JP2002341230A - Camera and af auxiliary light control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an error in range finding due to too intense or too weak reflected light from a subject when the emission of auxiliary light is controlled according to the state of the subject. SOLUTION: The camera with an automatic focus control function of controlling the emission of the auxiliary light according to the state of the subject 4 is equipped with an electronic flash 17 which emits the auxiliary light for making the luminance of the subject 4 higher, a range finder 26 which measures the state of the subject 4 corresponding to whether or not the electronic flash 17 emits the auxiliary light, and a CPU 25 which decides whether or not the auxiliary light is emitted according to the state of the subject 4 in the auxiliary- light absence state measured by the range finder 26 and performs control for photography inhibition according to the reflected light from the subject 4 which is increased in luminance by the electronic flash when it is decided that the auxiliary light is necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing apparatus and an AF system suitable for a passive camera having an automatic focus control function for controlling the emission of auxiliary light based on the state of a subject.
The present invention relates to an auxiliary light control method.

[0002]

2. Description of the Related Art In recent years, passive type single-lens reflex cameras with AF auxiliary light control, small cameras, and the like have been used in many cases. This type of passive AF camera often uses AF auxiliary light when distance measurement is impossible in a dark place or a place with low contrast, or in order to maintain the distance measurement accuracy.

In this AF auxiliary light control, whether or not auxiliary light is to be emitted is determined by pre-ranging before the actual ranging to measure the distance to the subject. When the brightness and contrast of the subject (hereinafter, also simply referred to as the state of the subject) are lower than the reference, the emission of the auxiliary light is permitted. A flash, a light-emitting body such as an LED or a lamp is used for the AF auxiliary light, and the brightness of the subject is increased. The reflected light from the subject whose luminance has been increased by the light emitter is measured by a distance measuring device. The distance measurement information based on the reflected light measured here is output from the distance measuring device to the camera control device.
The camera control device calculates the distance to the subject. Automatic focus control and the like are performed based on this distance.

[0004]

However, according to the conventional photographing apparatus having a passive AF auxiliary light control function, the light emission control of the auxiliary light and the automatic focus control are performed based on the state of the subject. . In addition, since the distance to the subject is calculated based on the reflected light from the subject whose brightness has been increased by the light-emitting body, there is the following problem.

In the case where a light emitter is used and the subject is located closer than the closest to the shooting, the reflected light from the subject becomes stronger, and the sensor in the distance measuring device becomes saturated. There is a possibility that the distance measurement may be impossible or the distance measurement may be incorrectly performed.

When a subject is located farther than the closest point of shooting, even if a light emitting body is used, the amount of reflected light from the subject may decrease due to failure of auxiliary light to reach. In this case, the reliability of the distance measurement function may be reduced, and distance measurement may not be possible or may cause erroneous distance measurement.

When the distance measurement is impossible, a reference table or the like when distance measurement is impossible, which describes information such as a normal focal length and an infinite distance, is referred to. The photographing lens is driven based on this table. However, there is a possibility that the image will be out of focus.

When the subject is dark, the photographer is often made to position the subject at the center of the viewfinder. Therefore, light is emitted toward the center of the subject, but unnecessary contrast is created in the peripheral area of the subject because the auxiliary light distribution is not uniform over the distance measurement range. As a result, light unevenness occurs in the distance measurement range, which becomes a noise component and causes erroneous distance measurement.

In view of the above, the present invention has been made to solve the above-described problem. When performing emission control of auxiliary light based on the state of a subject, erroneous distance measurement due to the intensity of reflected light from the subject is performed. It is an object of the present invention to provide a photographing apparatus and an AF auxiliary light control method capable of preventing such a situation.

[0010]

In order to solve the above-mentioned problems and to achieve the object, a first photographing apparatus according to the present invention comprises an automatic focusing device for controlling the emission of auxiliary light based on the state of a subject. A photographing machine with a control function, wherein a light emitter for emitting auxiliary light for increasing the brightness of the subject, light measuring means for measuring the state of the subject according to whether or not the light is emitted by the light emitter, The necessity of auxiliary light emission is determined based on the state of the subject when there is no emission of auxiliary light measured by the light measurement unit, and the reflected light from the subject whose luminance has been increased by the light emitter based on the necessity of light emission is determined. And a control device for executing the photographing prohibition control based on the control.

According to the first photographing apparatus of the present invention, when light emission control of the auxiliary light is performed based on the state of the subject, if the state of the object without the auxiliary light is measured by the light measuring means, The control device determines whether to emit the auxiliary light based on the state of the subject when the auxiliary light is not emitted. At the same time, the photographing inhibition control is executed based on the reflected light from the subject whose luminance has been increased by the light emitter based on the necessity of light emission.

For example, the control device determines whether or not the light emission of the auxiliary light by the light emitter is necessary from the photometric result of the state of the subject when there is no auxiliary light. The luminous body is controlled so as to emit light, and the distance to the subject is measured, and the brightness of the subject with the auxiliary light is compared with a preset reference brightness, and the brightness of the subject is compared with the reference brightness. When the image is bright, the photographing operation is prohibited.

Therefore, when the illuminator emits the auxiliary light, the subject is located closer to the object than the closest point of the image capturing, and when the reflected light by the auxiliary light becomes stronger, the image capturing is prohibited (near side lock). Can be performed, and a near-side warning display or the like can be executed. In addition, since there is no correlation processing or minimal calculation processing in the light measuring means, the "near-side lock" can be immediately notified to the photographer. Further, in the conventional method, when distance measurement is impossible, a preset distance is referred to. However, in this method, out-of-focus photograph can be prevented by realizing near lock processing.

A second photographing device according to the present invention is a photographing device having an automatic focus control function for controlling the emission of auxiliary light based on the state of a subject, and emits auxiliary light for increasing the brightness of the subject. A luminous body; light measuring means for measuring the state of the subject in accordance with whether or not the luminous body emits auxiliary light; and determining whether to emit auxiliary light based on the state of the subject measured by the light measuring means. In addition, there is provided a control device for executing reliability determination control based on the reflected light from the subject whose luminance has been increased by the light emitter based on the necessity of light emission.

According to the second photographing apparatus of the present invention, when light emission control of the auxiliary light is performed based on the state of the subject, if the state of the object without the auxiliary light is measured by the light measuring means, The control device determines whether or not the auxiliary light is required to be emitted based on the state of the subject measured by the light measuring means, and determines the reliability based on the reflected light from the subject whose brightness is increased by the illuminant based on the required emission. The determination control is executed.

For example, the control device determines whether or not the light emission of the auxiliary light by the illuminant is necessary from the photometric result of the state of the subject when there is no auxiliary light. A reliability judgment value for evaluating the reliability is set in advance, and thereafter, the light emission of the light emitter is controlled so as to emit the auxiliary light to the subject, and the evaluation value relating to the reliability in the light measuring means and the light reaching the subject are reached. The distance is measured, and the evaluated value of the light measuring means measured here is compared with the reliability judgment value. If the evaluated value of the light measuring means satisfies the reliability judgment value, the distance to the subject is measured. The photographing control is performed based on.

Therefore, when the subject is located farther than the closest point when the auxiliary light is emitted by the light emitter and the reflected light due to the auxiliary light is weak, the imaging control based on the reliability determination processing is performed. can do. Thereby, appropriate lens control can be performed at the time of shooting on the far side when the periphery of the subject is dark, and high focus accuracy can be secured.

A third photographing device according to the present invention is a photographing device having an automatic focus control function for controlling the emission of auxiliary light based on the state of the subject, and emits auxiliary light for increasing the brightness of the subject. A luminous body, light measuring means having a plurality of selected ranging areas, and measuring the state of the subject in accordance with the presence or absence of the auxiliary light emitted by the luminous body, and a light measuring means based on the state of the subject measured by the light measuring means. And determining whether or not light emission of the auxiliary light is necessary, and performing a distance measurement range selection control such as selecting an arbitrary distance measurement range from a selected distance measurement area based on the determination result. Is what you do.

According to the third photographing apparatus of the present invention, when light emission control of the auxiliary light is performed based on the state of the subject, if the state of the object without the auxiliary light is measured by the light measuring means, The control device determines whether to emit auxiliary light based on the state of the subject measured by the light measuring unit.
At the same time, based on the result of this determination, a ranging range selection control is performed to select an arbitrary ranging range from the selected ranging region.

For example, the control device determines whether or not the light emission of the auxiliary light is necessary by the light emitter from the photometric result of the state of the subject without the auxiliary light. A target distance measurement range is set in advance, and then the light emission of the light emitter is controlled so as to emit the auxiliary light to the object, and the distance to the object within the preset distance measurement range is measured. Photographing control is performed based on the distance at which the vehicle reaches.

Therefore, the distance measurement range without the auxiliary light is
Since a narrow distance measurement range can be set in the presence of the auxiliary light, erroneous distance measurement caused by noise due to uneven reflected light amount or the like can be prevented when the angle of view is wide and the light distribution of the auxiliary light becomes uneven.
Moreover, since the measurement range can be set narrower when the auxiliary light is present, the number of calculations can be reduced, and the distance measurement calculation time and the like can be shortened.

A first AF auxiliary light control method according to the present invention is a method of performing auxiliary light emission control based on a state of a subject in performing automatic focus control. In this case, the necessity of emitting the auxiliary light is determined based on the state of the subject measured here, and if it is determined that the emission of the auxiliary light is “necessary”, the auxiliary light is emitted to the subject and the distance to the subject is measured. And comparing the brightness of the subject with the auxiliary light with a preset reference brightness, and prohibiting the photographing operation when the brightness of the subject is higher than the reference brightness. It is.

According to the first AF auxiliary light control method of the present invention, when performing the automatic focus control, when performing the auxiliary light emission control based on the state of the subject, when the auxiliary light is emitted, the closest to the photographing The subject is closer than
When the reflected light by the auxiliary light becomes strong, the photographing prohibition process can be performed, and the near side warning display can be performed.

A second AF auxiliary light control method according to the present invention is a method of performing auxiliary light emission control based on a state of a subject in performing automatic focus control. It is determined here whether or not the auxiliary light emission is necessary based on the state of the photometric subject. If it is determined that the auxiliary light is required, a reliability determination value for evaluating the reliability of the distance measurement system is determined. Is set in advance, and then the auxiliary light is emitted to the subject, the evaluated value regarding the reliability in the distance measurement system and the distance to the subject are measured, and the evaluated value of the distance measurement system measured here and the reliability are measured. Compare with the gender judgment value, if the evaluated value of the distance measurement system satisfies the reliability judgment value,
It is characterized in that shooting control is performed based on a distance to a subject.

According to the second AF auxiliary light control method of the present invention, when performing the automatic focus control, when performing the auxiliary light emission control based on the state of the subject, when the auxiliary light is emitted, the closest to the shooting The subject is located farther than
When the reflected light by the auxiliary light becomes weak, it is possible to perform the photographing control based on the reliability determination processing. Therefore, at the time of near-side shooting when the periphery of the subject is dark, appropriate lens control can be performed, and high focus accuracy can be secured.

A third AF auxiliary light control method according to the present invention is a method for controlling the light emission of the auxiliary light based on the state of the subject in performing the automatic focus control. In this case, it is determined whether or not light emission of the auxiliary light is necessary based on the state of the photometric subject. After that, an auxiliary light is emitted to the subject, the distance to the front subject is measured within a preset distance measurement range, and shooting control is performed based on the distance to the subject.

According to the third AF auxiliary light control method according to the present invention, in performing the automatic focus control, when controlling the light emission of the auxiliary light based on the state of the subject, the distance measurement range is smaller than the distance measurement range without the auxiliary light. In addition, since a narrow distance measurement range can be set in the presence of the auxiliary light, erroneous distance measurement caused by uneven reflected light amount can be prevented when the angle of view is wide and the light distribution of the auxiliary light becomes uneven.
Since the measurement range is narrowed, the distance calculation time and the like can be reduced.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A photographing apparatus and an AF auxiliary light control method according to an embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to the following embodiment.

(1) First Embodiment FIG. 1 is a front view showing an example of the external configuration of a photographing apparatus 10 as each embodiment according to the present invention. FIG. 2 is a block diagram illustrating a configuration example of the camera drive control unit 51 applied in the first embodiment.

In this embodiment, when the light emission of the auxiliary light is controlled based on the state of the subject, the necessity of the light emission of the auxiliary light is determined based on the state of the object when the light of the auxiliary light is not emitted. A control device that performs shooting prohibition control based on reflected light from a subject whose luminance has been increased based on the illuminant based on emitting auxiliary light by the illuminant,
If the subject is located closer to the subject than the closest to the shooting, and the reflected light from the auxiliary light becomes stronger, it is possible to execute shooting prohibition (near-side lock) processing and execute near-side warning display etc. It is made possible (first photographing machine).

The photographing apparatus 10 shown in FIG. 1 has a function of controlling the light emission of the auxiliary light based on the state of the subject and a function of performing the automatic focus control. The photographing machine 10 has a camera body 1, and the camera body 1 is covered with a front cover 2 and a back cover (not shown). On the front side of the front cover 2, a flash 17 which is an example of a light emitting body is provided.

In the center of the front portion 1a of the camera body 1, a photographic lens 30, distance measuring windows 31a and 31b, and a light measuring window 32 are provided.
And a finder 35 are provided. Front cover 2
A release button 12 and a display unit (not shown) are provided on the upper surface of the camera, and the display unit displays a near-side alarm, a remaining film amount, a shooting date and time, and the like. The near-side alarm indicates that the photographer is notified that the subject is closer than the closest shooting.

A back cover is attached to the camera body 1 so as to be freely opened and closed. The back cover is provided with a back opening / closing lever (not shown), and the back cover is opened from the camera body 1 by pulling the lever. This is for taking the film in and out. A film confirmation window (not shown) is provided on the back cover, and a zoom operation button, a viewfinder window, a mode set button, a date set button, a manual rewind button, and the like are provided on the back cover.

A camera drive control unit 51 is provided in the camera body 1. For example, the camera drive control unit 51 shown in FIG.
U (central processing unit) 25 is provided. This CPU 25
Is connected to a flash circuit 16, and the flash circuit 16 is connected to the flash 17 described with reference to FIG.
At the time of actual distance measurement, auxiliary light is emitted based on the emission permission of the CPU 25. This is to increase the brightness when the subject is dark.

Further, a distance measuring device 26 which is an example of a light measuring means is connected to the CPU 25 so that the object 4 when there is no auxiliary light is provided.
Is measured, the amount of light reflected from the subject 4 whose luminance has been increased by the auxiliary light from the flash 17 is measured, and the distance to the subject 4 is measured. Here, the state of the subject 4 refers to the brightness and contrast of the subject 4. For the distance measuring device 26, a photoelectric double image coincidence detection method is used. The CPU 25 executes the shooting inhibition control based on the amount of reflected light received by the distance measuring device 26.

For example, the CPU 25 determines whether or not the flash 17 needs to emit auxiliary light from the photometric result of the state of the subject 4 when there is no auxiliary light. Here, the auxiliary light is emitted
Is determined, the flash 17 is controlled to emit the auxiliary light to the subject 4, and the distance U to the subject 4 is measured. At this time, the brightness of the subject 4 with the auxiliary light is compared with a preset reference brightness,
When the luminance of the subject 4 is higher than the reference luminance, the photographing operation is prohibited (near-side lock processing). This prohibition of the photographing operation is targeted when the subject is located closer to the photographing than the closest.

In the photographing apparatus 10, when the luminance of the subject is higher than the reference luminance, the CPU 25 executes the near side warning display control. In this control, a mark, a character, or a symbol indicating that a subject is present closer to the image than the closest to the image is displayed and displayed on the display unit in the viewfinder 35 that the photographer is looking through (near lock). control).

In addition to the distance measuring device 26, the CPU 25 includes a release button 12, a zoom position detector 21, a lens position detector 22, an EEPROM 23, a lens driver 24,
A zoom lever 27, a film driver 28, a shutter driver 29 and the like are connected. Lens driver 24
Includes a lens driving motor 44 and a film driver 28
Are connected to a motor 48 for driving the film, and a motor 49 for driving the shutter is connected to the shutter driver 29, respectively.

In the zoom position detector 21, the taking lens 30
Is detected. The lens position detector 22 detects the position of the taking lens 30. The zoom lever 27 is a zoom switch SWa, S
Wb, and is operated to set the photographing lens 30 to wide angle or telephoto. CP for manual operation
A wide-angle or telephoto instruction is issued to U25. For example, when a wide angle is instructed by turning on the zoom switch SWa, the lens motor 44 is driven by the lens driver 24, and the photographing lens 30 is widened. Switch S
When Wb is turned on and telephoto is instructed, the lens motor 44 is driven and the photographing lens 30 is telephoto.

In the film driver 28, a film motor 48 is driven, and a film (not shown) is wound up by one frame. In the shutter driver 29, when the shutter motor 49 is driven, a shutter (not shown) is opened. When the shutter is released, the film is exposed and exposed.

The EEPROM 23 stores data D2 necessary for AF auxiliary light control. For example, a reference table when distance measurement is impossible is stored. The release button 12 has two release switches S1 and S2. When the release switch S1 is pressed, the CPU 25 inputs analog distance measurement signals S11 and S12 from the distance measuring device 26, performs analog / digital conversion, and performs distance measurement and distance measurement based on the converted distance measurement information. Calculation and exposure calculation are performed. The release switch S2 is pressed continuously with the switch S1. When the release switch S2 is pressed, the CPU 25
4 (focus control), and then the shutter driver 2
9 is driven (exposed). Thereafter, the film driver 28 is driven to wind up the film.

Next, an example of the configuration of the distance measuring device 26 and an example of its operation will be described. FIG. 3 is a block diagram showing a configuration example of the distance measuring device 26. The distance measuring device 26 shown in FIG.
A pair of lenses 8A and 8B, a line sensor SR for the right,
It has a left line sensor SL and a processing circuit 9. A plurality of light receiving elements are provided in each of the line sensors SR and SL.

The left line sensor SL receives reflected light from the subject 4 through the lens 8A, and the right line sensor SR receives reflected light from the subject 4 through the lens 8B. Each line sensor S
The reflected light received by R and SL is photoelectrically converted to analog distance measurement signals S11 and S12. The distance measurement signals S11 and S12 include information for calculating the distance to the subject 4.

In this distance measuring device 26, when the subject 4 is located closer to the photographing than the closest point under the AF auxiliary light emitting condition, the reflection from the subject 4 whose brightness is increased by emitting the flash 17 is When the light quantity is measured, the reflected light by the auxiliary light becomes stronger as compared with the case where the subject 4 is located farther than the closest to the shooting.

Here, if the case where the sensor outputs of the line sensors SR and SL are high is defined as a dark field, and the case where the sensor output is low is defined as a bright field, the subject 4 is closer than the closest photographing point. 4, the sensor output is smaller than the predetermined value Vth in the line sensor output example shown in FIG.

The vertical axis shown in FIG. 4 is the sensor output, and the horizontal axis is the position of the light receiving element of each line sensor SR, SL. As described above, when the sensor output is smaller than the predetermined value Vth, the CPU that has received the distance measurement signals S11 and S12
At 25, it is determined that the near side is locked, and the release switch S
Even if 2 is pressed, the photographing operation is prohibited.

FIG. 5 is a conceptual diagram showing the principle of distance measurement in the distance measuring device 26. According to the distance measuring device 26 shown in FIG. 5, the line sensor SR is provided inside the distance measuring window 31a, and the light reflected from the subject 4 is received by the light receiving element through the lens 8A. A line sensor SL is provided inside the distance measuring window 31b, and the light reflected from the subject 4 is received by the light receiving element through the lens 8B. The distance between these lenses 8A and 8B is defined by a base length (hereinafter simply referred to as a base line) B.
Here, assuming that the distance from the lens 8A of the distance measuring device 26 to the subject 4 is U, the focal length from the lens 8A or the like to the light receiving element 39 is f, and the unknown distance on the light receiving element such as the line sensor SL is x. , From similar triangles, U: f = B: x
Is obtained.

By calculating the distance x on the light receiving element of the line sensor SL, the equation (1) corresponding to the distance U from the lens 8A to the subject 4, that is, U = fB / x (1) ) Can be measured (ranging principle).

Subsequently, an operation example of the first photographing machine will be described with respect to the first AF auxiliary light control method. 6 and 7 are flowcharts showing an operation example (Nos. 1 and 2) of the photographing device 10. In this embodiment, it is assumed that the emission control of the auxiliary light is performed based on the state of the subject 4. An example in which the subject 4 is located closer to the photographing than the closest point will be described. The CPU 25 determines whether or not the auxiliary light is necessary based on the pre-ranging. If it is determined that the auxiliary light is “necessary”, the CPU 25 emits the auxiliary light to the subject 4 and measures the distance to the subject 4 to measure the auxiliary light. The brightness of the subject 4 when it is present is compared with a preset reference brightness. If the brightness of the subject 4 is brighter than the reference brightness, it is assumed that the shooting operation is prohibited.

On the basis of these, the CPU 25 detects whether or not the release switch S1 has been pressed in step A1 of the flowchart shown in FIG. The switch S1
When is pressed, the flow shifts to pre-ranging in step A2.
In this pre-ranging, the brightness of the scene is measured. If the field is sufficiently bright, the difference between the minimum value and the maximum value of the outputs of the line sensors SR and SL increases.

Thereafter, based on the result of the pre-ranging, the CPU 25 determines whether or not the auxiliary light is necessary in step A3 (determination of whether or not the auxiliary light is necessary). At this time, the line sensor S
If the contrast of the outputs of R and SL is small and the integration time of the line sensors SR and SL is equal to or longer than a predetermined time, it is determined that the distance measurement is impossible due to darkness. When the contrast of the sensor output is large, the actual distance measurement can be performed without emitting the flash 17.

Therefore, if the result of the pre-distance measurement indicates that the subject brightness is low, there is no contrast, and auxiliary light is required, the flow proceeds to step A4, and the CPU 25 sets the permission of the auxiliary light emission during the main distance measurement. Then, step A5
The actual distance measurement is performed by the distance measurement device 26. At the time of the actual distance measurement, an auxiliary light emission permission signal Se is output from the CPU 25 to the flash circuit 16, and the flash 17 emits light based on the auxiliary light emission permission signal Se.

At this time, the distance measuring device 26 uses the flash 1
The reflected light amount from the subject 4 whose luminance has been increased by the auxiliary light by 7 is measured. In this example, since it is assumed that the subject 4 is located closer to the photographing than the closest point, the reflected light by the auxiliary light is smaller than when the subject 4 is located farther than the closest to the photographing. Become stronger. Therefore, the output of the line sensor shown in FIG. 4 becomes smaller than the predetermined value Vth. The value corresponding to the distance U from the lens 8A to the subject 4 is calculated by equation (1).

Thereafter, in step A6, the CPU 25 determines whether or not the auxiliary light near lock is necessary based on the distance measurement signals S11 and S12. In this example, since the sensor output is smaller than the predetermined value Vth, the CPU 25 determines that the camera is in the near side lock state, and prohibits the photographing operation even if the switch S2 is pressed. The correlation processing and the minimum calculation processing based on the distance calculation value at the time of the actual distance measurement are not performed.

The CPU 25 locks the lens driver 24, the shutter driver 29 and the like, and proceeds to step A7. In step A7, a near side alarm is displayed on the display unit.
The photographer looks at this near-side alarm and changes the photographing position so as to move away from the subject 4.

When the photographer changes the photographing position and the subject 4 is located closest to the photographing, the steps A1 to A4 are executed.
After step A4, the correlation processing and the minimum calculation processing based on the distance calculation value obtained by the actual distance measurement in step A5 are performed. Then, in step A6, the sensor output becomes equal to or more than the predetermined value Vth. In this case, the lens driver 24, the shutter driver 29, and the like are unlocked, and the process proceeds to step A9 in the flowchart shown in FIG. In step A9, the process waits until the switch S2 is pressed. Here, when the switch S2 is depressed, the lens motor 44 is driven by the lens driver 24 in step A10, and the focus of the photographing lens 30 is adjusted.

Thereafter, in step A11, the shutter motor 49 is driven by the shutter driver 29, the shutter is released, and the film surface is exposed and exposed. And
In step A12, the film motor 48 is driven by the film driver 28, and the film is wound up one by one. Thereafter, in step A13, the remaining film is checked, and if the film remains, the process returns to step A1, and
The above processing is repeated. After the film is rewound due to no remaining film, the control is terminated.

As described above, according to the photographing apparatus 10 and the AF auxiliary light control method according to the first embodiment of the present invention,
When the light emission control of the auxiliary light is performed based on the state of the subject 4, if the state of the object 4 without the auxiliary light is measured by the distance measuring device 26, the CPU 25 sets the state of the object 4 without the emission of the auxiliary light. The necessity of the emission of the auxiliary light is determined based on this. At the same time, the photographing inhibition control is executed based on the reflected light from the subject 4 whose luminance has been increased by the flash 17 based on the necessity of light emission.

Therefore, when the auxiliary light is emitted by the light emitter 4 and the subject 4 is located closer to the object than the closest to the image taking, and the reflected light by the auxiliary light becomes stronger, the image taking is prohibited (near side lock). ) Processing can be performed, and a near-side warning display or the like can be executed.

Moreover, the near-side lock is determined based on the amount of light reflected by the auxiliary light, and no correlation processing or minimal calculation processing is performed in the distance measuring device 26. I can let you know.

(2) Second Embodiment FIG. 8 is a block diagram showing a configuration example of a camera drive control unit 52 applied to a camera as a second embodiment according to the present invention. In this embodiment, a CPU 45 shown in FIG. 8 is attached to the camera drive control unit 52 instead of the CPU 25 of the camera drive control unit 51 shown in FIG. The camera drive control unit 52 includes the unit 51
When the light emission control of the auxiliary light is performed based on the state of the subject 4 and is mounted in the camera body shown in FIG. At the same time, the flash 1
The reliability judging control is executed based on the reflected light from the subject 4 whose luminance has been increased by 7.

In this example, when the subject 4 is located farther than the closest point of shooting and the auxiliary light is emitted by emitting the flash 17 and the reflected light by the auxiliary light is weak, the reliability determination processing is performed. , And appropriate lens control can be performed during near-side shooting when the periphery of the subject 4 is dark.

The second photographing device according to the present invention includes a camera drive control unit 52 shown in FIG. 8 for controlling the emission of the auxiliary light based on the state of the subject 4. The camera drive control unit 52 is provided with a CPU (central processing unit) 45 as an example of a control device. The flash circuit 16 is connected to the CPU 45, and the brightness of the subject 4 is increased by emitting the flash 17. A distance measuring device 26 is connected to the CPU 45, and measures the amount of reflected light from the subject 4 whose luminance has been increased by the flash 17. In the CPU 45, the distance measuring device 2
The reliability determination control is executed based on the amount of reflected light received by the controller 6.

For example, the CPU 45 determines from the photometry result of the state of the subject 4 when there is no auxiliary light, whether or not the flash 17 needs to emit the auxiliary light. A reliability determination value for evaluating the reliability in is set in advance. After that, the flash 17 is controlled to emit the auxiliary light to the subject 4.

At the same time, the evaluated value of the reliability in the distance measuring device 26 and the distance to the subject 4 are measured. The measured value of the distance measuring device 26 and the reliability determination value measured here are compared, and if the evaluated value of the distance measuring device 26 satisfies the reliability determination value, it is determined based on the distance to the subject 4. To control shooting.

At this time, when it is determined that the auxiliary light is “necessary”, the CPU 45 sets a lower reliability determination value than the reliability determination value when the auxiliary light is determined to be “no”. . The reliability determination control may be performed on the distance measuring device 26 instead of the CPU 45 (self-reliability evaluation function). Further, the components having the same names and the same reference numerals as those in the first embodiment have the same functions, and thus the description thereof will be omitted.

Next, an example of the reliability determination control according to the second embodiment will be described. 9A and 9B are image diagrams illustrating an operation example of the distance measuring device 26 including the line sensor SR for the right and the line sensor SL for the left. FIG. 10 is a state transition diagram showing an example of shifting the line sensors SL and SR.

In this example, the case where the object field is divided into bright and dark areas and the amount of reflected light from the subject 4 is measured by the right line sensor SR and the left line sensor SL will be described as an example. In the distance measuring device 26 shown in FIG. 9A,
The reflected light based on the dark and light portions of the subject 4
The light is received by the light receiving element of the left line sensor SL through A, and is received by the light receiving element of the right line sensor SR through the lens 8B. Each line sensor SL,
The bright and dark light distribution of the subject 4 is imaged on the light receiving element of the SR.

FIG. 9B is a signal level diagram of distance measurement signals S11 and S12 indicating light and dark in the line sensors SL and SR. In FIG. 9B, the vertical axis is the sensor output, the upper level is the “dark” level, and the lower level is the “bright” level.
The horizontal axis is the position of the light receiving element. In FIG. 9B, the distance measured by each of the line sensors SR and SL is a boundary position between the dark part and the light part of the subject 4.

In general, with finite light, the position of the part (light receiving element) measured by the line sensor SL and the position of the part (light receiving element) measured by the line sensor SR do not match. In this example, the distance measurement signal S11 of the line sensor SL and the line sensor S
When the R distance measurement signal S12 is input to the CPU 45, the CPU 45 converts the distance measurement signals S11 and S12 from analog to digital. From the converted distance measurement information, the sensor data of each of the distance measurement portions is extracted, and the correlation function of the left and right line sensors SR and SL is obtained while shifting the left and right sensor data. This is for matching the distance measurement positions (correlation function calculation).

In this example, the line sensor SL shown in FIG.
For example, assuming that the number of light receiving elements between the sensor SL and the line sensor SR is 3 elements in the state # 1 and the sensor SR is shifted by 3 elements, the state # At 2, the state transits to a shift of two elements between the sensor SL and the sensor SR. Further, when the sensor data is shifted by one, in the state # 3, the state shifts to a shift of one element between the sensor SL and the sensor SR. Therefore, when the sensor data is further shifted by one, the distance measurement position of the sensor SL and the distance measurement position by the sensor SR coincide in the state # 4.

FIG. 11 is a relationship diagram showing the degree of coincidence between the line sensors SL and SR. In FIG. 11, the vertical axis represents the correlation coefficient (correlation value) obtained from the correlation function, and is on a uniform scale. The horizontal axis is the sensor shift amount, and is on an equal scale. In this graph, the sensor data of the line sensor SR is fixed and the sensor data of the line sensor SL is shifted, and in the graph, the sensor data of the line sensor SL is fixed and the sensor data of the line sensor SR is shifted. . Of course, the sensor data may be shifted so that both approaches the minimum value.

To match the distance measurement positions, the CPU 4
In step 5, a correlation coefficient is obtained from the calculated correlation function, and the minimum value of the correlation coefficient is searched (minimum value search). The CPU 45 obtains the correlation coefficient difference values ε1 and ε2 before and after the minimum value as the evaluated value regarding the reliability in the distance measuring device 26, and obtains the correlation coefficient difference values ε1 and ε2.
And a predetermined reliability determination value ε0. When the correlation coefficient difference values ε1 and ε2 are larger than the reliability determination value ε0, it is determined that “there is reliability in the distance measuring device 26” (reliability determination).

In this example, when it is determined that there is "reliability", the CPU 45 obtains the sensor shift amount from the correlation function based on the minimum value search and obtains the object shift amount from the lens 8A.
The distance value U up to is obtained by the equation (1), that is, U = Bf / x (distance calculation). Photographing control is performed based on the distance measurement value U between the lens 8A and the subject 4.

Next, a description will be given of an operation example of the second photographing apparatus regarding the second AF auxiliary light control method. FIG. 12 and FIG. 13 are flowcharts showing operation examples (parts 1 and 2) of the second photographing machine. In this embodiment, it is assumed that the automatic focus control is performed by controlling the emission of the auxiliary light based on the state of the subject, and the reliability determination control is further performed based on the amount of reflected light from the subject 4 whose brightness has been increased by the flash 17. Is assumed to be executed. It is assumed that the subject 4 is located farther than the closest shooting point.

On the basis of these, the CPU 45 detects whether or not the release switch S1 has been pressed in step B1 of the flowchart shown in FIG. The switch S
When 1 is pressed, the flow shifts to pre-ranging in step B2. In this pre-ranging, the brightness of the scene is measured.

Thereafter, based on the result of the pre-ranging, the CPU 45 determines whether or not an auxiliary light is necessary in step B3. If the result of the pre-ranging indicates that the brightness of the subject is low, there is no contrast, and auxiliary light is required, the process proceeds to step B4, where the emission of auxiliary light during main ranging is set. At this time, an auxiliary light emission permission signal Se is output from the CPU 45 to the flash circuit 16.

After that, unlike the first embodiment, the process proceeds to step B5, where the reliability judgment value ε0 is set. Here, a lower reliability determination value ε0 is set as compared with the case where it is determined that the auxiliary light is “unnecessary”. This is to increase the reliability determination level. Then, the process proceeds to step B6, where the distance measurement device 26 performs the actual distance measurement. During the distance measurement, the flash 17 emits light based on the auxiliary light emission permission signal Se.

At this time, the distance measuring device 26 uses the flash 1
The reflected light amount from the subject 4 whose luminance has been increased by 7 is measured. In this example, the subject 4 is set under the AF auxiliary light emission condition.
Is located farther than the closest photographing point, the reflected light by the auxiliary light is weaker than when the subject 4 is located closer to the photographing closest point. Therefore, the output of the line sensor shown in FIG. 4 becomes larger than the predetermined value Vth.

Thereafter, in step B7, the CPU 45 determines the presence or absence of reliability based on the distance measurement signals S11 and S12. At this time, the distance measurement signal S of the line sensor SL
11 and the distance measurement signal S12 of the line sensor SR are C
When the distance measurement signals S11 and S12 are input to the PU 45, the distance measurement signals S11 and S12 are converted from analog to digital. From the converted distance measurement information, the sensor data of each of the distance measurement portions is extracted, and the correlation function of the left and right line sensors SR and SL is obtained while shifting the left and right sensor data (correlation function calculation).

Thereafter, in order to match the distance measurement positions, the CP
In U45, a correlation coefficient is obtained from the calculated correlation function, and the minimum value of the correlation coefficient is searched (minimum value search). Then, the CPU 45 obtains the correlation coefficient difference values ε1 and ε2 before and after this minimum value as the evaluated value relating to the reliability in the distance measuring device 26, and calculates the correlation coefficient difference value ε
1, .epsilon.2 and a preset reliability determination value .epsilon.0. When the correlation coefficient difference values ε1 and ε2 are larger than the reliability determination value ε0, the “range finding device 26”
Is determined ”(reliability determination).

In this example, if it is determined that there is no reliability, the process proceeds to step B8, and the reference table when distance measurement is impossible is read from the EEPROM 23 or the like. AF auxiliary light control based on the reference table is performed. If "reliable" is determined in step B7, the sensor shift amount is obtained from the correlation function based on the minimum value search by the CPU 45, and the distance value U to the subject 4 is calculated by equation (1) ( Distance calculation). Then, the process shifts to step B9 in the flowchart shown in FIG. 13 in order to perform the photographing control based on the distance measurement value U reaching the subject 4.

In step B9, the control waits until the release switch S2 is pressed. Here, when the switch S2 is pressed, the lens motor 44 is driven by the lens driver 24 in step B10, and the focus of the photographing lens 30 is adjusted.

Thereafter, in step B11, the shutter motor 49 is driven by the shutter driver 29, the shutter is released, and the film surface is exposed and exposed. And
In step B12, the film motor 48 is driven by the film driver 28, and the film is wound up one by one. Thereafter, in step B13, the remaining film is checked, and if the film remains, the process returns to step B1.
The above processing is repeated. After the film is rewound due to no remaining film, the control is terminated.

As described above, according to the photographing apparatus and the AF auxiliary light control method according to the second embodiment of the present invention, when the light emission of the auxiliary light is controlled based on the state of the subject 4,
When the state of the subject 4 when there is no auxiliary light is measured by the distance measuring device 26, the CPU 45 determines whether or not to emit auxiliary light based on the state of the subject 4, and based on the necessity of the light emission, the flash 17 uses the flash 17 to determine the luminance. Subject 4 with raised
The reliability determination control is executed based on the reflected light from the control unit.

Therefore, when the flash 17 emits the auxiliary light and the subject is located farther than the closest point of the image capturing, and the reflected light by the auxiliary light becomes weak, the image capturing control based on the reliability determination processing is performed. can do. Thereby, appropriate lens control can be performed at the time of shooting on the far side when the periphery of the subject is dark, and high focus accuracy can be secured.

(3) Third Embodiment FIG. 14 is a block diagram showing a configuration example of a camera drive control unit 53 applied to a camera as a third embodiment according to the present invention. FIG. 15 is an image diagram showing an example of selecting a ranging range in the selected ranging area. In this embodiment, the CPU of the camera drive control unit 51 shown in FIG.
When the CPU 55 shown in FIG. 14 is attached to the camera drive control unit 53 in place of the object 25 and the light emission control of the auxiliary light is performed based on the state of the object 4, the CPU 55 determines whether or not the light emission of the auxiliary light is necessary based on the state of the object 4. In addition to the determination, a distance measurement range selection control is performed to select an arbitrary distance measurement range from the selected distance measurement area based on the determination result.

In the third photographing apparatus, a narrower distance measurement range can be set with the auxiliary light than the distance measurement range without the auxiliary light, and the angle of view is wider and the light distribution of the auxiliary light is less. In this case, it is possible to prevent erroneous distance measurement due to reflected light amount unevenness when uniform.

The third photographing device according to the present invention includes a camera drive control unit 53 shown in FIG. 14 for controlling the emission of the auxiliary light based on the state of the subject 4. The camera drive control unit 53 includes a CPU as an example of a control device.
(Central processing unit) 55 is provided. The flash circuit 16 is connected to the CPU 55 and the flash 1
By emitting light 7, the luminance of the subject 4 is increased.

The distance measuring device 26 is connected to the CPU 55.
It has a plurality of selected ranging areas and measures the amount of reflected light from the subject 4. In the CPU 55, the distance measuring device 2
6 to determine the necessity of light emission of the illuminant based on the amount of reflected light received, and based on the result of this determination, executes range finding range selection control to select an arbitrary range finding range from the selected range finding region. It is done as follows.

For example, the CPU 55 determines whether the flash 17 needs to emit auxiliary light from the photometric result of the state of the subject 4 when there is no auxiliary light. When it is determined that the emission of the auxiliary light is “necessary”, the target distance measurement range is set in advance by the distance measurement device 26. After that, the flash 17 is controlled to emit the auxiliary light to the subject 4, and the distance to the subject 4 is measured within a preset distance measurement range,
Photographing control is performed based on the distance to the subject 4.

In this example, when a plurality of selected ranging areas are provided, an area selecting means is provided in the CPU 55, and the selected ranging areas are provided based on the amount of reflected light received by the ranging device 26. An arbitrary distance measurement range is selected from the following. At this time, when it is determined that the auxiliary light is “necessary”, the CPU 55 sets a distance measurement range narrower than the distance measurement range when it is determined that the auxiliary light is “no”.

For example, in FIG. 15, the photographing device 10 has five selected distance measuring areas P1 to P5 with respect to the photographing angle of view WP.
Is provided. The selected distance measurement areas P1 to P5 are provided with the selected distance measurement areas P1 and P2 on the left side of the selected distance measurement area P3 and the selected distance measurement area P on the right side thereof.
4, P5 are provided.

In this example, when the normal distance measurement range is the selected distance measurement region P1 + P2 + P3 + P4 + P5, the distance measurement range at the time of the auxiliary light is smaller than this, and the selected distance measurement region P2 + P
3 + P4 (center portion). In this case, the AF auxiliary light control is performed in a dark case where the flash 17 emits light.
Is difficult to recognize, and the photographer is likely to place the subject 4 at the center. As described above, by narrowing the measurement range, the distance calculation time and the like can be reduced. The components having the same names and the same reference numerals as those in the first embodiment have the same functions, and thus the description thereof will be omitted.

Next, a third AF auxiliary light control method will be described with respect to an operation example of a third photographing machine. FIGS. 16 and 17 are flowcharts showing an operation example (parts 1 and 2) of the third photographing machine. In this embodiment, it is assumed that the automatic focus control is performed by controlling the emission of the auxiliary light based on the state of the subject 4. The distance measuring device 26 measures the state of the subject when there is no auxiliary light, and the CPU 55 determines whether or not the auxiliary light needs to be emitted based on the measured state of the subject, and determines that the auxiliary light needs to be emitted. In this case, the distance measurement range targeted by the distance measurement device 26 is set in advance. Thereafter, the auxiliary light is emitted to the subject 4, and the distance measuring device 26 measures the distance to the subject within a preset ranging range, and the CPU 5 determines the distance to the subject based on the distance to the subject.
An example in which shooting control is performed in step 5 will be described.

On the basis of these, the CPU 55 detects whether or not the release switch S1 has been pressed in step C1 of the flowchart shown in FIG. The switch S
When 1 is pressed, the flow shifts to pre-ranging in step C2. In this pre-ranging, the brightness of the scene is measured.

Thereafter, based on the result of the pre-ranging, the CPU 55 determines whether or not the auxiliary light is necessary in step C3. If the result of the pre-ranging is that the field of view is dark, lacks contrast, and requires auxiliary light, the process proceeds to step C4, where the emission of auxiliary light during main ranging is set. At this time, C
The auxiliary light emission permission signal Se is output from the PU 55 to the flash circuit 16. Then, unlike the second embodiment,
The process proceeds to step C5, where a distance measurement range (area) is set. At this time, the selected distance measuring area P2 + P3 + P4 at the center of the five selected distance measuring areas P1 to P5 having the shooting angle of view WP shown in FIG. 15 is selected, and the distance is measured to the selected distance measuring area P2 + P3 + P4. The range is set.

Then, the flow shifts to step C6, where the distance measurement is performed by the distance measuring device 26. During the distance measurement, the flash 17 emits light based on the auxiliary light emission permission signal Se. At this time, the distance measuring device 26 measures the amount of reflected light from the subject 4 whose luminance has been increased by the flash 17. The distance U to the subject 4 is the selected ranging area P2 + P3 + P4
It is calculated by equation (1) based on only the distance measurement signals S11 and S12.

That is, when it is determined that the auxiliary light is present,
Distance measurement signal S1 of selected ranging areas P1 and P5 on both sides
1, S12 is invalidated and the selected ranging area P2 in the center portion is invalidated.
The distance is calculated using the distance measurement signals S11 and S12 of + P3 + P4. Therefore, the distance measurement signals S11 and S12 in the reduced brightness portion around the selected distance measurement area P2 + P3 + P4 do not intervene in the calculation, and the distance U
Erroneous measurement can be reduced as much as possible.

Then, the flow shifts to step C7 in the flowchart shown in FIG. 17 to perform photographing control based on the distance measurement value U reaching the subject 4. In step C7, the process waits until the switch S2 is pressed. Here, when the switch S2 is pressed, the lens motor 44 is driven by the lens driver 24 in step C8, and the focus of the photographing lens 30 is adjusted.

Thereafter, in step C9, the shutter motor 49 is driven by the shutter driver 29, the shutter is released, and the film surface is exposed and exposed. Then, in step C10, the film motor 48 is driven by the film driver 28, and the film is wound up one by one. Thereafter, the remaining film is checked in step C11, and if there is any remaining film, the process returns to step C1 and the above processing is repeated. After the film is rewound due to no remaining film, the control is terminated.

As described above, according to the photographing apparatus and the AF auxiliary light control according to the third embodiment of the present invention, the object 4
When the light emission control of the auxiliary light is performed based on the state of the object 4, when the state of the subject 4 without the auxiliary light is measured by the distance measuring device 26, the CPU 55 returns to the state of the object 4 measured by the distance measuring device 26. The necessity of the emission of the auxiliary light is determined based on this. At the same time, based on the result of this determination, a ranging range selection control is performed to select an arbitrary ranging range from the selected ranging region.

Accordingly, the distance measurement range without the auxiliary light is
Since a narrow distance measurement range can be set in the presence of the auxiliary light, erroneous distance measurement caused by noise due to uneven reflected light amount or the like can be prevented when the angle of view is wide and the light distribution of the auxiliary light becomes uneven.
Moreover, since the measurement range can be set narrower when the auxiliary light is present, the number of calculations can be reduced, and the distance measurement calculation time and the like can be shortened.

In the above embodiment, the photographing prohibition control, the reliability determination control, and the distance measurement range selection control are described separately. However, the present invention is not limited to this. + Reliability judgment control, reliability judgment control + distance measurement range selection control, photography inhibition control + distance measurement range selection control, photography inhibition control + reliability judgment control + CPU that executes distance measurement range selection control , A higher-performance camera can be provided.

[0105]

As described above, the first embodiment according to the present invention is described.
According to the photographing device, when the emission control of the auxiliary light is performed based on the state of the subject, the necessity of the emission of the auxiliary light is determined based on the state of the subject when the emission of the auxiliary light is not performed. And a control device for executing the prohibition of photographing based on the reflected light from the subject whose brightness has been increased by the light-emitting body.

With this configuration, when the illuminator emits the auxiliary light, the subject is located closer to the object than the closest point of the image capturing, and the image capturing is prohibited when the reflected light by the auxiliary light becomes stronger (near side lock). ) Processing can be performed, and a short distance warning display and the like can be executed. In addition, since there is no correlation function or minimal calculation processing in the light measuring means, the "near-side lock" can be instantaneously notified to the photographer. In the conventional method, when the distance cannot be measured, a preset distance is referred to. However, in the present method, out-of-focus photograph can be prevented by realizing the near lock process.

According to the second photographing apparatus of the present invention, when the emission control of the auxiliary light is performed based on the state of the subject, the necessity of the emission of the auxiliary light is determined based on the state of the subject, and the light emission is determined. It is provided with a control device that executes the reliability determination control based on the reflected light from the subject whose luminance has been increased by the light emitter based on the point.

With this configuration, when the illuminant emits the auxiliary light, the object is positioned farther than the closest point of shooting, and the reflected light by the auxiliary light becomes weaker. Shooting can be controlled. Accordingly, during close-up shooting when the periphery of the subject is dark, appropriate lens control can be performed, and high focus accuracy can be ensured.

According to the third photographing apparatus of the present invention, when the light emission control of the auxiliary light is performed based on the state of the subject, the necessity of the light emission of the auxiliary light is determined based on the state of the subject. A control device is provided for executing a ranging range selection control for selecting an arbitrary ranging range from a selected ranging region based on a determination result.

According to this configuration, it is possible to set a narrower distance measurement range with the auxiliary light than the distance measurement range without the auxiliary light. Therefore, when the angle of view is wide and the light distribution of the auxiliary light is not uniform, the amount of reflected light is small. Erroneous ranging due to unevenness can be prevented. In addition, the measurement range can be set narrower with the auxiliary light,
It is possible to reduce the distance calculation time and the like.

According to the first AF auxiliary light control method according to the present invention, when performing the automatic focus control, when controlling the emission of the auxiliary light based on the state of the object, the state of the object without the auxiliary light is measured. Then, the necessity of light emission of the auxiliary light is determined based on the state of the subject measured here, and when it is determined that the light emission of the auxiliary light is “necessary”, the auxiliary light is emitted to the subject and the distance to the subject is determined. The luminance of the subject with the auxiliary light is measured and compared with a preset reference luminance. If the luminance of the subject is higher than the reference luminance, the photographing operation is prohibited. With this configuration, when the auxiliary light is emitted, the subject is located closer than the closest point of shooting, and when the reflected light by the auxiliary light becomes stronger, the shooting prohibition process can be performed, and the short distance warning can be performed. Display and the like can be executed.

According to the second AF auxiliary light control method according to the present invention, in performing the automatic focus control, when controlling the light emission of the auxiliary light based on the state of the object, the state of the object without the auxiliary light is determined. Photometry, and determines whether or not the auxiliary light needs to be emitted based on the state of the subject measured here. If it is determined that the auxiliary light is required, the reliability for evaluating the reliability of the distance measurement system is determined. A gender determination value is set in advance, and then, an auxiliary light is emitted to the subject, and a value to be evaluated regarding reliability in the distance measuring system and a distance to the subject are measured, and the measured value of the distance measuring system measured here is measured. The value is compared with the reliability determination value, and if the evaluated value of the distance measurement system satisfies the reliability determination value, shooting control is performed based on the distance to the subject.

With this configuration, when the auxiliary light is emitted, the subject is located farther than the closest point of shooting, and when the reflected light by the auxiliary light becomes weak, the shooting control based on the reliability determination processing is performed. be able to. Therefore, at the time of near-side shooting when the periphery of the subject is dark, appropriate lens control can be performed, and high focus accuracy can be secured.

According to the third AF auxiliary light control method of the present invention, when performing the automatic focus control, when performing the auxiliary light emission control based on the state of the object, the state of the object without the auxiliary light is measured. Then, the necessity of auxiliary light emission is determined based on the state of the subject measured at this time, and when it is determined that auxiliary light emission is "necessary", a target distance measurement range is set in advance by the distance measurement system. After that, auxiliary light is emitted to the subject, the distance to the subject is measured within a preset distance measurement range, and shooting control is performed based on the distance to the subject.

With this configuration, it is possible to set a narrower distance measurement range with the auxiliary light than the distance measurement range without the auxiliary light. Therefore, when the angle of view is wide and the light distribution of the auxiliary light is not uniform, the amount of reflected light is small. Erroneous ranging due to unevenness can be prevented. Since the measurement range is narrowed, the distance calculation time and the like can be reduced. INDUSTRIAL APPLICABILITY The present invention is very suitable when applied to a passive camera or the like having an automatic focus control function for controlling the emission of auxiliary light based on the state of a subject.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of an external configuration of a photographing device 10 as each embodiment according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a camera drive control unit 51 applied in the first embodiment.

FIG. 3 is a block diagram illustrating a configuration example of a distance measuring device 26.

FIG. 4 is a diagram illustrating a sensor output example of a line sensor SR and the like.

FIG. 5 is a conceptual diagram showing a principle of distance measurement in the distance measuring device 26.

FIG. 6 is a flowchart illustrating an operation example (No. 1) of the photographing device 10.

FIG. 7 is a flowchart illustrating an operation example (No. 2) of the photographing device 10.

FIG. 8 is a block diagram illustrating a configuration example of a camera drive control unit 52 applied to a camera according to a second embodiment.

FIGS. 9A and 9B are image diagrams showing an operation example of the distance measuring apparatus 26 provided with the right line sensor SR and the left line sensor SL.

FIG. 10 is a state transition diagram illustrating a shift example of the line sensors SL and SR.

FIG. 11 is a diagram illustrating an example of the relationship between the coincidences of the line sensors SL and SR.

FIG. 12 is a flowchart illustrating an operation example (1) of the second photographing device.

FIG. 13 is a flowchart illustrating an operation example (part 2) of the second photographing device.

FIG. 14 is a block diagram illustrating a configuration example of a camera drive control unit 53 applied to a photographing machine according to a third embodiment.

FIG. 15 is a diagram illustrating selected distance measurement areas P1, P2, P3, P4, and P;
FIG. 9 is an image diagram showing an example of selecting a ranging range in FIG.

FIG. 16 is a flowchart illustrating an operation example (part 1) of the third photographing device.

FIG. 17 is a flowchart illustrating an operation example (part 2) of the third photographing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Camera body 51, 52, 53 Camera drive control unit 10 Camera (camera) 17 Flash (light-emitting body) 25, 45, 55 CPU (control device) 26 Distance measuring device (light measuring means)

Claims (13)

[Claims] 1. A photographing apparatus with an automatic focus control function for controlling emission of auxiliary light based on a state of a subject, wherein the illuminator emits auxiliary light for increasing the brightness of the subject; Light measuring means for metering the state of the subject according to whether or not the auxiliary light is emitted, and whether or not the auxiliary light needs to be emitted based on the state of the subject without emission of the auxiliary light measured by the light measuring means. And a control device for performing a shooting prohibition control based on reflected light from a subject whose luminance has been increased by the light emitting body based on the light emission requirement. 2. The control device determines whether or not light emission of the auxiliary light by the illuminant is necessary based on a photometric result of a state of the subject when there is no auxiliary light. Controlling the light emission of the illuminant so as to emit auxiliary light to the object, measuring the distance to the object, comparing the luminance of the object with the auxiliary light with a preset reference luminance, 2. The photographing apparatus according to claim 1, wherein the photographing operation is prohibited when the luminance of the image is higher than the reference luminance. 3. The photographing apparatus according to claim 1, wherein the control device executes a short-distance warning display control when the luminance of the subject is higher than the reference luminance. 4. A photographing apparatus with an automatic focus control function for controlling light emission of auxiliary light based on a state of a subject, wherein the light emitting body emits auxiliary light for increasing the brightness of the subject, and the light emitting body Light measuring means for measuring the state of the subject in accordance with whether or not the auxiliary light is emitted, and determining whether or not to emit the auxiliary light based on the state of the subject measured by the light measuring means; A control device for performing reliability determination control based on reflected light from a subject whose brightness has been increased by the light-emitting body based on the control signal. 5. The control device determines whether or not the light emission of the auxiliary light by the light emitting body is necessary from the photometric result of the state of the subject when there is no auxiliary light. A reliability determination value for evaluating the reliability in the light measurement unit is set in advance, and then the light emission of the light emitter is controlled so as to emit the auxiliary light to the subject. The evaluated value and the distance to the subject are measured, and the measured evaluated value of the light measuring means is compared with a reliability determination value, and the evaluated value of the light measuring means satisfies the reliability determination value. The photographing apparatus according to claim 4, wherein when there is, photographing control is performed based on a distance to the subject. 6. The reliability determination value, which is lower than a normal reliability determination value when the auxiliary light is determined to be “necessary”, when the auxiliary light is determined to be “required”. The photographing apparatus according to claim 4, wherein: 7. A camera with an automatic focus control function for controlling the emission of auxiliary light based on the state of a subject, comprising: a luminous body that emits auxiliary light for increasing the brightness of the subject; A light measuring unit that has a selected distance measurement area and measures the state of the subject in accordance with the presence or absence of emission of the auxiliary light by the illuminant; and A photographing apparatus comprising: a control device that determines whether or not light emission is required and that executes a ranging range selection control for selecting an arbitrary ranging range from the selected ranging region based on the determination result. . 8. The control device determines whether or not the light emission of the auxiliary light by the light emitting body is necessary from the photometric result of the state of the subject when there is no auxiliary light. The light-measuring unit sets a target ranging range in advance, and then controls light emission of the illuminant so as to emit auxiliary light to the subject, and reaches the subject within the preset ranging range. The photographing apparatus according to claim 7, wherein a distance is measured, and photographing control is performed based on a distance to the subject. 9. The control device, when it is determined that the auxiliary light is “necessary”, sets a narrower distance measurement range than when the auxiliary light is determined to be “no”. The photographing apparatus according to claim 8, wherein: 10. A case where a plurality of selected distance measurement areas are provided in the light measuring means, wherein an arbitrary distance is selected from the selected distance measurement areas based on reflected light received by the light measuring means. The photographing apparatus according to claim 7, further comprising an area selecting means for selecting a distance range. 11. A method for controlling light emission of auxiliary light based on a state of a subject in performing automatic focus control, wherein the state of the subject without auxiliary light is measured, and based on the measured state of the subject. To determine whether the auxiliary light needs to be emitted. If it is determined that the auxiliary light should be emitted, the auxiliary light is emitted to the subject and the distance to the subject is measured. And a preset reference luminance, and when the luminance of the subject is higher than the reference luminance, the photographing operation is prohibited. 12. A method for controlling light emission of auxiliary light based on a state of a subject in performing automatic focus control, wherein the state of the subject without auxiliary light is measured, and based on the measured state of the subject. It is determined whether or not the light emission of the auxiliary light is necessary.If it is determined that the light emission of the auxiliary light is “necessary”, a reliability determination value for evaluating the reliability of the distance measurement system is set in advance, and then the object While emitting auxiliary light, measuring the evaluated value regarding the reliability in the distance measuring system and the distance to the subject, comparing the evaluated value of the measured distance measuring system with the reliability determination value, When the evaluated value of the distance measuring system satisfies the reliability determination value, the photographing control is performed based on the distance to the subject. 13. A method for controlling emission of auxiliary light based on a state of a subject in performing automatic focus control, wherein the state of the subject without auxiliary light is measured, and based on the measured state of the subject. It is determined whether or not the auxiliary light needs to be emitted, and if it is determined that the auxiliary light should be emitted, “necessary” is set. An AF auxiliary light control method, wherein a distance to a front subject is measured within a preset distance measurement range, and shooting control is performed based on the distance to the subject.