JP2005284166A - Digital still camera and method for controlling its continuous photographing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital still camera suitable for continuous photographing. <P>SOLUTION: An amount of luminescence for performing proper exposure is calculated based on photographic distance, a diaphragm and photographic sensitivity and whether or not strobe luminescence with the amount of luminescence is possible is determined during the continuous photographing based on charged voltage of a main condenser, etc. In a period when luminescence is possible, strobe photography by performing the strobe luminescence is performed, after the strobe luminance becomes impossible, photography is performed by setting combination of the diaphragm, shutter speed and the photographic sensitivity and the continuous photographing with the number of sheets of the continuous photographing set by a user is performed so that the proper exposure is obtained under available light. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital still camera that emits strobe light in synchronization with continuous shooting and a method for controlling the continuous shooting.

  Digital still cameras that photograph a subject with an image sensor such as a CCD image sensor are widely used. Some digital still cameras have a continuous shooting function for continuously shooting a plurality of still images at short intervals. Further, there is known a digital still camera having such a continuous shooting function that emits strobe light in synchronization with each shooting at the time of continuous shooting.

  Strobe light emission is performed by discharging the main capacitor that was charged prior to the light emission, but even if charging is continued during continuous shooting, the charging speed is very slow compared to the discharge speed, so the strobe light emission progresses. If this happens, the charging voltage of the main capacitor will drop and the flash will not fire. Therefore, there is a limit to the number of times of continuous strobe light emission (hereinafter referred to as the number of continuous light emission possible).

  In addition, since the amount of one flash emission to be emitted changes depending on the brightness of the object to be imaged, the imaging sensitivity, the aperture value, and the imaging distance, the number of times that continuous emission is possible varies depending on these conditions. For example, when the shooting distance is relatively short, the number of flashes that can be continuously emitted increases because the amount of flash emitted once is small, but the number of flashes that can be flashed increases as the shooting distance increases. As described above, the number of times the flash can be emitted during continuous shooting varies depending on shooting conditions.

  The number of continuous flashes is calculated and displayed from the flash output obtained based on the shooting distance and the capacity of the main capacitor. When the shooting is instructed by operating the release button, the calculated number of shots is executed. A digital still camera that terminates the photographing operation is known (Patent Document 1).

  In addition, the number of continuous flashes is calculated based on the shooting sensitivity, shooting distance, and main capacitor charging voltage. When the number of continuous shots is determined to exceed this number, the number of continuous shots is limited to the same as the number of continuous flashes. A camera that performs continuous shooting is known (Patent Document 2).

JP 2000-321616 A JP-A-5-188438

  By the way, in the methods described in Patent Documents 1 and 2, strobe light emission can be performed in all continuous shooting, but as a result, the number of continuous shooting is limited, which is inconvenient.

  The present invention has been made in consideration of the above problems, and relates to a digital still camera suitable for continuous shooting using a strobe and a method for controlling the continuous shooting.

  In order to achieve the above object, in the digital camera according to claim 1, determination means for determining whether or not the strobe device can emit light with a light emission amount with an appropriate exposure of a main subject for each continuous shooting. During the continuous shooting, while the judgment result of the judgment means can be emitted, the strobe device is operated to perform the strobe shooting with the flash amount determined by the flash amount determination means, and the judgment result is emitted. Control means that prohibits strobe flashing after it has become impossible, and performs flash-free shooting with a combination of aperture, shutter speed, and shooting sensitivity so that proper exposure is obtained under available light It is equipped with.

  3. The digital still camera according to claim 2, wherein voltage detection means for detecting a charging voltage of a main capacitor for strobe emission, distance acquisition means for acquiring a shooting distance to a main subject, and luminance detection means for detecting subject brightness. And a light emission amount determining means for determining a light emission amount of strobe light for proper exposure based on the photographing sensitivity and aperture value, and the photographing distance acquired by the distance acquiring means, and the determining means comprises the voltage detecting means On the basis of the charging voltage detected in step S3 and the light emission amount determined by the light emission amount determination means, determines whether or not strobe light emission is possible for each continuous shooting. Based on the subject brightness detected by the detecting means, a combination of the aperture, shutter speed and photographing sensitivity is set.

  In the digital still camera according to the third aspect of the present invention, the wide aperture is used when photographing with no flash.

  5. The method of controlling continuous shooting of a digital still camera according to claim 4, wherein continuous shooting is performed while determining whether or not strobe light can be emitted with a light emission amount with an appropriate exposure of a main subject. While it is possible, take a strobe shot with the main subject at the appropriate exposure and set the aperture so that the appropriate exposure can be obtained under available light after the flash has become impossible. A combination of shutter speed and shooting sensitivity is set to perform shooting without flash emission.

  In the method for controlling continuous shooting of a digital still camera according to claim 5, when determining whether or not strobe light emission is possible, the appropriate exposure is determined based on the shooting sensitivity, the aperture value, and the shooting distance to the main subject. The combination of aperture, shutter speed, and shooting sensitivity is set based on the subject brightness when shooting without flash.

  According to a sixth aspect of the present invention, there is provided a method for controlling continuous shooting of a digital still camera.

  According to the present invention, until the flash emission becomes impossible, the flash photography is performed with the flash quantity that can be set to an appropriate exposure, and after the flash emission becomes impossible, the available light is emitted. The combination of aperture, shutter speed, and shooting sensitivity is set so that proper exposure can be obtained under the, so that shooting can be continued even if the flash does not fire during continuous shooting. Continuous shooting with can be performed.

  The front of the digital still camera embodying the present invention is shown in FIG. 1, and the back is shown in FIG. The front surface of the camera body 2 of the digital still camera is provided with a photographing lens 3, a release button 4, a strobe light emitting unit 5, and an operation unit 7 including various operation buttons 7a and cursor keys 7b and an LCD 9 are provided on the rear surface. ing.

  By pressing the release button 4, a still image is taken by the CCD image sensor 10 (see FIG. 3) provided in the back of the taking lens 3. The release button 4 can be pressed between a half-pressed position and a fully-pressed position further pressed from the half-pressed position. The camera body 2 is provided with a memory slot (not shown), and image data of a still image is written and stored in a memory card 11 (see FIG. 3) inserted in the memory slot.

  The strobe light emitting unit 5 emits strobe light toward the subject in synchronization with the shooting of a still image. The flash emission amount is determined according to the shooting distance, shooting sensitivity, and aperture value so that the exposure amount by the flash light is appropriate. When the subject brightness is below the specified level, the flash mode is automatically turned on and the flash fires. When the subject brightness is higher than the predetermined level, the flash mode is automatically turned off and the flash fires. I will not. Note that it may be possible to manually select whether or not strobe light emission is necessary.

  By operating the operation unit 7, the shooting mode can be selected. As the shooting mode, either the normal shooting mode or the continuous shooting mode can be selected. In the normal shooting mode, one still image is shot in response to one pressing operation of the release button 4, and one still image is recorded on the memory card 11. The continuous shooting mode is a so-called continuous shooting mode, in which a plurality of still images are continuously taken at a short interval in response to a pressing operation of the release button 4, and the obtained plurality of still images are stored in a memory card. 11 is recorded. The number of times of continuous shooting in the continuous shooting mode can be set by operating the operation unit 7, and still images are shot at the number of times of continuous shooting set in response to one pressing operation of the release button 4.

  When the strobe mode is on in the normal shooting mode, one strobe emission is performed in synchronization with one still image shooting. When the flash mode is on in continuous shooting mode, the flash fires in sync with the shooting of each still image until the flash cannot be fired, and when the flash cannot be fired, the available light is not fired. The shutter speed and the shooting sensitivity are adjusted so that an appropriate exposure can be obtained under the shooting condition, and shooting is performed with the set number of continuous shooting. When the flash mode is off The flash is not fired in either the normal shooting mode or continuous shooting mode.

  The LCD 9 functions as a so-called electronic viewfinder that displays a subject image photographed by the CCD image sensor 10 through the photographing lens 3 in real time and is used for image reproduction and the like. Further, the LCD 9 displays a menu screen related to camera function settings. By operating the operation unit 7 while viewing this menu screen, various function settings including the number of continuous shootings in the continuous shooting mode can be performed.

  FIG. 3 shows the configuration of the digital still camera. The main CPU 15 controls each part in response to an operation signal input from the release button 4 and the operation part 7. The main CPU 15 is connected to a ROM 15a and a RAM 15b. A program and parameters for executing various sequences are written in the ROM 15a, and the main CPU 15 controls each unit according to the program. The RAM 15b is used as a work memory that temporarily stores data necessary for executing a shooting sequence or the like.

  A CCD image sensor 10 is disposed behind the taking lens 3. The CCD image sensor 10 controls the charge accumulation time, that is, the shutter speed of the electronic shutter, the charge transfer, and the like by the driver 17, and converts an optical subject image into an electrical photographing signal and outputs it.

  A photographing signal from the CCD image sensor 10 is sent to the CDS / AMP circuit 18. The CDS / AMP circuit 18 amplifies the photographic signal with a gain corresponding to the set photographic sensitivity after removing noise from the photographic signal by correlated double sampling (CDS). That is, the shooting sensitivity is determined by the gain set in the CDS / AMP circuit 18. The A / D converter 19 digitally converts the photographic signal from the CDS / AMP circuit 18 and outputs it as image data. Note that a MOS type image sensor or the like may be used instead of the CCD image sensor 10.

  Image data from the A / D converter 19 is sent to the image input controller 20. The image input controller 20 controls input of image data to the bus 21. Connected to the bus 21 are a CPU 15, an image processing unit 23, a compression processing unit 24, an AF detection unit 25, an AE / AWB detection unit 26, an internal memory 27, a media controller 28, a VRAM 29, and an LCD driver 30. Are controlled by the CPU 15 via the bus 21 and exchange data with each other.

  The image processing unit 23 performs image processing such as gamma correction, white balance adjustment, pixel number change, sharpness processing, and color correction processing on the image data. The compression processing unit 24 performs data compression for recording image data on the memory card 11. In addition, the compression processing unit 24 decompresses the compressed image data read from the memory card 11 in the reproduction mode.

  The AF detection unit 25 detects the contrast of the image being captured using the image data output from the image input controller 20 for focusing the photographing lens 3, and the contrast information is sent to the sub CPU 31 via the main CPU 15. Send to. The sub CPU 31 refers to the contrast information, and drives the photographing lens 3 via the drive unit 32 so that the contrast of the image being photographed is maximized.

  Based on the image data from the image input controller 20, the AE / AWB detection unit 26 detects the subject brightness of the subject image being photographed and the type of the light source, and uses the subject brightness information and the light source information as main information. Send to CPU15.

  The main CPU 15 determines an appropriate aperture value, shutter speed, and photographing sensitivity based on the subject luminance information. The main CPU 15 sends the aperture value and shutter speed to the sub CPU 31 and sets the photographing sensitivity in the CDS / AMP circuit 18. Further, the main CPU 15 determines whether or not strobe light emission is necessary based on the subject luminance information. Further, the CPU 15 sets a white balance parameter of the image signal processing unit 23 based on the light source information.

  The internal memory 27 is used as a buffer memory that temporarily stores image data. Under the continuous shooting mode, the image data of a plurality of shot still images is once written in the internal memory 27 and then processed in the image processing unit 23 and the compression processing unit 24. Thereafter, the image data is stored in the memory card 11. Written.

  The media controller 28 controls writing and reading of data in the memory card 11. The image data of the still image obtained in response to the operation of the release button 4 is processed by the image processing unit 23 and the compression processing unit 24 and then sent to the media controller 28 and written to the memory card 11. . At the time of reproduction, the image data recorded on the memory card 11 is read out by the media controller 28, sent to the compression processing unit 24, decompressed, and written in the VRAM 29.

  In the VRAM 29, image data to be displayed on the LCD 9 is written. The LCD driver 30 drives the LCD 9 based on the image data read from the VRAM 29. As a result, the subject image being shot by the CCD image sensor 10 and the image read from the memory card 11 are displayed on the LCD 9.

  The sub CPU 31 communicates with the main CPU 15 to control the drive unit 32 and the strobe device 33. The drive unit 32 drives the focusing lens 3 a of the photographic lens 3, the shutter device 35 and the diaphragm 36 built in the photographic lens 3.

  Based on the contrast information input from the AF detection unit 25 via the main CPU 15, the sub CPU 31 focuses the focusing lens 3a in the photographing lens 3 via the driving unit 32 so that the contrast of the image being photographed is maximized. To move. As a result, the focus of the photographic lens 3 matches the subject.

  The shutter device 35 performs an opening / closing operation at a shutter speed determined by the main CPU 15. The aperture 36 is driven so as to have an aperture diameter corresponding to the aperture value determined by the main CPU 15. The shutter device 35 and the aperture 36 adjust the amount of incident light to the CCD image sensor 10 when taking a still image. When the strobe mode is on, shooting sensitivity, aperture value, and shutter speed predetermined for flash photography are used. As the aperture value for flash photography, for example, an open aperture is used, and the shutter speed is set in a range that can be synchronized with the flash emission.

  The drive unit 32 incorporates an encoder for detecting the lens position of the focusing lens 3 a, and a detection signal from this encoder is sent to the sub CPU 31. The sub CPU 31 determines the distance that the photographing lens 3 is in focus based on the detection signal, that is, the photographing distance to the main subject, and sends the photographing distance to the main CPU 15 as photographing distance information. This shooting distance information is used when determining the flash emission amount.

  The strobe device 33 includes a main capacitor 37, a strobe controller 38, and a strobe discharge tube 39. The strobe controller 38 controls charging of the main capacitor 37 and strobe light emission by the strobe discharge tube 39. As is well known, strobe light emission is performed by discharging a charged main capacitor 37 with a strobe discharge tube 39.

  The strobe control unit 38 monitors the charging voltage of the main capacitor 37 and controls the charging so that the charging voltage of the main capacitor 32 becomes a predetermined charging level (full charging) at the start of still image shooting. . The strobe controller 38 sends the charging voltage as charging voltage information to the main CPU 15 via the sub CPU 31.

  The sub CPU 31 inputs a sync signal synchronized with the opening / closing of the shutter blades to the strobe controller 38 when the main CPU 15 permits the strobe light emission. The strobe control unit 38 discharges the main capacitor 37 with a strobe discharge tube 39 each time a sync signal is input, and performs strobe light emission. Strobe light from the strobe discharge tube 33 is emitted from the strobe light emitting unit 5 toward the subject. When the flash emission time set by the sub CPU 31 has elapsed, the flash control unit 38 stops the flash emission. Note that the strobe light emission time in continuous shooting is calculated for each strobe light emission.

  The main CPU 15 obtains the strobe light emission amount so as to obtain an appropriate exposure amount based on the photographing distance, the aperture value, and the photographing sensitivity, and uses the strobe light emission amount as the charging voltage of the main capacitor 37, the capacitance, and the characteristics of the strobe discharge tube. Based on the above, convert to flash firing time. The converted strobe emission time is set in the strobe controller 38 via the sub CPU 31. In the case of performing strobe light emission in continuous shooting, the charging voltage of the main capacitor 37 decreases every time the strobe light is emitted. Therefore, the charging voltage obtained each time is used to convert to the strobe light emission time.

  In this example, strobe lighting is performed for a predetermined strobe lighting time, so that the amount of strobe light exposure is controlled to make the exposure amount appropriate to the strobe light. However, the strobe light reflected from the subject is received. It is also possible to make the exposure amount by the strobe light appropriate by performing light amount integration by receiving light with the element and stopping the strobe emission when the light amount integration value reaches a predetermined level.

  When the strobe mode is on, the main CPU 15 determines whether or not strobe light emission with the calculated strobe light emission amount is possible. In this determination, when the charging voltage of the main capacitor 38 is equal to or higher than the lowest light emission voltage capable of flash emission and higher than a voltage sufficient to obtain the flash emission amount to be emitted, the flash emission with the calculated flash emission amount is performed. Is determined to be possible. On the other hand, when the charging voltage of the main capacitor 37 is lower than the lowest light-emittable voltage capable of flash emission, and when the voltage does not reach a voltage sufficient to obtain the flash emission amount to be emitted, light emission at the calculated flash emission amount occurs. Judge that it is impossible.

  The main CPU 15 sends a light emission permission signal to the sub CPU 31 when the light emission with the strobe light emission calculated in the above determination is possible, and permits the flash light emission. Sent to the sub CPU 31 to inhibit the flash emission.

  In addition, when the flash mode is turned on under the continuous shooting mode and the calculated flash emission amount cannot be emitted, the main CPU 15 performs appropriate exposure with available light based on the subject luminance information. The shutter speed and photographing sensitivity are determined so as to be obtained, and control is performed so that continuous photographing after generation of the light emission inhibition signal is performed with the shutter speed and photographing sensitivity. At this time, shooting is performed with an open aperture with the aperture 36 having the maximum aperture, but the aperture value may be changed in addition to the shutter speed and the shooting sensitivity.

  As described above, when determining the shutter speed and photographing sensitivity, the main CPU 15 changes the shutter speed so as to achieve proper exposure. However, if the shutter speed is lower than the predetermined speed, photographing is performed. The sensitivity is increased so that the shutter speed does not become lower than a predetermined speed. In this way, by determining the shutter speed and the shooting sensitivity, image quality deterioration due to an increase in shooting sensitivity is suppressed, and camera shake due to a low shutter speed does not occur.

  Next, the operation of the above configuration will be described. Under the shooting mode, a moving image is shot by the CCD image sensor 10, and the subject image shot by the CCD image sensor 10 is output as a shooting signal. This photographed signal is subjected to noise removal and signal amplification by the CDS / AMP circuit 18, converted to image data by the A / D converter 19, and then processed by the image input controller 20 and the bus 21. Sent to the unit 23, the AF detection unit 25, and the AE / AWB detection unit 26, respectively.

  Then, contrast information based on the image data is sent from the AF detection unit 25 to the sub CPU 31 via the main CPU 15, and the focusing lens 3a is moved by the driving unit 32 controlled by the sub CPU 31, so that the current photographing is being performed. Adjustment is made so that the subject is in focus. Since this focus adjustment is performed as needed, even if the shooting distance to the subject changes, the focus is adjusted following the change.

  The AE / AWB detection unit 26 sends subject luminance information corresponding to the subject luminance and light source information to the main CPU 15. Based on the subject brightness information, the main CPU 15 determines the shutter speed (charge accumulation time) of the electronic shutter of the CCD image sensor 10, the aperture value of the aperture 36, and the imaging sensitivity so as to be appropriate. Among these, the shutter speed is sent to the driver 17, the CCD image sensor 10 is driven based on this shutter speed, and the aperture value is sent to the sub CPU 31, and the aperture 36 is sent via the drive unit 32 based on this aperture value. Is controlled. Further, a gain corresponding to the photographing sensitivity is set in the CDS / AMP circuit 18. In this way, the incident light quantity, charge accumulation time, and imaging signal amplification factor of the CCD image sensor 10 are adjusted according to the subject brightness. At this time, the shutter blades of the shutter device 35 are fully opened.

  On the other hand, the type of the light source is specified by the main CPU 15 based on the light source information, and a parameter for white balance corresponding to the light source is set in the image processing unit 23, and the image processing unit 23 outputs the image data input thereto. Predetermined processing such as white balance processing and gamma correction is performed. The processed image data is once written in the VRAM 29, read out by the media controller 28, and the LCD 9 is driven, so that the subject being shot is displayed on the LCD 9 as a moving image.

  The adjustment based on the subject luminance information and the light source information. Since the setting is also performed at any time, if the brightness of the subject and the type of the light source change, readjustment / update is performed accordingly.

  When performing continuous shooting, the operation unit 7 is operated to select the continuous shooting mode. Next, as shown in FIG. 4, the operation unit 7 is operated to set a desired number of continuous shootings. Thereafter, the photographer observes the LCD 9 to determine framing, and then presses the release button 4 to perform photographing. It should be noted that continuous shooting can be continued even after the strobe light is no longer emitted, so that continuous shooting is not set, and continuous shooting is continuously performed until the release button 4 is released. It may be.

  When the release button 4 is in the half-pressed position, the sub CPU 31 drives the focusing lens 3a based on the contrast information, and the focus of the photographing lens 3 is readjusted. After the focus is readjusted, the main CPU 15 obtains the subject brightness of the subject currently being photographed based on the subject brightness information, and the main CPU 15 determines the strobe light emission.

  When determining the flash emission, if the subject brightness is higher than the predetermined level, the flash emission is not necessary. In this case, the flash mode is turned off and normal continuous shooting without flash emission is released. This is performed in response to pressing of the fully pressed position of the button 4. On the other hand, if the subject brightness is below a predetermined level, it is determined that strobe light emission is necessary, and the strobe mode is turned on.

  For example, when it is determined that strobe light emission is necessary and the strobe mode is turned on, the main CPU 15 sets a gain corresponding to the shooting sensitivity for strobe shooting in the CDS / AMP circuit 18 and also to the sub CPU 31. On the other hand, instructions for the aperture value and shutter speed for flash photography are sent.

  Subsequently, the photographing distance information output from the sub CPU 31 based on the detection signal from the driving unit 32 is referred to by the main CPU 15 to obtain the photographing distance to the main subject. Then, the main CPU 15 calculates a flash emission amount necessary for properly exposing the main subject based on the acquired shooting distance, shooting sensitivity and aperture value for flash shooting.

  When it is detected that the release button 4 has been fully pressed after calculating the flash emission amount, the main CPU 15 sets the charging voltage of the main capacitor 37 based on the charging voltage information input from the flash controller 38 via the sub CPU 31. It is checked, and it is determined whether or not strobe light emission with the previously obtained strobe light emission amount is possible. In this determination, if the charging voltage of the main capacitor 38 is equal to or higher than the minimum light emission voltage capable of strobe light emission and a voltage sufficient to obtain the strobe light emission amount to emit light, it is determined that light emission is possible. If it is lower than the minimum flashable voltage at which strobe light can be emitted, or if the charging voltage is not sufficient to obtain the amount of strobe light to be emitted, it is determined that light cannot be emitted

  For example, when it is determined that light emission is possible, the main CPU 15 starts outputting the light emission permission signal to the sub CPU 31, and then the previously calculated strobe light emission amount is converted into the strobe light emission time. Is set in the strobe controller 38 via the sub CPU 31.

  After the strobe light emission time is set in the strobe control unit 38, the main CPU 15 gives a first shooting instruction to each unit. By this instruction, the shutter blades of the shutter device 35 are once closed and the aperture 36 is opened, so that the shutter device 35 is opened and closed at the shutter speed for the strobe, and the CCD is opened while the shutter blades are open. Exposure by the image sensor 10 is performed. Note that the exposure (charge accumulation) time may be controlled using the electronic shutter of the CCD image sensor 10 instead of using the mechanical shutter device 35.

  At the moment when the shutter blades are fully opened, a sync signal is input from the sub CPU 31 to the strobe controller 38, and strobe light emission is started. This strobe emission ends when the previously set strobe emission time has elapsed. Thus, the flash emission amount for photographing the main subject with an appropriate exposure amount is obtained.

  After the shutter blades are closed, a photographing signal is output from the CCD image sensor 10 and converted into image data through the CDS / AMP circuit 18 and the A / D converter 19, and then through the image input controller 20 and the bus 21. To the internal memory 27.

  When one strobe shooting is completed as described above, it is checked whether or not the number of shots that have been taken has reached the set number of consecutive shots. If not, for example, the charging voltage information at that time is displayed. Based on this, it is determined again whether or not the charging voltage of the main capacitor 37 is capable of strobe light emission with the strobe light emission amount obtained previously.

  If strobe light emission is possible with the previously obtained strobe light emission amount, the second flash photography is performed by the same procedure as described above. Then, after this strobe shooting, it is checked again whether the number of shots taken has reached the set number of continuous shots, and if not, the charging voltage is checked.

  In the following, if the number of executed shots has not reached the set number of continuous shots and the flash emission with the previously obtained flash emission amount is possible, the flash photography is repeated by the same procedure as above. .

  If it is determined that the strobe light emission with the previously obtained strobe light emission amount is impossible, the main CPU 15 sends a light emission prohibition signal to the sub CPU 31 to prohibit the strobe light emission during the subsequent photographing. In addition, based on the predetermined initial shooting sensitivity prepared in advance, the subject brightness previously obtained from the subject brightness information, and the aperture value (open aperture), it is possible to achieve proper exposure without performing strobe light emission. A proper shutter speed is calculated by the main CPU 15.

  When the shutter speed is calculated as described above, if the shutter speed is lower than the predetermined speed, the photographing sensitivity is increased by one step, the shutter speed is calculated again, and the shutter speed is equal to or higher than the predetermined speed. The shooting sensitivity is increased until An instruction of the shutter speed determined in this way is given to the sub CPU 31 and a gain corresponding to the photographing sensitivity is set in the CDS / AMP circuit 18.

  After the shutter speed instruction and the gain setting are completed, a photographing instruction is given to each unit. As a result, the shutter device 35 is opened and closed at the shutter speed determined as described above, and exposure by the CCD image sensor 10 is performed. At this time, since the flash prohibition signal is given to the sub CPU 31, no sync signal is input to the strobe control 38, so that strobe light emission is not performed.

  After completion of the opening / closing operation of the shutter device 35, a photographing signal is output from the CCD image sensor 10, and the photographing signal is converted into image data via the CDS / AMP circuit 18 and the A / D converter 19 before image input. The data is written into the internal memory 27 via the controller 20 and the bus 21. At this time, the CDS / AMP circuit 18 amplifies the shooting signal with a gain corresponding to the shooting sensitivity determined as described above.

  After shooting with no flash, the number of executed shots is checked to see if it has reached the set number of consecutive shots. If not, it is determined as described above. Using the shutter speed and shooting sensitivity, shooting without flash is performed again in the same procedure.

  Regardless of the presence or absence of strobe light emission, if it is determined that the number of shootings performed in the determination after shooting reaches the set number of continuous shootings, each image data for the number of continuous shootings written in the internal memory 27 Are sequentially read and written in the memory card 11 after each processing in the image processing unit 23 and the compression processing unit 24 is performed.

  As described above, the flash photography is performed until the flash can no longer be fired, and thereafter, the shutter speed and the photographing sensitivity are used to obtain the appropriate exposure under the availlab light, up to the set number of continuous photographing. Since shooting is being performed, each image shot in continuous shooting is appropriately exposed, and continuous shooting is performed with the number of continuous shots set by the user.

  In the above embodiment, the flash emission amount is obtained based on the shooting distance and subject brightness acquired immediately before the start of continuous shooting, and the shutter speed and shooting sensitivity when the flash is not flashing are determined. The flash emission amount may be calculated based on the shooting distance at that time, and it may be determined whether or not the flash can be emitted with the flash emission amount. The shutter speed may be determined.

  In each of the above embodiments, a digital still camera with a built-in strobe device has been described. However, a combination of a digital still camera and an external strobe device attached to the digital still camera may be used. In this case, for example, communication is performed between an external strobe device and a digital still camera, the specification information of the strobe device is read into the digital still camera, and the flash emission amount is controlled by an instruction from the digital still camera. As in the above embodiments, the digital still camera and the external strobe device may be controlled.

It is explanatory drawing which shows the front side of the digital still camera which implemented this invention. It is explanatory drawing which shows the back side of a digital still camera. It is a block diagram which shows the structure of a digital still camera. It is a flowchart which shows the process sequence in continuous imaging | photography mode.

Explanation of symbols

3 Shooting lens 5 Flash unit 15 Main CPU
18 CDS / AMP circuit 31 Sub CPU
33 Strobe device 35 Shutter device

Claims (6)

In a digital still camera equipped with a strobe device that has a continuous shooting function to perform continuous shooting and also emits strobe light for each shooting during continuous shooting,
A determination means for determining whether or not the strobe device can emit light with a light emission amount with an appropriate exposure for the main subject, and a period during which the determination result of the determination means can be emitted during continuous shooting In this mode, the flash unit is operated and the flash shooting is performed with the flash level determined by the flash level determining unit. After the judgment result indicates that the flash cannot be flashed, the flash is disabled and available. A digital still camera comprising control means for executing non-stroboscopic shooting in which a combination of an aperture, a shutter speed, and shooting sensitivity is set so that proper exposure is obtained under light.   Voltage detection means for detecting the charging voltage of the main capacitor for strobe emission, distance acquisition means for acquiring the shooting distance to the main subject, luminance detection means for detecting the subject brightness, shooting sensitivity and aperture value, and the distance A light emission amount determining means for determining a light emission amount of the strobe light that is appropriate exposure based on the shooting distance acquired by the acquisition means, wherein the determination means includes the charging voltage detected by the voltage detection means and the light emission. Based on the light emission amount determined by the amount determining means, whether or not strobe light emission is possible is determined for each continuous shooting, and the control means detects the subject brightness detected by the brightness detection means at the time of non-flash shooting. The digital still camera according to claim 1, wherein a combination of an aperture, a shutter speed, and a photographing sensitivity is set based on the camera.   3. The digital still camera according to claim 1, wherein an aperture is used as an aperture when photographing with no flash. In the control method of continuous shooting of a digital still camera that has a continuous shooting function for performing continuous shooting and also emits strobe light for each shooting during continuous shooting,
Continuous shooting is performed for each shooting to determine whether or not the flash can be emitted with the appropriate flash exposure for the main subject. After the flash photography with the flash fired and the flash emission became impossible, set the combination of aperture, shutter speed and shooting sensitivity so that proper exposure can be obtained under available light, and the flash will not fire A method for controlling continuous shooting of a digital still camera, wherein   When determining whether or not the flash can be fired, obtain the appropriate exposure based on the shooting sensitivity, aperture value, and shooting distance to the main subject. 5. The method for controlling continuous shooting of a digital still camera according to claim 4, wherein a combination of an aperture, a shutter speed, and shooting sensitivity is set based on the setting.   6. The method for controlling continuous shooting of a digital still camera according to claim 4 or 5, wherein an aperture is used at the time of shooting without flash.

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