JP2000131596A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a luminance level needed for focusing without lowering the resolution of focusing detection and to make generable image signals for focusing detection by taking in photographed subject lights for every pupil- divided area several times and performing exposure, and adding respective image signals. SOLUTION: Left AF2 image data generated by the driving of a pupil dividing device 14 and left AF1 image data stored in a memory 20 are read out, and they are added by an image processing circuit 19, and right AF2 image data and stored right AF1 image data are read out and added by an image processing circuit 19 similarly. A phase AF circuit 26 detects the phase difference on the basis of the image data of left AF1 + left AF2 and image data obtained by adding the image data of right AF1 + right AF2 twice respectively. This phase difference is supplied to a system controller 29 and compared with a data value, etc., stored in an EEPROM 30 to calculate a lens feed-out quantity for adjusting a focus lens and a focus motor 36b is driven and controlled through a focus motor driving circuit 36a to adjust the position of the focus lens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera which detects a focus position from a pupil-divided subject light beam and controls focusing of a photographing optical unit, particularly when the subject light has a predetermined brightness value or less. Related to focus adjustment control.

[0002]

2. Description of the Related Art As a main automatic focusing method in an electronic camera, a pupil splitting device built in a photographic optical system is used. A phase difference detection method of converting and generating an image signal based on the photoelectrically converted charge, detecting a phase difference of the image signal of the divided shooting subject light, and adjusting and controlling a focus lens position of the shooting optical system is adopted. Have been.

[0003] Various methods are used as a subject light dividing method of the pupil dividing device. The aperture / pupil dividing device described in Japanese Patent Application No. 10-213351 filed by the present applicant has been downsized. The best.

[0004] An aperture / pupil division apparatus described in Japanese Patent Application No. 10-213351 will be described with reference to FIG.

[0005] Two blades 4 on the left and right sides are arranged so as to cover a front open hole 41 in which a focus lens of a photographing optical system is disposed.
2, 43 are arranged. The blades 42 and 43 are rotatably supported by the rotating shafts 42a and 43a. These blades 42, 43 have cam holes 42b, 4 formed of elongated holes.
3b is formed, and a driving pin 44 is inserted through the cam holes 42b and 43b in common. The drive pin 44 is driven in a vertical direction in the figure by a drive actuator of a diaphragm / pupil division device (not shown), and a drive force is applied to the cam holes 42b and 43b by the drive pin 44. Transmitted to the blade 4
2, 43 rotate as described later. Further, the blades 42 and 43 have a configuration in which pupil openings 42c and 43c are formed at the edges away from the open hole 41.

An aperture / pupil splitting device having such a configuration is
The following rotation operation is performed.

FIG. 4A shows an open aperture state in which the blades 42 and 43 are opened from the open hole 41.
In this state, the drive pin 44 is located at the uppermost position in the drawing, and the blades 42 and 43 open left and right in the drawing to prevent the photographing light beam from passing through the opening hole 41. Has become.

[0008] From the open aperture state, the drive pin 44
Are moved downward in the figure, the left and right blades 42, 43
Move in a direction to increase the overlapping portion of each other, and FIG.
As shown in (b), a part of the open hole 41 is shielded by the left and right blades 42 and 43, and a small aperture state is obtained in which the photographic light beam passing through the open hole 41 is stopped down.

When the driving pin 44 is further moved from the small aperture state in a direction in which the overlapping portion of the left and right blades 42 and 43 is enlarged, as shown in FIG. The aperture is completely closed by the blades 42 and 43, and the aperture is in a closed state where the photographic light beam passing through the open hole 41 is shielded.

When the drive pin 44 is further moved downward from the aperture closed state, the left and right blades 42, 43
4 in a direction to further increase the superimposed portion of FIG.
As shown in (d), only the pupil opening 42c of the left wing 42 enters the opening 41, and the left automatic focus opening (hereinafter, left A) through which the photographic light beam passes through the pupil opening 42c.
F opening).

From the left AF opening state, the driving pin 4
4 is moved to the lowermost position in the figure,
2 and 43 maximize the overlapping portion with each other, and as shown in FIG. 4E, the pupil opening 43c of the right blade 43 is
1 and the pupil opening 42c of the left wing 42
Is closed by the right blade 43, and enters a right automatic focus opening (hereinafter referred to as a right AF opening) in which a photographing light beam passes through the pupil opening 43c of the right blade 43.

That is, by changing the opening amount of the opening hole 41 in the small aperture state shown in FIG. 4B from the open aperture state shown in FIG. 4A to the aperture closed state shown in FIG. 4C, The amount of luminous flux incident on the solid-state imaging device (not shown) from the photographic optical system is adjusted. Further, a left image signal generated based on a photographing light beam incident on the solid-state imaging device in the left AF opening state in FIG. 4D and a light incident on the solid-state imaging device in the right AF opening state in FIG. A phase difference from a right image signal generated based on the obtained photographing light beam is detected to adjust and control a focus lens position of the photographing optical system.

Next, using the aperture / pupil division device,
A method of generating a focus lens position adjustment control signal of the photographing optical system will be described with reference to FIG.

The VD in FIG. 5 is a vertical drive signal of the solid-state image sensor, which sets a charge accumulation time, which is an exposure time of subject light to the solid-state image sensor, and performs photoelectric conversion by the solid-state image sensor. It is used as a reference for control of read transfer timing of the read charge and for a control signal of various image signal generation circuits for generating an image signal based on the charge read and transferred from the solid-state imaging device.

When a subject light photographed by the photographing optical system is imaged on the solid-state image pickup device at the time of photographing the object with an electronic camera, the accurately focused object light without a focus shift is imaged on the solid-state image pickup device. Need to be done. For this reason,
When the automatic focus adjustment mode provided in the electronic camera is selectively inputted, the pupil division device is driven with reference to the first rising edge of the VD signal VD1, and FIG.
In the left AF opening state shown in (d), the subject light that has passed through the pupil splitting device in the left AF opening state is incident on the solid-state imaging device (hereinafter, referred to as a CCD) and exposes the CCD for a predetermined time. .

On the basis of the next rising edge of the VD signal VD2, the pupil splitting device shown in FIG.
The subject light that has been driven into the F opening state and passed through the pupil splitting device in the right AF opening state is incident on the CCD, and
The CD is exposed for a predetermined time. Further, the VD signal VD2
The left image charge in the left AF opening state obtained by exposing and photoelectrically converting the CCD with reference to the rising edge of is read and transferred, output to the various image signal generation circuits, and temporarily stored in a predetermined circuit.

Next, based on the rising edge of the VD signal VD3, the pupil splitting device is driven to open the aperture stop shown in FIG. 4A and open the right AF aperture photoelectrically converted by the CCD. The right image charges photoelectrically converted in the above are read and transferred, and output to the various image signal generation circuits. The various image signal generation circuits generate image signals based on the charges of the left image and the right image read and transferred from the CCD, and detect a phase difference detected by a phase difference detection circuit based on the generated left and right image signals. Using a calculation formula stored in advance in a system controller formed by a microcomputer or the like based on a, a lens extension amount for adjusting the position of the focus lens is calculated, and the imaging optical system of the imaging optical system is calculated via a focus actuator. Automatic focusing control (hereinafter referred to as AF control) for performing position adjustment control of the focus lens is performed.

[0018]

In a conventional electronic camera using focus detection by pupil division, phase shift amounts of respective images captured in different pupil regions are compared to calculate a focus shift amount. Therefore, if the brightness of the image captured in each area is insufficient, accurate focus adjustment cannot be performed. In particular, in pupil division, since the aperture diameter of the pupil opening is reduced and a light beam of a small aperture is used, the influence is large when the subject light is darker than a predetermined value.

When the diameter of the pupil opening is increased in order to obtain a sufficient amount of light by one CCD exposure on the left and right, the difference between the pupil-divided left and right images is reduced. There is a problem that a proper focusing cannot be performed.

According to the present invention, there is provided an electronic apparatus for generating an image signal for focus detection by securing a brightness level necessary for focusing without lowering the resolution of focus detection even when the subject light is lower than a predetermined brightness value. An object of the present invention is to provide a camera focusing device.

[0021]

According to the present invention, there is provided a photographing optical means comprising a plurality of lenses including a focus lens, a pupil dividing means for dividing a photographing light beam of the photographing optical means into two regions in time series, A solid-state imaging device that forms an image of subject light photographed by the photographing optical unit and converts the light into an electric signal; an image signal generation unit that generates an image signal based on the electric signal converted by the solid-state imaging device; A focus detection unit that generates a focus position control signal based on image signals of different regions generated by the solid-state imaging device and the image signal generation unit, and is generated by the focus detection unit. A focus drive control unit for controlling a position of a focus lens of the photographing optical unit by the in-focus position control signal, wherein the image signal generated by the image signal generation unit is:
The pupil dividing means fetches and generates the same two or more times for each of the same regions, adds the image signals of each region twice or more, and supplies the added image signal to the focus detecting means. Is an electronic camera that generates a focus position control signal based on the added image signal supplied from the image signal generating means.

The electronic camera according to the present invention further comprises signal level determining means for determining the luminance level of the subject light based on the image signal generated by the image signal generating means, and the signal level of the subject light determined by the signal level determining means is determined. According to the luminance level, the number of times of capturing the subject light in the area divided by the pupil dividing means into the image signal generating means and the number of generations of the image signal are selected.

In the electronic camera according to the present invention, the image signal generation of the subject light in the area divided by the pupil dividing means selected according to the luminance level of the subject light determined by the signal level determining means. Based on the capture to the means and the number of generations of the image signal for each area, the subject light capture and the image signal generation of one of the areas divided by the pupil division means are continuously performed, and then the division is performed by the pupil division means. The subject light in the other area is taken in and the image signal is generated continuously.

Further, according to the electronic camera of the present invention, the subject light of the area divided by the pupil dividing means is transmitted to the image signal generating means in accordance with the luminance level of the subject light determined by the signal level determining means. Based on the number of captures and the number of generations of image signals, subject light capture and image signal generation are alternately performed in one area and the other area divided by the pupil division means.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of an electronic camera according to the present invention.

Reference numeral 11 in the drawing denotes a photographing lens system for taking in light from a subject, and a zoom lens 12 for changing the magnification of the subject at least, a shutter 13, and a pupil splitting device 14 also serving as an aperture.
And a focus lens 15. In addition,
The aperture / pupil division device 14 performs the configuration and operation described with reference to FIG.

The subject light photographed by the photographing lens system 11 forms an image on the solid-state imaging device 16. The solid-state imaging device (hereinafter, referred to as a CCD) 16 converts the formed subject light into electric charges. The charges converted by the CCD 16 are sequentially read and transferred to the imaging circuit 17 to generate an image signal. The image signal generated by the imaging circuit 17 is A / A
The image data is converted from an analog signal to a digital image signal by the D circuit 18, converted into digital data format image data by the image signal processing circuit 19, and temporarily stored in the memory 20.

The image data stored in the memory 20 is converted into an image reproduction signal by an image display circuit 21 on the basis of an operation input to be described later, and the image of the subject light is reproduced and displayed on the image display section 22. The image display unit 22 uses a liquid crystal display element.

The image data temporarily stored in the memory 20 is compressed by a compression / expansion circuit 23 in response to an operation input, and is written and stored in a removable memory 25 via a memory interface (hereinafter, referred to as a memory I / F) 24. I do. The removable memory 25 is a memory medium formed as an IC card. The image data written and stored in the removable memory 25 is read out via the memory I / F 24, and the image data read out by the compression / expansion circuit 23 is expanded, and the memory 20 and the image display processing circuit 2 are expanded.
1, the image display unit 22 can also reproduce the image of the image data written and stored in the detachable memory 25.

The digital image signal converted by the A / D circuit 18 is supplied to a phase automatic focus circuit (hereinafter referred to as a phase A
F circuit 26), a hill-climbing automatic focus circuit (hereinafter, hill-climbing AF circuit) 27, and a signal level determination circuit 28. The image data generated by the image processing circuit 19 is supplied to the phase AF circuit 26 and the hill-climbing AF circuit 27. The phase AF circuit 26
Detects a digital image signal generated based on the subject light pupil-divided by the aperture / pupil division device 14 or a phase difference of image data. The hill-climbing AF circuit 27 detects a digital image signal generated based on subject light that has not been pupil-divided by the aperture / pupil division device 14 or a high-frequency component of image data. The signal level determination circuit 28
Determines the luminance value of the photographic subject from the signal level of the digital image signal supplied from the A / D circuit 18.
The phase AF circuit 26, the hill climbing AF circuit 27,
The output of the signal level determination circuit 28 is supplied to a system controller (hereinafter, referred to as a syscon) 29 formed by a microcomputer.

The system controller 29 is connected to the phase AF circuit 2
6 and the high-frequency component from the hill-climbing AF circuit 27 to perform focus drive control, which will be described later, and the luminance value from the signal level determination circuit 28 to control the drive of the aperture opening of the aperture and pupil division device 14. At the same time, the operation of the image processing circuit 19 is controlled. Further, the CC
D16 and a timing generation circuit (hereinafter, referred to as a TG circuit) 32 for controlling the operation of the imaging circuit 17 are also controlled.

An EEPROM 30 is added to the system controller 29, and stores various reference data necessary for operating or operating the electronic camera and processing procedures of the system controller 29 according to the operation.

Further, in the system controller 29, various photographing modes of the electronic camera, for example, selection of phase AF or hill-climbing AF at the time of focus adjustment, display of the image data temporarily stored in the memory 20 on the image display section 22, And writing / recording in the detachable memory 25, or selection of reproduction display of the image data stored in the detachable memory 25 on the image display unit 22, selection of the magnification of the zoom lens, selection of the operation of the strobe, and input of the photographing release. Each operation unit 31 for inputting various operations such as the above is connected.

From the system controller 29, a zoom motor 33b is driven via a zoom circuit 33a for driving the zoom lens of the taking lens system 11, and an actuator 34b is driven via a shutter circuit 34a for driving the shutter 13.
A driving circuit 3 for driving the aperture / pupil dividing device 14
A focus motor driving circuit 36a for driving the focus lens 15
And the focus motor 36b is connected to each other. The system controller 29 includes a strobe circuit 37a.
And strobe condenser 37b and strobe light emitting part 37
The series circuit c and the automatic focus auxiliary light (hereinafter, referred to as AF auxiliary light) 38 are connected.

In the electronic camera having such a configuration, a phase difference detection method using a pupil-divided photographed image is selectively input from each of the operation units 31 to adjust the position of the focus lens of the photographing lens system 11. The focusing operation at the time of photographing a dark subject whose luminance of the subject captured by the system 11 and formed on the CCD 16 is a predetermined value or less will be described with reference to FIG.

In general, when performing focusing, a focusing mode is input in a state where a release switch (not shown) which is a part of each of the operation sections 31 is half-pressed. When the focus mode is input by the release switch, the system controller 29 supplies a drive control signal to the drive circuit 35a on the basis of the rising edge of VD1 of the VD signal, and the drive control by the drive circuit 35a Then, the actuator 35b is driven to bring the aperture / pupil division device 14 into the left AF opening state. On the other hand, the system controller 29 controls the TG circuit 32 to generate a timing signal based on the VD signal, and supplies the timing signal to the CCD 16 and the imaging circuit 17. The CCD 16 is provided with the pupil splitting device 1
4 is defined as the start of exposure,
With the falling edge of the D signal VD1 as the end of the exposure, the first exposure (hereinafter referred to as left AF1 exposure) is performed with the subject light incident in the left AF opening state of the aperture / pupil division device 14.

At the next VD2 of the VD signal, the pupil division device 14 maintains the left AF opening state, and
The left AF1 exposure of D16 is temporarily stopped, and the second exposure of the CCD 16 (hereinafter, referred to as left AF2 exposure) is performed again, and the charge by the left AF1 exposure of the CCD 16 is read out to the image pickup circuit 17 and transferred and output. Imaging circuit 17
The electric charge of the CCD 16 transferred to and outputted from the CCD 16 is formed into an image signal, A / D converted by the A / D circuit 18, and
At 9, it is converted into left AF image data and temporarily written and stored in the memory 20 (denoted as left AF1 (W) in the figure).

Next, at VD3 of the VD signal, the pupil splitting device 14 is driven to make the right AF opening state, and the first exposure (hereinafter, right AF1 exposure) of the CCD 16 is performed in the right AF opening state. To do). Further, the charge of the left AF2 exposure of the CCD 16 is transferred and output to the left AF2.
2 image data is generated, the generated left AF2 image data and the left AF1 image data stored in the memory 20 are read out (denoted as left AF1 (R) in the figure), and added by the image processing circuit 19 (left figure in the figure). AF1 + left AF2)
The data is output to the phase AF circuit 26 and temporarily stored.

Next, at VD4 of the VD signal, the pupil division device 14 is maintained in the right AF opening state,
The right AF1 exposure of the CCD 16 is temporarily stopped, the second exposure of the CCD 16 is performed again (hereinafter, referred to as right AF2 exposure), and the charge by the right AF1 exposure of the CCD 16 is read out to the image pickup circuit 17 and transferred and output. Imaging circuit 17
The electric charge of the CCD 16 transferred to and outputted from the CCD 16 is formed into an image signal, A / D converted by the A / D circuit 18, and
At step 9, the data is converted into right AF image data and temporarily written and stored in the memory 20 (denoted as right AF1 (W) in the figure).

Next, at VD5 of the VD signal, the pupil splitting device 14 is driven to be in an open state, and the charge of the right AF2 exposure of the CCD 16 is transferred and outputted.
Image data is generated, the generated right AF2 image data and the right AF1 image data stored in the memory 20 are read out (denoted as right AF1 (R) in the figure), and added by the image processing circuit 19 (right AF1 + in the figure). Right AF2) and outputs it to the phase AF circuit 26.

The phase AF circuit 26 is provided with the left AF 1+
On the basis of the image data of the left AF2 and the image data of the right AF1 + right AF2, which is added left and right twice each,
Detect the phase difference. The phase difference detected by the phase AF circuit 26 is supplied to the system controller 29, and the EEPR
It is compared with a data value or the like stored in the OM 30 to calculate a lens extension amount for adjusting the focus lens, and controls and drives the focus motor 36b via the focus motor drive circuit 36a based on the extension amount. Adjust the position of the focus lens.

That is, after setting the pupil division device 14 to the left AF opening state, the CCD 16 is exposed to the subject twice continuously based on the VD signal, and the left AF 1 and the left AF 2 ( Of the image data generated based on the charges of the right AF1 and the right AF2, the left AF1 (the right AF
1) Image data is temporarily stored, and the temporarily stored left A
F1 (right AF1) image data and the left AF2 (right AF
2) The apparent signal level of the subject light is doubled by adding the image data. Thus, the phase A
The phase difference between the left AF and right AF image data in the F circuit 26 is reliably detected, and the drive control of the focus lens 15 to an appropriate in-focus position becomes possible.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In another embodiment, the left AF opening state and the right AF opening state of the pupil division device 14 are determined by the V
Left and right AF by alternately setting once for each D signal
The CCD 16 is exposed twice in the open state.

With the VD1 of the VD signal, the pupil division device 14 is set to the left AF opening state, and the CCD 16 is exposed to the left AF1.

Next, with the VD signal VD2, the pupil splitting device 14 is set to the right AF opening state, and the CCD 16 is set to the right AF1.
Exposure is performed, and the charge by the left AF1 exposure is transferred and output from the CCD 16, and the left AF1 image data generated based on the left AF1 exposure charge is temporarily stored and written in the memory 20 (left AF1 in the figure). (W)).

Next, the pupil splitting device 14 is returned to the left AF opening state again by the VD3 of the VD signal, the CCD 16 is again subjected to the left AF2 exposure, and the charge by the right AF1 exposure is transferred and output from the CCD 16. Together with this right A
The right AF1 image data generated based on the F1 exposure charge is temporarily stored and written in the memory 20 (shown as right AF1 (W) in the drawing).

Next, the pupil splitting device 14 is returned to the right AF opening state again by the VD4 of the VD signal, the CCD 16 is again subjected to the right AF2 exposure, and the charge from the CCD 16 is transferred and output from the left AF2 exposure. With this left A
The left AF2 image data generated based on the F2 exposure charge and the left AF1 image data temporarily stored in the memory 20 are read (indicated as left AF1 (R) in the drawing) and added (left AF1 + left AF2 in the drawing). Notation).

Next, the pupil splitting device 14 is set to the open aperture state at VD5 of the VD signal, and the right A
The charge generated by the F2 exposure is transferred and output.
The right AF2 image data generated based on the two exposure charges and the right AF1 image data temporarily stored in the memory 20 are read out (indicated as right AF1 (R) in the figure) and added (right AF1 + right AF2 in the figure). Notation).

Next, the left image data (left AF1 + left AF2) and the right image data (right AF1 + right AF2) added by the image processing circuit 19 based on the VD signal VD4 and VD5 at the VD signal VD6. The phase AF circuit 26
To detect the phase difference, and based on the phase difference,
Is used to calculate the amount of extension of the focus lens.

Thus, the subject light is divided into right and left by the pupil splitting device 14, and the subject light is exposed twice by the CCD 16 and dark subject light of a predetermined value or less is added, so that the brightness value of the proper subject image data is obtained. Is obtained, and the phase difference is detected from the left and right video data having the appropriate luminance value, and the appropriate focusing adjustment control of the focus lens of the photographing lens system 11 can be performed.

Next, the setting of the number of exposures of the subject light divided right and left by the pupil division device 14 by the CCD 16 will be described.

The digital image signal generated by the A / D circuit 18 and divided by the aperture / pupil division device 14 is supplied to the signal level determination circuit 28. The signal level determination circuit 28 determines and detects the signal level of the supplied digital image signal of each area (left AF and right AF), and supplies this signal level to the system controller 29. The system controller 29 compares the number of exposures of the CCD 16 and the number of image signal generations of the imaging circuit 17 by comparing with a reference signal level stored in advance in the EEPROM 30, and sets the number of times of image signal generation of the imaging circuit 17 via the drive circuit 35 a of the aperture / pupil division device 14. The CCD 16 and the imaging circuit 17 are driven via the image processing circuit 19 and the TG circuit 32 by driving the actuator 35b.
Control of exposure and signal generation.

This makes it possible to set the number of pupil divisions at the time of automatic focusing using the aperture / pupil division device 14 and the number of exposures of the CCD 16 and generation of image signals in accordance with the luminance value of the subject light.

As described above, according to the present invention, when the subject light is equal to or less than the predetermined luminance value, the subject light is captured a plurality of times for each of the pupil-divided areas, and the image generated from the captured plurality of subject lights is obtained. The signals are added, and the optimum focus adjustment can be performed by the focus adjustment control signal based on the added phase difference of the image signals in the different areas.

In the description of the embodiment of the present invention, the addition of the pupil-divided left and right AF image data is performed by the image processing circuit 19, but the phase AF circuit 26 has a memory function and an addition function. A / D
It is clear that the phase difference can be detected after the left and right AF digital image signals generated by the circuit 18 are stored and added. The pupil-divided image signals are added, and the added image signals are used as a basis. In order to generate a focus position adjustment control signal for the photographing lens system by detecting the phase difference, it is possible to select and adopt it as needed.

[0056]

According to the present invention, even when the luminance value of the subject light is lower than a predetermined value, the subject light for each pupil-divided region is captured and exposed a plurality of times, and the image signal for each region is added. The phase difference obtained from the subject image signal can be detected appropriately, and the subject can be adapted to the subject light by setting the number of subject light exposure captures for each pupil division area using the signal level of the image signal. This has the effect of enabling the setting of the number of times of exposure taking in and the optimal focusing control.

Further, by continuously exposing one of the pupil division regions, the driving operation of the pupil division device can be minimized, and the memory capacity of temporarily stored video data can be reduced. Becomes possible.

Further, by subjecting pupil-divided subject light to alternate exposure, the effect of minimizing the motion error in the pupil-divided left and right regions can be obtained when the subject is photographed with a motion and a luminance value is equal to or less than a predetermined value. are doing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of an electronic camera according to the present invention.

FIG. 2 is a timing chart illustrating the operation of one embodiment of the present invention.

FIG. 3 is a timing chart illustrating an operation of another embodiment of the present invention.

FIG. 4 is a plan view for explaining the operation of the pupil division device according to the present invention.

FIG. 5 is a timing chart for explaining a problem of a phase difference detection AF used in a conventional pupil division device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Photographing lens system 12 ... Zoom lens 13 ... Shutter 14 ... Aperture / pupil division device 15 ... Focus lens 16 ... Solid-state imaging device 17 ... Imaging circuit 18 ... Analog / Digital conversion circuit 19 ... Image processing circuit 20 ... Memory 21 ... Image Display circuit 22 ... Image display device 23 ... Compression / expansion circuit 24 ... Memory interface 25 ... Removable memory 26 ... Phase difference automatic focus circuit 27 ... Chill climbing automatic focus circuit 28 ... Signal level judgment circuit 29 ... System controller 30 ... EEPROM 31 ... Each operation Unit 32: Timing generator circuit 33a: Zoom circuit 33b: Zoom motor 34a: Shutter circuit 34b: Actuator 35a: Drive circuit 35b: Actuator 36a: Focus motor drive circuit 36b: Focus Motor 37a ... strobe circuit 37b ... flash capacitor 37c ... flash projector 38 ... autofocus auxiliary light

Claims (4)

[Claims] A photographing optical unit comprising a plurality of lenses including a focus lens; a pupil dividing unit for dividing a photographing light beam of the photographing optical unit into two regions in a time series; and a subject photographed by the photographing optical unit. A solid-state imaging device that forms light and converts the light into an electric signal; an image signal generation unit that generates an image signal based on the electric signal converted by the solid-state imaging device; Based on image signals of different regions generated by the image sensor and the image signal generating means,
Focus detection means for generating a focus position control signal, and focus drive control means for controlling the position of the focus lens of the photographing optical means based on the focus position control signal generated by the focus detection means. An image signal generated by the image signal generating means is captured and generated at least twice for the same area of the area divided by the pupil dividing means, and is added with two or more image signals for each area. An electronic camera, wherein the electronic camera is supplied to the focus detection unit, and the focus detection unit generates a focus position control signal based on the added image signal supplied from the image signal generation unit. 2. The image processing apparatus according to claim 1, further comprising: a signal level determining unit configured to determine a luminance level of the subject light based on the image signal generated by the image signal generating unit, according to the signal level of the subject light determined by the signal level determining unit. 2. The electronic camera according to claim 1, wherein the number of times of capturing the subject light in the area divided by the pupil dividing means into the image signal generating means and the number of times of generating the image signal are selected. 3. A method according to claim 1, further comprising: taking in the subject light of an area divided by said pupil dividing means, which is selected according to the luminance level of the subject light determined by said signal level determining means, into said image signal generating means; Based on the number of times of generation, the subject light capturing and image signal generation of one of the areas divided by the pupil dividing means are continuously performed, and then the subject light of the other area divided by the pupil dividing means is captured and the image signal is captured. 3. The electronic camera according to claim 2, wherein the generation is performed continuously. 4. A method according to claim 1, wherein the subject light of the area divided by said pupil dividing means is taken into said image signal generating means and the number of times of generation of an image signal is determined according to the luminance level of the subject light determined by said signal level determining means. 3. The electronic camera according to claim 2, wherein subject light capture and image signal generation of one area and the other area divided by the pupil division unit are alternately performed based on the number of times.