JP2000115630A - Image pickup device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always attain the accurate control of exposure, even in a photographing state by providing a control means which sets the different value of a light quantity control means between the 1st and 2nd light emission states of a light emission means, based on the focus information and the measured light information, etc. SOLUTION: Exposure of light is performed before the 1st emission of light and defined as the 1st light reading value. Then an electronic flash trigger pulse is sent under the control of an arithmetic control part 9, and the 1st emission of light is performed by an electronic flash emission part 15 synchronously with the rise of the said trigger pulse and defined as the 2nd light reading value. The part 9 calculates the quantity of light reflected on an object via the 1st emission of light and based on the image data signal that is outputted from a signal processing part 7 through a solid-state image pickup device 4 and an image pickup processing A/D conversion part 5. Based on the measured light results, the 2nd light emission time is decided. With such a constitution, the accurate measured light result is obtained via the preliminary emission of light and the accurate control of exposure is attained, regardless of the distance set from the object, the brightness, etc., when the photographing is performed by the emission of an electronic flash.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an imaging apparatus that performs preliminary light emission for exposure control.

[0002]

2. Description of the Related Art Conventionally, in an image pickup apparatus provided with a light emitting means such as a strobe light, prior to actual exposure for actually photographing,
It is widely known that preliminary light emission is performed in advance to measure the exposure condition of a subject, the light emission condition at the time of main light emission at the time of main exposure is determined based on the photometric data, and the main light emission is performed.

In this conventional method, the aperture value at the time of preliminary light emission and main exposure is a system in which the aperture value is determined based on distance information.

[0004]

However, even when the photographing conditions are dark, such as when the photographing condition is dark, and when it is desired to perform photographing with the diaphragm set near the maximum aperture, the aperture determined based on the distance information becomes a value smaller than the maximum aperture. In such a case, there is a problem that the exposure control cannot be accurately performed depending on the photographing conditions, such as when the photographing is performed under such conditions, the background may be lower than when the photographing is performed in the open state.

Accordingly, in the present invention, accurate exposure control and accurate exposure control are always performed regardless of the photographing state so that the photographing can be performed at an appropriate dimming level even when the aperture must be reduced during preliminary flashing because the subject is close. It is an object of the present invention to provide an imaging device capable of controlling strobe light emission.

[0006]

According to a first aspect of the present invention, there is provided an image pickup means for photoelectrically converting a subject image and outputting an image pickup signal. Light amount control means for controlling light amount to the means, light emitting means for performing first light emission and second light emission for irradiating a subject, focus detection means for detecting focus state of the subject and outputting focus information, Performing photometry on the subject, photometric means for outputting photometric information, and the focus information,
An image pickup apparatus characterized by comprising control means for making a set value of the light quantity control means different between the first light emission and the second light emission of the light emitting means based on the photometric information.

According to a second aspect of the present invention, in the first aspect of the present invention, the focus information is information on a distance from the subject, and the control means is configured to control the light quantity control means. A set value is determined based on the focus information at the time of the first light emission of the light emitting means, and a second value of the light emitting means is determined.
The image pickup apparatus is characterized in that the light emission is determined based on the photometric information by the photometric means before the first light emission.

According to a third aspect of the present invention, in the second aspect of the present invention, the focus detecting means and the photometric means are operated in response to pressing of a first stroke of a release switch for instructing a photographing operation. Respectively, to obtain the focus information and the photometric information, determine whether or not the light emitting unit emits light based on the photometric information. When the light emitting unit is operated, the second stroke of the second stroke deeper than the first stroke is determined. An imaging apparatus is configured to cause the light emitting unit to sequentially perform the first light emission and the second light emission in response to pressing.

According to the invention described in claim 4 of the present application, in the invention according to claim 2, the second light source of the light emitting means is provided.
Is a main light emission at the time of photographing, and the first light emission is a preliminary light emission for setting the light amount control means and setting the second light emission amount at the time of photographing.

According to the invention described in claim 5 of the present application, an image pickup means for photoelectrically converting a subject image and outputting an image pickup signal, a light amount control means for controlling a light amount to the image pickup means,
A light emitting unit for emitting light for irradiating the subject, a focus detecting unit for detecting a focus state of the subject and outputting focus information, a photometric unit for performing photometry on the subject and outputting photometric information, and the focus Control means for selectively using the set value determined based on the information and the set value determined based on the photometric information to determine the set value of the light quantity control means when the light emitting means emits light. The imaging device is characterized in that:

According to the invention described in claim 6 of the present application, in the invention according to claim 5, the control means causes the light emitting means to emit first light before photographing and second light during photographing. Are sequentially performed, and when the first light emission of the light emitting means is performed, the control means determines based on the set value determined based on the focus information and the photometric information before the first light emission. An imaging device configured to select a smaller aperture of the set value, and to select a set value determined based on the photometric information before the first light emission at the time of the second light emission. I do.

According to a seventh aspect of the present invention, in the fifth aspect of the invention, the control means causes the light emitting means to emit a first light before photographing and a second light during photographing. Are sequentially performed, and the control unit controls the first of the light emitting units.
At the time of light emission, a set value determined based on the focus information,
The smaller aperture of the set value determined based on the photometric information before the first light emission is selected. At the time of the second light emission, the set value determined based on the focus information and the first light emission are selected. An imaging apparatus is configured to select any one of the setting values determined based on the previous photometric information according to a shooting mode.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the control means causes the light emitting means to emit first light before photographing and second light during photographing. Are sequentially performed, and the control unit controls the first of the light emitting units.
At the time of light emission, a set value determined based on the focus information,
The smaller aperture of the set value determined based on the photometric information before the first light emission is selected, and in the case of the second light emission in the macro mode, the setting of the one selected at the time of the first light emission is selected. It features an imaging device configured to select a value.

According to a ninth aspect of the present invention, in the fifth aspect of the present invention, the focus detecting means and the photometric means are operated in response to pressing of a first stroke of a release switch for instructing a photographing operation. Respectively, to obtain the focus information and the photometric information, determine whether or not the light emitting unit emits light based on the photometric information. When the light emitting unit is operated, the second stroke of the second stroke deeper than the first stroke is determined. An imaging apparatus is configured to cause the light emitting means to sequentially perform the first light emission and the second light emission in response to pressing.

According to the invention described in claim 10 of the present application, an image pickup means for photoelectrically converting a subject image and outputting an image pickup signal, a light amount control means for controlling a light amount to the image pickup means,
Light-emitting means for performing first and second light emission for irradiating a subject, focus detection means for detecting a focus state of the subject and outputting focus information, performing photometry on the subject, and obtaining photometric information. An imaging method for performing imaging by controlling a photometric unit that outputs light, wherein the light amount at the time of the first light emission and the second light emission of the light emitting unit based on the focus information and the photometric information. It is characterized by an imaging method of controlling so that the set value of the control means is made different.

According to an eleventh aspect of the present invention, in the tenth aspect of the present invention, the focus information is information on a distance from the subject, and the control means controls the light amount control means. The set value is determined on the basis of the focus information when the light emitting unit is emitting the first light, and when the light emitting unit is emitting light for the second time, the photometric information by the light measuring unit before the first light emitting is determined. The imaging method is characterized in that it is determined based on

According to a twelfth aspect of the present invention, in the eleventh aspect, the focus detecting means and the photometric means are operated in response to pressing of a first stroke of a release switch for instructing a photographing operation. Respectively, to obtain the focus information and the photometric information, determine whether or not the light emitting unit emits light based on the photometric information. When the light emitting unit is operated, the second stroke of the second stroke deeper than the first stroke is determined. An image pickup method is characterized in that the first light emission and the second light emission are sequentially performed by the light emitting means in response to pressing.

According to the invention of claim 13 of the present application, an image pickup means for photoelectrically converting a subject image and outputting an image pickup signal, a light amount control means for controlling a light amount to the image pickup means,
A light emitting unit that emits light for irradiating the subject, a focus detecting unit that detects a focus state of the subject and outputs focus information, and a photometric unit that performs photometry on the subject and outputs photometric information are controlled. An imaging method for performing imaging by selectively using a set value determined based on the focus information and a set value determined based on the photometric information, wherein the light amount control when the light emitting unit emits light is performed. An imaging method for controlling so as to determine a set value of the means is characterized.

According to a fourteenth aspect of the present invention, in the thirteenth aspect of the invention, the light emitting means sequentially emits a first light emission before photographing and a second light emission during photographing, At the time of the first light emission of the light emitting unit, a smaller aperture of a set value determined based on the photometric information before the first light emission and a set value determined based on the focus information is selected. Second
In the case of the light emission, the imaging method is characterized in that a set value determined based on the photometric information before the first light emission is selected.

According to a fifteenth aspect of the present invention, in the thirteenth aspect, the light emitting means sequentially emits a first light emission before photographing and a second light emission during photographing, At the time of the first light emission of the light emitting unit, a smaller aperture of a set value determined based on the photometric information before the first light emission and a set value determined based on the focus information is selected. Second
At the time of light emission, a set value determined based on the focus information,
An imaging method is characterized in that any one of the setting values determined based on the photometric information before the first light emission is selected according to a shooting mode.

According to a sixteenth aspect of the present invention, in the fifteenth aspect, the light emitting means sequentially emits a first light before photographing and a second light during photographing, At the time of the first light emission of the light emitting means, a smaller aperture of the set value determined based on the focus information and the set value determined based on the photometric information before the first light emission is selected, and a macro is selected. An image pickup method is characterized in that, when the second light emission is performed in the mode, the set value selected at the time of the first light emission is selected.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an image pickup apparatus according to the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows an example of an image pickup apparatus to which the present invention is applied.
Is a barrier for protecting the lens, 2 is a lens for forming an optical image of a subject on the solid-state imaging device 4, 3 is a stop as light amount control means for controlling the amount of light passing through the lens 2, 4 is a lens 2 Solid-state image pickup device for taking in the subject formed in the above as an image signal;
An image processing A / D conversion unit having an A / D converter for performing various corrections, clamping, and the like on an image signal output from the analog signal to convert the analog signal into a digital signal. A timing generation unit 7 for outputting to the imaging processing A / D converter 5 performs various corrections on the image data input from the imaging processing A / D conversion unit 5 and the arithmetic control unit 9, and then performs the arithmetic control unit 9 again. D / A for outputting image data to the amplifier or outputting an analog signal to the amplifier 8
A signal processing unit having a converter, 8 is an amplifier for amplifying the signal from the signal processing unit 7 and outputting it to an external monitor such as a television monitor or a liquid crystal monitor, and 9 is a book for controlling the entire digital camera and performing various calculations. An arithmetic control unit corresponding to the control means of the present invention, which is constituted by a CPU.

Reference numeral 10 denotes an auxiliary control unit for detecting operation states of the main switch 17 and the release switch 18 and assisting the arithmetic control unit 9, and 11 for compressing and expanding image data from the arithmetic control unit 9. Compression / decompression processing unit, 12 is a memory unit for temporarily storing image data, 13 is a removable recording medium such as a semiconductor memory for recording or reading out image data, and 14 is an external computer or the like. Interface part for communication,
Reference numeral 15 denotes a strobe light emitting unit as a light emitting unit; 16, an auxiliary light emitting unit that emits light when external light is dark or when a subject has low contrast; 17, a main switch that also performs various mode settings; A release switch having a first stroke and a second stroke, 19 is a display control unit for controlling the display unit 20, and 20 is a display unit for displaying an image signal.

In the above configuration, the operation of the imaging device at the time of photographing will be described with reference to the flowchart of FIG.

The lens position of the imaging lens is driven to the reset position, and the apparatus stands by until the first switch of the two-stage pressing type release switch 18 which is turned on according to the first stroke is turned on.

When the first switch is turned on (S20)
1) The lens position of the AF lens is driven again to a predetermined position, and the power of an imaging system circuit such as the imaging processing A / D converter 5 and the timing generator 6 is turned on.

After the diaphragm 3 is opened according to a command from the arithmetic and control unit 9 (S202), the image pickup processing A through the solid-state image pickup device 4 is performed.
The image data converted by the / D converter 5 is input to the arithmetic and control unit 9 after passing through the signal processing unit 7, where the photometric value is calculated and the photometric result is stored (S203). This is referred to as photometry 1 in the sense of preliminary exposure.

The brightness is determined on the basis of the result of the photometry (S204).
Aperture and shutter speed are determined and controlled according to the program diagram shown in (2) (S206).

On the other hand, if it is determined in S204 that the light is dark or backlit, or if the external operation member for strobe forced light emission is pressed, a flag is set, and the strobe light emission unit is controlled by the arithmetic control unit 9. 15 fully charges the capacitor that stores energy when emitting light (S
205) In other cases, no flag is set and charging is not performed.

Next, based on the signal output from the signal processing unit 7 through the solid-state imaging device 4 and the imaging processing A / D conversion unit 5, a high-frequency component that changes according to the focus state is extracted.
In order to focus on the subject, calculation of the drive control signal of the AF lens is performed by the calculation control unit 9 (S209).

At this time, when it is determined that the contrast difference between the objects is small or dark (S207), the auxiliary light emitting section 16 emits auxiliary light (S208). After that, AF
The lens is driven to determine whether or not focus is achieved (S210). If it is determined that focus is not achieved, the AF lens is driven again to perform a focus control operation.

After focusing, if the flag is set in S205, it is determined that the flash mode is set (S211).
If not, the process waits until the second switch that is turned on in response to the second stroke of the release switch 18 is turned on (S212), and performs the main exposure when the second switch is turned on (S213).

When the exposure is completed, the image data output from the solid-state imaging device 4 and processed and output by the imaging processing / A / D converter passes through the signal processor 7 and is stored in the memory 12 by the arithmetic controller 9. Is done.

Thereafter, the data stored in the memory unit 12 is transferred to the compression / decompression processing unit 11 under the control of the arithmetic control unit 9.
After being compressed by the above, it is recorded on a removable recording medium 13 such as a semiconductor memory. At this time, if the second switch has been kept pressed (S214), the captured image is displayed on the display unit 20 (S215), and the display is continued until the second switch is turned off. To stop shooting. If the second switch has been turned off from the beginning in S214, the photographing is terminated without displaying it on the display unit 20.

If it is determined in step S211 that the flash mode is set, the flash sequence is started, and the flow waits until the second switch that is turned on in response to the second stroke of the release switch 18 is turned on (S216).

When the second switch is turned on, the aperture value is calculated by the following equation (1) based on the distance information obtained in step S209, and the shutter speed is further obtained and reset from the program diagram of FIG. 3 ( S217).

Here, the aperture control in S217 is performed in S21.
In the case where the first light emission of No. 9 always emits with a constant light amount, control is performed such that reflected light that changes depending on the distance to the subject and the reflectance enters the solid-state imaging device 4 with an appropriate light amount. The aperture value at that time can be expressed by equation (1).

Av = 2 ^* Log2 (D / L) + Y (1) Av: aperture value L: distance information D, Y: predetermined value

D and Y shown in equation (1) are predetermined values.
If the light emission amount of the first light emission is constant, there is no need to change it. However, even if the aperture control amounts D and Y are switched depending on the mode, the reflected light from the subject enters the solid-state imaging device 4 with a more appropriate light amount. good.

For example, a macro mode for photographing at a close distance, a document mode for photographing paper with high reflectivity, a day / day mode forcibly emitting light in a backlight, a black and white mode for expressing by contrast, etc. may be provided and switched. . Needless to say, the modes may be combined to set a more detailed mode for switching.

This makes it possible to accurately perform photometry by the first light emission. For example, when the subject is at a short distance in a relatively dark situation, the aperture set based on the photometry result in S203 is in a relatively open state. When the first light emission is performed in the state of the aperture, reflected light exceeding the dynamic range of the solid-state imaging device 4 may return.

However, as a result of the focus adjustment in S209, it is possible to control the aperture based on the distance information detected from the position of the AF lens or the like and to stop the aperture, so that an appropriate amount of light can be incident on the solid-state imaging device 4. An accurate photometric result can be obtained.

In the control of the shutter speed in step S217, a value is obtained from the program diagram shown in FIG. 3 such that the fluctuation in the aperture value is compensated for and the exposure condition becomes the same as the set value in step S206.

Thereafter, the second photometry is performed and the value of the steady light is stored (S218). Further, the first light emission is performed (S2
19) At the same time, third photometry is also performed (S220). At this time, the first light emission is not more than 4 to 4 times at the time of full light emission for the reason that the charging energy for the second light emission is not reduced as much as possible and that the light emission amount necessary and sufficient for photometry can be sufficient.
The amount of light emission that drops by about 5 steps is good. In this case, the first
The voltage drop of the charging capacitor due to the light emission is about 7 to 10% of the full charge, and the remaining charge voltage after the first light emission is characterized by having a substantially constant value.

Photometry 2 (S218) and Photometry 3 (S22)
0), based on the data signal that has passed through the solid-state imaging device 4 and has been processed by the imaging processing A / D conversion unit 5 and the signal processing unit 7,
The amount of reflected light from the subject is calculated by the calculation control unit 9 to obtain a photometric value. Then, a difference (ΔEv) from the appropriate level of the first light emission is obtained from the photometric value from the equation (2).

ΔEv = Log 2 ((Pre_D−Prepre_D) / (Ref−Prepre_D)) (2) Prepre_D: photometric data of photometry 2 Pre_D: photometric data of photometry 3 Ref: reference value

At this time, the output from the solid-state image sensor in photometry 3 is a mixture of strobe light and external light. First
In order to obtain the reflected light amount of the pure strobe light in the light emission of, the result of the photometry 2 which is a photometry value of only the external light is subtracted from the result of the photometry 3 in which the strobe light and the external light are mixed. Therefore, it is possible to know an accurate reflected light amount of only the strobe light by the first light emission.

Further, the level at which the strobe light is required at the time of exposure varies depending on the brightness of the external light, but this is handled by subtracting the photometric value of photometry 2 from the reference value, that is, subtracting the external light component. The required strobe light can be determined accurately.

Each correction item is added to the calculation result of the equation (2), and a guide number (GN) required for final main light emission is obtained.
o.) is obtained from equation (3).

GNo. = 2 (−ΔEv + α + β) (3) GNo .: guide number ΔEv: calculation result α: correction term 1 β: correction term 2

The correction term 1 is a term that changes according to the brightness of external light as shown in FIG. Also, by changing the pattern that changes as in (b) depending on the mode, it is possible to cope with various scenes.

The correction term 2 is a term that can be set flexibly, for example, when fine adjustment of the light emission amount is desired. For example, when the photographer wants to emit a strobe light brighter by +0.2 steps, it is possible to cope by setting β = 0.2 by setting the operation member to +0.2 steps.

From the guide number for the second light emission obtained as described above, the light emission time of the second light emission is calculated using the "guide number and light emission time table" showing the characteristics of the strobe shown in FIG. It is calculated by the control unit 9 (S22
1).

Then, the aperture and shutter speed are set to S2.
It returns to the value set in 06 (S222). This is S21
With the aperture and shutter speed conditions reset in step 7,
This is because the background may be lower than when the image is captured with the value set in S206.

For example, if the set value of S206 is the aperture Av =
3. If the shutter speed Tv = 6, S20
When the aperture calculated in 9 is Av = 5, the shutter speed must be Tv = 4.

However, according to the program diagram of FIG.
Is set to 4.91, so that in S217, Tv =
Must be set to 4.91. Therefore, S21
If the exposure is performed under the condition set in step 7, the background will be 0.91 step lower than in the condition set in step S206.

Then, the main exposure is started (S223), and a strobe trigger pulse is sent to the strobe light emitting unit 15 under the control of the arithmetic control unit 9, and the strobe 15 is synchronized with this pulse.
Starts the second light emission, and stops the light emission at the moment when the light emission time obtained in S221 elapses (S224).

When the exposure is completed (S225), the image data output from the solid-state imaging device 4 and processed and output by the imaging processing / A / D conversion unit passes through the signal processing unit 7 and is processed by the arithmetic and control unit 9 by the memory unit. 12 is stored.

Thereafter, the data stored in the memory section 12 is compressed by the compression / decompression processing section 11 under the control of the overall control / operation section 9 and then recorded on a removable recording medium 13 such as a semiconductor memory.

At this time, if the second switch has been kept depressed (S214), the photographed image is displayed on the display unit 20 (S215), and the display is continued until the second switch is turned off. Is stopped and the shooting is terminated.

In S214, the second switch is set to O from the beginning.
If it is FF, the photographing is terminated without displaying it on the display unit 20.

Next, the timing of strobe light emission of the present embodiment having the above configuration will be described with reference to the timing chart of FIG.

When the first switch is turned on by the first stroke of the release switch 18 (t1), the lens position of the AF lens is driven to a required position (t2), and the A / D converter 5 and the timing generator are processed. The power of the imaging signal processing circuit system such as 6 is turned on.

The arithmetic control unit 9 opens the aperture 3 (t
3) Based on the image data signal output from the signal processing unit 7 through the solid-state imaging device 4 and the imaging processing A / D conversion unit 5,
The calculation of the amount of reflected light from the subject is performed by the calculation control unit 9.

As a result of the photometry, when it is determined that the light is dark, the arithmetic and control unit 9 sufficiently charges a capacitor for light emission constituting the strobe light emitting unit 15 (t4) and controls the aperture (t5).

Next, based on the image data signal output from the signal processing unit 7 through the solid-state imaging device 4 and the imaging processing A / D conversion unit 5, the arithmetic control unit 9 performs an automatic focus adjustment operation. As a result, the arithmetic control unit 9 calculates the distance to the subject from the AF lens position information and the like.

Then, the AF lens is driven (t6), and it is determined whether or not the lens is in focus. If it is determined that the lens is not focused, the AF lens is driven again to measure the distance. When measuring the distance to the subject, when it is determined that the surroundings are dark or when the contrast of the subject is uniform, the arithmetic control unit 9 sends a signal for prompting the auxiliary light emitting unit 16 to emit light, and the auxiliary light emitting unit 16 The auxiliary light is irradiated (t7).

After focusing, the operation waits until the second switch which is turned on in response to the second stroke of the release switch 14 is turned on. When the flash mode is ON, the second
Is turned on (t8), the aperture is controlled to the aperture value obtained from the distance information (9).

Next, exposure is performed before the first light emission, and this is set as a first photometric value. Subsequently, a strobe trigger pulse is sent under the control of the arithmetic and control unit 9, and the strobe light emitting unit 15 performs the first light emission in synchronization with the rise of this pulse (t11), and sets this as the second photometric value. Based on the image data signal output from the signal processing unit 7 through the solid-state imaging device 4 and the imaging processing A / D conversion unit 5 by the first light emission, the calculation of the amount of light reflected from the subject is totally controlled. The calculation is performed by the arithmetic unit 9. The light emission time of the second light emission is determined from the result of the photometry.

Next, the aperture is controlled again (t12) to return to the aperture value of t5. Subsequently, the main exposure is started, and a strobe trigger pulse is sent under the control of the arithmetic control unit 9, and the strobe light emitting unit 15 starts the second light emission in synchronization with the rise of this pulse (t13). When the predetermined time has elapsed, the light emission is instantaneously stopped (t14), and the main exposure ends.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In this embodiment, the configuration is the same as that of the first embodiment in FIG. 1, and the description is omitted. This embodiment is different from the first embodiment in the control processing by the arithmetic control unit 9, and the processing is shown in the flowchart of FIG.

In the flowchart of FIG. 7, the same reference numerals are used for steps for performing the same processing as in the flowchart of the first embodiment of FIG. The difference from the flowchart of FIG. 2 is that the process of S701 is added after the process of S216, and that the process of S702 is added after the process of S221. The description will be made in the following order.

In step S211, a process for shooting by emitting a flash is selected. In step S216, the release switch 1 is turned on.
When the second switch is turned on by the second stroke of No. 8, the process proceeds to S217 in the first embodiment of FIG.
Based on the distance information obtained in S209, the aperture value was calculated by equation (1), the shutter speed was obtained from the program diagram of FIG. 3, and resetting was performed. That is, a process of obtaining a value that compensates for the change in the aperture value and makes the exposure condition equal to the set value of S206 was performed.

On the other hand, in the second embodiment, S2
Immediately after the second switch is turned on at S21, S21
7, the process proceeds to step S701 to select whether or not to set an aperture value based on distance information.

That is, the current aperture value set in S206 obtained based on the result of photometry 1 in S203 and the program diagram shown in FIG. 3 and the distance information obtained in S209 are calculated by equation (1). The selected aperture values are compared, and the value on the small aperture side is selected. At this time, if the current aperture value set in S206 is selected, the setting is not reset, and if the aperture value obtained based on the distance information obtained in S209 is selected, S217 is selected.
Then, reset the aperture and shutter speed.

The aperture control in S217 is performed according to the first control in S219.
When the light emission always emits at a constant light amount, the reflected light that changes depending on the distance to the subject and the reflectance is controlled to enter the solid-state imaging device 4 with an appropriate light amount. This is as represented by equation (1).

As a result, it is possible to accurately perform a photometric result by the first light emission. As described above, when the subject is at a short distance in a relatively dark situation, the aperture set based on the photometry result in S203 is in a relatively open state. Reflected light exceeding the dynamic range of the image sensor 4 may return. However, by controlling the aperture based on the distance information in step S209 and stopping down, it is possible to cause the solid-state image sensor 4 to enter an appropriate amount of light. As a result, accurate photometric results can be obtained.

On the other hand, in a bright situation such as the daytime, the magnitude relationship between the aperture values is reversed. That is, even if the aperture is small, the aperture is small because the subject is bright even at a short distance. 4 may exceed the dynamic range. In such a case, by selecting the setting of S206, which is a smaller aperture, it is possible to eliminate the possibility that the dynamic range of the solid-state imaging device 4 is exceeded by the steady light. Therefore, it is possible to obtain a reliable photometric result by selecting a value on the small aperture side.

As described above, by the processing of S701, S20
By using the smaller aperture value obtained in the process of S209 and the smaller aperture value obtained in the process of S209,
The processing after S218 can be performed accurately.

Thereafter, the second photometry is performed in S218 to store the value of the steady light, the first light emission is performed in S219, the third photometry is performed in S220, and the light emission time of the second light emission is determined in S221. Calculate. These processes are the same as in the first embodiment.

Thereafter, in S702, it is determined whether the aperture and the shutter speed are reset to the values set in S206.

At this time, if the main switch 17 also serving as the mode setting is in the non-macro mode, and if the value of S206 is selected in S701, the process proceeds to the main exposure with the current value as it is. Conversely, even when the value of the distance information is selected in S701, the value is reset to the value of S206 again (S222), and the process proceeds to the main exposure.

When the main switch 17 also serving as the mode setting is in the macro mode, no matter whether the value of the distance information or the value of S206 is selected in S701,
S701 without resetting the aperture and shutter speed
Move to the main exposure with the value selected in.

The judgment in S702 may be made in the mode as described above, or may be made in another judgment condition. For example, the determination may be made based on whether the background is lower than the condition set in S206 in the setting in S217 without being limited to the macro / non-macro.

For example, if the set value in S206 is the aperture Av =
3. If the shutter speed Tv = 6, S20
When the aperture calculated in 9 is Av = 5, the shutter speed must be Tv = 4.

However, according to the program diagram of FIG.
Is 4.91 and therefore Tv = 4.9 in S217.
Must be set to 1. As a result, if exposure is performed under these conditions, the background will be lower than the conditions set in S206. In such a case, the aperture and shutter speed are returned to the values set in S206 (S22
2).

After that, the main exposure is started in S223, a strobe trigger pulse is sent to the strobe light emitting section 15, and the strobe 15 starts the second light emission in synchronization with this pulse.
When the light emission time obtained in S221 elapses, light emission is stopped (S224), and the exposure ends.

The subsequent processing is the same as in the first embodiment.

Next, the timing of strobe light emission according to the second embodiment will be described with reference to the timing chart of FIG.

When the first switch of the release switch 18 is turned on (t1), the lens position of the AF lens is driven to a required position (t2), and the imaging signal of the imaging processing A / D converter 5 and the timing generator 6 is transmitted. Power on the processing circuit system
I do. The overall control / calculation unit 9 opens the aperture 3 (t
3) Based on the image data signal output from the signal processing unit 7 through the solid-state imaging device 4 and the imaging processing A / D conversion unit 5,
Overall control / calculation unit 9 for calculating the amount of reflected light from the subject
Do with. As a result of the photometry, if it is determined that the light is dark, the overall control / arithmetic unit 9 sufficiently charges the light emitting capacitor constituting the strobe light emitting unit 15 (t4), and controls the aperture (t5).

Then, based on the image data signal output from the signal processing unit 7 through the solid-state imaging device 4 and the imaging processing A / D conversion unit 5, the arithmetic control unit 9 calculates the distance to the subject.

Then, the AF lens is driven (t6) to determine whether or not focus is achieved. If it is determined that focus is not achieved, the AF lens is driven again to perform distance measurement. When measuring the distance to the subject, when it is determined that the surroundings are dark or when the contrast of the subject is uniform, the overall control / arithmetic unit 9 sends a signal prompting light emission to the auxiliary light emitting unit 16 and sends the signal to the auxiliary light emitting unit 16. 16
Irradiates auxiliary light (t7).

After focusing, the operation waits until the second switch which is turned on in response to the second stroke of the release switch 14 is turned on. When the flash mode is ON, the second
Is turned on (t8), the current aperture value set at t5 is compared with the aperture value obtained from the distance information, a small aperture value is selected, and if the current value is selected, resetting is performed. If the aperture value obtained from the distance information is selected, the aperture is controlled (t9).

Next, exposure is performed before the first light emission, and this is set as a first photometric value. Subsequently, a strobe trigger pulse is sent under the control of the overall control / arithmetic unit 9, and the strobe light emitting unit 15 performs the first light emission in synchronism with the rise of this pulse (t11). I do. Based on the image data signal output from the signal processing unit 7 through the solid-state imaging device 4 and the imaging processing A / D conversion unit 5 by the first light emission, the calculation of the amount of light reflected from the subject is totally controlled. The calculation is performed by the arithmetic unit 9. The light emission time of the second light emission is determined from the result of the photometry.

Next, in the non-macro mode, the aperture is controlled again to the same value as t5 (t12). In the macro mode, the aperture is not reset because the aperture value remains at t9. Subsequently, the main exposure is started, and a strobe trigger pulse is sent under the control of the overall control / arithmetic unit 9, and the strobe light emitting unit 15 is synchronized with the rising edge of this pulse.
(T13). When the predetermined time has elapsed, the light emission is instantaneously stopped (t14), and the main exposure ends.

As described above, in the first embodiment,
In the first light emission, the aperture is reset to the aperture determined by the distance information, and in the second light emission, the aperture is reset to the first aperture, so that an accurate photometric value can be obtained in the first light emission. Further, in the second light emission, it is possible to perform accurate main exposure including the background level.

In the second embodiment, in the first light emission, the current aperture is compared with the aperture obtained from the distance information to select the value on the small aperture side, and in the second light emission, the small aperture is selected depending on the mode or the like. By selecting whether to proceed to the main exposure with the values on the side or to return to the initial value, it is possible to obtain an accurate photometric value in the first light emission, and to obtain the light with the brightness obtained from the result. The light measurement accuracy in the light emission of No. 2 is also improved, and the main exposure can be accurately performed.

[0099]

As described above, according to the present invention, when taking an image with a strobe light, an accurate photometric result can be obtained in the preliminary flash regardless of the state of the subject, such as the distance and brightness. The main light emission for the light emission time obtained from the photometric result can be performed with high-precision light control, and accurate exposure control can always be performed.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an imaging device according to an embodiment of the present invention.

FIG. 2 is a flowchart during a shooting operation according to the first embodiment of the present invention.

FIG. 3 is a program diagram of the first and second embodiments of the present invention.

FIG. 4 is a diagram showing a correction term 1 of the first and second embodiments of the present invention.

FIG. 5 is a table for obtaining light emission times according to the first and second embodiments of the present invention.

FIG. 6 is a time chart at the time of a photographing operation according to the first and second embodiments of the present invention.

FIG. 7 is a flowchart during a shooting operation according to the second embodiment of the present invention.

[Description of Signs] 1 barrier 2 lens 3 aperture 4 solid-state imaging device 5 imaging processing A / D conversion unit 6 timing generation unit 7 signal processing unit 8 amplifier 9 operation control unit 10 auxiliary control unit 11 compression / decompression processing unit 12 memory unit DESCRIPTION OF SYMBOLS 13 Recording medium 14 I / F part 15 Strobe light emission part 16 Auxiliary light emission part 17 Main switch 18 Release switch 19 Display control part 20 Display part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 15/05 G02B 7/11 N 5C052 H04N 5/907 G03B 3/00 A F-term (Reference) 2H002 AB01 CC21 CC31 CD11 CD13 DB01 DB06 DB19 FB21 FB28 FB32 FB33 FB84 GA54 JA07 2H011 AA01 BA33 BB02 DA01 DA07 2H051 BA45 BA47 CB22 CC02 CC16 CE02 CE14 CE24 EA10 EA11 EA20 EA22 EB01 EB04 EB07 2A05 AA13 AB01A13 AB01A01 AB01 AB26 5C052 GA02 GB01 GC05 GE08

Claims (16)

[Claims] An imaging unit that photoelectrically converts a subject image and outputs an imaging signal; a light amount control unit that controls a light amount to the imaging unit; and a first light emission and a second light emission for irradiating a subject. A light-emitting means for performing, a focus detection means for detecting a focus state of the subject and outputting focus information, a photometric means for performing photometry on the subject and outputting photometric information, An image pickup apparatus, comprising: a control unit that makes a set value of the light amount control unit different between the first light emission and the second light emission of the light emitting unit. 2. The method according to claim 1, wherein the focus information is information on a distance from the subject.
The control means determines a set value of the light quantity control means based on the focus information at the time of the first light emission of the light emitting means, and determines the first light emission at the time of the second light emission of the light emitting means. An imaging apparatus characterized in that it is configured to be determined on the basis of photometric information obtained by the photometric means before. 3. The photometry according to claim 2, wherein the focus detection means and the photometry means are operated in response to pressing of a first stroke of a release switch for instructing a photographing operation, thereby obtaining the focus information and the photometry information, respectively. It is determined whether or not the light emitting means emits light based on information, and when the light emitting means is operated, the first light emitting means is caused to emit the first light by the second stroke deeper than the first stroke. An imaging device configured to sequentially perform the second light emission. 4. The light emitting device according to claim 3, wherein the second light emission of the light emitting means is a main light emission at the time of photographing, and the first light emission is a setting of the light amount control means at the time of photographing and the second light emission amount. An image pickup apparatus, which is a preliminary light emission for performing setting of (1). 5. An imaging unit for photoelectrically converting a subject image and outputting an imaging signal; a light amount control unit for controlling a light amount to the imaging unit; a light emitting unit for emitting light for irradiating the subject; Focus detection means for detecting and outputting focus information; photometric means for performing photometry on the subject and outputting photometric information; and a set value determined based on the focus information, and based on the photometric information. An imaging device comprising: a control unit for selectively using the determined set value to determine a set value of the light amount control unit when the light emitting unit emits light. 6. The light emitting device according to claim 5, wherein the control means causes the light emitting means to sequentially perform a first light emission before photographing and a second light emission during photographing. At the time of the first light emission, a smaller aperture of the set value determined based on the focus information and the set value determined based on the photometric information before the first light emission is selected, and the second light emission of the second light emission is selected. An imaging apparatus configured to select a set value determined based on the photometric information before the first light emission at the time of the first light emission. 7. The light emitting device according to claim 5, wherein the control means causes the light emitting means to sequentially perform a first light emission before photographing and a second light emission during photographing. At the time of the first light emission, a smaller aperture between the set value determined based on the focus information and the set value determined based on the photometric information before the first light emission is selected, and the second stop is selected.
At the time of light emission, a set value determined based on the focus information,
An imaging apparatus characterized in that any one of setting values determined based on the photometric information before the first light emission is selected in a shooting mode. 8. The light emitting device according to claim 7, wherein the control means causes the light emitting means to sequentially perform a first light emission before photographing and a second light emission during photographing. At the time of the first light emission, a smaller aperture between the set value determined based on the focus information and the set value determined based on the photometric information before the first light emission is selected, and the second stop in the macro mode is selected. An imaging apparatus characterized in that, in the case of the second light emission, the set value selected in the first light emission is selected. 9. The photometry according to claim 5, wherein the focus detection means and the photometry means are operated in response to pressing of a first stroke of a release switch for instructing a photographing operation, thereby obtaining the focus information and the photometry information, respectively. It is determined whether or not the light emitting means emits light based on information, and when the light emitting means is operated, the first light emitting means is caused to emit the first light by the second stroke deeper than the first stroke. An imaging device configured to sequentially perform the second light emission. 10. An image pickup means for photoelectrically converting a subject image to output an image pickup signal, a light amount control means for controlling a light amount to the image pickup means, and a first light emission and a second light emission for irradiating the object. An imaging method for controlling the light emitting unit, a focus detection unit for detecting a focus state of the subject and outputting focus information, and a photometric unit for performing photometry on the subject and outputting photometric information. And controlling the light emitting unit so that a set value of the light amount control unit at the time of the first light emission and at the time of the second light emission of the light emitting unit is made different based on the focus information and the photometric information. Imaging method. 11. The method according to claim 10, wherein the focus information is information on a distance from the subject.
The control means determines a set value of the light quantity control means based on the focus information at the time of the first light emission of the light emitting means, and determines the first light emission at the time of the second light emission of the light emitting means. An imaging method, characterized in that it is determined on the basis of previous photometric information by said photometric means. 12. The photometry according to claim 11, wherein the focus detection means and the photometry means are operated in response to pressing of a first stroke of a release switch for instructing a photographing operation, thereby obtaining the focus information and the photometry information, respectively. It is determined whether or not the light emitting means emits light based on information, and when the light emitting means is operated, the first light emitting means is caused to emit the first light by the second stroke deeper than the first stroke. And sequentially performing the second light emission. 13. An imaging means for photoelectrically converting a subject image and outputting an imaging signal; a light quantity control means for controlling a light quantity to the imaging means; a light emitting means for emitting light for irradiating the subject; A focus detecting unit that detects the object and outputs focus information; anda photometric unit that performs photometry on the subject and outputs photometric information. And selectively using the set value determined based on the photometric information and the set value determined based on the photometric information, performing control so as to determine the set value of the light amount control unit when the light emitting unit emits light. Imaging method. 14. The light emitting device according to claim 13, wherein the light emitting means includes a first light emission before photographing and a second light emission during photographing.
Are sequentially performed, and at the time of the first light emission of the light emitting means, a small aperture between a set value determined based on the focus information and a set value determined based on the photometric information before the first light emission. And selecting a set value determined based on the photometric information before the first light emission at the time of the second light emission. 15. The light emitting device according to claim 13, wherein the light emitting means includes a first light emission before photographing and a second light emission during photographing.
At the time of the first light emission of the light emitting means, and a small aperture of a set value determined based on the focus information and a set value determined based on the photometric information before the first light emission. In the case of the second light emission, one of a set value determined based on the focus information and a set value determined based on the photometric information before the first light emission is selected according to a shooting mode. An imaging method characterized by doing so. 16. The light emitting device according to claim 15, wherein the light emitting means includes a first light emission before photographing and a second light emission during photographing.
Are sequentially performed, and at the time of the first light emission of the light emitting means, a small aperture between a set value determined based on the focus information and a set value determined based on the photometric information before the first light emission. Wherein the setting value selected at the time of the first light emission is selected at the time of the second light emission in the macro mode.