JP3335702B2 - camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention relates to a camera, to a camera to prevent red-eye in particular by performing a preliminary irradiation by the flash light emission device at the time of ranging.

[0002]

2. Description of the Related Art Conventionally, there has been used an apparatus which performs preliminary irradiation at the time of distance measurement, receives light applied to the object, and measures the object distance based on the luminance thereof.

For example, Japanese Patent Laying-Open No. 59-195605 discloses a device that controls the light emission operation of a light emitting means when low luminance of a subject is detected by using an integrating light receiving element.

[0004] Further, in photographing using a strobe, when illuminating light is directly applied to a subject, a so-called red-eye phenomenon in which the subject's eyes appear red (hereinafter abbreviated as red-eye) may occur. is there. For this reason, conventionally, prior to stroboscopic photography, preflash irradiation was performed to reduce the pupil of the subject, and then stroboscopic photography was performed again.

For example, Japanese Patent Application Laid-Open No. Hei 2-201430 discloses an apparatus that emits a plurality of flashes for pupil contraction before an exposure operation.

[0006]

However, according to the above-mentioned Japanese Patent Application Laid-Open No. Sho 59-195605, preliminary irradiation is performed when a low luminance state is detected during distance measurement.
The total amount of flash light emission is increased as compared with the distance measurement in which the preliminary irradiation is not performed.

Further, in the method disclosed in Japanese Patent Application Laid-Open No. Hei 2-201430, the flash light emission is performed a plurality of times before the exposure operation, so that the total amount of flash light emission for preventing red-eye increases, and the flash light emitting device has There is a problem that the charging time of the main capacitor is prolonged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a camera capable of reducing the total amount of flash light emission for red-eye prevention and reducing the charging time of a main capacitor without impairing the effect of red-eye prevention. The purpose is to provide.

[0009]

According to the first aspect of the present invention, the subject light is divided into two images, the light intensity distribution of each image is measured, and the defocus amount of the photographing optical system is determined from the image interval. An automatic focusing device to be sought, an auxiliary light irradiating device for irradiating an auxiliary light having an emission wavelength in the visible region to the subject at the time of measuring the light intensity distribution, and a red-eye preventing light for irradiating a red-eye preventing light for pupil contraction before starting the exposure Device, and a time measuring means for measuring the time from the end of irradiation of the auxiliary light, comprising: if the time measured by the time measuring means is smaller than a predetermined time, the light amount of the red-eye preventing light is reduced. It is characterized by the following. The invention according to claim 2 is
Dividing the subject light into two images, measuring the light intensity distribution of each image,
An automatic focus adjustment device for obtaining a defocus amount of the photographing optical system from the image interval; an auxiliary light irradiation device for irradiating an object with auxiliary light having an emission wavelength in a visible region at the time of measuring the light intensity distribution; A red-eye prevention light-emitting device that irradiates red-eye prevention light for contraction, and time-measuring means that measures time from the end of the irradiation of the auxiliary light, and a time measured by the time-measuring means is a predetermined time. When the value is also smaller, irradiation of the red-eye preventing light by the red-eye preventing light emitting device is prohibited.

[0010]

According to the first aspect of the present invention, the subject light is divided into two images by the automatic focusing device, the light intensity distribution of each image is measured, and the defocus amount of the photographing optical system is determined from the image interval. Is determined, the subject is illuminated with auxiliary light having an emission wavelength in the visible region at the time of the light intensity distribution measurement by the auxiliary light irradiating device, and the red-eye preventing light is emitted for pupil contraction before the start of exposure by the red-eye preventing light emitting device, The time from the end of the irradiation of the auxiliary light is measured by the timer. And
If the time measured by the time measuring means is smaller than a predetermined time, the light amount of the red-eye preventing light is reduced.
Further, in the invention according to claim 2, the subject light is divided into two images by the automatic focusing device, the light intensity distribution of each image is measured, and the defocus amount of the photographing optical system is determined from the image interval. The auxiliary light irradiating device irradiates the subject with auxiliary light having an emission wavelength in the visible region at the time of measuring the light intensity distribution, and the red-eye preventing light-emitting device irradiates red-eye preventing light for contracting the pupil before the start of exposure, and The time from the end of the irradiation of the auxiliary light is measured by the means. If the time measured by the time measuring means is shorter than a predetermined time, irradiation of the red-eye preventing light by the red-eye preventing light emitting device is prohibited.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing an electric circuit of the camera according to one embodiment of the present invention. In the figure, the CPU
Numeral 10 sequentially executes the programs stored in the internal ROM to control peripheral ICs and the like.
The CPU 10 includes an AFIC 11 and an EEPROM 1
2. The liquid crystal display panel 13, the data bag 14, the strobe unit 15, the interface IC 16, the motor driver IC 23, and various switches to be described later are connected.

The AFIC 11 is an autofocus IC. In the camera of the embodiment, AF is performed by employing a TTL phase difference detection method. The subject light passes through a photographing lens 17, an AF optical system 20 including a condenser lens 18, separator lenses 19 L and 19 R, an AFIC 1
Photo sensor arrays 21L and 21R arranged on one upper surface
Reached on. Then, processing such as light intensity integration and quantization is performed inside the AFIC 11. This distance measurement information is transferred from the AFIC 11 to the CPU 10.

If the characteristics of each element of the photosensor array vary, accurate distance measurement information cannot be obtained as it is. Therefore, the variation information of the photo sensor array is stored in advance in the EEPROM 12 which is a nonvolatile storage element, and the CPU 10 performs the correction calculation of the distance measurement information obtained from the AFIC 11. In addition, the EEPROM 12 stores various adjustment values such as mechanical variations and variations in electrical characteristics of various elements. These adjustments may be adjusted as necessary
It is sent to the PU 10 and various operations are performed. CPU1
The transfer of data among the 0, AFIC 11, and EEPROM 12 is performed by serial communication.

The liquid crystal display panel 13 displays the number of film frames, a photographing mode, a strobe mode, an aperture value, a remaining battery level, and the like according to a signal sent from the CPU 10. Further, the data bag 14 is controlled by a control signal from the CPU 10.
This is for imprinting the date on the film.
The light quantity of the imprinting lamp changes stepwise according to the ISO sensitivity of the film. Further, the strobe unit 15
During shooting or AF ranging, when the luminance of the subject is insufficient, the light emitting tube is caused to emit light to give the required luminance to the subject.
It is controlled by C16.

The above interface IC (hereinafter referred to as IFIC)
16) performs 4-bit parallel communication with the CPU 10 to measure the subject brightness, measure the temperature in the camera,
Waveform shaping of the output signal of the photo interrupter, etc., constant voltage drive control of the motor, generation of various constant voltages such as temperature stabilization, temperature proportionality, voltage, etc., battery remaining amount check, infrared light remote control reception, motor driver IC22, The control of the LED 23, the control of various light emitting diodes (LED) 24, the check of the power supply voltage, the control of a booster circuit, and the like are performed.

To check the remaining amount of the battery, a low resistance is connected to both ends of the battery, the voltage at both ends of the battery when a current flows is divided in the IFIC 16 and output to the CPU 10, and the CPU 10 performs A / D conversion. Perform the conversion and get the value to check.

The IFIC 16 is provided with a dedicated terminal for monitoring the low voltage of the power supply voltage. When the power supply voltage input here falls below a specified value, a reset signal is output from the IFIC 16 to the CPU 10. Thereby, the CPU 10
Runaway is prevented beforehand. The control of the booster circuit operates the booster circuit when the power supply voltage falls below a predetermined value.

The IFIC 16 has a two-part silicon photodiode (SPD) 2 for photometry of subject brightness.
5 is connected. The light receiving surface of the SPD 25 is divided into two parts, such as a central part of the screen and a peripheral part thereof. There are two types, a spot metering that measures light only at a part of the center of the screen, and an average metering that measures light using the entire screen.
Street photometry can be performed. From the SPD 25, the current corresponding to the subject brightness
16 is output. In the IFIC 16, the SPD
The output from 25 is converted to a voltage and transferred to CPU 10.

In the CPU 10, exposure calculation, backlight determination, and the like are performed based on the converted voltage information. The measured value of the temperature in the camera is obtained by a circuit built in IFIC16.
A voltage proportional to the absolute temperature is output, and the signal is
It is obtained by performing A / D conversion at 10. The obtained temperature measurement value is used for correction of a mechanical member whose state changes depending on the temperature, an electric signal, and the like.

A light-receiving silicon photodiode 26 is connected to the IFIC 16. The silicon photodiode 26 is for receiving infrared light remote control, and the light emitting LE of the remote control transmission unit 27 is used.
The infrared light modulated and emitted from D28 is received. The output of the silicon photodiode 26 is IFIC1
Processing such as waveform shaping is performed inside 6 and transferred to the CPU 10.

Further, the AFIC 16 has an AF distance measurement end,
An LED for display in a viewfinder for strobe light emission warning or the like or an LED used for a photo interrupter or the like is connected. The on / off of these LEDs and the control of the amount of emitted light are controlled by the CPU 10, the EEPROM 12, the IFIC
The communication between the ICs 16 is performed by the IFIC 16 directly. Also,
Various motors are connected to the IFI via the motor driver IC22.
Constant voltage control is performed by C16.

The motor driver IC 22 has a shutter charge (S) for feeding the film and charging the shutter.
C) Driving three motors, a motor 29, a lens driving (LD) motor 30 for focus adjustment, a ZM motor 31 for zooming the lens frame, driving a booster circuit, driving a self-timer operation display LED, and the like. I do. Then, these operation controls, for example, which device is to be driven, whether the motor is rotating normally or reversely, and whether to apply braking, are determined by the CPU.
10 signal is received by the IFIC 16 and the IFIC 16
Is performed by controlling the motor driver IC 22.

Whether the SC motor 29 is in the shutter charge, film winding or film rewinding state
It is detected by a shutter charge photo interrupter (SCPI) 32 using a photo interrupter and a clutch lever, and the information is output to the CPU 10.

The extension amount of the photographing lens 17 is as follows.
It is detected by a lens driving photointerrupter (LDPI) 33 attached to the LD motor 30. The output is subjected to waveform shaping by the IFIC 16 and then output to the CPU.
Sent to 10.

The extension amount of zooming of the lens frame is ZMPI.
(Photo interrupter for zooming) 34 and ZMPR
(Zooming photo reflector) 35. When the lens frame is between the telephoto end and the wide end, the ZMPR 35 is configured to detect the reflection of a silver seal (not shown) attached to the lens frame. The output of ZMPR35 is C
It is input to the PU 10 and the tele end and the wide end are detected. On the other hand, the ZMPI 34 is attached to the ZM motor 31, and its output is
It is input to U10, and the zooming amount from the telephoto end or the wide end is detected.

The motor driver IC 23 is a stepping motor for driving the aperture adjustment unit, and drives the AV motor 36 according to a control signal from the CPU 10. Also,
The output of the AVPI 37 is input to the CPU 10 after waveform shaping by the IFIC 16, and the aperture open position is detected.

Incidentally, the waveform shaping of the photo interrupter and the like is as follows.
The output photocurrent of a photo interrupter or a photoreflector is compared with a reference current,
16 is output. At this time, noise is removed by giving the reference current a hysteresis. Further, the IFIC 16 can change the reference current and the hysteresis characteristics by communicating with the CPU 10.

Various switches coupled to the CPU 10 are provided to perform the following operations.

The first release switch R 1 SW is
It is turned on when the release button is half-pressed, and performs a distance measurement operation. Also, the second release switch R2S
W is turned on when the release button is fully depressed, and performs a shooting operation based on various measured values.

The zoom-up switch ZUSW and the zoom-down switch ZDSW are switches for zooming the lens frame. When the zoom up switch ZUSW is turned on, the camera moves in the long focal direction, and the zoom down switch ZDSW
Zooms in the short focus direction when is turned on.

[0032] When the self-switch SEL F SW is turned on, the standby state of the self-timer shooting mode or the remote control. In this state, if the second release switch R2SW is turned on, self-timer shooting is performed,
When a photographing operation is performed by the remote control transmitting unit 27, photographing is performed by the remote control.

When the spot switch SPOTSW is turned on, a spot metering mode in which metering is performed only at a part of the center of the photographing screen is set (this is metering by the AF sensor). In the case of normal photometry with the spot switch SPOTSW turned off, evaluation photometry is performed at the photometric spot 25.

Picture switches PCT1SW to PCT4
The SW and the program switch PSW are switches for switching a program photographing mode, and the photographer selects a mode according to photographing conditions.

When the picture switch PCT 1 SW is turned on, a portrait mode is set, and the aperture and shutter speed are determined so that the depth of field becomes shallow within an appropriate exposure range. When the picture switch PCT2SW is turned on, the night view mode is set, and the exposure is set one step lower than the value of the appropriate exposure during normal shooting. Picture switch PCT3S
When W is turned on, a landscape mode is set, and the values of the aperture and the shutter speed are determined so that the depth of field becomes as deep as possible within the appropriate exposure range. Picture switch PCT4S
When W is turned on, a macro mode is set. This mode is
Used during close-up photography.

The above picture switches PCT1SW-P
The CT4SW cannot be selected two or more at the same time.

The program switch PSW is a switch for a normal program photographing mode. By pressing this program switch PSW, the picture switch P
Reset of CT 1SW to PCT4SW, and A
The reset of the V priority program mode is performed.

When the AV priority switch AVSW is turned on,
The shooting mode becomes the AV priority program mode. In this mode, the AV value is determined by the photographer, and the shutter speed is determined by a program according to the AV value. In this mode, picture switches PCT2SW and PCT2
The T4SW does not have the above-described function, and serves as an AV value setting switch. That is, the picture switch PCT2S
W is a switch for increasing the AV value, and picture switch PCT4SW is a switch for decreasing the AV value.

The strobe switch STSW is a switch for switching the strobe light emission mode. That is, the normal automatic light emission mode (AUTO) and the red-eye reduction automatic light emission mode (A
A switch for switching between UTO-S), forced light emission mode (FILL-IN), and strobe off mode (OFF) .

The panorama switch PANSW is a switch for detecting whether the photographing state is panoramic photographing or normal photographing, and is turned on during panoramic photographing. When the photographing mode is panoramic photographing, a photometric correction calculation or the like is performed.
This is because the upper and lower portions of the photographing screen are masked during panoramic photographing, and a part of the photometric sensor is also masked accordingly, so that accurate photometry cannot be performed.

The back cover switch BKSW is a switch for detecting the state of the back cover of the camera, and is turned off when the back cover is closed. When the back cover switch BKSW changes from on to off, it means that film loading has started.

The power switch PWSW is a switch for turning on and off the power supply, and the shutter charge switch SCSW is a switch for detecting shutter charge. Mirror up switch MUSW
Is a switch for detecting mirror up, and is turned on when the mirror is up. Furthermore, DX switch DXSW
Is a switch for reading the DX code indicating the film sensitivity printed on the film cartridge and for detecting the presence or absence of the film loaded. The switch is composed of five switch groups (not shown).

Next, referring to the flowchart of FIG.
The operation of the first release process of the camera will be described.

First, in step S1, FIG.
G-ON of the power supply control circuit 58 of the electronic flash circuit
Is set to “H (high level)”, and a charging voltage check is performed in step S2. Next, AF is performed in step S3.
Perform distance measurement. Details of this AF distance measurement subroutine will be described later.

Then, in step S4, it is determined whether or not the AF distance measurement result is undetectable by referring to an undetectable flag. Here, when the detection is not possible, the process proceeds to step S5, and after performing out-of-focus display using the LED in the finder or the like, the process returns. On the other hand, if the detection has been successful, the process proceeds to step S6, where it is determined whether or not the auxiliary light has been irradiated at the time of AF distance measurement with reference to the auxiliary light flag.

If the auxiliary light has been turned on in step S6, that is, if the auxiliary light has been irradiated during AF distance measurement, the flow advances to step S7 to refer to the light amount over flag and the light amount under flag. If the light amount is over or under, the process returns to step S3 assuming that the distance measurement result is unreliable, changes the auxiliary light amount, and sets A again.
F distance measurement is performed. If the light amount is appropriate, the process proceeds to step S8 as in the case where the auxiliary light is turned off, and it is determined whether or not focusing is performed by referring to the focusing flag.

Here, if out of focus, the flow shifts to step S9 to drive the lens based on the result of the AF distance measurement. Then, in step S10, it is determined whether or not focusing is performed by referring to the focusing flag. Here, if in-focus, step S11
When the focus is out of focus, the process returns to the AF ranging in step S3 to perform the AF ranging.

On the other hand, if it is determined in step S8 that the object is in focus, the process proceeds to step S11, where the LED in the finder is set.
In-focus display is performed by display and buzzer sound. Then, the G-ON of the power supply control circuit 58 is set to “L (low level)”.
And then return.

Next, referring to the flowchart of FIG.
A subroutine of AF ranging will be described.

In step S21, AF sensor integration is performed by the photoelectric conversion element arrays 21R and 21L in the AFIC 11. Here, the AF optical system 20 for forming a subject image on the photoelectric conversion element arrays 21R and 21L will be described.

A subject image formed by a photographing lens is divided into two subject images by a re-imaging optical system, re-formed on a photoelectric conversion element array, and a positional shift between the two subject images is detected. 2. Description of the Related Art A focus detection optical system that performs focus detection by using a conventional method has been proposed. A typical example is, as shown in FIG.
1 and a pair of re-imaging lenses 19R and 19L. An object image 42 is formed on the image forming surface 41 when the photographing lens 17 is in focus.
Is imaged. This subject image 42 is formed by the condenser lens 1
8 and a pair of re-imaging lenses 19R and 19L, are re-formed on a two-row imaging surface 43 of a photoelectric conversion element array perpendicular to the optical axis O, and a first subject image 42L and a second subject Statue 4
2R.

When the taking lens 17 forms a so-called front focus, that is, a subject image 44 in front of the image forming plane 41, the subject images 44 are positioned close to the optical axis O with respect to the optical axis O. Vertically re-imaged, the first subject image 4
4L and the second subject image 44R. When the imaging lens 17 forms a back focus, that is, a subject image 45 behind the imaging surface 41, the subject images 45 are perpendicular to the optical axis O at positions away from the optical axis O. The image is re-formed to become the first subject image 45L and the second subject image 45R. These first and second subject images 45L, 45R
Are oriented in the same direction, and the in-focus state of the photographing lens 17 can be detected including the front focus, the rear focus, and the like by detecting the interval between corresponding portions in both images.

Next, the processing operation of the AF sensor integration in step S21 will be described with reference to the flowchart of the AF sensor integration of FIG.

First, in step S41, it is determined whether or not the flash-off mode has been set. If the flash-off mode has been set, the flow advances to step S42 to set the integral limit time to twice the normal value. If the integration is not being performed in step S43, the integration is started in step S44 (S123). The start of integration is shown in FIG.
The reset signal AFRES is output from the CPU 10 to the AFIC 11 and starts.

On the other hand, if the integration has been started in step S43, the flow advances to step S46 to determine whether or not the mode is the auxiliary light mode, that is, the mode in which the auxiliary light is applied to the subject to perform integration. . If the mode is not the auxiliary light mode, the process proceeds to step S51 to determine whether or not the integration has been completed by referring to the integration end output AFEND of the sensor control circuit SCC in the AFIC 11 in FIG.

When the integration is completed, the process returns. When the integration is not completed, the process proceeds to step S52 to determine whether or not the integration limit time has been reached. If the integration time exceeds the integration limit time, the integration operation of the AFIC 11 is forcibly stopped in step S53. If it is determined in step S52 that the time does not exceed the integration limit time, the process returns to step S43, and the loop of steps S43, S46, S51, and S52 described above is repeated until the integration is completed or the integration limit time is reached. It should be noted that the integration time is stored in the RAM by an interrupt process corresponding to the integration control circuit AFEND signal.

If it is determined in step S46 that the mode is the auxiliary light mode, the process proceeds to step S47, in which the auxiliary light irradiation, which will be described in detail later, is performed in a certain time pattern. If the integration is completed in step S48 during this auxiliary light irradiation (AFEND signal), the integration time is fetched by interruption processing and stored in a predetermined RAM. If the integration is not completed in step S48, the integration operation is forcibly stopped in step S49. Next, step S50
Then, the integration limit flag is set, and the process returns to end the integration control operation.

The above-mentioned integration limit time is provided in order to prevent the integration time from being lengthened when the subject has low luminance, and to prevent the time lag from becoming large.
Therefore, when the subject has low brightness, the subject image signal may not be obtained correctly. Therefore, when the integration time exceeds a predetermined value, auxiliary light is radiated to the subject at the next integration to compensate for the shortage of the subject light amount.

By the way, in the camera of this embodiment,
A flash mode is provided as a shooting mode in addition to a normal flash low-brightness automatic light emission mode, and is generally used when shooting in a place where flash shooting is prohibited or in an undesirable place. In this case, irradiation of strobe light as auxiliary light is also prohibited, and at the same time, as shown in steps S41 and S42 in FIG. 6, the integration limit time is set to double to prevent deterioration of focus detection accuracy at low luminance. ing.

Next, referring to FIG. 7 and FIG.
Will be described.

In the seventh embodiment, the sensor control circuit SCC
The operation of the entire AFIC 11 is controlled in accordance with a control signal from the CPU 10. When the reset signal AFRES is input from the CPU 10, the reset signal is supplied to each block in the AFIC 11, and the accumulation operation is started. During the accumulation operation, the AFEND signal is held at “L” and output to the CPU 10.

The CPU 10 monitors the AFEND signal, and outputs an AFEXT signal when the "L" section exceeds the integration limit time. In response, the sensor control circuit SCC forcibly stops the accumulation operation. Further, the sensor control circuit SCC outputs signals A to E to the sensor circuit SC to switch the sensitivity mode. Also, the sensor data D _(I) is communicated to the CPU 10 by the CLK and DATA signals. Although the photodiode PD and the sensor circuit SC will be described later, the sensor circuit SC outputs an accumulation end signal T _S to the latch circuit LC and the OR generation circuit ORC when the accumulation operation ends.

The accumulation termination signal T _S of the sensor circuit SC which has first completed the charge accumulation in the photoelectric conversion element row is converted into an OR signal via the OR generation circuit ORC by the sensor control circuit SC.
C, and the sensor control circuit SCC outputs this as a T _OR signal (see T _{OR in} FIG. 7). Further, in the photoelectric conversion element array, the sensor circuit SC which has finished the charge accumulation last.
The accumulation end signal T _S from, the AND generating circuit ANDC, outputs a AFEND signal via the sensor control circuit SCC (see FIG. 9 (e)). Hereinafter, FIG.
The (e) AFEND L section is referred to as the integration time T _E.

The CPU 10 sets the AFEND signal “L” →
When "H" is detected, it is determined that the integration of the AF sensor is completed.
The time of the section is measured to determine the integration limit.

The clock pulse generator CG generates a clock pulse CP for digitizing the charge storage time T _S into sensor data D _(I) . In FIG. 9, the clock pulse generator CG receives the AFRES signal at the same time as the input of the AFRES signal. When the operation is started, a clock pulse CP whose period increases with time as shown in FIG. 9G is generated. This change in the cycle is substantially inversely proportional to the light intensity incident on the photodiode PD in the charge storage time T _S.

An accumulation end signal T _S from the sensor circuit SC which has first completed electric charge accumulation in the photoelectric conversion element row is input to the OR generation circuit ORC, and the switch SW is closed by the ORS signal. When the switch SW is turned on, the counter COT starts counting the clock pulses CP of the clock generator CG. Therefore, the counter output “0” is latched in the latch circuit LD of the photodiode PD that has received the strongest light in the photoelectric conversion element row. In other photodiodes, as the incident light intensity is lower, the charge accumulation time becomes longer, and a time difference occurs until the accumulation end signal T _S is generated. Therefore, counter outputs corresponding to this time difference are respectively output by the latch circuit LC. Latched.

Although not shown, the OR generation circuit ORC has an accumulation end signal T from the sensor circuit SC corresponding to the photodiode located in the center range of the photoelectric conversion element row.
_Enable only _S. This is because there is a possibility that the back light of the main subject background on both sides of the photoelectric conversion element array may enter. Therefore, the accumulation end signal T from the predetermined number of left and right sensor circuits SC in this range.
_S is excluded and is not input to the OR generation circuit ORC.

Next, referring to FIGS. 8 and 9, AFIC
The sensor circuit SC in 11 will be described.

The operation mode of the block of the sensor circuit SC is switched according to the luminance of the subject. That is, when the subject has low luminance, the mode is set to the high sensitivity mode, and when the subject has high luminance, the mode is set to the low sensitivity mode. First, the sensor control circuit SC
C sets the signal A to the sensor circuit SC to set the high sensitivity mode.
To E, and switches AS1 off and A in FIG.
Set S2 ON, AS3 ON, AS4 OFF, AS5 ON. In this state, both ends of the storage capacitor C _I are short-circuited, fixed at the potential V ₂ by the operation of the operational amplifier AP, and reset. The photodiode PD has a cathode connected to the fixed potential _Vr , and generates a photocurrent according to the amount of received light.

Here, when the switch AS3 is switched from on to off, the accumulation operation starts, and the photodiode P
D pouring photocurrent in the storage capacitor C _I in accordance with the received light amount of the charge corresponding thereto are accumulated. Similarly,
The potential of the output P ₂ of the operational amplifier AP is the reset potential V ₁
From the point of inclination with a slope corresponding to the amount of received light (see FIG. 9).
(C)).

The output P ₂ of the operational amplifier AP is connected to a comparator CP whose non-inverting input terminal is fixed to a predetermined potential V _3.
When the output P ₂ of the operational amplifier AP exceeds the potential V ₃ , the output P of the comparator CP
₃ is inverted from “H” to “L”, and outputs an accumulation end signal T _S via the switch AS4. The first signal of the accumulation end signal T _S is output as the T _OR signal via the above-described OR generation circuit ORC and sensor control circuit SCC (FIG. 9 (f)).

Further, the last signal of the accumulation end signal T _S is output as an AFEND signal via the AND generation circuit ANDC and the sensor control circuit SCC described above (FIG. 9E). If the shortest accumulation time in the photoelectric conversion element row is shorter than the predetermined time, the mode is switched to the low sensitivity mode and the accumulation operation is performed again (FIGS. 9H to 9M).

Next, the sensor circuit S in the low sensitivity mode
The operation of C will be described. In the low sensitivity mode, the signals A to E are set by the sensor control circuit SCC, and the switches AS1 are turned on, AS2 is turned off, AS3 is turned off, AS4 is turned off, and AS5 is turned on. In the low-sensitivity mode, the operational amplifier AP to operate as a comparator which is fixed to the non-inverting input to V _2. Inverting input terminal P of comparator AP
₁ is fixed to the potential V ₁ and resets the junction capacitance C _J.

Next, the signal A is inverted, the switch AS1 is turned off, and the junction capacitance C _J of the photodiode PD is discharged by a photocurrent corresponding to the amount of light received by the photodiode PD. Then, the potential of the inverting input terminal P ₁ of the comparator the AP, rises with a gradient corresponding to the amount of received light from the reset potential V _1. The clock GETS discriminator CG with accumulation start, counter COT is reset, the potential of the inverting input terminal P ₁ of the comparator AP exceeds the potential V _2, the output P ₂ of the comparator AP is "H" → "L"
And outputs an accumulation end signal T _S via the switch AS5.

In the same manner as in the high sensitivity mode, the switch SW is turned on via the OR generation circuit ORC in response to the accumulation termination signal T _S from the sensor circuit SC which has completed accumulation most quickly.
N, and a _TO signal is output from the sensor control circuit SCC. On the other hand, in response to the accumulation end signal T _S from the sensor circuit SC whose accumulation has ended the latest, the AND generation circuit ANDC
, An AFEND signal is output from the sensor control circuit SCC.

Here, the accumulation time corresponding to the photodiode PD having the largest incident light amount in the photoelectric conversion element row,
That is, the shortest, that is, the accumulation time corresponding to the above-mentioned T _OR signal is T ₀ . Then, the charge accumulation time T _(I) corresponding to an arbitrary photodiode PD in the photoelectric conversion element row
And the counter output D _(I) latched in the corresponding latch circuit LC have the following relationship. T _(I) = T ₀ × 16 × 256 / (16 × 256−15 × D _(I) ) (1) By transforming this, the digitized counter output D _(I)
D _(I) = 273 · (1−T ₀ / T _(I) ) (2) Here, since the charge accumulation time T _(I) is proportional to the amount of light incident on each photodiode, the above D _{( I)} By reading out _I) , a subject image signal can be obtained. Note that the counter COT stops counting when it counts for 8 bits. Thus, weak incident light intensity on the photodiode PD, the output of the longer elements than the predetermined time in which the charge storage time T _(I) is determined by the T _o is fixed to 255.

Next, in step S22 in the AF distance measurement flowchart of FIG. 4, a sensor reading operation is performed. C
When a clock is input from the PU 10 to the CLK terminal of the sensor control circuit SCC in the AFIC 11, the count output D _(I) latched in each latch circuit LC in synchronization with the clock.
Are sequentially output to the DATA terminal as sensor data. The CPU 10 sequentially stores the sensor data D _(I) in a predetermined RAM. When the reading of all sensor data D _(I) is completed, the operation mode of the sensor circuit SC is also performed communication Kandodeta D _K if it were a high sensitivity mode or low sensitivity.

Next, in step S23, the photometric value of the subject is calculated using the sensor data D _(I) . The photometric value is used for calculation of exposure data, determination of necessity of auxiliary light, determination of reliability of obtained sensor data, and the like. The sensor data D _(I) and the charge accumulation time T _(I) are as described in (1) above.
Since the relationship of the formula is satisfied, a photometric value can be obtained by obtaining the storage time T _(I) of each element from each sensor data D _(I) . On the other hand, the integration time T _E, as described above, since the amount of light incident on the photodiode PD is accumulated time corresponding to the smallest element, the sensor data D corresponding to the device
_(I) is the maximum value among all the elements.

Assuming that the maximum sensor data is D _MAX ,
Applying the equation (1), T _E = T ₀ × 16 × 256 / (16 × 256−15 × D _MAX ) (3) Therefore, T ₀ = ((16 × 256−15 × D _MAX ) / 16 × 256)) · T _E (4), and the element having the largest amount of light incident on the photodiode PD in the photoelectric conversion element array it can be determined storage time T _o. This is substituted into equation _{(1), T (I) = (16} × 256 / (16 × 256-15 × D (I))) × ((16 × 256-15 × D MAX) / 16 × 256) · T _E = ((16 × 256−15 × D _MAX ) / 16 × 256−15 × D _(I) ) · T _E (5), and the integration time T _E , the maximum sensor data D _MAX and Based on each sensor data D _(I) , the accumulation time T _{(I) of} each element
Can be calculated.

Here, when obtaining the photometric value, it is effective to use the average value of the accumulation time T _(I) obtained from each sensor data D _(I) . Further, when the element at the center in the photoelectric conversion element row is obtained, a part of the subject image that is not formed due to the background or the like can be deleted. Further, since the first and second subject images divided by the AF optical system described above are equal, either one of the photoelectric conversion element rows 21L or 21L
What is necessary is just to calculate about 1R.

[0081]

(Equation 1) Here, n is the number of elements. By approximating this, equation (7) is obtained.

[0082]

(Equation 2) The average accumulation time of equation (7) is logarithmically compressed to obtain a photometric value E
Is as shown in equation (8).

[0083]

(Equation 3) Correction value H _E is the adjustment value for correcting the relationship between the light measurement value E with integration time T _E, measures the integration time for the uniform light source, is stored in the EEPROM12 for each camera. This is because the optical system varies from one camera to another and the sensitivity differs from photoelectric conversion element to another. Further, the high-sensitivity mode and the low-sensitivity mode AFIC11, the correction value H _E are different, have a respective correction value.

[0084] In the same embodiment, it is performed the calculation of the photometric values by using the integration time T _E, T in FIG. 7 described above
The time of the L section of the T _OR signal output from the _OR terminal (FIG. 9
(F)) to obtain T ₀ = T _OR , calculate the accumulation time T _{(I )} of each element by applying the above equation (1), and further express the relationship by the relational expression of the number 4 of the number n of elements. Finding the average accumulation time
Equation (9) is obtained.

[0085]

(Equation 4)

(Equation 5) Even when this is applied to the equation (8), the photometric value E 'can be obtained similarly.

[0086]

(Equation 6) Next, in step S24 of FIG. 4, when the AFIC 11 integrates, if the luminance is insufficient at low luminance, the subject is irradiated with auxiliary illumination light. That is, it is determined whether or not it is necessary to turn on the auxiliary light, and a process of setting the light amount of the auxiliary light is performed.

FIG. 10 shows a subroutine for this auxiliary light determination. First, in step S61, it is determined whether or not the current integration was performed in the high sensitivity mode by using sensitivity data D
_Judge with reference to _K. Here, in the low sensitivity mode, the subject brightness is sufficiently high and no auxiliary light is required, so the process returns as it is. In the case of the high sensitivity mode, the process proceeds to step S62, and it is determined whether or not the auxiliary light has been irradiated at the time of the current integration.

If the auxiliary light has not been irradiated, the flow shifts to step S63 to determine whether or not the auxiliary light is necessary at the next integration. Here, the integration time T of the AFIC 11
By comparing _E with the determination value T _S1, it is determined that the auxiliary light is necessary when the integration time T _E is longer, that is, when the subject has low luminance. Next, the irradiation light amount of the auxiliary light is set. In this embodiment, the strobe light is used as the auxiliary light.
At 64, the GNO (guide number) is set. This will be described with reference to FIG.

FIG. 11 is a flowchart for performing the initial setting of the auxiliary light amount AGNO.

The camera according to the present embodiment has a macro mode as a photographing mode. When the macro mode switch is turned on by the photographer, the camera is set to the macro mode. In step S81, it is determined whether the macro mode has been set as the shooting mode. Here, in the case of the macro mode, since the photographer intends to photograph a subject located in the close vicinity, the flow shifts to step S82, and in response to this, the auxiliary light amount AGNO is set to an appropriate value for the close subject. A relatively small light amount AGNO = D is set (see FIG. 12). On the other hand, if the mode is not the macro mode in step S81, the process proceeds to step S83.

The light amount AGNO of the auxiliary light is
A predetermined value is set according to the focal length f. General focal length shooting lens (28-180m
In m), it is known that the photographing magnification is most frequently 1/40 to 1/60. Therefore, the subject distance with a high shooting frequency is almost determined according to the focal length.
The auxiliary light amount AGNO corresponding to this is initialized.

In this embodiment, the focal length is divided into three regions, and an appropriate amount of auxiliary light is set for each region. That is, first, in step S83, the first widest side first
Is set as the auxiliary light amount AGNO = A corresponding to the focal length region of the above.

FIG. 12 shows the number (1) of the auxiliary light amount AGNO.
12) and a table of GNO values of AGNO. This is because, from the minimum value of the auxiliary light amount AGNO appropriate for the subject having the shortest shooting distance and high reflectance of the camera, the auxiliary light appropriate for the subject having the longest shooting distance and low reflectance during flash shooting determined by the flash GNO at the time of shooting. AGNO
Are divided up to the maximum value. An appropriate one is selected from these auxiliary light amounts AGNO.

In the software, the numbers (1 to 1)
Select 2) and select AGNO.

Next, in step S84, ZMPI
The value of the zoom pulse ZP from No. 34 is set to a first determination value ZP1.
Then, it is determined whether or not the area 1 is set. Here, in the case of the area 1, the process returns. If it is not the area 1, the process proceeds to step S85, and an appropriate amount of auxiliary light AGNO = B is set in the area 2, which is an intermediate area.
Next, in step S86, the zoom pulse ZP is similarly compared with the second determination value ZP2 to determine whether the region is the region 2. Further, the same processing is performed for the area 3, and in step S 87, the auxiliary light amount A
GNO = C is set.

In this embodiment, the initial setting value of the auxiliary light amount AGNO is set according to the focal length of the photographing lens. In addition, the FNO of the photographing lens, the photometric value E, the integration time T _E , or the peak value The same effect can be obtained even if it is changed according to the accumulation time T _OR . Also, it may be determined by a combination of these.

When the AGNO has been set in this way, the flow advances to step S65 to set the auxiliary light flag, and then returns.

On the other hand, the case where the auxiliary light is irradiated in the current integration in step S62 will be described below.

When the integration time is short, that is, when the subject is located at a close distance, or when the amount of illumination of the auxiliary light is too large, the sensor data output from the AFIC 11 has a very large variation and is reproduced with respect to the subject image. Poor data can be easily obtained. Therefore, the result of the correlation operation using the sensor data has low reliability.

Next, this will be described with reference to FIG.

FIG. 13A shows the relationship between the accumulation time T _S and the accumulation voltage V _S during integration while projecting auxiliary light. The figure shows three cases A, B, and C in which the amount of light incident on the subject image photoelectric conversion element has a ratio of 1: 2: 4. FIGS. 4B and 4C show a timing chart of an AFRES signal and a timing chart of irradiating a subject with periodic strobe pulse light as auxiliary light.
Shown in Further, for convenience of explanation, C in FIG. 3A is an element having the largest incident light amount among all the photoelectric conversion elements. For such storage waveform, set the accumulation determination voltage V _3,
13 (f), (e) and (d) show timing charts of the accumulation times T _S ( _TSA , _TSB , _TSC ) corresponding thereto.

By applying the above equation (2) of the above-mentioned quantization method, digitized sensor data D _(I) can be calculated.

[0103] Incidentally, the amount of incident light is 1: 2: If having 4 ratio, and when not irradiated with assist light, i.e. the steady mode sensor data D _(I), respectively by equation (2) D _{( I)} = 0, 137, 205. The sensor data, the absolute value and the accumulation determination voltage V ₃ of the amount of incident light be varied, does not change as long as the incident light quantity ratio is not changed.

However, when the auxiliary light is projected, even if the incident light amount ratio does not change, the sensor data D
_(I) may change, making it difficult to accurately recognize the subject image. Such a case will be described below.

[0105] In FIG. 13, the change in subject brightness, i.e. it is assumed that the change in the absolute value of the amount of light incident on the photoelectric conversion element, consider replacing the change of the accumulation determination voltage V ₃ for simplicity.

[0106] Figure 14 is a variation of the sensor data D _S of the photoelectric conversion elements B and C in the case of changing the storage determining voltage V _3, based on the sensor data D _S in the steady light mode,
It is a figure showing the difference from it.

As is clear from FIG. 14, the error ΔD _S of the sensor data D _(I) at the time of projecting the auxiliary light is equal to the accumulation determination voltage V
_The lower the value of _{3, the} larger the value. In other words, the sensor data error ΔD _S increases as the subject reflectivity or the auxiliary light projection light amount increases, and accurate subject image data cannot be obtained. As a result, the accuracy of focus detection is significantly reduced. Further, from FIG. 14, the sensor data error [Delta] D _S indicates that the greater the shorter the storage time T _S, will reduce the focus detection accuracy in the same manner as a short storage time T _S.

Therefore, by setting an appropriate amount of auxiliary light in consideration of the reflectivity and the distance of the object and controlling so as to have an appropriate accumulation time, accurate object image data can be obtained even when the auxiliary light is projected. As a result, the focus detection accuracy can be maintained.

Therefore, if the integration time T _E is shorter than the predetermined value, it is determined that the reliability is low, and the amount of irradiation of the auxiliary light is reduced, and the AF sensor integration is performed again.

Next, returning to FIG. 10, in step S66, a first determination is made by comparing the integration time _TE with a predetermined value _Ts2 . If the integration time T _E ≧ T _S2 , the process returns because the light amount is not over. On the other hand, the integration time T
_{If E} <T _S2 , it is determined that the light amount is over, and the process proceeds to step S67 to set the light amount over flag. Next, at step S68, AG
A predetermined number N is subtracted from NO to make AGNO anew.

In step S69, if this AGNO is smaller than 1, it means that it is beyond the light amount control range shown in FIG. 12, that is, since the subject is located at a very short distance and has a high reflectance. Then, the process shifts to step S73 to set an undetectable flag, and then returns. If AGNO ≧ 1 in step S69, the process proceeds to step S70 to make a second determination. Here, the first determination value T _S2 described above, compared with T _S2> T _S3 becomes the second determining value T _S3 integration time T _E. This is for judging a case where the light amount of the second level is larger than that of the second level, and setting the appropriate auxiliary light amount AGNO more effectively.

In step S70, the integration time T
_{If E} ≧ T _S3 , the light amount is over, but the light amount is over the first level, so the routine returns and the above-mentioned AGNO = AGNO−N is stored. On the other hand, when the integration time T _E <T ₃ , the light amount of the second level is larger than that. Therefore, in order to further reduce the light amount of the auxiliary light,
In step S71, a predetermined number M is subtracted from AGNO to newly set AGNO. Next, in step S72, if this AGNO is smaller than 1, it is out of the light amount control range in the same manner as described above, so the flow shifts to step S73 to set a detection impossible flag and returns.

In this embodiment, the integral time _TE is used for the determination of the light quantity excess. However, it is effective to make a determination using the photometric value E, the peak accumulation time T _OR , and a combination thereof. is there.

Here, the flow returns to the AF distance measurement flowchart of FIG. 4 again. In step S25, it is determined whether the detection is impossible by referring to the detection impossible flag. Here, if the detection is not possible, the process moves to step S26, the out-of-focus flag is set, and the AF distance measurement operation ends.

On the other hand, if the detection is not impossible in step S25, then the light quantity over flag is referred to in step S27. Here, if the light amount is excessive, the process returns, and the AF distance measurement routine is called again via the main flowchart, and the AF sensor integration is performed while irradiating the set AGNO auxiliary light. Step S2 above
If the light amount is not over in 7, the illuminance distribution correction processing of step S28 is performed next.

In the illuminance distribution correction in step S28, non-uniformity correction of the obtained subject image signal is performed. This is to correct the sensitivity variation caused by the non-uniform illuminance on the AF sensor surface due to the re-imaging optical system and the variation of the photodiode PD and the storage capacitor of the photoelectric conversion element array. The correction coefficient calculated based on the sensor data D _(I) of each element with respect to the uniform light source is stored in advance in the EEPROM 12 for each element, and the correction coefficient is read out each time an object image signal is detected, and the correction calculation is performed for each element. Do.

The correction coefficient is obtained as follows.
Assuming that the photoelectric conversion element output D _{0 (I)} for a uniform light source is, the accumulation time T _(I) of each element is expressed by the following equation from the above equation (1). T _(I) = T ₀ × 16 × 256 / (16 × 256−15 × D _{0 (I)} ) (11) where T ₀ is the _value of the photoelectric conversion element having the largest incident light amount in the photoelectric conversion element row. The accumulation time. Ideally, the storage time of all the elements should be T ₀ for a uniform light source, but in practice, variations occur due to the above factors. As a correction method, a correction coefficient that makes each accumulation time T _(I) coincide with T ₀ is obtained. The correction coefficient H _(I) is as follows using the equation (12). H _(I) = T _(I) / T ₀ = 16 × 256 / (16 × 256−15 × D _{0 (I)} ) (12) Next, sensor data before correction obtained by subject image signal detection D _(I), 'When _(I), T' sensor data after correction using the correction coefficient _{H (I) D (I)} = T (I)
/ H _(I) , 16 × 256 / (16 × 256−15 × D ′ _(I) ) = (16 × 256 / (16 × 256−15 × D _(I) )) · 1 / H _{( I)} D ′ _(I) = 16 × 256/15 − ((16 × 256−15D _(I) ) / 15) · H _(I) (13)

The correction coefficient H _(I) needs to be transformed into a form that can be easily stored in the EEPROM 12. EEPROM 12
Is limited, the coefficient H _{(I) is set} to a constant A _S , in order to effectively store the correction coefficient within this range.
B _S by _{H '(I) = (16} × 256 / (16 × 256-15 × D 0 (I))) × A S -B S ... deformed to be compressed (14).

In the following, when the constants are actually determined as an example, variations in illuminance on the AF sensor surface due to the re-imaging optical system and variations in sensitivity of the AF sensor including the photoelectric conversion element array and the like are described. For example, assuming ± 15%, the range of the correction coefficient H _(I) is 1 ≦ H _(I) ≦ 1.15.

On the other hand, due to the limitation of the storage capacity of the EEPROM 12, the constants A _S and B _S may be set to 104 so that the deformation correction coefficient H ′ _(I) is, for example, 4 bits.

H ′ _(I) = H _(I) × 104−104 = (16 × 256 / (16 × 256−15 × D0 _(I) )) × 104−104 (15), and 0 ≦ H ′ _(I) ≦ 15.6.

Using the above equation (15), H
_{When (I)} is deleted, the corrected sensor data D ' _(I) is D' _(I) = ((H ' _(I) +104) / 104) .D _(I) -(512/195) .H ′ _(I) … (16) Here, the constant C is set so that D ' _(I) <0 is not satisfied.
Add _S. For example, D as _{C S = 40 '(I)} = ((H' (I) + 104) / 104) · D (I) - from _{(512/195) · H '(I} ) +40 ... (17) or Equation (15) is the equation for calculating the correction coefficient H ′ _(I) ,
Equation (17) is an illuminance distribution correction equation. Since the incident light amount is small in the photoelectric conversion element array and the sensor data D _(I) is at the limit of quantization 255, the illuminance distribution correction is not performed because the incident light amount is not correctly photoelectrically converted.

Next, in step S29 of AF ranging in FIG. 4, a correlation operation is performed on the two subject images to detect an interval between the two images. For the sake of convenience, the first subject image is assumed to be an L image,
Let L (I) be the subject image signal. The second subject image is defined as a P image, and the second subject image signal is defined as R (I).
Here, I is an element number, and is 1, 2, 3,... That is, each element 21
Each of L and 21R has 64 elements.

Referring to the flowchart of FIG. 15, the correlation calculation processing will be described.

First, in steps S91 and S92, variables SL, SR, and J are set to 5, 37,
Set 8 Here, SL is the subject image signal L (I)
Is a variable for storing the head number of the small block element row for which the correlation is detected from among
In (I), a variable for storing the head number of a small block element row for which a correlation is detected, and J is a variable for counting the number of movements of a small block in the subject image signal L (I).

Then, in step S93, the correlation output F (S) is calculated by the equation (18).

(Equation 7) In this case, the number of elements in the small block is 27. The number of elements in the small block is determined by the size of the distance measurement frame displayed on the viewfinder and the magnification of the detection optical system.

Next, in step S94, the minimum value of the correlation output F (S) is detected. Where F (S) is Fmi
If F (S) is smaller than Fmin, the process proceeds to step S95, where F (S) is substituted for Fmin, and the SL and SR at that time are stored as SLM and SRM. In step S96, 1 is subtracted from SR, and 1 is subtracted from J.

Then, in step S97, if J is not 0, the correlation calculation is repeated. That is, the correlation is obtained while fixing the small block position in the image L and shifting the small block position in the image R by one element. When J becomes 0, next, in step S98, 4 is added to SL, and 3 is added to SR, and the correlation calculation is continued. That is, the correlation calculation is repeated while shifting the small block position in the image L by four elements. Thus, in step S99, when the value of SL becomes 29, the correlation calculation ends.

As described above, the correlation calculation can be performed efficiently, and the minimum value of the correlation output can be detected. The position of the small block indicating the minimum value of the correlation output indicates the positional relationship of the image signal having the highest correlation.

Next, in step S100, the correlation outputs FM and FP expressed by the equations (19) and (20) are calculated in order to determine the correlation of the detected block image signal having the highest correlation. I do.

[0131]

(Equation 8)

(Equation 9) In other words, the correlation output is calculated when the subject image R is shifted by ± 1 element from the small block position indicating the minimum correlation output. At this time, FM, Fmin, FP are as shown in FIG.
6 and FIG. Note that FIG.
17, the horizontal axis indicates the position of the photoelectric conversion element, and the vertical axis indicates the correlation output.

The correlation output F (S) becomes 0 at the point ZR. On the other hand, when the correlation is low, it does not become 0 as shown in FIG.

In step S101, correlation indexes SK and FS represented by the following equations are obtained in order to determine the correlation.

When FM ≧ PF, SK = (FP + Fmin) / (FM−Fmin) (21) FS = FM−Fmin (22) When FM <FP: SK = (FM + Fmin) / (FP−Fmin) (22) 23) FS = FP−Fmin (24) As can be seen from FIGS. 16 and 17, the correlation index SK is SK = 1 when the correlation is high, and SK> 1 when the correlation is low. Therefore, it is possible to determine whether or not the detected image shift amount is reliable based on the value of the correlation index SK.

Since the correlation index FS corresponds to the contrast of the small block image signal having the highest correlation, the larger the value, the higher the contrast.

In the AF distance measurement flowchart of FIG.
In step S30, the correlation indices SK and FS are used to determine the correlation.

By the way, the correlation index SK is actually the same because the first and second subject images do not completely match due to variations in the optical system, noise of the photoelectric conversion element, conversion error, and the like. SK does not equal 1. Therefore,
The determination is made using a predetermined determination value α. Also, the correlation index F
For S, a predetermined determination value β is used. That is, S
It is determined that there is a correlation only when K ≦ α and FS ≧ β, and S
If K> α or FS <β, it is determined that there is no correlation and A
F It is determined that detection is not possible, and a detection impossible flag is set. Since these judgment values α and β vary depending on the product and use different judgment values depending on the photographing mode and the AF operation mode, they are stored in the EEPROM 12, respectively.

If there is a correlation in step S30, the flow advances to step S31 to calculate an image shift amount. The distance ZR between the first and second subject images is equal to SO
Therefore, when FM ≧ FP, ZR = SRM−SLM + (FM−FP) / (FM−Fmin) · 2 (25) When FM <FP, ZR = SRM−SLM + (FP−FM) / (FP−) Fmin) ・ 2 (26). Next, the image shift amount ΔZR from the focusing is ΔZR = ZR−ZR0 (27) where ZR0 is a subject image interval at the time of focusing and is stored in the EEPROM for each camera.

Next, in step S32, the image shift amount ΔZR is converted into a defocus amount ΔDF. The shift amount of the imaging position on the optical axis with respect to the film surface, that is, the defocus amount ΔDF can be obtained by the following equation. _{ΔDF = B D / (A D} -ΔZR) -C D ... (28) _{However, A D, B D, C} D is a constant determined by the AF optical system. This is described in JP-A-62-10
0718, the description is omitted here.

Next, in step S33, aberration correction is performed. Here, depending on the focal length and the extending position of the focusing lens due to the spherical aberration of the taking lens 17,
Since the focal point position of the AF optical system is shifted, this is corrected.
This correction is performed using a correction value stored in the EEPROM 12 according to the focal length of the photographing lens 17 and the subject distance.

Then, in step S34, a release defocus correction process for correcting defocus at the time of exposure is performed. This is to predict and correct the shift of the image forming position during the photographing stop-down operation.
Since it is disclosed in Japanese Patent Application Publication No. 669, description thereof is omitted here.

Next, in step S35, it is determined whether or not the detected defocus amount ΔDF is within the allowable focusing range. The allowable focus range is determined by the depth of field, that is, the aperture value at the time of shooting and the focal length of the shooting lens. In the case of a low-contrast subject, a low-luminance subject, when illuminating auxiliary light, or when the focal length of the photographing lens is long, the fluctuation of the detected defocus amount is large. If it is within the allowable focus range, the process proceeds to step S37, sets the focus flag, and returns. On the other hand, if it is out of the permissible focusing range, the process returns after calculating the lens drive pulse amount in step S36.

Since various proposals have been made for converting the detected defocus amount ΔDF to the lens extension amount ΔLK in the optical axis direction, detailed description thereof will be omitted here. For example, in Japanese Unexamined Patent Publication No. 64-54409, the value is obtained by the following equation. _{ΔLK = A a - (A a} × B a) / (A a + ΔDF) + C a × ΔDF ... (29) _{where, A a, B a, C} a is a constant, respectively stored for each focal length is there.

The focusing lens of the photographing lens 17 is driven by an AF motor via a gear train, and the amount of movement of the focusing lens is input to the CPU 10 as AFPI pulses by an encoder. Therefore, the lens extension amount ΔLK in the optical axis direction is set to A per unit extension amount.
The number of lens driving pulses DP is obtained by multiplying the number of FPI pulses K.

DP = K × ΔLJ (30) Note that the image shift amount ΔZR in the above equation (27) and the defocus amount ΔDF in the equation (28) are both signed values.
In the positive case, the image is formed on the rear pin, that is, on the rear side of the film surface, and indicates the direction in which the lens is extended. A negative value indicates the direction in which the lens is retracted by the front focus.

If there is no correlation in step S30, the flow advances to step S38 to refer to the auxiliary light mode flag and determine whether or not auxiliary light irradiation has been performed during the current AF sensor integration. I do. If the auxiliary light is off, the process proceeds to step S26, the out-of-focus flag is set, and the AF ranging routine ends. on the other hand,
If the auxiliary light is on, in the next step S39, FIG.
The auxiliary light amount increasing routine shown in the flowchart of FIG.

[0147] That is, in step S111, first reference integral limit flag, determines whether or not the integration time T _E exceeds the integration limit time T _L. Here, in the case of the integration limit, it is highly probable that proper subject image data could not be obtained due to the lack of the auxiliary light amount, and the correlation could not be obtained. Therefore, the process proceeds to step S112, where a predetermined number L is added to the auxiliary light amount AGNO to newly set AGNO. This is to obtain more appropriate subject image data by irradiating the increased amount of auxiliary light during the next integration of the auxiliary light mode sensor.

Next, in step S113, it is determined whether or not the new AGNO is within the control range. AG
If NO> 12, it is outside the control range shown in FIG. 12, so that the detection impossible flag is set in step S114, and the routine returns. In such a case, the subject is located at a long distance, the reflectance is low, and the brightness is very low. On the other hand, step S
At 113, if AGNO ≦ 12, it is within the control range, so the routine returns.

If it is determined in step S111 that the value is not the integration limit, it is unlikely that improvement will occur even if the amount of auxiliary light is increased. Therefore, the flow shifts to step S114, where the detection impossible flag is set. Return later.

[0150] Here, it was determined by whether the insufficient light is integral limit, comparing the predetermined value with the integration time T _E, or it is also effective to determine with photometric value.

After the process of increasing the amount of auxiliary light has been performed, the flow returns to the AF distance measurement flowchart of FIG. 4 and the detection impossible flag is referred to in step S40. Here, if the detection is not possible, the process moves to step S26, sets the out-of-focus flag, and returns. If the detection is not possible, the process returns as it is, and again returns to A in the main flowchart.
Call F range finding.

Here, in this embodiment, the shortage of the auxiliary light irradiation light amount is determined by determining whether or not the integration limit (step S111 in FIG. 18) is satisfied. However, instead of the integration time _TE (the storage time of the element with the smallest amount of received light in the photoelectric conversion element array), the determination is made using the _TOR signal (the storage time of the element with the largest amount of received light in the photoelectric conversion element array). It is still effective. Alternatively, the determination may be made using the photometric value E described above. Alternatively, if the determination is made based on a combination of the integration times T _E , T _OR , and the photometric value E, more effective control can be performed.

Next, the photographing lens 17 is driven based on the result of the AF distance measurement.

The operation of the lens driving process will be described with reference to the flowchart of FIG.

First, in step S121, it is determined whether or not the number of lens driving pulses calculated in the AF distance measurement processing is larger than a predetermined value. The predetermined determination value uses the number of lens drive pulses that can drive the lens within the focusing range by one lens drive. Here, for example, 400 pulses are used. That is, the number of lens drive pulses is 40
If it is smaller than 0 pulse, the process proceeds to step S122, and it is determined from the flag whether the backlash drive has already been completed.

If it is determined in step S122 that the backlash drive has not been completed, the process proceeds to step S12.
Proceeding to 3, it is determined whether or not the lens driving direction is reversed from the previous time. If the direction is the same as the previous lens driving direction, the process proceeds to lens driving in step S124, and AF is performed.
The lens drive is executed based on the number of lens drive pulses obtained as a result of the distance measurement. Thereafter, the focus flag is set in step S125, and the routine returns. In this case, as described above,
This is the number of drive pulses that are always focused by one lens drive.
The lens driving direction is the same as the previous one. Therefore,
Since there is no backlash, focusing is performed without performing AF ranging again.

If backlash driving has been completed in step S122, the flow advances to step S124 to drive the lens. In step S125, a focusing flag is set, and the flow returns.

If it is determined in step S123 that the lens driving direction is the reverse direction with respect to the previous time, the flow advances to step S126 to calculate the amount of backlash.
The amount of backlash changes depending on the focal length and the driving direction of the photographing lens 17, and accordingly, calculation is performed in accordance with the change. Next, in step S127, based on the calculated backlash amount, the lens is driven by the number of lens driving pulses corresponding to the backlash amount. Then, in step S128, a backlash driven flag is set, and the process returns. In this case, the AF ranging processing and the lens driving processing are performed again on the main flowchart.

Further, in step S121, if the number of lens drive pulses calculated by AF distance measurement is 400 pulses or more, the flow advances to step S129 to subtract a predetermined value from the lens drive pulse and newly drive the lens. Pulse. This predetermined value is a correction value indicating a position before the focal point in the lens driving pulse. In this flowchart, for example, 200 pulses are set.

In step S130, the lens is driven based on the corrected lens drive pulse. Also, in this lens driving, even if there is backlash, it is removed. Next, in step S131, a backlash driven flag is set, and the process returns. As a result, the photographing lens is located almost before the focal point and at the position of 200 pulses in terms of the number of driving pulses, so that the AF distance measurement and the lens driving process are called again in the main flowchart to bring the lens into focus.

The correction value is set so as to give a sense of speed of the AF operation related to the appearance of the viewfinder (not shown) of the camera. For example, consider a case in which AF ranging and lens driving processing are repeated twice from a state where the defocus amount is large to achieve focusing.

When the stop position of the first lens drive is relatively close to the focal point, for example, at 50 pulses before, the finder is almost in focus, but at 200 pulses before, the focus is still out of focus. When the second lens drive is executed from this state, focusing is performed in any case. However, in the latter viewfinder, the sense of speed can be obtained by changing the focus from defocusing to focusing. Therefore, the appearance of the finder greatly changes depending on the focal length of the photographing lens, and the correction value is changed accordingly.

FIG. 20 is a block diagram of a circuit of the strobe unit 15.

In this figure, the strobe unit 15
Is a power supply E, and a DC connected in parallel with the power supply E to boost the power supply voltage until a strobe can emit light.
/ DC converter 51 and this DC / DC converter 5
1 and a main capacitor 53 for storing light-emitting energy through a diode 52;
The configuration includes a main capacitor voltage measurement circuit 54 connected to the output of the DC converter 51 and measuring the voltage charged in the main capacitor 53.

The circuit of the strobe unit 15 is connected to the cathode of the diode 52 and emits light by consuming the energy of the main capacitor 53.
e) Xe connected to the tube 55 and the output of the DC / DC converter 51 similarly to the main capacitor voltage measuring circuit 54
Trigger circuit 56 for applying a trigger for light emission to tube 55
And a light emission amount control circuit 57 for controlling the light emission amount of the Xe tube 55, and a power supply control circuit 58 for controlling the power supply of the light emission amount control circuit 57.

The control of the DC / DC converter 51, the main capacitor voltage measuring circuit 54, the trigger circuit 56, the light emission amount control circuit 57, and the power supply control circuit 58 is as shown in FIG.
Control the IFIC 11 as an interface.

FIG. 21 is a detailed circuit diagram of this strobe unit.

That is, the main capacitor voltage measuring circuit 54 includes a series circuit of the resistors R1 and R2,
And a capacitor C1 connected in parallel.
When the DC / DC converter 51 is on, the resistance R
The voltage of the main capacitor 53 is measured by the voltage generated between the resistor R and GND by the voltage dividing ratio of 1 and the resistor R2.

In the trigger circuit 56, resistors R3 and R4, capacitors C2 and C3, a trigger transformer T1, and a thyristor D2 are connected as shown. The trigger circuit T1 applies a trigger to the Xe tube 55 and simultaneously applies a negative main capacitor voltage to the cathode of the Xe tube 55,
The voltage doubler circuit that emits light from the Xe tube 55 is also used.

Here, the operation of the trigger circuit 56 will be described.

The operation of the trigger circuit 56 is as follows.
The converter 51 is activated for a certain period of time, and the output charging current is
The capacitors C2 and C3 are charged via the resistor R3.
When the thyristor D2 is turned on, the charged electric charge flows from the capacitor C2 to the thyristor D2, between the primary terminals a and b of the trigger coil T1, and then to the capacitor C2. When a current flows through the primary side of the trigger coil T1, a magnetic flux linkage between the primary winding and the secondary winding is generated in the coil. Therefore, a high voltage is induced at the terminal c on the secondary winding side of the trigger coil T1. In addition, by driving the trigger circuit, the capacitor C3
→ A current flows through the thyristor D2 → the resistor R4 → the capacitor C3, and the anode voltage of the thyristor D2 (the capacitor C3
Thyristor side) instantaneously becomes 0 V from the voltage at which the Xe tube 55 can emit light.
The voltage on the side becomes a negative light emission enabling voltage from 0V. Then, the voltage on the cathode side of the Xe tube 55 is maintained at a negative voltage by the diode D3, and a double luminous voltage is applied to both ends of the Xe tube 55 to facilitate light emission.
A so-called voltage doubler circuit is driven.

The light emission amount control circuit 57 includes an IGBT 1, a Zener diode D4, resistors R5 and R6, and a transistor Q1, which are connected as shown in FIG. The light emission amount control circuit 57 uses the voltage supplied from the power supply control circuit 58 to control the Zener diode D4
Creates the gate voltage of IGBT1, and turns IGBT1 on. At this time, a light emission current flows through the Xe tube 55, and I
The same emission current flows through the GBT 1. Then, when a light emission stop signal is input to the transistor Q1 through the resistor R6 to the light emission amount control circuit 57, the transistor Q1 is turned on, the electric charge accumulated in the gate of the IGBT1 is released through the transistor Q1, and the IGBT1 is turned off. Xe tube 5
Light emission of 5 stops.

In the power supply control circuit 58, the emitter of the transistor Q2 is connected to the plus side of the main capacitor 53, the collector is connected to the light emission amount control circuit 57, and the base is connected to the collector of the transistor Q3 via the resistor R8. It is connected to the. The emitter of the transistor Q3 is connected to GND, the base is connected to a microcomputer (not shown) via a resistor R9, and the resistor R7 is connected between the emitter and the base of the transistor Q2.

Power supply control circuit 5 thus connected
In 7, when an ON signal is input to the G-ON terminal, the transistor Q3 is turned on. This transistor Q
When the switch 3 is turned on, the transistor Q2 is turned on, and the driving power is supplied to the emission light amount control circuit 57. Then, when the off signal is input to the G-ON terminal, the supply of the driving power of the emission light amount control circuit 57 is cut off.

FIG. 22 shows a change in the pupil diameter when the strobe light is intermittently emitted.

In this figure, when the strobe light is intermittently emitted from time t _{0 to} t ₁ , the pupil diameter is reduced to φ ₁ . Then, after stopping the light emission at time t _2, the pupil gradually expands gradually.

Here, the pupil diameter which has the effect of preventing red eye is:
When phi _0, pupil diameter, by performing exposure while extended to phi ₁ to [phi] _0, significant eye pictures are not captured. Note that φ
Pupil diameter to ₁ to [phi] ₀ is the # T1 time to expand.

FIG. 23 is a subroutine for checking the charging voltage in step S2 of the flowchart in FIG.

First, in step S141, the voltage of the power supply E is measured and stored. Next, in step S142, the temperature of the power supply E is measured and stored. Then, step S14
At 3, based on the result of the power supply voltage temperature in steps S141 and S142, the time for performing the precharge for the voltage check is determined. Subsequently, in step S144, the STC
An “H” signal is input from the HRG terminal to activate the DC / DC converter 51 and start charging.

In step S145, step S1 is executed.
Charging is performed for the time determined in step 43, and V
The voltage of the main capacitor 53 is A / D converted from the ST terminal, and the A / D value is stored. In the next step S147, the A / D value measured in the above step S146 is EEP
A comparison is made with the A / D value of the light emission enabling voltage stored in the ROM 12. Here, if the measured voltage is high, step S14
Proceeding to 8, the light emission enable flag is set. On the other hand, if the measured voltage is low, the process proceeds to step S149, and the light emission enable flag is cleared.

Thereafter, in step S150, STCHRG
The “L” signal is input to the terminal and the DC / DC converter 51
Is stopped, and the subroutine ends.

FIG. 24 is a subroutine for illuminating the auxiliary light called in step S47 of FIG.

First, in step S151, the number of times of emission of the auxiliary light is set, and subsequently, in step S152, precharging described later is performed. Next, in step S153, AF
Light is emitted for a light emission time corresponding to the guide number determined by the calculation. Then, after a predetermined time (equivalent to a light emission interval) is set in step S154, light is emitted a predetermined number of times in step S155.

Thereafter, in step S156, the timer counter TCO is reset and started. The timer / counter TCO measures the time from the end of auxiliary light irradiation to the start of red-eye prevention light emission (hereinafter, referred to as red-eye light emission).

FIG. 25 is a subroutine for explaining the precharging operation.

Steps S161 to S165 are the same as those in FIG.
3 is the same as steps S141 to S145 of the charge voltage check. Then, in step S166, STCHR
After the G terminal is set to "L", the routine returns.

FIG. 26 is a subroutine for explaining the light emission operation.

First, in step S171, the light emission time for obtaining the required light emission amount is read, and in step S172.
Then, an "H" signal is output from the STON terminal to emit light.
Next, in step S173, the above-described step S171 is performed.
The light emission is continued for the time read by. Here, when the predetermined time has elapsed, the process proceeds to step S174, where an "H" signal is input to the STOFF terminal to turn off the IGBT 1, and the Xe tube 5
5 stops emitting light. Next, STON in step S175
The terminal is set at "L", and at step S176, the STOFF terminal is set at "L" and the processing ends.

FIG. 27 is a sequence illustrating the exposure operation.

When the second release switch R2SW is pressed, a subroutine 2R is called. Then, in step S181, the G-ON terminal is set to “H”, the power supply control circuit 58 is turned on, and electric charges are supplied to the gate terminal of the IGBT1. Next, in step S182, if it is determined that red-eye emission is necessary, step S1
Proceed to 83 to perform red-eye emission.

In steps S184 to S188, an exposure sequence such as mirror up, exposure, mirror down, shutter charge, and film winding is performed. Then, in step S189, the G-ON terminal is set to "L" and the processing ends.

FIGS. 28 and 29 are subroutines for explaining the operation of red-eye emission.

At step S191 in FIG. 28, when the time until red-eye emission is performed is shorter than ΔT1 in FIG. 22, the pupil diameter is sufficiently small, and the routine returns without performing red-eye emission. After performing the auxiliary light irradiation, step S191 is performed.
For the time up to, refer to the timer counter TCO.

In step S191, when the time until red-eye emission is performed, that is, when the value of the timer counter TCO is larger than # T1, the pre-charge is performed a predetermined number of times set in step S192 (step S19).
3), light emission (step S194), and interval (step S195) are performed, and the processing is repeated until the predetermined number of times is completed (steps S196 and S197). Note that the interval of step S195 is a time for determining a light emission interval of red-eye light emission.

FIG. 29 shows a second embodiment of the red-eye emission. In this embodiment, the time until red-eye emission is performed is #T
When it is shorter than 1, the number of times of red-eye emission is reduced and the emission interval is extended.

In step S201, (TC0) <
If it is # T1, the process proceeds to step S202 and the RAM (AS
N) is set to the number of times of light emission # ASN0. On the other hand, (TC
If 0) ≦ # T1, the process proceeds to step S203 to set the number of times of light emission # ASN1. Note that # ASN1>#AS
N0.

Next, in step S204, pre-charging is performed.
Light emission is performed in step S205. Next, step S2
At 06, (TC0) is compared with # T1. As a result, in steps S207 and S208, (TC
The light emission interval is changed according to the value of 0).

If it is determined in steps S209 and S210 that the predetermined number of times has been repeated in steps S204 to S208, the process ends.

As described above, according to the present invention, the total amount of red-eye emission is reduced by the time from irradiation of auxiliary light to red-eye emission.

Further, the pupil diameter φ ₁ in which the amount of the pupil is also reduced in FIG. 22 is determined by the light emission guide number at the time of illuminating the auxiliary light.
Since it is slightly affected, the amount of light emitted at the time of illuminating the auxiliary light may be added as a parameter for determining the light emission pattern.

Further, in the above-described embodiment, the flash light emitting device is used as the auxiliary light. However, even if an LED having an emission wavelength in the visible region is used, the effect of similarly constricting the pupil can be expected. Thus, LED is a pupil diameter to phi _1, if having an emission energy for miosis can reduce the total amount of the same red-eye emission in the above embodiment.

FIG. 30 shows a light emitting circuit of the LED. The output of the CPU 10 causes the transistor Q
Turning on the LED 11 causes the LED D11 to emit light. Note that R11 is a shunt resistor, R12 is a base current limiting resistor, and R13 is an LED current limiting resistor.

[0203]

As described above, according to the present invention, there is provided a camera capable of reducing the total amount of flash light emission for red-eye prevention and reducing the charging time of the main capacitor without impairing the effect of preventing red-eye. Can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic concept of a camera according to the present invention.

FIG. 2 is a block diagram showing an electric circuit of the camera according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of a first release process of the camera.

FIG. 4 is a subroutine illustrating an operation of AF ranging.

FIG. 5 is a diagram illustrating an example of a focus detection optical system.

FIG. 6 is a flowchart illustrating a processing operation of AF sensor integration.

FIG. 7 is a circuit block diagram showing details of an AFIC 11 of FIG. 2;

FIG. 8 is a circuit block diagram showing details of a sensor circuit SC of FIG. 7;

9 is a timing chart showing signal output and the like in each unit of FIG. 8;

FIG. 10 is a subroutine for explaining an auxiliary light determination operation.

FIG. 11 is a flowchart for performing initial setting of an auxiliary light amount AGNO.

FIG. 12 is a diagram showing a relationship between an auxiliary light amount AGNO and a guide number GNO.

13A is a diagram showing a relationship between a storage time T _S and a storage voltage V _S during integration while projecting an auxiliary light, and FIGS. 13B and 13C are diagrams showing an AFRES signal and an auxiliary light periodically. Timing chart that irradiates the subject with a strobe pulse light,
(D), is a timing chart of (e), (f) is to set the accumulation determination voltage V _3, the accumulation time for it _{T S (T SC, T SB} , T SA).

[14] The variation of the photoelectric conversion elements B and C of the sensor data D _S in the case of changing the storage determining voltage V _3, based on the sensor data D _S in the steady light mode, showing the difference from it Figure It is.

FIG. 15 is a flowchart illustrating a correlation calculation process.

FIG. 16 is a diagram illustrating a relationship between a correlation output value and a position of a photoelectric conversion element.

FIG. 17 is a diagram illustrating a relationship between a correlation output value and a position of a photoelectric conversion element.

FIG. 18 is a flowchart illustrating an operation of increasing the amount of auxiliary light.

FIG. 19 is a flowchart illustrating an operation of a lens driving process.

FIG. 20 is a block diagram of a circuit of the strobe unit 15;

FIG. 21 is a detailed circuit diagram of the strobe unit.

FIG. 22 is a diagram showing a change in pupil diameter when a strobe is intermittently emitted.

FIG. 23 is a flowchart illustrating a subroutine for checking a charging voltage in step S2 of the flowchart in FIG. 3;

FIG. 24 is a sub-light irradiation subroutine called in step S47 of FIG. 6;

FIG. 25 is a subroutine for explaining a precharge operation.

FIG. 26 is a subroutine for explaining an operation of light emission.

FIG. 27 is a sequence illustrating an exposure operation.

FIG. 28 is a subroutine for explaining the operation of the first example of red-eye emission.

FIG. 29 is a subroutine for explaining the operation of the second example of red-eye emission.

FIG. 30 is a diagram illustrating an example of a light emitting circuit of an LED.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flash light-emitting device, 2 ... Light emission control part, 3 ... Light emission amount setting part, 4 ... Preliminary irradiation instruction part, 5 ... Red-eye emission instruction part, 6 ... Focus detection part, 7 ... Clock part, 10 ... CPU, 11 ... AFI
C, 12: EEPROM, 13: Liquid crystal display panel, 14
... data bag, 15 ... strobe unit, 16 ... interface IC, 17 ... photographing lens, 18 ... condenser lens, 19L, 19R ... separator lens, 20 ...
AF optical system, 21L, 21R photosensor array, 2
2, 23: motor driver IC, 24: light emitting diode (LED), 25: photometric silicon photodiode (SPD), 26: light receiving silicon photodiode,
27: remote control transmitting unit, 28: light emitting LED,
29: shutter charge (SC) motor, 30: lens driving (LD) motor, 31: zooming (ZM) motor, 32: shutter charge photo interrupter (SC)
PI), 33 ... Lens drive photo interrupter (LD)
PI), 34 ... Photo interrupter for zooming (ZM)
PI), 35 ... Zooming photo reflector (ZMP)
R), 36 ... AV motor, 37 ... AVPI.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-335621 (JP, A)

Claims (2)

(57) [Claims] An automatic focus adjustment device that divides subject light into two images, measures a light intensity distribution of each image, and obtains a defocus amount of a photographing optical system from an image interval; Emission wavelength in the visible region
Comprising an auxiliary light irradiating device that irradiates auxiliary light, and red-eye preventing emission device for irradiating the red-eye preventing light before the exposure start for the pupil constriction, and counting means for counting the time from the end of the irradiation of the auxiliary light, having If the time measured by the time measuring means is shorter than a predetermined time, the amount of the red-eye preventing light is reduced. 2. A divide object light in two images, the light intensity distribution of each image were measured, and an automatic focusing device for determining the defocus amount of the photographing optical system from the image distance, the subject at the time the light intensity distribution measurement Emission wavelength in the visible region
Comprising an auxiliary light irradiating device that irradiates auxiliary light, and red-eye preventing emission device for irradiating the red-eye preventing light before the exposure start for the pupil constriction, and counting means for counting the time from the end of the irradiation of the auxiliary light, having If the time measured by the time measuring means is smaller than a predetermined time, irradiation of the red-eye preventing light by the red-eye preventing light emitting device is prohibited.