described with reference to the flowchart of FIG. The flowchart of FIG. 2 shows a subroutine for a warning display operation performed by the control means 6 of the electronic flash device 2 in the system of FIG. This subroutine, for example, in the camera system,
The process is entered from a predetermined main routine that is executed after a shutter button (not shown) is pressed to perform photographing using the electronic flash device.

In this subroutine, first, the process starts with START in step S1, and in step S2, the control means 6 controls the light emission mode setting means 7 via the line L4.
Is determined to be single emission or FP emission. If it is a single light emission, the process proceeds to step S3 of the normal light emission processing (Norm). In step S3, the warning flag is set to zero, and then the process proceeds to RETURN in step S8, and returns to the main routine. The warning display means 9 is configured to operate according to the warning flag, and does not issue any warning in this case.

On the other hand, if it is determined in step S2 that the mode is the FP light emission mode, the process proceeds to step S4. In step S4, it is determined whether or not the light emitting means 10 has started to emit light. If the light emitting means 10 emits light, the process proceeds to step S5 and the camera 1
It is determined whether or not the rear curtain of the shutter has started running and the rear curtain has finished running. This is the rear curtain detection means 3 of the camera 1
To line L1, camera interface 4, line L
2, the electronic flash device interface 5 of the electronic flash device 2,
And the information input through the line L3. The trailing end of the trailing curtain is determined to be finished when the traveling to B in FIGS. 6 and 7 is completed.

In step S5, the process waits for the trailing curtain to end, and then proceeds to step S6 to determine whether or not the light emitting means 10 emits light. That is, at time t5 in FIG. 6 or FIG. 7, it is detected whether or not the light emitting means 10 emits light based on the information from the light emission detecting means 8.
If the light is emitted, the process proceeds to step S3. If the light is not emitted, the process proceeds to step S7. In step S3, the warning flag of the warning display means 9 is set to zero via the line L6.
Move to 8 and return to the main routine. On the other hand, in step S7, the warning flag is set to 1 and the warning display means 9 is set.
After the warning display, the process returns to the main routine via step S8. As the warning display, a visual display using a light emitting diode or the like, an audio display using a buzzer or the like, or any other display can be used.

Therefore, in this configuration, when the light emission is completed while the shutter is performing the slit synchronizing operation by performing the FP light emission, a warning display is performed by the warning display means 9, so that the user can take a picture. Is found to have failed, and photographing is performed again to prevent the failure.

FIG. 3 shows the configuration of a camera system including the electronic flash device according to the present invention. The system shown in FIG. 1 includes a camera 11 and an electronic flash device 12. The camera 11 and the electronic flash device 12 may be integrated, or may be separate units. The camera 11 has a function necessary for photographing, similar to the camera 1 of FIG. 1, and generates a trigger timing for FP emission in response to pressing of a shutter button (not shown). 12 can be supplied. Further, the camera 11 includes a shutter speed setting unit 13 and a camera interface 14. The shutter speed setting means may be the same as that of the conventional camera, and instructs the camera 11 on a desired shutter speed. The camera interface 14 is an interface for exchanging information with the electronic flash device 12 via the line L8.

The electronic flash unit 12 includes a control unit 16, a light emission mode setting unit 17, a warning display unit 18, an electronic flash unit interface 14, and a light emission unit 19, which are the same as those in the reference example of FIG. The control means 6, the light emission mode setting means 7, the warning display means 9, the electronic flash device interface 5, and the electronic flash device 2 in the electronic flash device 2 of FIG.
The same as the light emitting means 10 may be used.

However, the camera system shown in FIG.
1 is different from the camera system of FIG. 1 in that the warning display means 9 provides a post-warning in the system of FIG. 1, whereas the system of FIG. 3 is necessary when the shutter speed is set in the FP emission mode. In that a warning is issued in advance according to That is, FP light emission is set by the light emission mode setting means 17, and FP light emission is set by the shutter speed setting means 13.
When the shutter speed corresponding to a time longer than the light emission possible time is set, the control means 16 sets the warning display means 1
8, a warning instruction is issued, and in response to this, the warning display means 17 is displayed.
Displays an advance warning. The light emission mode setting means 17
When the single-shot light emission is set, the warning display is not performed regardless of the setting of the shutter speed.

Next, the operation related to the warning display of the system of FIG. 3 will be described in detail with reference to the flowchart of FIG.
The flowchart in FIG. 4 is a subroutine for a process related to a warning display performed by the control unit 16 of the electronic flash device 12. This subroutine is executed, for example, when a desired shutter speed is set by the shutter speed setting means 13 of the camera 11 when photographing using the electronic flash device 12. First, the process starts with START in step S101, and in step S102, the control unit 1
6 is a single light emission mode based on the information input from the light emission mode setting means 16 via the line L10,
It is determined whether the mode is the light emission mode. If it is the single light emission mode, the process proceeds to step S103, the warning flag is set to zero, and then the process returns to the main routine via step S106. In this case, since the warning flag is zero, the warning display means 18 does not display a warning. The warning flag is constituted by a bit such as a memory or a register, and is provided in the control unit 16 or the warning display unit 18.

If it is determined in step S102 that the light emission mode is FP light emission, the control means 16 determines whether the shutter opening time at the shutter speed set in step S104 is longer than the light emission time capable of FP light emission. Is determined. This is because the information set by the shutter speed setting means 13 of the camera 11 is the line L
7. The shutter opening time is input to the control means 16 via the camera interface 14, the line L8, the electronic flash device interface 15, and the line L9, and obtained based on this information. The shutter opening time is compared with a preset FP emission time. Is done. If the shutter opening time corresponding to the set shutter speed is shorter than the FP light emission, the process proceeds to step S103, and if longer, the process proceeds to step S105.
The processing after step S103 is the same as described above, and the warning display means 18 returns to the main routine without displaying any warning. On the other hand, in step S105, the warning flag is set to 1, and in response to this, the warning display unit 18 displays a warning, and then returns to the main routine via step S106.

In this system, when performing slit synchronization with FP light emission, if the set shutter speed is inappropriate, a warning is issued to the photographer in advance. Therefore, the photographer can change the shutter speed, or, in some cases, change the setting from FP light emission to single light emission to perform photographing, thereby preventing photographing failure.

[0025]

As described above, according to the present invention, when the shutter opening time determined by the shutter speed is longer than the FP light emission time, the shutter speed is set or the shutter button is pressed. In this case, a warning is issued in advance, so that the photographer can prevent failure in photographing by changing the setting of the shutter speed or the light emission mode before photographing.

Therefore, according to the present invention, when the photographing is being performed at the photographing site, it is possible to recognize the failure of the photographing setting and restart the photographing. For this reason, the inconvenience of noticing the failure of photographing after returning from the photographing site and developing the film can be properly removed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a camera system including an electronic flash device according to a reference example of the present invention.

FIG. 2 is a flowchart showing an operation of the electronic flash device in the system of FIG.

FIG. 3 is a block diagram showing a configuration of a camera system including the electronic flash device according to the present invention.

FIG. 4 is a flowchart showing an operation of the electronic flash device in the camera system of FIG. 3;

FIG. 5 is an explanatory diagram showing a movement of a shutter curtain and a light emission waveform of single emission at the time of a low-speed shutter in a conventional electronic flash device.

FIG. 6 is an explanatory diagram illustrating movement of a shutter curtain and movement of a light emission waveform of FP light emission during a high-speed shutter.

FIG. 7 is an explanatory diagram showing a movement of a shutter curtain at the time of a high-speed shutter and a light emission waveform of FP light emission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Camera 2, 12 Electronic flash device 3 Rear curtain end detecting means 4, 14 Camera interface 5, 15 Electronic flash device interface 6, 16 Control means 7, 17 Emission mode setting means 8 Emission detection means 9, 18 Warning display means 10, 19 light emitting means 13 shutter speed setting means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Susumu Hagiuda 3-2-3 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation (56) References JP-A-61-190324 (JP, A) JP-A-56 -92530 (JP, A) JP-A-58-152230 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03B 15/05

Claims (1)

(57) [Scope of request for utility model registration] An electronic flash device having a function of performing continuous light emission over the entire shutter open time of a camera, wherein a shutter open time at a set shutter speed and a time during which the electronic flash device can continuously emit light are determined. Comparison means for comparing; and warning display means for performing a preliminary warning display when the comparison means detects that the shutter open time is longer than the time during which the electronic flash device can continuously emit light. An electronic flash device characterized by the above-mentioned.