JP2003084343A - Automatic exposure camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make beautifully photographable a night view as a background without spoiling the expression of a person to be photographed by restraining the glare of strobe light in the case of photographing the person with the night view for the background in an automatic exposure camera. SOLUTION: Whether or not the person is going to be photographed with the night view for the background, is judged (step S4) based on the result of night view judging processing (step S3) by a CPU 1. In the case of judging that a subject is going to be photographed with the night view for the background, the photographing mode of the camera is switched to a slow synchro photographing mode (step S10) so as to perform control to that a small quantity of strobe light may be emitted many times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic exposure camera (AE camera). More specifically, the present invention relates to an automatic exposure camera with a strobe that measures a focus position up to a subject based on an optical image formed by divided subject light fluxes, and performs focusing.

[0002]

2. Description of the Related Art Due to recent advances in electronics technology, the automation of cameras has advanced, and some strobes are built into the camera body and are capable of strobe emission by automatic control by the CPU inside the camera. Are known.

The strobe is used as an auxiliary light at the time of exposure, but when a camera with a strobe is used to take a photograph in which the background is far from the person who is the main subject. Although people could be exposed to strobe light, sufficient light did not reach the background, and the background as a whole had a dark background and a bad atmosphere. Therefore, Japanese Patent Laid-Open No. 12-1853
As the camera disclosed in Japanese Patent Publication No. 4, the distance between the main subject and the background is measured by the multi-AF, and when it is determined that the background is farther than the main subject, the light amount is calculated by using the slow sync photography. It has been proposed to supplement the exposure with exposure. Here, the slow sync photography is a technique for slowing the shutter speed when strobe light is emitted.

That is, if the camera disclosed in Japanese Patent Laid-Open No. 12-18534 is used, even if the background is far from the main subject, a strobe can be used to provide a background of sufficient brightness. You can shoot.

[0005]

However, in the camera disclosed in Japanese Patent Laid-Open No. 12-18534,
Since only the distance between the main subject and the background is checked by the multi-AF, slow sync photography is performed even when shooting a scene with a dark background. At this time,
When the main subject is illuminated, in the case of slow sync photography in which the shutter speed is slowed, the side effect of camera shake can be considered.

Further, when a conventional strobe is used for exposure as a scene with a dark background, especially when shooting a scene with a night view as the background, the beautiful illumination light is not reflected on the film, resulting in a failure photo. Often becomes. Further, when a person is photographed in a dark scene using a conventional strobe, sometimes the expression of the person as a subject is impaired due to too intense light from the strobe light.

The present invention has been made in view of the above circumstances, and when shooting a person against a night view, the glare of strobe light is suppressed so that the facial expression of the person is not impaired. It is an object of the present invention to provide an auto-exposure camera that can capture beautiful night views.

[0008]

To achieve the above object, an automatic exposure camera according to the present invention comprises a stroboscopic light emitting means for irradiating a subject with stroboscopic light, and a shutter control means for controlling the opening / closing time of a shutter. Image detecting means for detecting the image signal of the subject, computing means for computing information on focusing of the subject based on the image signal detected by the image detecting means, and focusing information computed by the computing means By means of focusing means for focusing on the subject, and based on the image signal detected by the image detecting means, switching control means for switching the stroboscopic light emission during the shutter control operation to a large number of times or one-shot light emission, It is characterized by including.

That is, according to the automatic exposure camera of the present invention,
It is possible to obtain an image signal of a subject by the image detection means, and switch the flash pattern of flash light emission to multiple flashes based on the result of focusing information based on the image signal to perform stroboscopic photography without glare.

In order to achieve the above object, the automatic exposure camera according to the present invention is an automatic exposure camera having a slow sync photographing mode setting means, wherein the slow sync mode photographing setting means sets the slow sync mode. It is characterized in that it comprises a light emission control means for changing the flash light emission to light emission with a small amount of light a plurality of times.

That is, according to the automatic exposure camera of the present invention,
In slow sync shooting mode, you can use flash photography that is not dazzling. In addition, since the flash is fired many times during the slow sync photography, it is possible to save time loss due to the flash firing many times.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS.

First, the structure of the automatic exposure camera according to the present embodiment will be described with reference to FIG. FIG. 2 is a block configuration diagram showing a main part of the configuration of the automatic exposure camera according to the present embodiment.

That is, the camera 100 includes a CPU 1 for performing various calculations such as night scene determination and operation control of the entire camera 100, and an interface IC 4 for outputting a control signal to each circuit based on a command from the CPU 1. An AF auxiliary light source 5 that emits auxiliary light for autofocus according to a control signal from the interface IC 4, and an AF auxiliary light optical system 6 for projecting the light emitted from the AF auxiliary light source 5 toward a subject. And an AF optical system 3 for collecting the light from the subject, and an AF for calculating the distance to the subject by the light collected by the AF optical system 3.
Distance measuring device 7 including IC2, AFIC2, AF optical system 3, AF auxiliary light source 5, and AF auxiliary light optical system 6
A motor 10 whose drive is controlled via the CPU 1 and the interface IC 4 based on the object distance measured by, and a focus adjusting optical system 9 in the photographing optical system 8 whose position is changed by the driving force of the motor 10. A drive amount detection circuit 11 for detecting the drive amount of the focus adjustment optical system 9 by the motor 10, a shutter 12, and a driver 13 for driving the shutter 12 under the control of the CPU 1.
And a strobe 14 used as auxiliary light at the time of exposure.

In a camera, the distance measuring device is often constructed as a unit, and accordingly, also in FIG. 2, the AFIC 2, AF optical system 3, AF auxiliary light source 5, AF auxiliary light optical system 6 are also shown. Although it is illustrated as the distance measuring device 7 including the above, the CPU 1 and the like built in the camera body 100 are functionally responsible for a part of the functions of the distance measuring device 7.

The AFIC 2 and the AF optical system 3 will be described with reference to FIG. FIG. 3A is a perspective view showing the configuration of the AFIC 2 in the distance measuring device 7, and FIG.
(B) is an exploded perspective view showing the configuration of the AF optical system 3.

That is, the AF optical system 3 includes the AFIC.
2 includes a light receiving lens 31 for condensing a subject image, and an AF housing 32 formed of a box-shaped member for holding the light receiving lens 31 and the AFIC 2 at a predetermined interval.

The light receiving lens 31 is a pair of light receiving lenses, that is, the left light receiving lens 31L and the right light receiving lens 31.
R and R are formed integrally with each other by a transparent material.

Further, the AF casing 32 is divided into a left chamber 35L and a right chamber 35R corresponding to the left-side light receiving lens 31L and the right-side light receiving lens 31R, respectively, by a partition wall 34 provided inside. Rectangular holes 33L and 33R are provided on the sides of the chambers 35L and 35R facing the light receiving lens 31.
However, the rectangular holes 36L and 3L are provided on the side facing the AFIC2.
6R is drilled, respectively. Also, these left ventricle 35
A structure portion 37 for preventing diffused reflection of light is formed on the inner wall surfaces of the L and the right chamber 35R.

The AFIC 2 is a main body 2 in which a light receiving portion 22 packaged in a transparent mold and a circuit for processing a signal output from the light receiving portion 22 are formed.
1 and a left photoelectric conversion element row 23L for photoelectrically converting light incident on the light receiving portion 22 through the left light receiving lens 31L and the right light receiving lens 31R. A right photoelectric conversion element row 23R is provided respectively, and a plurality of connection terminals 2 for outputting processed signals to the CPU 1 from the side portion of the main body portion 21.
4 is extended.

Next, the strobe 14 will be described with reference to FIG.

That is, the strobe 14 stores a capacitor 14a for storing electric charge that becomes energy for strobe light emission, a charging section 14b for charging and discharging the capacitor 14a, a xenon (Xe) tube 14c for emitting strobe light, and Xe
Trigger unit 1 for ionizing the Xe gas in the tube 14c
4d, and a thyristor 14e and a pulse switching unit 14f for controlling the stroboscopic light emission pattern.

The operation of the strobe 14 will now be described. First, the charging unit 14b starts charging the capacitor 14a according to a command from the CPU 1. After the charging is completed, when the photographer presses the second-stage pressing switch (not shown) of the two-stage pressing type, the high-voltage current charged in the capacitor 14a is transferred to the Xe tube 14 via the trigger portion 14d.
As a result, the Xe gas in the Xe tube 14c is ionized and discharge (strobe light emission) occurs.

Further, the Xe tube 14c has an O
A thyristor 14e for performing N / OFF is connected.
The control of the thyristor 14e is performed by the pulse switching unit 14f which is controlled by the port control of the CPU 1, and the light emission pattern of the strobe 14 is shown by the ON / OFF timing of the current in the Xe tube by the thyristor 14e. As shown in FIG. 1B, (a) strong light is emitted only once (hereinafter referred to as one-shot emission).
And (b) weak light can be switched to multiple emission (hereinafter, simply referred to as multiple emission).

The operation of the camera 100 having the above configuration is as follows.

That is, when the photographer presses the release switch (not shown) in the first step, the CPU 1
Is detected and the distance measuring operation is started.

First, the CPU 1 commands the AFIC 2 to initialize the integral value and the like. Next, the subject image incident through the AF optical system 3 is photoelectrically converted by the AFIC 2 and the integration of the signal is started. At this time, the CPU 1
The progress of integration of the AFIC 2 is monitored, and the AF auxiliary light source 5 is turned on via the interface IC 4 if necessary. This AF auxiliary light source 5 is normally turned on.
The control is performed so that it is performed when the subject has a low brightness, and of course, it is controlled so that it is turned on even in the night view itself or a shooting scene with the night view as a background.

When the auxiliary light from the AF auxiliary light source 5 is turned on, the CPU 1 causes the AFIC 2 up to that point.
Interrupt integration by. Then, the current integration value in the AFIC2 is reset, and control is performed so that the integration by the AFIC2 is started again with the auxiliary light turned on.

After the integration of the subject image signal by the AFIC2 is completed, the CPU 1 or the AFIC 2 performs the distance measurement calculation to complete the distance measurement.

Next, the CPU 1 measures the brightness of the subject using a photometric device (not shown).

Then, based on the distance measurement result and the photometric result obtained as described above, the CPU 1 performs the exposure calculation including the control of the light amount of the strobe 14 and the focusing of the photographing optical system 8. .

The focusing of the photographing optical system 8 is performed by driving the focus adjusting optical system 9 of the photographing optical system 8. That is, the drive amount of the focus adjustment optical system 9 is calculated, and the CP amount is calculated based on the drive amount obtained as a result.
U1 drives the focus adjustment optical system 9 via the interface IC 4 and the motor 10.

The position of the focus adjusting optical system 9 at this time is
It is detected by the drive amount detection circuit 11, and based on the detection result, the focus adjustment optical system 9 is further detected.
Feedback control. In this way, the autofocus (AF) operation ends when the subject image reaches a position on the film surface (not shown).

After that, when the photographer presses the release switch in the second stage, the optical path of the photographing optical system 8 is passed through the driver 13 according to the exposure condition obtained by the above-described exposure calculation. The shutter 12 at the center is opened to start exposure on the film. In addition, CPU1
Controls the flash 14 according to the situation of the subject at this time. When the shutter 12 is closed and the exposure is completed after a predetermined time corresponding to the exposure value has passed, C
PU1 winds the film up one frame and waits for input to the next operation.

At this time, the strobe 14 emits a strong light only once in the stroboscopic light emission pattern according to the scene currently being photographed, and a large number of weak light in many times. It is controlled by the CPU 1 so as to be switched to the flash emission.

In this way, a series of photographing operations in the automatic exposure camera including the distance measuring operation are performed.

FIG. 4 is a diagram showing an example of a shooting scene when the main subject is against a night view.

In the photographic scene shown in FIG. 4, a street lamp 42 with high brightness is located on the left side of the screen 41, a tower 43 with a slightly high brightness part is located on the slightly left side of the screen 41, and the center of the screen 41 is slightly high. An example is shown in which a person 44 having a low brightness, which is a main subject, is located on the right side, and a building 45 having a slightly low brightness part is located on the right side of the screen 41.

FIG. 5 is a diagram showing the positional relationship between the target mark 52 shown in the finder field 51 and the AF sensor field 53.

A target mark 52 is displayed in the finder field 51 shown in FIG. 5, and the AF sensor field 53 in the finder field 51 is
In the center of the screen, it is in a state of being spread horizontally and horizontally. The AF sensor field of view 53 shows an area corresponding to a range of a subject imaged through the AF optical system 3 on the photoelectric conversion element arrays 23R and 23L of the AFIC 2.

FIG. 6 is a diagram showing a state of a subject image signal obtained by the AFIC 2 when distance measurement is performed on the scene shown in FIG.

The AFIC 2 in the present embodiment is designed to integrate the photocurrent obtained from the photoelectric conversion element arrays 23R and 23L from the predetermined reference voltage V _CC to the GND side, and thus the image signal of the object. The level of is low in bright areas and high in dark areas. AFIC2 is set to G
If it is configured to integrate from ND to the side of the reference voltage V _CC, it is possible to invert bright / dark in the image signal of the subject.

When the AFIC 2 of the present embodiment is used to measure the distance of a scene as shown in FIG.
The sensor output of the left photoelectric conversion element row 23L is as shown in FIG. 6 (A), and the sensor output of the right photoelectric conversion element row 23R is as shown in FIG. 6 (B).

That is, the output of the sensor position corresponding to the streetlight 42 having the highest brightness has the lowest level as indicated by reference numerals 42a and 42b, and the output of the sensor position corresponding to the tower 43 having a slightly higher brightness part. Is a reference numeral 43a, 4
As shown by 3b, the level becomes, for example, a medium level according to the brightness, and the output of the sensor position corresponding to the building 45 where there is a slightly low brightness has a level, for example, as shown by symbols 45a and 45b. It is high.

In the sensor output shown in FIG. 6, the order of arrangement of the building 45, the tower 43, the street lamp 42, etc. is as shown in FIG.
This is because the AF optical system 3 is constructed as a single lens. Therefore, the appearance of the image signal of the subject may have various variations depending on the configuration of the lens and the like.

When the scene shown in FIG. 4 is photographed, the luminance is low because the person 44, which is the main subject, is far from the illumination range of the street lamp 42.
Almost no image signal can be obtained (reference numerals 44a and 44b in FIG. 6). Therefore, even if the distance measurement calculation is performed based on the sensor output as shown in FIG. 6, for example, the distance (long distance or infinity) to the tower 43 is calculated, and the person 44 who is the main subject is so-called. It will be out of focus.

Next, FIG. 7 shows the above-mentioned FIG.
FIG. 6 is a diagram showing a state of a subject image signal obtained by the AFIC 2 when distance measurement is performed on the scene shown in FIG. Here, FIG. 7A shows the sensor output of the left photoelectric conversion element array 23L, and FIG. 7B shows the right photoelectric conversion element array 23L.
The sensor output of R is shown. Person 4, the main subject
When the luminance of 4 is low, as described in FIG. 6 above,
Since almost no image signal can be obtained, the AF
FIG. 7 shows an example of the sensor output when the auxiliary light source 5 is caused to emit light to increase the brightness of the person 44.

In the example of FIG. 7, the output by the image of the person 44 is slightly obtained as shown by reference numerals 44a and 44b, but still not sufficient contrast is obtained. Therefore, in almost the same manner as in the case of FIG. 6 described above, the obtained distance measurement result is almost always the distance to the tower 43 (long distance or infinity), and the person 44 who is the main subject is still the same. It will be out of focus.

In this way, even when the auxiliary light is used, it is possible to prevent the main subject from becoming extremely out of focus when it is still difficult to focus on the main subject. The processing is as shown in the flowchart of FIG.

FIG. 1A is a flow chart for explaining the release operation in the automatic exposure camera according to this embodiment.

When the photographer presses the release switch (not shown) in the first step to start the distance measuring operation,
The CPU 1 inside the camera 100 operates the distance measuring device 7 to measure the distance by, for example, a known external light passive method (step S1). Next, it is determined whether or not the distance measurement result is infinity or more than a predetermined distance (step S2). If the distance is less than the predetermined distance, the result of distance measurement in step S1 is used as it is, and therefore the process proceeds to the normal exposure operation steps of steps S5 to S8.

On the other hand, if it is determined in step S2 that the distance is infinity or greater than the predetermined distance, the night scene determination process analyzes the photographed scene (step S2).
3) Based on the analysis result, whether the main subject is the night view itself or the background of the night view, or other than that (for example, when the main subject is present at a long distance or the main subject itself is It is determined whether the brightness is low) (step S4).

If it is determined that the shooting scene is neither the night view itself nor the background of the night view, the distance measurement result in step S1 is used as it is, and the normal exposure operation of steps S5 to S8 is performed. Go to step.

Steps S5 to S8 are steps of a normal exposure operation when the distance measurement result in step S1 is used as it is.

First, the focus adjusting optical system 9 is driven according to the distance measurement result of the step S1 to focus the photographing optical system 8 (step S5). Next, it is determined whether or not the auxiliary light from the strobe 14 is required at the time of exposure in response to the second step of pressing the release switch by the photographer (step S6). If the strobe 14 is not necessary, the exposure is performed without using the strobe 14 (step S7), and if the strobe 14 is necessary, the exposure is performed using the strobe 14 (step S8). In addition,
The stroboscopic light emission pattern at this time is the one-shot light emission.

In either case, after the exposure operation is completed, the exposure operation of the camera 100 is completed.

If it is determined in step S4 that the shooting scene is the night view itself or the night view in the background, the focus adjusting optical system 9 is driven according to the result of distance measurement. Then, the photographing optical system 8 is focused (step S9). When focusing on a night view, the distance measurement result obtained in step S1 may be used as it is for focusing, or the distance corrected for the night view may be used for focusing. Is also good.

After the focusing in step S9, slow sync photography for exposing the night view is performed in response to the second step of the release switch pressed by the photographer (step S10). Slow synchro photography is a technique for shooting the background light as much as possible by opening the shutter 12 even after the strobe light is emitted when the background exposure cannot be compensated by the strobe light. However, in the present embodiment, the exposure is supplemented by setting the light emission pattern of the strobe 14 at the time of slow sync photography to the above-described multiple light emission. Then, when the exposure by the slow sync photographing in step S10 is completed, the exposure operation of the camera 100 is completed.

Now, the night view determination processing in step S3 will be described.

First, with reference to FIGS. 6 and 7, the characteristics of the image signal of the subject when the subject is the night view itself or the background is the night view will be described. In a night view or the like, there are both bright portions (high luminance portions) and dark portions (low luminance portions), and the luminance difference between them is often large. Therefore, in such a case, as shown in FIG.
Also, as shown in FIG. 7, the dynamic range of the image signal becomes large.

Further, in a night view, the area occupied by the dark portion is often larger than the area occupied by the bright portion, and the output level becomes higher when the area is dark as in the present embodiment. The configuration is characterized in that the value increases when the average output level of the image signal is taken. On the other hand, in the case of a night view in which the area occupied by the bright portion is larger, if the main subject is a person, it is considered that an output with sufficient contrast can be obtained as the image signal of the person. It is possible to measure the distance with respect to, and it does not become a defocused photograph.

Next, with reference to FIG. 8, the night view determination processing in step S3 will be described.

First, when the night view determination process is started, a flag F_night indicating whether or not the subject is photographed with the night view itself or the night view as a background is cleared to 0 (step S11). This flag F_night is used in the determination of step S4 executed after the night scene determination process, that is, step S4 described above.
In the case of the flag F_night = 0, it is determined that it is not a night view or the like, and when F_night = 1, it is determined that it is a night view or the like.

Next, the integration time of the distance measuring operation by the AFIC 2 is detected in advance, and it is determined whether this integration time is longer than the predetermined time (step S12). This is because, in the case of a night view or the like, the luminance is low, and therefore the integration time is generally long. Here, when the integration time is shorter than the predetermined time, it is determined that the night view is not a night view, and the night view determination process is ended without changing the value of the flag F_night.

On the other hand, when the integration time is longer than the predetermined time, it is next determined whether or not the difference between the maximum value and the minimum value of the sensor data which is an image signal is a predetermined value or more ( Step S13). This is a process of determining whether or not the dynamic range of the image signal is large as described above. Here, when the level difference of the sensor data is smaller than the predetermined value, the value of the flag F_night is not changed, as in the case of step S12, as described above.
The night view determination process is ended as it is.

On the other hand, if the level difference between the maximum value and the minimum value of the sensor data is greater than or equal to the predetermined value, then it is determined whether the average value of the sensor data is greater than or equal to the predetermined value (step S14). . Here, when the average value of the level of the sensor data is smaller than the predetermined value, the night scene determination process is directly terminated without changing the value of the flag F_night, as in steps S12 and S13.

On the other hand, when the average value of the sensor data levels is equal to or greater than the predetermined value, it is determined that the object is a night view or a night view, and the flag F_night is determined.
After t is set to 1 (step S15), the night view determination process is terminated.

Thus, only when the integration time is longer than the predetermined time, the difference between the maximum value and the minimum value of the sensor data is more than the predetermined value, and the average value of the sensor data is more than the predetermined value, the night view And so on.

The method of the night view determination processing shown in FIG. 8 is an example, and the night view determination in the present embodiment is not limited to this. That is, there are many other variations in night scene determination, and these can be widely applied.

Other means for determining the night view include the following, for example.

First, as a first example, when the night scene photographing mode is set by a mode setting switch or the like provided on the camera, the state of the mode setting switch is detected. It is possible to judge whether or not it is a night view.

Next, as a second example, when the integration time is longer than a predetermined time and most of the image signals consist of steep edges, that is, the adjacent difference data of the image signals is obtained (edge enhancement processing). ), If there are many large edges in the image signal, a means for determining that it is a night view or the like can be considered.

Further, as a third example, there can be considered a means for judging that it is a night view or the like when the image signal of the subject is not obtained even if the auxiliary light is turned on.

Further, as a fourth example, the image signal has a valley whose width is narrower than a predetermined width and deeper than a predetermined depth,
Alternatively, when there is a mountain whose width is narrower than the predetermined width and whose height is higher than the predetermined height, a means for determining the night view or the like can be considered.

As a fifth example, when the photometric result by a photometric device (not shown) is below a predetermined brightness,
A means for automatically determining that it is a night view or the like is conceivable.

As a sixth example, when the photometric result is below a predetermined brightness and the area of the low contrast area where the image signal is below a predetermined contrast occupies a predetermined ratio or more of the whole area, a night view It is possible to consider a means to judge that it is etc.

Of course, the night view determination may be performed by combining a plurality of the above-mentioned means.

As described above, according to this embodiment,
When shooting in a dark scene such as a night view, it is possible to perform exposure with a sufficient amount of light even with strobe light that is not dazzling.

That is, in shooting in a scene with a dark background, considering that the eyes of the person who is the subject are also sensitive to the dark environment and have become sensitive, light emission with less stimulus is made and the glare of the strobe light is made. Is reduced. However, with such a weak light, a sufficient amount of light for exposure cannot be obtained unless the light is emitted many times. Therefore, in the present embodiment, the slow sync mode in which the shutter is open for a long time is used to make the strobe of weak light emit many times. That is, by performing stroboscopic light emission a number of times during slow sync photography, it is possible to obtain a sufficient amount of light for exposure even with a small amount of stroboscopic light with little stimulation.

Further, although it takes time to make the strobe emit a large number of times, in the present embodiment, the strobe is made to emit a large number of times during slow sync photography in which the shutter is originally kept open for a long time. It is designed to save time loss due to light emission.

[Second Embodiment] Next, the second embodiment of the present invention will be described.
Embodiments will be described with reference to FIGS. 9 to 11.

In the second embodiment, the conventional 10
In this example, a small Xe tube having an arc length of 5 mm is used instead of the Xe tube having a discharge path (arc length) having a length of mm or more.

That is, in the first embodiment described above, the CPU controls the amount of light emitted from the Xe tube itself in order to realize the stroboscopic light emission that is not dazzling. However, in the second embodiment, From the beginning, a small Xe tube that emits a small amount of light is used. However, in the present embodiment, in order to handle not only shooting at nighttime but also shooting when a subject is present at a long distance, a normal X-ray is used.
The e-tube and the small Xe tube are used together.

First, the appearance of the automatic exposure camera according to the present embodiment will be described with reference to FIG.

That is, in the automatic exposure camera according to this embodiment, the camera body 100 shown in FIG. 10 (A) has a light receiving lens 31 and a reflector for reflecting the light of the normal Xe tube 14c to the front of the camera. 61, a small light quantity strobe 62 including a small Xe tube, a taking lens 63, and the release switch 101.

In this case, since the small Xe tube requires a small opening space for the light emitting portion, the window of the small light quantity strobe 62 can be made small as in the example of FIG.

Further, as shown in FIG. 10B, by popping up the reflector 61, the light from the normal Xe tube 14c is reflected, so that strobe light can be projected in front of the camera. ing.

Next, the electrical configuration of the camera 100 according to the present embodiment will be described with reference to FIG. It should be noted that the first embodiment described above can be applied to the devices not shown in FIG. 11 as they are.

That is, the camera 100 according to the present embodiment.
Is a light quantity strobe 62 including a small Xe tube 62c added to the first embodiment. That is, in addition to the small Xe tube 62c, the small light amount strobe 62 has a condenser 62a that performs the same operation as that included in the strobe 14, a charging unit 62b, a trigger unit 14d, and
And a pulse switching unit 62f. In this embodiment, the trigger unit 14d is commonly used by the strobe 14 and the small light quantity strobe 62.

When using the small Xe tube 62c, the charging voltage of the capacitor 62a is reduced in order to suppress the current in the tube. In the example, the charging voltage of the capacitor 62a of the small Xe tube 62c is set to half or less the charging voltage of the capacitor 14a of the strobe 14, thereby preventing the capacitor 62a from being destroyed by an excessive current inflow. .

The pop-up mechanism 64 is the CPU 1
The reflector 61 is controlled to be popped up. Although not particularly mentioned in the first embodiment, it is assumed that the reflector 61 is used also when the strobe 14 in the first embodiment is used.

Based on the above structure, the release operation of the automatic exposure camera according to the present embodiment will be described with reference to the flowchart of FIG.

When the photographer depresses the release switch 101 by one step, the CPU 1 issues an instruction to the distance measuring device 7 to start distance measurement (step S20). Then, based on the result of distance measurement by the distance measuring device 7, the inside of the photographing optical system 8
The focus adjustment optical system 9 is driven via the motor 10 to perform focusing (step S21). Next, CPU1
Performs photometry for measuring the brightness of the subject with a photometric device (not shown) (step S22).

After the above operation, when the photographer presses the release switch 101 in the second step, the CP
U1 starts the exposure operation. First, in order to determine whether or not a strobe is necessary at the time of exposure, the above step S2 is performed.
The brightness is determined based on the photometric result of step 2 (step S2).
3). The brightness is determined to be bright if the brightness measured by the photometric device is equal to or higher than a predetermined value.

When it is determined that the subject is sufficiently bright as a result of the determination in step S23, it is determined whether or not the photographing condition of the subject is backlight (step S30).
If the result of this determination is that there is no backlight, it is not necessary to use a strobe, so normal exposure is carried out without using a strobe (step S31). On the other hand, if there is backlight, the normal Xe tube 1 is sent through the pop-up mechanism 64.
4c is popped up to expose the flash 14 by one emission (step S29).

Further, as a result of the judgment in step S23,
When it is determined that the subject is dark, the distance of the subject is determined from the result of the subject distance calculated by the distance measuring device 7 (step S24). It should be noted that, similarly to step S23, this determination is determined to be far if the subject distance is equal to or greater than a predetermined value.

If it is determined that the subject exists at a short distance as a result of the determination in step S24, in order to give priority to reducing the glare of the strobe light by suppressing the amount of light emitted from one shot, a small amount of strobe light 62 is emitted. The exposure is performed by continuously emitting a large number of times (step S26). The shutter opening time at this time is about 1/50 second. this is,
The time is shorter than the shutter opening time (for example, 1 second or more) in the slow sync photographing mode described later. That is, since exposure can be performed with a small amount of light at a short distance, camera shake can be reduced by not opening the shutter more than necessary.

In addition, as a result of the determination in step S24,
If it is determined that the subject exists at a long distance, the CPU 1
Determines whether the shooting mode of the camera is the slow sync shooting mode described above (step S25). It should be noted that this determination is made by night scene determination processing or the like as in the first embodiment.

As a result of the determination in step S25, if it is not necessary to shoot in the slow sync shooting mode, for example, if the subject is not a person, or if the night view itself or the night view is not taken as the background, step S2
Strobe shooting is performed by one-shot flash using a normal strobe 14 of 8 or less.

On the other hand, when the photographing mode of the camera is the slow sync photographing mode, in order to reduce the glare of the strobe light by suppressing the amount of light emitted from one shot, a small number of strobes 62 are used. Light is emitted twice (step S27). Note that, as described above, the shutter opening time at this time is, for example, one second or more, which is a time during which exposure can be performed with a sufficient light amount even when the subject is present at a long distance.

As described above, according to this embodiment, the Xe having the normal length used in the first embodiment is used.
A small Xe tube is used instead of the tube, and in slow sync shooting mode or in short-distance shooting, as in the first embodiment, using strobe light that is not dazzling and shooting with a sufficient amount of light You can If this small Xe tube is used, the design on the front surface of the camera can be put together with the same shape parts, so that a camera with a soft design can be manufactured.

Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications and applications are possible within the scope of the gist of the present invention. Of course.

For example, if a strobe that emits a large number of times is used for the AF
It can be used instead of the auxiliary light source.

Further, the strobe 1 of the second embodiment described above.
4 is equipped with a thyristor and a pulse switching unit and strobe 14
May also have a light emitting function many times. However, in this case, it is necessary to perform pop-up by the pop-up mechanism 64 every time the strobe 14 is used.

Further, in the first and second embodiments described above, when the photographing mode of the camera is switched to the slow sync mode, the mode is switched by causing the CPU to perform night scene determination and the like. The camera body should be provided with a switch that can switch the shooting mode to the slow sync shooting mode, so that the slow sync mode, that is, shooting with multiple flashes can be performed by the photographer's arbitrary operation. Of course, it is possible.

[0107]

As described in detail above, according to the present invention,
Provides an auto-exposure camera that captures the nightscape correctly when shooting a scene with the nightscape as the background, and also uses appropriate strobe light to reduce glare and allows you to take pictures without damaging the facial expressions of people. can do.

Furthermore, by combining a flash with a large number of flashes and slow sync photography, the photographer and the person being photographed can recognize from the flash firing that the camera is currently shooting in slow sync mode, and camera shake or motion blurring. There is also a secondary effect that it can be prevented.

[Brief description of drawings]

1A is a diagram showing a flowchart for explaining a release operation of an automatic exposure camera according to a first embodiment of the present invention, and FIG. 1B is a first diagram. It is a figure which shows the light emission pattern of the flash in embodiment.

FIG. 2 is a block configuration diagram of an automatic exposure camera according to the first embodiment of the present invention.

FIG. 3A is a perspective view showing a configuration of an AFIC, and FIG. 3B is an exploded perspective view showing a configuration of an AF optical system.

FIG. 4 is a diagram showing an example when a night view is photographed as a background.

FIG. 5 is a diagram showing a viewfinder field of an automatic exposure camera.

FIG. 6 is a diagram showing a subject image signal obtained by AFIC when a night view is photographed against a background without an auxiliary light source.

FIG. 7 is a diagram showing a subject image signal obtained by AFIC when a night scene is photographed against a background using an auxiliary light source.

FIG. 8 is a diagram showing a flowchart for explaining night scene determination processing.

FIG. 9 is a diagram showing a flowchart for explaining a release operation of the automatic exposure camera according to the second embodiment of the present invention.

FIG. 10 is an external perspective view of an automatic exposure camera according to a second embodiment of the present invention.

FIG. 11 is a block configuration diagram of an automatic exposure camera according to a second embodiment of the present invention.

[Explanation of symbols]

1 CPU 2 AFIC 3 AF optical system 4 Interface IC 5 AF auxiliary light source 6 AF auxiliary light optical system 7 ranging device 8 Shooting optical system 9 Focusing optical system 10 motors 11 Drive amount detection circuit 12 shutters 13 drivers 14 Strobe 14a, 62a capacitors 14b, 62b Charging part 14c Normal Xe tube 14d Trigger part 14e, 62e thyristor 14f, 62f pulse switching unit 61 reflective umbrella 62 low light strobe 62c Small Xe tube 64 Pop-up mechanism 101 Release switch

Claims (4)

[Claims] 1. A strobe light emitting means for irradiating a subject with strobe light, a shutter control means for controlling an opening / closing time of a shutter, an image detecting means for detecting an image signal of the subject, and an image detecting means for detecting the image signal. A computing means for computing information relating to the focusing of the subject based on an image signal, a focusing means for focusing on the subject based on the focusing information computed by the computing means, and an image detected by the image detecting means. Based on the signal
An automatic exposure camera, comprising: switching control means for switching strobe light emission during a shutter control operation to a large number of flashes or one-shot light emission. 2. A night scene judging means for judging that the subject is photographed with the night scene as a background on the basis of the image signal detected by the image detecting means, and the night scene judging means with the night scene as a background. The shutter control means extends the opening time of the shutter and the switching control means switches the stroboscopic light emission to a large number of times when it is determined that the subject is being photographed. The automatic exposure camera according to Item 1. 3. The night view determination means includes an average value of output signals of the image detection means, a width from a maximum value to a minimum value of output signals of the image detection means, and a charge accumulation time of the image detection means. The automatic exposure camera according to claim 1 or 2, wherein the night view determination is performed based on. 4. An automatic exposure camera having a setting means for setting a photographing mode of the camera to a slow synchro photography mode, when the photographing mode is set to the slow synchro photography mode by the setting means, a strobe light emission amount is set. An automatic exposure camera, characterized in that it comprises a light emission control means for making light emission with less light emission repeated a plurality of times.