JPH0719017B2 - Flash photography device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a photometric means for photometrically measuring the brightness information of the field and a control means for exposure control using the photometric means, and a flash mode. The present invention relates to a flash image capturing device.

2. Description of the Related Art A conventional flash photographing device of this type is configured to monitor a flash emission amount corresponding to a subject condition by flash preliminary emission and perform exposure control so as to match the monitored flash emission amount. There is.

However, the conventional example has a problem that the operability is poor because the flash preliminary light emission operation must be performed prior to the shutter release operation.

Also, a configuration for determining and calculating an appropriate flash emission amount based on the flash preliminary emission becomes indispensable,
The configuration is complicated.

The present invention has been made in view of the above circumstances, and improves the operability of photography by controlling the light emission amount in real time rather than by the preliminary light emission of the flash, and simplifies the configuration. The purpose is to achieve

Means for Solving Problems The present invention has the following configuration in order to solve the above problems.

That is, according to the present invention, in a flash photographing apparatus provided with a photometric device that divides an object field into a plurality of areas for photometry, reflected light of a flash light from a subject is divided into a plurality of areas, and the result is obtained. It is characterized in that control is performed so that the flash emission is stopped when the maximum output of the output reaches a predetermined value.

Operation The operation of this configuration is as follows.

In the present invention, the flash emission is stopped when the integrated value of the photometric amount of the flash light reflected by the film reaches a predetermined level, but in order to control the emission amount, it is divided into a plurality of areas for photometric measurement. , The light emission amount is controlled by using the output from the maximum area of the photometric output from each area.

That is, in general, since the probability that the subject portion closest to the camera is the main subject to which the flash light is to be emitted is very high, the flash dimming level is determined by the information of the light receiving element having the maximum photometric output. Is preferable.

As described above, since the field of view is divided into a plurality of areas and the flash emission amount is controlled by the output from the area where the photometric output measured in the plurality of areas is maximum when the flash is fired, Regardless of where in the viewfinder field of view, regardless of this, the flash survey light will always be focused on the main subject.

Although the photometry of the object field is divided into a plurality of regions, the flash dimming is performed when the maximum of the plurality of photometric values reaches a predetermined value. Therefore, there is no need to perform discrimination and calculation based on the integral value in each area, and the configuration of the flash photographing device becomes simple.

In addition, since the calculation of the appropriate flash light emission amount is performed in real time in parallel with the shutter release operation, not in the flash preliminary light emission, the operability of photographing is improved as compared with the conventional example.

Embodiment Hereinafter, the present invention will be described in detail based on an embodiment shown in FIGS. 1 to 11.

1 and 2 are schematic configuration diagrams of a photometry and distance measuring system.

In the figure, (TL) is the taking lens, (M1) is the main mirror,
(M2) is a sub-mirror, (F) film, (SO) is a focusing screen, (PE) is a pentaprism, (SE) is an eyepiece,
(AF) is a focus detection system, (L) is a condenser lens, and (SP) is a multi-division light receiving element for photometry.

As shown in FIG. 3, this multi-divided light receiving element (SP) is composed of nine light receiving elements (SP _c1 ) to (SP _c9 ) in the vertical and horizontal directions.

Let's assume that you attach a flash to the camera body and take a picture of the completion of charging.

The light beam that has passed through the taking lens (TL) is split into a finder system and a photometric system by the main mirror (M1). Light rays to the finder system are observed through the reticle (SO), pentaprism (PE) and eyepiece (SE). The light beam that reaches the focusing screen (SO) enters the focus detection system (AF) and is used for distance measurement for autofocus. The light beam that has passed through the main mirror (M1) is diffused and reflected by the sub mirror (M2), passes through the condenser lens (L), and enters the multi-divided light receiving element (SP).

The aperture value Av and the shutter speed Tv are calculated based on the subject brightness Bv received by the multi-segment light receiving element (SP).

When the shutter is released, the aperture value Av and the shutter speed Tv immediately before that are locked, and the main mirror (M1) and the sub-mirror (M2) are raised as shown in FIG. The reflected light from F), that is, (natural light) + (flash light) is received by the multi-segment light receiving element (SP).

The flash emission is stopped when the amount of light received by the multi-segment light receiving element (SP) reaches a predetermined amount.

FIG. 4 is a block diagram of the flash photographing device.

In the figure, (1) is a microcomputer (hereinafter, referred to as a microcomputer) that controls the entire flash photographing apparatus, (2) is a lens ROM, (3) is a DX code reading unit,
(4) is an autofocus control unit, (5) is a photometry unit,
(6) is a flash, (7) is an exposure control unit, and (8) is a display unit.

(S ₁ ) is a photometric switch that is turned on at the first step of pressing down the shutter button, and (S ₂ ) is 2 when pressing down the shutter button.
The release switches (R ₁ ) and (R ₂ ) that turn on at the stage are pull-up resistors.

The photometric section (5) is provided with the multi-divided light receiving element (SP) of FIG. This multi-segment light receiving element (SP) is also related to the exposure control section (7). The auto focus control section (4) is provided with the focus detection system (AF) shown in FIG.

(R ₀ ), (C ₀ ) are resistors and capacitors that compose the power-on reset circuit, and when the power supply battery (9) is installed, the clear terminal (▲ ▼) of the microcomputer (1) is momentarily set to “L”.
It is a level. The microcomputer (1) is configured to execute the operation of the reset routine of steps # 1 to # 5 of FIG. 6 when the clear terminal (▲ ▼) momentarily becomes the “L” level. (AFE) is
This is a signal line that is in the “H” level when the autofocus control section (4) completes the autofocus and transmits the focus state to the microcomputer (1).

(Sx) turns on when the shutter is fully open and flashes (6)
This is a synchronized contact that starts the emission of light. (FS) is a signal line which outputs a flash emission stop signal to the flash (6) when the integrated value of the photometric amount reaches a predetermined value in the photometric section (5) and becomes "H" level.

FIG. 5 is a block circuit diagram of the photometric section (5).

(OP ₁ ) to (OP ₉ ) are head amplifiers, each of which is a light receiving element (SP _c1 ) of the multi-divided light receiving element (SP) shown in FIG.
~ (SP _c9 ) is connected. (D ₁ ) to (D ₉ ) are diodes for logarithmic compression connected to the negative feedback loops of the head amplifiers (OP ₁ ) to (OP ₉ ).

Each of the output terminals of the head amplifiers (OP ₁ ) to (OP ₉ ) is connected to the input terminal of the multiplexer (MPX).
Output terminal of multiplexer (MPX) is A / D conversion circuit (AD)
, And the output terminal of the A / D conversion circuit (AD) is connected to the subject brightness data input terminal of the microcomputer (1).

A / D conversion control terminal of the photometric switch (S ₁₎ on the response of the "H" level and becomes a microcomputer (1) is connected to a multiplexer (MPX) and A / D converter (AD). Subject brightness Bv from each light-receiving element (SP _c1 ) to (SP _c9 )
Data from _{1 to} Bv ₉ is sent through the sequential multiplexer (MPX) to A
It is configured such that it is input to the / D conversion circuit ((AD), A / D converted, and then input to the microcomputer (1).

The output terminal of each head amplifier _{(OP 1) ~ (OP 9} ) is connected to the positive input terminal of the operational amplifier _{(OP 11) ~ (OP 19} ) , a negative input of the operational amplifier _{(OP 11) ~ (OP 19} ) terminal is connected to the cathode of the diode _{(D 11) ~ (D 19} ), is connected to the output terminal of each diode (D ₁₁₎ ~ anodes each operational amplifier _{(D 19) (OP 11)} ~ (OP 19) There is. The cathodes of the diodes (D ₁₁ ) to (D ₁₉ ) are connected to each other, and the diodes (D ₁₁ ) to (D ₁₉ ) and the operational amplifier (OP ₁₁ ) are connected.
~ (OP ₁₉ ) form the maximum value output circuit (MAX).

The maximum value output circuit (MAX) itself is a known circuit. For example, when the output of the light receiving element (SP _c1 ) is larger than that of the other light receiving elements (SP _c2 ) to (SP _c9 ), the output of the maximum value output circuit (MAX) is the operational amplifier (OP ₁₁ ) and the diode (D ₁₁ ) output specified by other op amps (OP ₁₂ )
Since the level of the negative input terminal of ~ (OP ₁₉ ) becomes higher than the level of the positive input terminal, the operational amplifier (OP ₁₂ ) ~ (OP ₁₉ )
Output goes to "L" level and the diode (D ₁₂ ) ~
(D ₁₉ ) does not conduct. That is, only the diode (D ₁₁ ) is conductive, and only the circuit of the operational amplifier (OP ₁₁ ) and the diode (D ₁₁ ) corresponding to the light receiving element (SP _c1 ) having the maximum output is output.

The cathodes of the diodes (D ₁₁ ) to (D ₁₉ ) are connected to the base of a transistor (Tr) for logarithmic expansion. The maximum voltage of the output voltages of the light receiving elements (SP _c1 ) to (SP _c9 ) is input to the base of the transistor (Tr).

The collector of the transistor (Tr) is connected to the DC power source via the integrating capacitor (C), and its emitter is grounded. A normally closed analog switch (ASw) is connected between both ends of the integrating capacitor (C). The analog switch (ASw) is turned off by turning on the synchro contact (Sx).

The connection point between the integrating capacitor (C) and the collector of the transistor (Tr) is connected to one input terminal of the comparator (Cmp). The input terminal of the D / A conversion circuit (DA) is connected to the output terminal of the film sensitivity Sv data in the microcomputer (1), and the output terminal of the D / A conversion circuit (DA) is another input of the comparator (Cmp). It is connected to the terminal. The output terminal of the comparator (Cmp) is connected to the signal line (FS) that outputs the flash emission stop signal.

Operation Next, the operation of this embodiment will be described.

When the photometric switch (S ₁ ) is turned on in the first step of pressing down the shutter button, the microcomputer (1) is
The maximum aperture value Av _{0 and} other lens information are read from (2), and the film sensitivity Sv is read from the DX code reading unit (3).
Data is read, and further, the autofocus control unit (4) is driven to start autofocus, and information on whether or not the charging is completed is read from the flash (6).

Autofocus is performed by taking lens (TL), main mirror (M
1) It is performed based on the fact that light is received by the focus detection system (AF) through the focusing screen (SO).

The microcomputer (1) also supplies power to the head amplifiers (OP ₁ ) to (OP ₉ ) in response to the turning on of the photometric switch (S ₁ ), and also the multiplexer (MPX) and the A / D conversion circuit ( Output a start signal to AD).

As a result, the nine light receiving elements (SP _c1 ) to (SP _c9 ) of the multi-segment light receiving element (SP) pass through the taking lens (TL), the main mirror (M1), the sub mirror (M2), and the condenser lens (L). The data of the received subject brightness Bv _{1 to} Bv ₉ is received by the multiplexer (MP
X) are sequentially input to the A / D conversion circuit (AD), converted into digital signals, and sequentially input to the microcomputer (1).

The microcomputer (1) calculates the aperture value Av and the shutter speed Tv based on the subject brightness Bv _{1 to} Bv ₉ input in one sampling period. This calculation will be described in detail later.

Then, the display unit (8) is driven to display the calculation result.

When the lens reaches the in-focus position under the control of the autofocus control unit (4), the autofocus control unit (4)
Outputs a focus detection signal from the microcomputer (1) via the signal line (AFE). Then, the microcomputer (1) outputs a stop signal to the lens motor driver in the autofocus control section (4) to fix the lens at the in-focus position.

When the release switch (S ₂ ) is turned on by pressing the shutter button in the second step, the microcomputer (1) outputs a stop signal to the autofocus control section (4).
As a result, the autofocus function is stopped.

Next, the microcomputer (1) executes the correction calculation of the flash light amount. This correction calculation will be described later in detail.

When the release switch (S ₂ ) is turned on, the exposure control unit (7) starts the automatic diaphragm, and the diaphragm is fixed when the diaphragm reaches the diaphragm amount corresponding to the diaphragm value Av.

On the other hand, the main mirror (M1) is interlocked with the second-step depression of the shutter button for turning on the release switch (S ₂ ).
And the sub-mirror (M2) is raised, and the front curtain of the shutter starts running. When the running of the first curtain is completed, the synchro contact (Sx) is turned on, and the analog switch (ASw) that was on until then is turned off.

After the mirror is raised, the subject light incident on the multi-segment light receiving element (SP) becomes reflected light from the film (F).

Nine subject brightness from the multi-divided light receiving element (SP) Bv ₁ ~Bv ₉
The maximum brightness output circuit (MAX) outputs the data signal of the maximum brightness Bv _max among these, and the transistor (Tr) is driven by this signal, but the analog switch (AS
When w) is on, the integration capacitor (C) is not being charged.

Integration capacitor (C) from the moment the synchro contact (Sx) turns on and the analog switch (ASw) turns off
Charging is started, and charges are accumulated in the integrating capacitor (C) at a speed corresponding to the maximum brightness Bv _max .

The comparator (Cmp) already has a microcomputer (1) to D
An analog voltage corresponding to the corrected (Sv−ΔAv) data is applied via the / A conversion circuit (DA). The corrected (Sv-ΔAv) data will be described later (8th
Step S3 in the figure).

Therefore, when the charging voltage of the integrating capacitor (C) reaches the analog voltage as the reference, the output of the comparator (Cmp) is inverted and the flash emission stop signal is output to the flash (6) via the signal line (FS). The flash emission is stopped.

The timer count is started in association with the start of the running of the front curtain, and when the count value reaches a value corresponding to the shutter speed Tv, the rear curtain runs and the photographing ends.

Next, detailed operation will be described with reference to FIGS. 6 to 8.

FIG. 6 shows a flowchart from battery mounting to flash light control and exposure control.

Initialization is performed in step # 1, and it is determined in step # 2 whether or not the photometric switch (S ₁ ) that is turned on by pressing down the first shutter button is turned on. If it is off, the process proceeds to step # 3, the photometry is stopped, the autofocus is stopped in step # 4, and the step #
At 5, the various displays are turned off.

If it is determined in step # 2 that the photometric switch (S ₁ ) is on, the process proceeds to step # 6 to start photometry.

Next, at step # 7, the lens information, that is, the maximum aperture value Av ₀
Read, and in step # 8 DX code or film sensitivity
Read Sv.

Autofocus in step # 9, then step # 10
The flash information, that is, the charging completion signal is read with.

Step nine light receiving elements # Maybe 11 constituting the split light-receiving element (SP) (SP _c1) ~ object brightness by (SP _c9) Bv ₁ ~Bv ₉
In step # 12, the aperture value Av and the shutter speed Tv are calculated before the flash light is emitted (step 7).
See figure ... later).

In step # 13, the exposure control information such as the aperture value Av and the shutter speed Tv calculated above and other information are displayed.

Next, in step # 14, it is determined whether or not the release switch (S ₂ ) which is turned on by pressing the second shutter button is turned on. If it is turned on, the process proceeds to step # 15, the autofocus is stopped, and the correction calculation of the flash emission amount is executed in step # 16 (see FIG. 8; described later).

Then, in step # 17, the exposure is controlled. This exposure control is performed based on the aperture value Av and the shutter speed Tv calculated in step # 12.

On the other hand, in the determination of step # 14, if the release switch (S ₂ ) is off, the process immediately proceeds to step # 18,
Determine if the metering switch (S ₁ ) is on.

If the photometric switch (S ₁ ) remains on, the process returns to step # 17 to repeat a series of operations for exposure control (steps # 7 to # 17). If the photometric switch (S ₁ ) is off, the process returns to step # 2.

FIG. 7 is a flowchart of the calculation of the aperture value Av and the shutter speed Tv executed in step # 12.

The step determines if the flash is fully charged. In the case of the flash mode, it is determined that charging is completed, and the process proceeds to step. In step, the maximum brightness Bv _max and the minimum brightness Bv _min of the object brightness Bv _{1 to} Bv ₉ by the nine light receiving elements (SP _c1 ) to (SP _c9 ) read in step # 11 are detected. The subject brightnesses Bv _{1 to} Bv ₉ are for the light reflected by the sub mirror (M2).

Next, in step, a difference between the maximum brightness Bv _max and the minimum brightness Bv _min is calculated, and it is determined whether the difference 8 (Bv _max −Bv _min ) is larger than a predetermined value α.

The predetermined value α is an arbitrary positive value. The predetermined value α varies depending on the number of divisions of the multi-divided light receiving element (SP) and the like, but normally, about 2 to 4 is suitable.

The maximum brightness Bv _max is a constant value k (eg, k = 11).
If it is above, it is determined that sunlight has entered, and Bv _max = k is limited so that the main subject is not underexposed.

If (Bv _max −Bv _min )> α in the judgment of the step,
The shooting conditions are supposed to be daytime synchronization and backlight. That is, this is the case when there are many sky and clouds in the finder field of view.

In such cases, the step decides to use the maximum brightness Bv _max as the highlight criterion. When the shift amount from the highlight reference to the normal reference is W, if the exposure value Ev is calculated using the maximum brightness Bv _max , then Ev = (Bv _max −W) + Sv. This makes it possible to express high brightness as if it were high brightness even when there are many sky and clouds in the viewfinder field.

The value of the shift amount W usually changes depending on the latitude of the film (F) and the number of divisions of the multi-divided light receiving element (SP), but about 1.5 to 3 is appropriate, and this value can be determined based on the measurement results. Good.

Nine light receiving elements (SP _c1 ) read in step # 11 ~
In the subject brightness Bv _{1 to} Bv ₉ according to (SP _c9 ), when the difference between the maximum brightness Bv _max and the minimum brightness Bv _min is small, that is,
If (Bv _max −Bv _min ) ≦ α in the judgment of the step,
Without much difference between exposed controlled using nine which luminance of the subject luminance Bv ₁ to BV _9, in this embodiment, for the sake of more accurate, their nine subject luminance Bv ₁ to BV ₉ Average value
I am using Bv _mean . The average value Bv _mean is Is.

That is, when (Bv _max −Bv _min ) ≦ α, the process proceeds to step, and it is determined to use the average value Bv _mean as the normal reference, and the exposure value Ev is calculated. That is, Ev = Bv _mean + Sv.

After the exposure value Ev is calculated in step or step, the process moves to step and the aperture value Av is calculated based on Av = Ev-Tv.

When (Bv _max −Bv _min )> α, Av = (Bv _max −W) + Sv−Tv _x , and when (Bv _max −Bv _min ) ≦ α, Av = Bv _mean + Sv−Tv _x .

However, when the calculated aperture value Av becomes smaller than the maximum aperture value Av ₀ (Av <Av _o ), Av = Av _o is set. Further, when the calculated aperture value Av becomes larger than the predetermined aperture value Av _x (Av ≧ Av _x ), Av = Av _x is set. That is,
If the calculated aperture value Av becomes too large (small aperture), the amount of flash light reaching the film (F) becomes too small, so a certain limit is set. Predetermined aperture value Av
_About 6 to 8 is usually suitable as the value of _x .

Shutter speed Tv _x is flash sync speed, 1/60 to 1
When / 250 (seconds) can be selected, (Bv _max −Bv _min )> α
If the shutter speed is 1/250, then (Bv _max −Bv _min ) ≦
In the case of α, it is possible to selectively use the shutter speed of 1/60.

With the above routine, the aperture value in flash mode
Av and shutter speed Tv _x are determined. Then, in step # 17 of FIG. 6, the aperture value Av and the shutter speed are
Exposure control is performed based on Tv.

On the other hand, in the judgment of the step, in the case of the natural light metering mode, since the flash is not charged, the step moves to the step. In step, the shutter speed Tv and the aperture value Av in the natural light metering mode are calculated based on a known arithmetic expression.

In this case, the subject brightness may be based on spot photometry or average photometry.

After the step or steps, the process proceeds to the step and it is determined whether or not the autofocus is completed. If autofocus is not completed, move to step and set the subject brightness Bv ₅ from the light receiving element (SP _c5 ) in the center including the distance measuring section (focus detection sensitivity area) to the flash light amount control register (Bv _FL ). Store.

Central object brightness Bv stored in this register (Bv _FL )
₅ is sequentially updated until autofocus is completed or shutter release is performed.

When the auto focus is completed, the step operation is not executed. That is, the central object brightness Bv ₅ at the completion of autofocus is set to the object brightness Bv ₅ for flash light amount control.
Lock as _FL (Bv ₅ ). This is because it is possible to determine that the central subject at the completion of autofocus is the main subject.

In addition, step or step #
Move to 13.

FIG. 8 is a flowchart of the correction calculation of the flash emission amount in step # 16 of FIG.

Subject luminance Bv _FL for flash light amount control, the a subject luminance Bv ₅ by the central light receiving element (SP _c5) as this is assumed luminance of the main object in the case of natural light alone.

Therefore, in step S1, the subject aperture Bv _FL (= Bv ₅ ) for flash light amount control is used to calculate an appropriate aperture value Av ′ when only natural light is used. This aperture value Av ′ is calculated based on Av ′ = Bv _FL + Sv−Tv _x .

In the next step S2, the difference ΔAv between the aperture value Av in flash mode and the appropriate aperture value Av ′ when only natural light is used.
Is calculated by ΔAv = Av−Av ′.

FIG. 9 shows the relationship between the flash emission intensity and time.
The flash emission amount is the integral of the characteristic curve. If the light emission stop time is advanced, the flash light emission amount is reduced accordingly.

FIG. 9A shows an appropriate exposure amount H when exposed with only natural light, that is, with the brightness Bv _{FL of the} main subject, the shutter speed Tv _x , and the aperture value Av ′.

In the following description, the aperture value Av when the flash fires
Is on the smaller aperture side than the aperture value Av ′ according to the brightness of the main subject.

FIG. 9B shows the relationship of the exposure amount when there is no natural light and a flash is emitted.

Since the aperture value at the time of flash emission is Av, in the conventional case, the emission was stopped when the exposure amount became H _N.

In this embodiment, since the found proper exposure amount H of the main subject, the aperture value ΔAv = Av-Av 'amount corresponding correction so that the exposure amount of the flash increases the difference (+ H _F correction), and light emission stop Control the time of day.

In this figure, H _N + H _F = H.

FIG. 9 (C) shows the relationship between the amounts of exposure due to natural light and flash emission.

The exposure amount of natural light at the aperture value Av is H _S. The normal light emission amount H _N at the aperture value Av is added with the correction amount H _F for ΔAv, and the total exposure amount is controlled to be the proper exposure amount H (H = H _S + H _N
+ H _F).

That may be controlled to flash light emission amount so that the amount of exposure by flash is H-H _S. Here, H-H _S
Corresponds to the aperture value ΔAv of the difference. Therefore, instead of controlling the flash emission amount based on the film sensitivity Sv data, the flash emission amount is calculated based on the apparent film sensitivity (Sv-ΔAv) data obtained by subtracting the difference aperture value ΔAv from the film sensitivity Sv. It should be controlled.

For the above reason, in the flash emission amount control circuit, the time from the moment the sync contact (Sx) is turned on and the flash (6) starts emitting light until it stops emitting light,
That is, the film sensitivity Sv of the data for controlling the flash emission amount is calculated as (Sv-ΔAv) in step S3.
Correct to.

The corrected (Sv-ΔAv) data is output from the microcomputer (1) to the D / A conversion circuit (DA) shown in FIG.

By the way, when the integrated value of the photometric amount of (natural light) + (flash light) reflected by the film (F) reaches a predetermined level, the flash emission is stopped. Light receiving element (SP _c1 ) to (S
Use the photometric value of the light receiving element with the largest integral value in P _c9 ).

That is, in general, the probability that the subject part closest to the camera is the main subject to which the flash light is to be emitted is very high. Therefore, the flash dimming level is determined based on the information of the light receiving element with the largest integral value. It is preferable to do so.

Fig. 10 shows a multi-segmented light receiving element (SP) at the same time as flash emission.
An example of the state of the integrated value of the amount of light incident on is shown.

In this case, flash dimming is performed by the photometric value of the light receiving element (SP _c1 ) having the maximum integrated value (corresponding to the maximum brightness Bv _max ). That is, this photometric value is integrated by the integrating capacitor (C).

In this embodiment, the subject luminance Bv ₅ of the light-receiving element of the center at the time of auto-focusing completion (SP _c5) as a subject luminance Bv _FL for flash light amount control, proper in the case of the natural light alone on the basis of the subject brightness Bv _FL was calculated Do aperture value Av ', the present invention is subject luminance Bv _L that AE lock in addition to this
An example is also included in which an appropriate aperture value Av ′ is calculated when natural light is used alone based on

Such an embodiment will be described based on the flowchart shown in FIG.

The subject brightness is AE locked by placing the main subject in the center of the screen, for example, in the light receiving area of the central light receiving element (SP _c5 ), locking the photometric value, and then changing the composition of the shooting to set the main subject to the light receiving element ( This is the case where the shutter is released while it is out of the light receiving area of SP _c5 ). AE lock not shown
It is performed based on the manual operation of the AE lock operation button.

This AE lock corresponds to the photometric value of the light receiving element (SP _c5 ) when the AE lock signal corresponding to the above manual operation is output.
This is performed based on storing the output value of the A / D conversion circuit (AD) in a predetermined register.

Further, as the subject brightness Bv _L to be AE locked, the subject brightness in a single-area photometric system (spot photometry or center-weighted photometry) may be AE-locked instead of the multi-segment photodetector (SP).

In step ST1, it is determined whether the AE lock signal is output. If AE locked, step ST2
Then, the AE-locked subject brightness Bv _L is stored in the register (Bv _FL ) for storing the flash brightness control subject brightness Bv _FL (Bv _FL = Bv _L ).

If the AE lock signal is not output in the judgment of step ST1, the process proceeds to step ST3, and the present time (latest)
The subject brightness Bv of is stored in the register (Bv _FL ) (Bv _FL
= Bv).

The routine of steps ST1 to ST3 is the step of FIG.
Is an alternative to.

Also, the subject brightness Bv _FL for controlling the flash light amount
The correction calculation of the flash emission amount based on is also performed in the same manner as the flow of FIG.

When shooting with the AE locked in this way, it is possible to perform flash light control that includes the photographer's intention.

The present invention also includes embodiments having the following configurations.

(A) In the above embodiment, the multi-segment light receiving element (SP) was composed of nine vertical and horizontal light receiving elements (SP _c1 ) to (SP _c9 ), but as shown in FIG. Element (SP ₁ )
A circular light receiving element (SP _c10 ) in the center including the distance measuring section,
You may comprise from the light receiving element ( _SPc11 ) of the circumference.

In this case, as the average value Bv _mean in the step of FIG. 7, the subject brightness Bv of both light receiving elements (SPC ₁₀ ) and (SPC ₁₁ )
The average value of ₁₀ and Bv ₁₁ (Bv ₁₀ + Bv ₁₁ ) / 2 is used.

When the AE-locked subject brightness Bv _L is used as the subject brightness Bv _FL for flash light amount control, the AE-locked subject brightness Bv _{L is set} as the center light-receiving element (SPc
The subject brightness Bv ₁₀ of ₁₀ ) is used (Bv _FL = Bv _L = Bv ₁₀ ).

However, the aperture value Av and the shutter speed Tv during flash emission are determined based on the subject brightness immediately before the release switch (S ₂ ) is turned on.

(B) The multi-segment light receiving element (SP ₂ ) in FIG. 13 is a circular light receiving element (SPc ₁₂ ) in the center including the distance measuring section, and four light receiving elements (SPc ₁₃ ) to (SPc ₁₆ ) around it. It consists of

In this case, the seventh average value Bv _mean in view of the step, the average value of the subject luminance Bv ₁₂ to BV ₁₆ of all the photodetectors _{(SPC 12) ~ (SPC 16} ) To use.

When the AE-locked subject brightness Bv _L is used as the subject brightness Bv _FL for flash light amount control, the AE-locked subject brightness Bv _{L is set} as the center light-receiving element (SPc
The subject brightness Bv ₁₂ of ₁₂ ) is used (Bv _FL = Bv _L = Bv ₁₂ ).

(C) FIG. 14 is a schematic configuration diagram of a photometry and distance measuring system different from those of FIGS. 1 and 2. In the case of FIG. 1 and FIG. 2, in order to measure the subject brightness necessary for the calculation of the aperture value Av and the shutter speed Tv performed before the flash emission, and for the control of the flash emission amount performed during the flash emission. The necessary photometry is performed by the common multi-divided light receiving element (SP), but these photometry may be performed by different light receiving elements. The flash photographing device shown in FIG. 14 is configured in this way.

In the figure, (L1) is a condenser lens for photometry, (P1) is a light receiving element, and even if it is a multi-divided light receiving element as shown in FIG. 3, FIG. 12 or FIG. It may be one light receiving element. When performing multi-division photometry on the object field before flash emission, a multi-division photo detector is used as the photo detector (P1). This light receiving element (P1) is in the finder system.

(P2) is a multi-divided light receiving element as shown in FIG. 3, FIG. 12 or FIG. This multi-divided light receiving element (P2) is used during flash dimming. (L2) is a condenser lens, (HM) is a half mirror, and (M3) is an auxiliary mirror.

When a multi-divided light receiving element is used as the light receiving element (P1), steps from FIG. 7 to step S1 in FIG.
Steps S3 to S3 are executed based on the photometry in the multi-division light receiving element (P1), and the timing control for stopping the flash emission is executed based on the photometry in the multi-division light receiving element (P2).

(D) Particularly important, the point of the present invention is
It is divided into a plurality of areas to perform photometry, and the timing for stopping the flash emission is determined based on the maximum value of the integrated values of the reflected light. The correction calculation of the flash emission amount in FIG. Not necessarily required.

If daytime synchronization or backlighting does not matter, there is no need to use the configuration shown in FIG. That is, the steps, ... Of FIG. 7 may be omitted. Therefore, as the light receiving element (P1) in FIG. 1, a single light receiving element may be used instead of the multi-divided light receiving element.

FIG. 15 is another flowchart of the calculation of the aperture value Av and the shutter speed Tv executed in step # 12 of FIG. 6, and corresponds to FIG. 7 described above. Steps common to those in FIG. 7 are designated by the same reference numerals, and only different step portions will be described here.

When the completion of charging is determined by the step, the maximum brightness Bv _max of the subject brightness Bv _{1 to} Bv ₉ is determined by the step.
Is detected. Then the maximum brightness Bv in the step
Calculate the difference between _max and Bv _FL (the brightness of the center subject when autofocus is completed or not completed) calculated in step 1 above, and check whether the difference (Bv _max −Bv _FL ) is greater than the specified value α. Determine whether

This is to determine whether the shooting condition is backlight.

In general, the center subject at the completion of autofocus has a very high probability of being the main subject. In addition, the backlight means that there is a partial image having a higher brightness than the main subject within the shooting angle of view.

Therefore, in this modification, by calculating the difference between the maximum brightness Bv _max and the main subject brightness Bv _{FL in the} center and determining whether the difference (Bv _max −Bv _FL ) is larger than a predetermined value α, The backlight condition can be detected more accurately.

Effects According to the present invention, the following effects are exhibited.

Generally, since the probability that the subject portion closest to the camera is the main subject to which the flash light is to be emitted is very high, the flash dimming level is determined based on the information of the light receiving element having the largest integral value. Is preferred.

When the integrated value of the photometric amount of the flash light reflected by the film reaches a predetermined level, the flash emission is stopped. The maximum value of the integrated light values is detected and the maximum value is used for controlling the light emission amount.

That is, since the flash emission amount is controlled by the maximum value of the reflected light integrated values measured in a plurality of areas during flash emission, regardless of the position of the main subject in the viewfinder field, this is irrelevant. , It is possible to always carry out flash dimming with a focus on the main subject.

Although the photometry of the object field is divided into a plurality of regions, flash dimming is performed based on only the maximum value of the integrated values, so individual flash dimming is performed. Since it is not necessary to perform discrimination and calculation based on the integral value in the area, the configuration of the flash photographing device can be simplified.

Moreover, since the calculation of the appropriate flash light emission amount is performed in real time in parallel with the shutter release operation, not in the flash preliminary light emission, the operability of photographing can be improved as compared with the conventional example.

[Brief description of drawings]

1 to 10 relate to an embodiment of the present invention, FIGS. 1 and 2 are schematic configuration diagrams of a photometry and distance measuring system in a flash photographing apparatus, and FIG. 3 is a configuration diagram of a multi-divided light receiving element. FIG. 4 is a block diagram of a flash photographing device, FIG. 5 is a block circuit diagram of a photometry unit, FIG. 6 is a flowchart from battery mounting to flash dimming and exposure control, and FIG. 7 is performed before flash emission. FIG. 8 is a flow chart for calculation of aperture value and shutter speed, FIG. 8 is a flow chart for calculation of correction of flash emission amount, FIG. 9 is a characteristic diagram for explaining flash emission amount, and FIG. FIG. 11 is a characteristic diagram showing an example of the integrated value of the amount of light incident on the device, and FIG. 11 relates to another embodiment.
Flowchart for calculating an appropriate aperture value when natural light alone is used based on the locked subject brightness, Figs. 12 and 13 are configuration diagrams of different multi-divided photodetectors, and Fig. 14 is FIG. 15 is a schematic configuration diagram of a photometry and distance measuring system according to still another embodiment, and FIG. 15 is a flow chart for further calculation of another aperture value and shutter speed. (1) ... Microcomputer (2) ... Lens ROM (3) ... DX code reading section (4) ... Autofocus control section (5) ... Photometry section (6) ... Flash (7) ... Exposure control section (SP) ... Many Split light receiving element (SP1) ... Multi-split light receiving element (P2) ... Light receiving element (S ₁ ) ... Metering start switch (S ₂ ) ... Release switch (Sx)… Sync contact (MAX)… Maximum value output circuit (Tr ₂ )… Logarithmic expansion transistor (C)… Integrating capacitor (AD)… A / D conversion circuit (Cmp) ... Comparator (MPX) ... Multiplexer (DA) ... D / A conversion circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Nakai, 2-30 Azuchi-cho, Higashi-ku, Osaka-shi, Osaka, Osaka, Osaka International Building Minolta Camera Co., Ltd. (72) Nobuyuki Taniguchi 2-chome, Azuchi-cho, Higashi-ku, Osaka-shi, Osaka No. 30 Osaka Osaka International Building Minorta Camera Co., Ltd. Examiner Norimasa Ohbuchi (56) References JP-A-55-135823 (JP, A)

Claims (2)

[Claims] 1. A flash photographing apparatus equipped with a photometric device for dividing a field into a plurality of areas for photometry, and measuring reflected light of a flash light from a subject by dividing the photometry into the plurality of areas. The flash photographing device is characterized in that control is performed so that the flash emission is stopped when the maximum output among the outputs reaches a predetermined value. 2. The control according to claim 1, wherein the output obtained from each photometry region is integrated from the region where the output is maximum, and the flash emission is stopped when the integrated value reaches a predetermined value. The flash photographing device according to item 1.