JP3617057B2 - Electronic still camera - Google Patents

Description

[0001]
[Industrial application fields]
This invention relates to an electronic still camera that records a photographed still image (still image), in particular when insufficient light is directed to an electronic still camera capable of flash photography.
[0002]
[Prior art]
The electronic still camera converts light that has passed through an imaging lens system into an electronic signal by a CCD (Charge Coupled Device), and the electronic signal is recorded as image data on a dedicated magnetic medium (for example, a magnetic disk). The subject is confirmed by an electronic viewfinder.
[0003]
By the way, when photographing in night or in a dim room with such an electronic still camera, an electronic flash (Electronic flash) having a built-in xenon discharge tube generally called a strobe (trade name) is caused to emit light. The light is insufficient due to the flash.
In order to perform such flash photography, the electronic still camera has a flash synchronization mechanism that controls the electronic shutter to be released when the electronic flash is at maximum light emission, and an appropriate aperture according to the brightness of the subject. An AE mechanism (automatic exposure mechanism) that automatically sets a value and a shutter speed value is provided.
That is, the optimum aperture value corresponding to the shutter speed (shutter priority method) or the optimum shutter speed value corresponding to the aperture value (aperture priority method) is stored as a program diagram in a storage means configured by a ROM or the like. When taking a picture, the aperture value or shutter speed value is read from the storage means to perform so-called automatic exposure.
[0004]
[Problems to be solved by the invention]
However, with a conventional electronic still camera, when flash photography is performed in a state where the amount of light is insufficient, it is possible to record a photographed image in a state where the illuminance of the subject irradiated with the flash of the electronic flash is high (that is, the subject is bright). Because an appropriate aperture value and shutter speed value (for example, a state where the iris diaphragm is stopped to about F4 to F5.6 with respect to a shutter speed value of about 1/60 seconds to 1/125 seconds) are set. In order to display the subject before the flash of the electronic flash (that is, the subject in the dark state) on the electronic viewfinder by so-called video-through, the screen becomes too dark (that is, the shutter speed value is There was a drawback that the subject could not be clearly confirmed (too fast or the aperture value was too large).
In other words, in a dark situation where electronic flash emission is necessary, in order to clearly check the subject with the electronic viewfinder, it is necessary to set the aperture value close to full open and the shutter speed value to a low speed. If shooting is performed with the electronic flash actually emitted with this setting value, the image will be overexposed and the highlight portion of the shot image will be out of tune.
In addition, since the state of the image displayed on the electronic viewfinder is different between the image shot with the electronic flash emitted and the normal video-through image, the image taken after shooting with the electronic flash emitted is taken. There was a problem that it was difficult to confirm.
[0005]
The present invention has been made to solve the above problems, even in the case of performing the photographing in dark conditions requiring emission of flash can be confirmed clearly a subject in electronic view finder together, and to provide an electronic still camera that can therefore be carried out flash photography at a proper exposure.
[0006]
[Means for Solving the Problems]
Means of the present invention are as follows.
In other words, in order to solve the above-described problem, an electronic still camera according to the present invention includes a photographing unit, a determining unit that determines a photographing condition for displaying a finder image based on subject illuminance, and a finder determined by the determining unit. First photographing control means for setting photographing conditions for image display in the photographing means and causing the photographing means to perform a photographing operation, and a subject image photographed by the first photographing control means using the photographing means. Finder image display means for electronically displaying a finder image as a finder image, storage means for storing information relating to shooting conditions for finder image display determined by the determination means , light emission means, and shooting conditions for flash photography A second photographing control unit which is set in the photographing unit, causes the photographing unit to perform a photographing operation and causes the light emitting unit to perform a light emitting operation; After 2 photographing control means is to perform the light emitting operation to the light emitting means together to perform a photographing operation in the photographing means, said storage means has already been stored, the viewfinder image for display determined by the determining means It is characterized by comprising a third photographing control means for setting photographing conditions in the photographing means based on information relating to photographing conditions and causing the photographing means to perform photographing operations.
The viewfinder image display means includes means for electronically displaying a subject image photographed by the third photographing control means using the photographing means as a finder image.
Further, the storage means stores information relating to a shooting condition for displaying a finder image before the second photographing control means causes the photographing means to perform a photographing operation and causes the light emitting means to perform a light emitting operation. It is said.
Further, the storage means displays the finder image displayed by the first display control means in the photographing means before the second photographing control means causes the photographing means to perform a photographing operation and causes the light emitting means to perform a light emitting operation. It is characterized by storing information on photographing conditions for use .
[0007]
Further, the determining means determines a shooting condition for displaying the finder image based on the brightness of the subject image shot by the shooting means.
Further, the determining means is based on the brightness of the subject image photographed by the photographing means before the second photographing control means causes the photographing means to perform a photographing operation and causes the light emitting means to perform a light emitting operation. Further, it is characterized in that shooting conditions for finder image display are determined.
In addition, second storage means for storing information relating to the shooting conditions for flash shooting is provided, and the second shooting control means is information related to shooting conditions for flash shooting stored in the second storage means. On the basis of the above, a photographing condition is set in the photographing unit, and the photographing unit performs a photographing operation and the light emitting unit performs a light emitting operation.
The shooting condition for displaying the finder image is an optimal shooting condition for clearly displaying the finder image, and the shooting condition for flash shooting is the optimal shooting condition for storing and recording the flash shot image. It is characterized by being.
The photographing conditions include an aperture value and / or a shutter speed value.
[0008]
【Example】
Hereinafter, embodiments will be described with reference to FIGS.
FIG. 1 is a block diagram showing a schematic configuration of an electronic still camera according to the present invention. In FIG. 1, reference numeral 1 denotes a lens system constituting an imaging optical system. This lens system 1 is an autofocus (not shown). It is configured to be movable along the optical axis by a focus motor of the mechanism, and is configured to perform focus adjustment of image formation.
[0009]
A one-chip CCD (Charge Coupled Device) 2 serving as an image pickup device constituting a light receiving unit is disposed on the optical axis of the lens system 1, and a photographed image of a subject is captured by the CCD 2 through the lens system 1. It is made to form an image.
Although not shown in the figure, the imaging operation of the CCD 2 is controlled by a CCD driver that measures the operation timing by a timing generator.
[0010]
Further, in front of the CCD 2, a iris diaphragm (iris diaphragm) 3 for adjusting the amount of incident light is provided, and an aperture adjustment motor 4 for adjusting the opening degree of the diaphragm 3 is provided.
Then, the image signal picked up by the CCD 2 is output to an operational amplifier (Op-Amp) constituting the amplifier 5 and amplified to a predetermined level.
The amplified image signal from the amplifier 5 is output to the A / D converter 6 and converted from an analog signal to a digital signal.
The digitized image signal is output to the image signal processing circuit 7 to extract the luminance signal YH and the color difference signals (CR (= R−Y), CB (= B−Y)), and each signal is stored in the image memory. 8 and temporarily stored in a recording medium such as a dedicated magnetic disk or IC card.
[0011]
Further, the luminance signal YH and the color difference signals (CR (= R−Y), CB (= B−Y)) temporarily stored in the image memory 8 are output to the D / A converter 17 and converted from the digital signals to analog signals. The signal is converted into a signal and output as an image reproduction signal to the electronic viewfinder 20 through the control of the encoder 19.
[0012]
On the other hand, the luminance signal YH and the color difference signals (CR (= R−Y), CB (= B−Y)) extracted by the image signal processing circuit 7 are a control unit 9 composed of a CPU (Central Processing Unit) or the like. The illuminance of the subject imaged on the CCD 2 (that is, the brightness of the subject) is detected based on the luminance signal YH, and is optimal for clearly outputting the image of the subject to the electronic viewfinder 20. For example, an appropriate value corresponding to the subject illuminance is selected and read out from a ROM (Read Only Memory) 15 storing a program diagram as shown in FIG. It is stored in a RAM (Random Access Memory) 16 constituting one photographing information storage means.
Then, based on the aperture value and shutter speed value stored in the RAM 16, the CCD driving unit 10 and the aperture driving unit 12 connected to the control unit 9 are driven, and the CCD 2 has a photosensitive time corresponding to a predetermined shutter speed. Under the control, the iris diaphragm 3 is set to a predetermined aperture value.
Thereby, even if the subject illuminance is low (that is, when the subject is dark), the aperture value and the shutter aperture value are displayed on the electronic viewfinder 20 based on the program diagram stored in the ROM 15. Is automatically set to a value that can be clearly output, so that the subject can be surely seen.
In the program diagram of the embodiment shown in FIG. 2, the horizontal axis indicates the shutter speed value (2 seconds to 1/500 seconds), and the vertical axis indicates the aperture value (F number: 1.6 to 16). ), And a certain correlation is established between the value on the horizontal axis and the value on the vertical axis.
That is, when the subject illuminance corresponding to the EV (exposure value) value, which is a value representing the exposure amount, is specified by a combination of the shutter speed value and the aperture value, the program diagram arbitrarily designated by the photographer (that is, the same EV value) Thus, since there are a plurality of combinations of aperture values and shutter speed values, the appropriate aperture value and shutter speed value that can clearly output the subject to the electronic viewfinder are determined. Therefore, for example, when the EV value of the subject illuminance obtained by the control unit 9 is EV5, the shutter speed value is 1/8 from the intersection (point A) with the program line designated by the photographer on the program diagram. Second, the aperture value is set to F2. However, it is a matter of course that an appropriate EV value for the subject varies depending on the sensitivity of the CCD 2.
[0013]
The control unit 9 is connected to an electronic flash 13 incorporated in the electronic still camera body or a hot shoe contact (not shown) for setting an external electronic flash, and an operation switch 14 constituting a shutter release button or the like. When shooting is performed with the electronic flash 13 emitted by the above operation, a program diagram is stored with the optimum aperture value and shutter speed value for recording the subject image on the magnetic disk of the recording device 18 or the like. Read out from the ROM 15 and stored in the RAM 16 constituting the second photographing information storage means.
Then, the CCD driving unit 10 and the aperture driving unit 12 are driven, and the photosensitive time of the CCD 2 and the iris diaphragm 3 are instantaneously stored in the RAM 16 from the state set by the first photographing information of the RAM 16. state set by the second shooting information (i.e., shutter speed value when the EV value when electronic flash 13 is irradiated on the object is EV11 is set to 1/60 seconds, the aperture value is F5.6 The image signal obtained by flash photography with an appropriate exposure is temporarily stored in the image memory 8 and recorded on a magnetic disk or the like by the recording device 18.
When the electronic flash 13 is turned on to finish photographing, the control unit 9 controls the aperture value and the shutter speed value that are stored again in the RAM 16 to the same values as before photographing, and the subject by the electronic viewfinder 20 is set. It returns to a state where it can be clearly confirmed.
Therefore, according to the electronic still camera of the present invention, when shooting a dark subject that needs to be emitted by an electronic flash, the subject can be clearly confirmed by an electronic viewfinder, and a flash with an appropriate exposure can be obtained. It is possible to take a picture.
[0014]
The exemplary configuration of the electronic still camera according to the present invention has been described above. Next, the operation will be described.
However, in order to simplify the explanation, it is assumed that the photographing environment is such that photographing with an electronic flash is performed in a dim room.
In order to perform photographing using an electronic flash in this photographing environment , first, the power of the electronic still camera is turned on. When the electronic flash 13 is a built-in type, a flash ON / OFF which is a kind of operation switch 14 is used. When the switch is turned on and the electronic flash is an external type, the electronic flash is set on the hot shoe and the shooting mode switch is set to the flash shooting mode.
Next, when the subject is caught in the electronic viewfinder 20, the lens system 1 is driven by the autofocus mechanism to focus on the subject.
Then, the illuminance of the subject determined by the control unit 9 based on the image signal from the CCD 2, point when the EV value of the Utsushitai illuminance is, for example, EV5, the program diagram is stored in ROM 15 (FIG. 2) From A, the shutter speed value is set to 1/8 second, the aperture value is set to F2, and is stored in the first storage area in the RAM 16.
Based on the shutter speed value and the aperture value, the CCD drive unit 10 and the aperture drive unit 12 are driven, and the drive time of the CCD 2 and the iris 3 are changed so as to correspond to the values.
Thereby, the image of the subject is clearly output to the electronic viewfinder 20, and the subject before photographing can be accurately captured.
Further, when the use of the electronic flash 13 is detected, it corresponds to the subject illuminance (for example, EV 11) when the flash of the electronic flash 13 is irradiated from the program diagram stored in the ROM 15 under the control of the control unit 9. The shutter speed value (1/60 seconds) and aperture value (F5.6) are set and stored in the second storage area in the RAM 16 (corresponding to the point B in FIG. 2).
[0015]
Then, after the composition to be photographed is determined by the electronic viewfinder 20, when the shutter release button, which is a kind of the operation switch 14, is pressed one step, the shutter speed value and the aperture value stored in the second storage area in the RAM 16 are displayed. Based on the above, the CCD drive unit 10 and the aperture drive unit 12 are driven, the exposure time of the CCD 2 and the iris diaphragm 3 are instantaneously changed to the above values, and then the shutter release button is further pressed, the control from the control unit 9 In response to the signal, the electronic flash 13 emits light, and the CCD 2 is exposed for a predetermined time. The image photographed by the CCD 2 is temporarily stored in the image memory 8 and is recorded by a recording device 18 on a recording medium such as a magnetic disk or an IC card.
When the flash photography is finished, the shutter speed value and the aperture value are controlled by the control unit 9 to the same values as before the photography, that is, the shutter speed value (1/8 second) and the aperture value corresponding to the subject illumination EV5 ( Returning to F2), video-through image output to the electronic viewfinder 20 is clearly performed again.
Therefore, according to the electronic still camera of the present invention, the image of the subject can be clearly output to the electronic viewfinder 20 before and after the flash photography, and the flash photography with appropriate exposure can be performed. It becomes.
[0016]
In this embodiment, the first view information storage means for storing the optimum aperture value and shutter speed value for clearly outputting the image of the subject on the electronic viewfinder, and the electronic flash are used for shooting. Although the case where the RAM 16 is provided with the second photographing information storage means for storing the optimum aperture value and shutter speed value for recording the subject image during execution has been described, the present invention is not limited to this. The storage area of the RAM may be divided and used.
In the present embodiment, the case where the aperture value and the shutter speed value before the shooting are restored after the flash shooting has been described, but separately, the flash memory is temporarily stored in the image memory 8 after the flash shooting is finished. the captured image is provided a photographed image display means for outputting a predetermined time to an electronic viewfinder 20 (can also be shared with control unit), the structure capable of flash photography to check whether or not performed satisfactorily You can also
Further, it may be configured such that the photographer can set the aperture value and shutter speed value at the time of flash photography to arbitrary values by manual operation.
Furthermore, the present invention can be applied not only to an electronic still camera having an autofocus function but also to an electronic still camera having a manual focus function.
[0017]
【The invention's effect】
As described above, according to the electronic still camera according to the present invention, it is possible to verify clearly the subject in electronic view finder even dark emission requires the flash, the flash photography with appropriate exposure There is an excellent effect that it can be performed .
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an electronic still camera according to the present invention.
FIG. 2 is a program diagram showing a correlation between a shutter speed value and an aperture value and a program line.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lens system 2 Image sensor (CCD (Charge Coupled Device))
3 Glossy Aperture 4 Aperture Adjustment Motor 5 Amplifier 6 A / D Converter 7 Image Signal Processing Circuit 8 Image Memory 9 Control Unit (CPU (Central Processing Unit))
10 CCD drive unit 12 Aperture drive unit 13 Electronic flash 14 Operation switch 15 ROM
16 RAM (first shooting information storage means, second shooting information storage means)
17 D / A converter 18 Recording device 19 Encoder 20 Electronic viewfinder

Claims (9)

Photographing means;
A determining means for determining a shooting condition for displaying the finder image based on the illuminance of the subject;
First shooting control means for setting shooting conditions for finder image display determined by the determining means in the shooting means and causing the shooting means to perform shooting operations;
Finder image display means for electronically displaying a subject image photographed by the first photographing control means using the photographing means as a finder image;
Storage means for storing information relating to shooting conditions for finder image display determined by the determination means ;
Light emitting means;
Second photographing control means for setting photographing conditions for flash photographing in the photographing means, causing the photographing means to perform a photographing operation, and causing the light emitting means to perform a light emitting operation;
After the second shooting control unit has to perform the light emitting operation to the light emitting means together to perform a photographing operation in the photographing means, said storage means has already been stored, a finder image display determined by the determining means Third shooting control means for setting shooting conditions for the shooting means based on information on shooting conditions for the image shooting and causing the shooting means to perform shooting operations;
An electronic still camera comprising: 2. The electronic still according to claim 1, wherein the finder image display means includes means for electronically displaying a subject image photographed by the third photographing control means using the photographing means as a finder image. camera. The storage means stores information related to a shooting condition for displaying a finder image before the second shooting control means causes the shooting means to perform a shooting operation and causes the light emission means to perform a light emission operation. The electronic still camera according to claim 1 or 2. The storage means is for displaying a finder image set in the photographing means by the first display control means before the second photographing control means causes the photographing means to perform a photographing operation and causes the light emitting means to perform a light emitting operation. 4. The electronic still camera according to claim 3, wherein information relating to photographing conditions is stored. The determination unit, based on the brightness of the subject image taken by the imaging unit, an electronic still camera according to any one of claims 1 to 4, characterized in that to determine the imaging condition for displaying the finder image. The deciding means is a finder based on the brightness of a subject image photographed by the photographing means before the second photographing control means causes the photographing means to perform a photographing operation and causes the light emitting means to perform a light emitting operation. 6. The electronic still camera according to claim 5 , wherein photographing conditions for image display are determined. Second storage means for storing information relating to the shooting conditions for the flash shooting;
The second photographing control means sets photographing conditions in the photographing means based on information on photographing conditions for flash photographing stored in the second storage means, and causes the photographing means to perform a photographing operation. electronic still camera according to any one of claims 1 to 6, characterized in that to perform the light emitting operation to the light emitting means. The shooting condition for displaying the finder image is an optimal shooting condition for clearly displaying the finder image.
The imaging condition for flash photography, electronic still camera according to any one of claims 1 to 7, characterized in that the optimum shooting conditions for archival flash captured image. The photographing conditions, the electronic still camera according to any one of claims 1 to 8, characterized in that it comprises an aperture value and or the shutter speed value.

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