JP2002300470A - Imaging device and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device, capable of preventing generation of overexposure at performing of main exposure, even if an emitted light quantity lower than the minimum emitted light quantity is calculated at performing of an imaging operation using a stroboscope. SOLUTION: When exposure is over even at allowing a stroboscope 48 to emit lights, by setting the main light emitting time as the minimum light- emitting time, the opening diameter of the diaphragm of a shutter 12 is reduced or the gain of an image signal imaged by the imaging element 14 is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus for picking up, recording, and reproducing still images and moving images, and a control method therefor.

[0002]

2. Description of the Related Art An image pickup apparatus (image processing apparatus) such as an electronic camera for recording and reproducing a still image and a moving image using a memory card having a solid-state memory element as a recording medium is already on the market. Electronic cameras with a viewfinder are also available.

In these electronic cameras, it is possible for a user of the electronic camera to continuously display an image before photographing, determine the composition, and to reproduce and confirm the photographed image.

[0004] In particular, the function of reproducing a photographed image immediately after photographing is highly convenient and is a useful function for a user of an electronic camera.

[0005] Most of such image pickup apparatuses such as electronic cameras have a built-in strobe, and when photographing by flash emission, the subject conditions must be set before the actual shutter release for actual exposure. In order to perform measurement (light control), photometry is performed in advance by pre-emission in which a strobe light is emitted, and after determining exposure conditions, the flash device of main exposure emits light (main emission).

In the above method, conventionally, the exposure control value of the main light emission is determined, and then the light emission time of the main light emission is calculated.

[0007]

However, as described above, in the prior art, after determining the exposure control value of the main light emission,
Since the light emission time of the main light emission is calculated, even if a light emission time shorter than the minimum light emission time (minimum light emission amount) of the main light emission is calculated, the main light emission can be performed only in the minimum light emission time. There was a problem of overrun.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an image pickup apparatus which does not overexpose at the time of main exposure even if a light emission amount lower than the minimum light emission amount is calculated. And a control method thereof.

[0009]

An image pickup apparatus and a control method thereof according to the present invention are configured as follows.

(1) In an image pickup apparatus, a strobe control means for controlling light emission of a strobe, an aperture for adjusting a light amount,
Exposure control means for controlling the aperture, wherein the exposure control means reduces the aperture diameter of the aperture if the exposure is over when the main flash amount of the strobe light is minimized.

(2) In the image pickup apparatus of (1), the exposure control means stops the aperture by an amount corresponding to the overexposure when the main light emission amount of the strobe is minimized.

(3) In the image pickup apparatus of the above (1), when the aperture is a fixed aperture, the strobe control means adjusts an excessive amount of the aperture to extend exposure time of the strobe to make exposure proper. did.

(4) In the image pickup apparatus, a strobe control means for controlling light emission of a strobe, an image pickup sensitivity adjusting means for adjusting a gain of an image signal picked up by the image pickup means,
Exposure control means for controlling the imaging sensitivity adjustment means, wherein the exposure control means reduces the gain amount when the exposure is over when the main flash amount of the strobe light is minimized.

(5) In the image pickup apparatus of (4), the exposure control means causes the flash to emit light by minimizing the main light emission time of the strobe and lowers the gain by an amount corresponding to the overexposure. .

(6) In the image pickup apparatus of any of the above (1) to (5), when the amount of light emission of the strobe is minimum, the light emission time is minimized.

(7) In the control method of the image pickup apparatus, when the light emission of the strobe is controlled by the strobe control means, the aperture for adjusting the light quantity is controlled by the exposure control means, and the main light emission amount of the strobe is minimized. When the exposure is excessive, the aperture diameter of the aperture is reduced.

(8) In the control method of the image pickup apparatus according to the above (7), the exposure control means narrows the aperture by an amount corresponding to the overexposure when the main light emission amount of the strobe is minimized. .

(9) In the control method of the image pickup apparatus according to the above (7), when the aperture is a fixed aperture, the flash control means appropriately adjusts the exposure by extending the light emission time of the flash by increasing the amount of excessive aperture. I did it.

(10) In the control method of the image pickup apparatus, the light emission of the strobe is controlled by the strobe control means, the gain of the image signal picked up by the image pickup means is adjusted by the image pickup sensitivity adjusting means, and the image pickup is controlled by the exposure control means. In addition to controlling the sensitivity adjusting means, the gain amount is reduced when the exposure becomes excessive when the main emission amount of the strobe is minimized.

(11) In the control method of the image pickup apparatus according to the above (10), the exposure control means causes the flash to emit light by minimizing the main emission time of the strobe, and lowers the gain by an amount corresponding to the overexposure. I did it.

[0021]

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

FIG. 1 is a block diagram showing the configuration of the embodiment of the present invention.

In FIG. 1, reference numeral 100 denotes an imaging device (image processing device).

Reference numeral 10 denotes a variable power lens group, 11 denotes a focusing lens group, 12 denotes a shutter having an aperture function, 14 denotes an image pickup device for converting an optical image into an electric signal, and 15 denotes an image pickup device (image pickup means) 14. This is an imaging sensitivity adjustment unit that sets sensitivity.

Reference numeral 16 denotes an A / D converter for converting an analog signal output of the image sensor 14 into a digital signal. Reference numeral 18 denotes a clock signal and a control signal to the image sensor 14, A / D converter 16, and D / A converter 26. This is a timing generation circuit for supplying, and is controlled by the memory control circuit 22 and the system control circuit 50.

The magnification of the variable magnification lens group 10 is Wid.
The end from the e end to the Tele end is divided into six, and the Wide end and the Te end
It employs a configuration that enables zooming in 7 positions including the end of the le.

An image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on data from the A / D converter 16 or data from the memory control circuit 22.

Further, in the image processing circuit 20, predetermined arithmetic processing is performed using the captured image data, and based on the obtained arithmetic result, the system control circuit 50 causes the automatic exposure control means (exposure control means) 40, The TTL (through-the-lens) type AF (auto focus) processing, AE (auto exposure) processing, and EF (flash pre-emission) processing for controlling the distance measurement control means 42 are performed.

Further, the image processing circuit 20 performs predetermined arithmetic processing using the captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

Reference numeral 22 denotes a memory control circuit, which includes an A / D converter 16, a timing generation circuit 18, an image processing circuit 20,
Image display memory 24, D / A converter 26, memory 30,
The compression / decompression circuit 32 is controlled.

The data of the A / D converter 16 is transmitted through the image processing circuit 20 and the memory control circuit 22 or the data of the A / D converter 16 is transmitted directly through the memory control circuit 22 to the image display memory 24 or the memory. 30 is written.

Reference numeral 24 denotes an image display memory; 26, a D / A converter; and 28, an image display unit composed of a TFT LCD or the like. The display image data written in the image display memory 24 is a D / A converter 26. Is displayed by the image display unit 28 via the.

If image data captured by the image display unit 28 is sequentially displayed, an electronic finder function can be realized.

The image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control circuit 50. When the display is turned off, the image pickup device 1
00 can be greatly reduced.

Reference numeral 30 denotes a memory for storing photographed still images and moving images, which has a sufficient storage capacity for storing a predetermined number of still images and moving images for a predetermined time.

Accordingly, even in the case of continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, it is possible to write a large amount of images to the memory 30 at high speed.

The memory 30 is provided with a system control circuit 50.
Can also be used as a work area.

32 is an adaptive discrete cosine transform (ADCT)
A compression / decompression circuit for compressing / decompressing image data by, for example, reading an image stored in the memory 30 and performing compression or decompression processing, and storing the processed data in the memory 3
Write to 0.

Reference numeral 40 denotes a shutter 12 having an aperture function,
Electronic shutter control means for controlling the accumulation time from the charge discharging operation of the image sensor 14 to the reading operation by the timing generation circuit 18 and automatic exposure control means for controlling the imaging sensitivity adjusting means 15. ) 48, it also has a flash dimming function.

Reference numeral 42 denotes a distance measurement control unit that controls focusing of the focusing system lens 11, 44 denotes a zoom control unit that controls zooming of the variable power lens 10, and 46 denotes a barrier that controls the operation of the protection unit 102 which is a barrier. Control means.

Reference numeral 48 denotes a flash, which also has a function of projecting AF auxiliary light and a function of controlling flash light.

Automatic exposure control means 40, distance measurement control means 42
Is controlled using the TTL method, and the system control circuit 50 controls the automatic exposure control means 40 based on the calculation result obtained by calculating the captured image data by the image processing circuit 20.
It controls the distance measurement control means 42. The details of the automatic exposure control means 40 will be described later.

Reference numeral 50 denotes a system control circuit for controlling the entire image pickup apparatus 100, and reference numeral 52 denotes a memory for storing constants, variables, programs, and the like for operating the system control circuit 50.

Reference numeral 54 denotes a display unit such as a liquid crystal display or a speaker for displaying an operating state or a message using characters, images, sounds, or the like in accordance with the execution of the program by the system control circuit 50. Is installed at one or more locations in the vicinity of the operation unit where it is easily visible.
It is composed of a combination of D, LED, sound element and the like.

The display unit 54 has a part of its functions installed in the optical viewfinder 104.

Among the display contents of the display unit 54, those displayed on the LCD or the like include a single shot / continuous shooting display, a long time shooting display, a night view shooting display, a self-timer display, a compression ratio display, and the number of recording pixels. Display, number of recorded images, remaining shots, shutter speed, aperture, exposure compensation, flash, red-eye reduction,
Elapsed time display (from red-eye reduction lamp lighting, previous shooting), macro shooting display, buzzer setting display, battery remaining battery display, battery remaining display, error display, multi-digit information display, recording medium 200 , 210, communication I / F operation display, date / time display, and the like.

Of the display contents of the display section 54, those displayed in the optical viewfinder 104 include a focus display, a camera shake warning display, a flash charge display, a shutter speed display, an aperture value display, an exposure correction display, and the like. There is.

Reference numeral 56 denotes an electrically erasable and recordable nonvolatile memory, for example, an EEPROM or the like.

60, 62, 64, 66, 68 and 70
Is an operation means for inputting various operation instructions of the system control circuit 50, and is constituted by one or a combination of a switch, a dial, a touch panel, pointing by gaze detection, a voice recognition device, and the like.

Here, these operation means will be specifically described.

Reference numeral 60 denotes a mode dial switch, which can switch and set various function modes such as power-off, automatic photographing mode, photographing mode, panoramic photographing mode, reproducing mode, multi-screen reproducing / erasing mode, and PC connection mode.

Reference numeral 62 denotes a shutter switch SW1, which is turned on during the operation of a shutter button (not shown), and
(Auto focus) processing, AE (auto exposure) processing, A
It instructs to start operations such as WB (auto white balance) processing and EF (flash pre-emission) processing.

Reference numeral 64 denotes a shutter switch SW2, which is turned on when the operation of a shutter button (not shown) is completed, and transfers a signal read from the image sensor 12 to the memory 30 via the A / D converter 16 and the memory control circuit 22. Exposure processing for writing, development processing using operations in the image processing circuit 20 and the memory control circuit 22, reading image data from the memory 30, performing compression in the compression / decompression circuit 32, and storing the image data in the recording medium 200 or 210. Is instructed to start an operation of a series of processing of recording processing for writing.

Reference numeral 66 denotes an image display ON / OFF switch.
ON / OFF of the image display unit 28 can be set.

With this function, it is possible to save power by cutting off the current supply to an image display unit such as a TFT LCD when taking a picture using the optical finder 104.

Reference numeral 68 denotes a quick review ON / OFF switch for setting a quick review function for automatically reproducing image data taken immediately after shooting. In this embodiment, a function for setting the quick review function when the image display unit 28 is turned off is provided.

Reference numerals 67 and 69 denote Tele Sw and Wide Sw for instructing the driving direction of the zoom lens group 10, respectively.
It is. The Tele Sw and the Wide Sw are configured so that only one of the Sw is mechanically turned on.

An operation unit 70 includes various buttons, a touch panel, etc., and includes a menu button, a set button, a macro /
Non-macro switching button, multi-screen playback page break button, flash setting button, single shot / continuous shooting / self-timer / long time (slow shutter) / mode switching button, menu move + (plus) button, menu move-
There are a (minus) button, a play image move + (plus) button, a play image-(minus) button, a shooting image quality selection button, an exposure correction button, a date / time setting button, and the like.

The flash settings include an automatic light emission / forced light emission / prohibition of issuance / automatic red-eye reduction light emission / night scene light emission mode. Here, the configuration in which the flash mode is automatically switched to the light emission inhibition mode when the slow shutter mode is switched by the shooting mode switching button may be performed in any combination according to the design policy of the camera. It goes without saying that everything is left to the user's settings.

Numeral 80 denotes a power control means, a battery detection circuit, D
It comprises a C-DC converter, a switch circuit for switching a block to be energized, and the like, and detects the presence or absence of a battery, the type of battery, the remaining battery level, and performs DC based on the detection result and an instruction from the system control circuit 50. Control the DC converter to supply a required voltage to each unit including the recording medium for a required period.

Reference numeral 82 indicates a connector, 84 indicates a connector, and 86 indicates power supply means including a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, and an AC adapter.

Reference numerals 90 and 94 denote interfaces with recording media such as memory cards and hard disks.
Is a connector for connecting to a recording medium such as a memory card or a hard disk, and 98 is a recording medium attachment / detachment detecting means for detecting whether or not the recording medium 200 or 210 is attached to the connectors 92 and / or 96.

In this embodiment, the description has been made assuming that there are two interfaces and connectors for attaching a recording medium. Of course, the interface and the connector for attaching the recording medium may have a single or plural number of systems. In addition, a configuration may be adopted in which interfaces and connectors of different standards are provided in combination.

As the interface and the connector,
It may be configured by using a card conforming to a standard such as a PCMCIA card or a CF (Compact Flash (registered trademark)) card.

Further, the interfaces 90 and 94 and the connectors 92 and 96 are connected to a PCMCIA card or CF.
(Compact flash) When using a card conforming to the standard such as a card, a LAN card, a modem card, a USB card, an IEEE1394 card, a P128
By connecting various communication cards such as a 4-card, a SCSI card, a communication card such as a PHS, and the like, image data and management information attached to the image data are transferred to and from other peripheral devices such as a computer and a printer. be able to.

Reference numeral 102 denotes a protection unit that is a barrier that covers the imaging unit including the variable power lens 10 and the focusing lens 11 of the imaging device 100 to prevent the imaging unit from being stained or damaged.

Reference numeral 104 denotes an optical finder, which allows photographing using only the optical finder without using the electronic finder function of the image display unit 28. The display unit 5 is provided in the optical finder 104.
4, some functions such as focus display, camera shake warning display,
A flash charge display, a shutter speed display, an aperture value display, an exposure correction display, a macro shooting setting display, and the like are provided.

Reference numeral 110 denotes communication means, such as RS232C or US
It has various communication functions such as B, IEEE1394, P1284, SCSI, modem, LAN, wireless communication, and the like.

Reference numeral 112 denotes the imaging device 1
In the case of wireless communication, it is an antenna for connecting a connector 00 to another device.

Reference numeral 200 denotes a recording medium such as a memory card or a hard disk.

The recording medium 200 includes a recording unit 202 composed of a semiconductor memory, a magnetic disk, or the like, and the imaging device 100.
Interface 204, and a connector 206 for connecting to the imaging apparatus 100.

Reference numeral 210 denotes a recording medium such as a memory card or a hard disk.

The recording medium 210 includes a recording unit 212 composed of a semiconductor memory, a magnetic disk, or the like, and the imaging device 100.
Interface 204, and a connector 206 for connecting to the imaging apparatus 100.

The operation of the first embodiment will be described with reference to FIGS. 1, 2 and 3.

FIG. 2 is a flowchart showing an image pickup control operation of the image pickup apparatus of the present embodiment.
00 main routine will be described. This operation is performed in the memory 5
2 is executed according to an instruction from a CPU (not shown) in the system control circuit 50 based on the program stored in the CPU 2.

When the mode dial 60 is turned from the power-off state to the power-on state (imaging mode), the system control circuit 50 detects the mode dial state (S10).
1).

Next, when the shutter switch (SW1) 62 is depressed (S102), the system control circuit 50 activates the image pickup means (S103), and performs predetermined arithmetic processing using the image signal data from the image pickup device 14. Then, based on the obtained calculation result, a distance measurement process is performed on the distance measurement control unit 42 to focus the focusing lens 11 on the subject, and AF control is performed (S104).

Subsequently, the system control circuit 50 activates the exposure control means 40, performs aperture means and shutter means so as to obtain an appropriate exposure, and performs aperture control (AvAE).
Value, shutter control (TvAE) value, imaging sensitivity (SvA)
AE for calculating a subject brightness (BvAE) value from the E) value
Control is performed (S105). Next, the system control circuit 50
Performs AWB (auto white balance) control using the image processing circuit 20 until a predetermined calculation process is performed using image signal data from the image sensor 14 and the obtained calculation result is determined to be appropriate as a white balance. (S
105).

Next, the shutter switch (SW2) 62
Is pressed (S106), the system control circuit 50
Activating the strobe control means 49 and the exposure control means 40,
The EF control (S200) is performed so that the light can be properly adjusted.
Next, main exposure for photographing an image to be recorded is performed (S
107).

Finally, the interface 90 or 9
4. Image data is written to the recording medium 200 or 210 such as a memory card or a compact flash card via the connector 92 or 96 (S10).
8). If the shutter switch (SW2) 62 is not pressed, the process waits until the switch SW2 is pressed.

Next, EF control will be described with reference to FIG.

FIG. 3 is a flowchart showing the EF control operation according to the first embodiment.

The system control circuit 50 controls the exposure control value AvAE value, TvAE value, SvAE value (S20
1) Distance information (L) value in AF control (S202)
To get. Next, the system control circuit 50 activates the exposure control means 40, controls the shutter 12 having the aperture function, and performs aperture control (1) (S203).

The system control circuit 50 compares the aperture determined by the switching point formula with the aperture (AvAE) value in the AE control based on the distance information (L) in the AF control, and selects the smaller aperture side. An aperture (AvPre) value at the time of pre-emission is obtained. This is to prevent overflow during pre-flash, assuming that the subject is too close or the reflectance is too high. The equation for the switching point (Lp) is shown below.

Lp = −2.5 × Zp + 70 Zp (ZoomPosition): Wide = 0, m1 = 1, m2 = 2, m3 = 3, m4 = 4, m5 = 5, Tele = 6 L (distance information from AF) Open when Lp is smaller than Lp Small aperture Next, the exposure control means 40 controls the imaging sensitivity adjustment means 15 to perform PDG (gain at pre-flash) calculation (S2).
04). The system control circuit 50 calculates the PDG from the following function formula based on the distance information (L) in the AF control and the aperture in the aperture control. However, the gain is increased up to +3 steps. The function expression is shown below.

DeltaGain = 2 × Log ₂ (L
/ 100) + Gn + Log ₂ (Zp / 6 + 1) When open Gn = 0.72 With small aperture Gn = 3.72 Next, the exposure control means 40 controls the shutter 12 having an aperture function, and the exposure control value calculation means However, although not shown, aperture control (AvPre) is performed from a program diagram.
Control (TvP) during pre-flash based on values and PDG
re) The value is analyzed and calculated, and shutter control (1) is performed (S205).

Next, the system control circuit 50
4 to read out the imaged charge signal. Image processing circuit 20
Performs luminous flux integration calculation on the photographed image data sequentially read through the A / D converter 16 for each of a plurality of divided regions set in the system control circuit 50 in advance.

The photometric means is programmed in the memory 52 of the system control circuit 50, converts the luminous flux integration operation output into an integrated value in units of one pixel, and then converts the integrated value for each area according to the area ratio of the divided areas. Calculate the evaluation value. A predetermined weight is given to the evaluation value for each area, and the luminance (Δ
YDLn) value is calculated.

Aperture control (AvPre) value, shutter control (TvPre) value when ΔYDLn is obtained,
Gain (PDG) value during pre-flash, imaging sensitivity (SvA)
E) A steady light luminance value (YDLn) value is calculated based on the value, and a steady light photometry is performed (S206).

Next, the system control circuit 50 activates the strobe control circuit 49, controls the strobe 48, and
Light emission is performed at μS to perform pre-emission (S207). afterwards,
A pre-emission luminance (YFLn) value is calculated by control and calculation equivalent to the above-described steady light photometry (S208).

Next, the system control circuit 50 recalculates the gain (PDG) value at the time of the pre-emission to 0 and sets it as the provisional gain (XDG) value at the time of the main emission. Also, if the aperture control value is less than the predetermined distance, the aperture control (A
vPre) value, if it is equal to or longer than the predetermined distance, the aperture control (AvAE) value in the AE control is selected again, and is set as the temporary aperture control (XAv) value at the time of main light emission. Next, the exposure control value calculation means is started, and although not shown, the XAv
Shutter control (XT
v) The values are analyzed and recalculated, and XDG, XAv, XT
v is set as the main light emission temporary exposure control value (S209).

Next, the system control circuit comprises the XDG and PD
G, correction values (AvDG_Hosei, AvTvDG_Hos) based on the difference between XAv and AvPre, and between XTv and TvPre.
ei) is calculated. Next, a predetermined weighting (P) is applied to the steady light photometry value (YDLn) and the Pre light emission photometry value (YFLn) for each region from the results of the constant light and the Pre light emission photometry.
[N]), and the averaged steady light photometric value (YDL)
n) Calculate the pre-flash photometry value (YFLn). The above correction value, the target level Yref, and the average stationary light photometric value (YD
Ln) and the average pre-flash photometry value (YFLn) to calculate each flash emission amount (ΔEF). The calculation formula is shown below.

ΔEF = Log ₂ ((YFL−YDL) ×
AvDG_Hosei) / (Yref−YDLn × Av)
TvDG_Hosei)) The system control circuit 50 obtains the light emission time (Time) corresponding to ΔEF calculated above from the table of the flash light emission amount (EF_Ev) and the light emission time programmed in the memory 52 by linear interpolation (S21).
0).

The system control circuit 50 determines the main light emission time (T
image) (S210), the object brightness (BvAE) value in the AE control is obtained (S211), and the memory 5
2 (S21).
2) When the camera shake value of the BvAE value is large, the system control circuit controls the maximum value of the gain (DG) at the time of the main light emission by activating the imaging sensitivity adjusting means up to +0.4 steps as described below ( S213). When the BvAE value is equal to or less than the camera shake value, the maximum value of the gain (DG) at the time of main light emission is set to +1.
Control is performed for up to two stages (S214).

The system control circuit 50 activates the image pickup sensitivity adjusting means 15 to store the strobe light emission amount (ΔEF) and the memory 5.
2 is compared with the maximum light emission amount (EF_EvMax) of the table programmed, and the strobe light emission amount (ΔE
If F) exceeds the maximum light emission amount in the table, the excess is calculated as the gain (DG) for the main light emission, and the temporary gain value of the main light emission is calculated again. The gain is controlled as the gain (DG) (S215). The maximum value of DG is controlled in S213 and S214.

Next, the system control circuit 50 activates the exposure control means 40, compares the strobe light emission amount (ΔEF) with the minimum light emission amount (EF_EvMin) of the table programmed in the memory 52 (S216). When the light emission amount (ΔEF) falls below the minimum light emission amount in the table, if the temporary aperture control (XAv) value is open, the aperture is switched to a small aperture, and the aperture control (Av) value at the time of main emission is set.
Steps S9 to S210 are repeated, and the main emission time is recalculated for the portion that has been excessively stopped down (S217), and the shutter 12 having the aperture function is controlled based on the aperture control value (Av) at the time of the main emission (2). Is performed (S218).

Further, a shutter 12 having an aperture function
However, if the aperture can be adjusted in countless steps, the flash emission amount (ΔEF) is compared with the minimum emission amount (EF_EvMin) of the table programmed in the memory 52 (S216), and the flash emission amount (ΔEF) is set in the table. When the light emission amount falls below the minimum light emission amount, the temporary aperture control (XAv) value becomes
The aperture control value that is reduced to the extent that the strobe light emission amount (ΔEF) is less than the minimum light emission amount of the table is set as the aperture control (Av) value at the time of the main light emission. There is no need to perform this, and the aperture control (2) is performed by controlling the shutter 12 having the aperture function from the aperture control value (Av) at the time of the main light emission (S218).

If the strobe light emission amount (ΔEF) is equal to or larger than the minimum light emission amount in the table, the temporary aperture control (XAv) value is set as the aperture control (Av) value in the main light emission, and the aperture control value (Av) in the main light emission is used. ), The aperture control (2) is performed by controlling the shutter 12 having the aperture function (S218).

Next, the exposure control means 40 is started, and the aperture control (2) is performed by controlling the shutter 12 having the aperture function from the aperture control value (Av) at the time of the main light emission (S21).
8) The exposure control value calculating means analyzes and calculates the shutter control (TvPre) value at the time of pre-flash based on the aperture control (Av) value and DG from a program diagram, not shown, and calculates the shutter control value. Control (2) is performed (S219).

Finally, the system control circuit 50 activates the strobe control circuit 49 to control the strobe 48, and
Light emission is performed for the main emission time (Time) calculated above (S220).

As described in the first embodiment, after calculating the main light emission amount, the calculated main light emission amount is compared with the minimum light emission amount in the table programmed in the memory, and then the aperture is corrected as a correction. By calculating the control value and performing aperture control, it is possible to eliminate the problem that the exposure is over even with the minimum light emission during the main light emission.

Next, the operation of the second embodiment will be described with reference to FIGS. 1, 2 and 4. 1 and 2 are the same as in the first embodiment, and a description thereof will be omitted.

FIG. 4 is a flowchart showing the EF control operation according to the second embodiment. Referring to FIG.
The F control will be described.

It should be noted that the calculation of the main light emission time from the start (S
Steps up to 214) are the same as those in the first embodiment, and will be described with the same step numbers.

The system control circuit 50 activates the imaging sensitivity adjusting means 15 and determines the maximum amount of gain at the time of main light emission (S213, S214), and thereafter, the amount of strobe light emission (ΔEF).
And the minimum light emission amount (EF # EvMax) of the table programmed in the memory 52 (S315),
If the strobe light emission amount (ΔEF) is less than the minimum light emission amount of the table, the predetermined gain amount is reduced, and this is set as the gain (DG) at the time of main light emission (S317).
Step 10 is repeated, and the main light emission time is calculated again for the amount by which the gain is excessively lowered (S316).

Further, the gain amount is changed to the strobe light emission amount (ΔE
If F) is reduced by less than the minimum light emission amount of the table, this is set as the gain (DG) for the main light emission (S31).
7) It is not necessary to calculate the main light emission time again.

If the amount of strobe light emission (ΔEF) is equal to or greater than the minimum light emission amount of the table, the amount of strobe light emission (ΔEF)
Is compared with the maximum light emission amount (EF # EvMax) of the table programmed in the memory 52. If the flash light emission amount (ΔEF) exceeds the maximum light emission amount of the table, the gain (DG) at the time of the main light emission is exceeded. Is calculated, and the temporary gain value of the main light emission is recalculated. If not, the gain is controlled as the gain (DG) at the time of the main light emission (S317). The maximum value of DG is calculated in the above S213,
It is controlled by 214.

Next, the exposure control means 40 is activated, the shutter 12 having the aperture function is controlled using the temporary aperture control (XAv) value as the aperture control value (Av) at the time of the main light emission, and aperture control 2 is performed (S318). ).

Except for gain control and aperture control at the time of main light emission, this embodiment is the same as the first embodiment. The following shutter control (2)
The processing from (S219) to the end is the same as in the first embodiment.

As described in the second embodiment, after calculating the main light emission amount, the calculated main light emission amount is compared with the minimum light emission amount in the table programmed in the memory, and the gain is corrected as a correction. Is calculated, and gain control is performed, whereby the problem of overexposure even at the minimum light emission at the time of main light emission can be solved.

In the present embodiment, the recording medium 200
And 210 are not only memory cards such as PCMCIA cards and compact flash, hard disks, but also
Micro DAT, magneto-optical disk, CD-R and CD-W
Of course, there is no problem even if it is constituted by an optical disk such as R or a phase change optical disk such as DVD. Also, the recording medium 200
Of course, there is no problem even if each of them is a composite medium in which a memory card and a hard disk are integrated.

Further, there is of course no problem even if a part of the composite medium is detachable. In the description of the embodiment, the recording media 200 and 210
Although it has been described as a detachable recording medium which is separated and arbitrarily connectable, it goes without saying that any or all of the recording media may remain fixed to the imaging device 100. Further, the recording medium 200 or 21
0 may be a configuration in which one or more arbitrary numbers can be connected.

Then, the recording medium 200 is
And 210 have been described as being mounted, but it goes without saying that there is no problem irrespective of whether the recording medium has a single or a plurality of combinations.

Further, in this embodiment, the image display is performed by the image display section in the present apparatus. However, instead of the image display section 28 composed of a TFT LCD or the like, a video amplifier and a video signal output terminal are provided. The same effect is exhibited when displaying on an external display device or when transferring and displaying image data to an external device using the communication means 110 and the connector 112.

Also, the strobe 4 in the above embodiment is used.
Reference numeral 8 indicates that the light emission amount is minimum when the light emission time is minimum.

[0116]

As described above, according to the present invention,
Even if a light emission amount lower than the minimum light emission amount is calculated, it is possible to prevent overexposure during the main exposure.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment.

FIG. 2 is a flowchart illustrating an imaging control operation according to the embodiment.

FIG. 3 is a flowchart showing an EF control operation according to the first embodiment;

FIG. 4 is a flowchart showing an EF control operation according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 14 imaging element 15 imaging sensitivity adjustment means 40 automatic exposure control means 42 distance measurement control means 44 zoom control means 46 barrier control means 48 flash (strobe) 50 system control circuit 100 imaging apparatus

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H002 CC37 CD05 CD13 2H053 AD08 AD23 BA84 5C022 AA13 AB12 AB15 AB20 AC02 AC32 AC41 AC69

Claims (11)

[Claims] 1. An electronic apparatus comprising: a strobe control unit for controlling the emission of a strobe; an aperture for adjusting the amount of light; and an exposure control unit for controlling the aperture, wherein the exposure control unit minimizes a main emission amount of the strobe. An image pickup apparatus characterized in that, when the exposure is over when the setting is made, the aperture diameter of the stop is reduced. 2. The image pickup apparatus according to claim 1, wherein the exposure control means stops the aperture by an amount corresponding to an overexposure when the main light emission amount of the strobe is minimized. 3. The image pickup apparatus according to claim 1, wherein, when the aperture is a fixed aperture, the strobe control unit adjusts the exposure by extending an emission time of the strobe by an excessive amount of aperture. . 4. An image pickup apparatus comprising: strobe control means for controlling light emission of a strobe; imaging sensitivity adjustment means for adjusting a gain of an image signal captured by the imaging means; and exposure control means for controlling the imaging sensitivity adjustment means. , The exposure control means comprises:
The image pickup apparatus according to claim 1, wherein the exposure amount is reduced when the main light emission amount of the strobe is minimized, and the gain amount is reduced. 5. The imaging apparatus according to claim 4, wherein the exposure control means causes the flash unit to emit light by minimizing a main emission time of the strobe and to reduce the gain amount by an amount corresponding to an overexposure. 6. The image pickup apparatus according to claim 1, wherein the light emission time of the strobe is minimum when the light emission amount is minimum. 7. When the strobe light is controlled by strobe control means, the aperture control for controlling the light amount is controlled by the exposure control means, and when the main light emission amount of the strobe light is minimized, the exposure becomes over. A method for controlling an imaging device, wherein the aperture diameter of the stop is reduced. 8. The method according to claim 7, wherein the exposure control means reduces the aperture by an amount corresponding to the overexposure when the main light emission amount of the strobe is minimized. 9. The image pickup apparatus according to claim 7, wherein, when the aperture is a fixed aperture, the flash control means adjusts the exposure by extending the light emission time of the flash when the aperture is excessively reduced. Control method. 10. A flash control unit controls light emission of a strobe, an imaging sensitivity adjustment unit adjusts a gain of an image signal captured by the imaging unit, and an exposure control unit controls the imaging sensitivity adjustment unit. A method for controlling an image pickup apparatus, comprising: reducing an amount of gain when an overexposure occurs when the main emission amount of the strobe is minimized. 11. An image pickup apparatus according to claim 10, wherein said exposure control means reduces said gain amount by minimizing a main light emission time of said strobe light, and lowers the gain amount by an amount of overexposure. Control method.