WO2016076514A1

WO2016076514A1 - Device and method for continuous image capturing

Info

Publication number: WO2016076514A1
Application number: PCT/KR2015/008640
Authority: WO
Inventors: 타카하시마리
Original assignee: 삼성전자 주식회사
Priority date: 2014-11-14
Filing date: 2015-08-19
Publication date: 2016-05-19

Abstract

Provided is an image capturing device comprising: an image capturing unit for continuous image capturing, including second image capturing and third image capturing; a storage unit; and a control unit for acquiring a first parameter stored in the storage unit, controlling the image capturing unit to perform the second image capturing on the basis of the first parameter, acquiring a second parameter on the basis of an output signal corresponding to the result of the second image capturing, and performing a control to store the second parameter in the storage unit, wherein the second parameter is used for image capturing after the third image capturing.

Description

Apparatus and method for continuous shooting

TECHNICAL FIELD The present invention relates to an imaging apparatus and method, and more particularly, to an imaging apparatus and method for performing continuous shooting.

In recent years, imaging devices such as digital cameras have continued to improve their speeds. Patent Document 1 (Japanese Patent Laid-Open No. 2006-129076) describes a technique for performing an operation of calculating an operation parameter in photographing according to an image signal for recording at the time of continuous shooting in parallel with the transmission of the image signal for recording. .

Patent Document 2 (Japanese Patent Laid-Open No. 2001-211391) describes performing an exposure calculation using an image signal obtained by the previous exposure. In addition, in the continuous shooting, it is described that the second and subsequent exposures are performed while overlapping the exposure mode and the signal reading mode.

Patent Document 3 (Japanese Patent Laid-Open No. 2010-26173) describes that continuous shooting photographing is set to the same value as the aperture value at the time of immediately preceding photographic exposure without driving the aperture during the second and subsequent photographings. .

As in Patent Document 1, in a digital camera without a mirror, photometric and exposure calculations are performed using an image signal obtained by an imaging device. For example, during continuous shooting, exposure calculation is performed using the immediately previous captured image, and the next shooting is performed using the calculated exposure value. In this case, the exposure operation is performed after the photographed image is output, and the driving of the aperture for the next photographing is performed by using the exposure value calculated after the exposure operation is completed. For this reason, the next shooting cannot be performed until the stop of the stop is completed, and the continuous shooting speed is slowed.

In order to solve this problem, it is an object of the present invention to provide an image pickup apparatus and method that can change the parameters on the image in conjunction with the change in the brightness of the subject without sacrificing the shooting speed.

According to one or more exemplary embodiments, an image capturing apparatus includes: a photographing unit configured to perform continuous photographing including second photographing and third photographing; Storage unit; And obtaining a first parameter stored in the storage unit, controlling the photographing unit to perform a second photographing based on the first parameter, obtaining a second parameter based on an output signal corresponding to the result of the second photographing, A control unit controlling to store two parameters in a storage unit; And a second parameter is used for photographing after the third photographing.

In an imaging device which performs photometric calculation using an output signal of an imaging device, it is possible to perform an exposure calculation in conjunction with a change in the luminance of a subject without lowering the continuous shooting speed. In addition, the continuous shooting interval can be kept constant regardless of the magnitude of the subject brightness change.

1 is a block diagram schematically illustrating an image capturing apparatus according to an exemplary embodiment.

2 is a block diagram showing the configuration of the imaging device according to the first embodiment.

3 is a flowchart schematically illustrating an image pickup method, according to an exemplary embodiment.

4 is a diagram illustrating an example of a continuous shooting method according to an exemplary embodiment.

5 is a diagram illustrating a driving sequence of an imaging device according to an exemplary embodiment, in chronological order.

6 is a diagram illustrating a shooting preparation period according to an exemplary embodiment.

7 is a diagram illustrating a driving sequence of an imaging device having a mirror according to an exemplary embodiment, in chronological order.

8 is a diagram illustrating an example of a driving sequence of an imaging device having a mirror in chronological order.

9 is a diagram illustrating an example of a driving sequence of the imaging device in chronological order.

The continuous shooting may further include first shooting before the second shooting, and the photographing unit may perform the first shooting, and when the first shooting is the first shooting of the continuous shooting, the first parameter may be used for the first shooting. It may be characterized by the same as at least one of the parameters.

Also, when the first photographing is not the first photographing of the continuous shooting, the first parameter may be a parameter obtained based on an output signal corresponding to one of the previous photographings of the first photographing.

The first parameter and the second parameter may include at least one of a brightness of an object, an exposure value of an imaging device, an aperture value, a shutter speed, and a gain.

In addition, the photographing unit includes an aperture, a shutter, and an imaging device, and the control unit is within a range in which the driving of the aperture is completed in a shooting preparation period in which preparation for starting the next exposure is completed after the exposure by the imaging device is completed. It may be characterized by calculating the aperture value.

In addition, the shooting preparation period is between the period required for transmitting the output signal and the period starting from the beginning of the charge period of driving the shutter to the charge state capable of opening / closing the next shooting from the beginning period to the later ending period. It can be characterized.

According to an embodiment of the present disclosure, a method of performing continuous shooting including second shooting and third shooting by using the imaging apparatus may include: obtaining a first parameter stored in the imaging apparatus; Performing a second imaging based on the first parameter; Obtaining a second parameter based on an output signal corresponding to the result of the second imaging; Storing the second parameter in the imaging device; And performing a third photographing. The second parameter may be used for photographing after the third photographing.

Also, the continuous shooting may further include first shooting before the second shooting, and the method may include: performing first shooting; Further, when the first shooting is the first shooting of the continuous shooting, the first parameter may be characterized in that the same as at least one of the parameters used for the first shooting.

The aperture value may be calculated within a range in which driving of the aperture included in the imaging device is completed in an imaging preparation period in which preparation for starting the next exposure is completed after the exposure by the imaging device is completed. Can be.

In addition, the shooting preparation period is a period which is ended late from the period which is started first among the period required for transmitting the output signal and the period in which the shutter included in the imaging device is driven to a charge state capable of opening / closing the next photographing operation. It can be characterized by being between.

A computer readable recording medium having recorded thereon a program for executing an imaging method in a computer is provided.

The imaging apparatus according to an exemplary embodiment includes a continuous shutter mode in which photographing is continuously performed while the shutter button is pressed. An imaging apparatus and an imaging method according to an exemplary embodiment relate to a technology capable of changing an imaging parameter such as an aperture value, a shutter speed, and a gain in conjunction with a change in luminance of a subject without lowering the continuous shooting speed. The technology disclosed herein may be applied to a digital camera or a smart phone in which a high speed of continuous shooting is desired, but is not limited thereto.

Before describing an embodiment, the problem to be solved will be described.

First, with reference to FIG. 8, an example of the imaging method in the imaging device containing a mirror is demonstrated. In FIG. 8, the procedure at the time of continuous shooting of the imaging device containing a mirror is shown. In Fig. 8, the exposure time 810 is made while the mechanical shutter is opened in the mirror up state. When the exposure ends, the transfer of the output signal from the image pickup device is started during the transfer time 820.

In the case of an imaging device having a mirror, there may be a case in which an independent photometric element for measuring the brightness of a subject is measured separately from the imaging element. In such an imaging device, exposure to the imaging device can be completed even during transmission of the output signal. Therefore, when the mirror down is completed, the exposure value of the next shot may be calculated by immediately metering during the exposure calculation time 830 (Exposure Calculation), and a parameter (Calculation Result) required for the next shot may be determined.

In the second photographing immediately after the first photographing, the aperture is driven according to the parameter calculated after the first photographing (Set Iris), and the photographing is performed using the shutter speed (Set Shutter) and gain (Set Gain) calculated after the first photographing. This can be done.

Next, with reference to FIG. 9, an example of the imaging method in the imaging device which does not contain a mirror is demonstrated. In FIG. 9, the procedure at the time of continuous shooting of the imaging device which does not contain a mirror is shown. In an imaging device having no mirror, photometric calculation is performed using the output signal of the imaging device.

Such an image pickup device has a still mode that reads a telephone station to obtain a high-precision still image, and a live view mode that reads out pixels on the entire screen at high speed by thinning the pixels for live view display before shooting. It may include. Metering operations are often performed using the output signal in this live view mode. When the live view mode is operated between the still mode and the still mode in order to link the exposure value to the change in the brightness of the subject during continuous shooting, the continuous shooting speed is slowed.

Therefore, the continuous shooting speed can be increased by calculating the exposure value of the next shooting by using the output signal of the recording still mode. As shown in Fig. 9, after the transfer of the output signal from the image pickup device is completed, the exposure value of the next shot is calculated using the transmitted output signal (Exp. Calc.), And the parameters necessary for immediately after shooting (Calc. Result) can be determined.

In the example shown in FIG. 9, after the output signal is output, the calculation of the exposure value is performed 930, and then the setting of the aperture 940, the exposure 950, and the gain are made. In this case, since the addition of the transmission time 920 of the output signal from the imaging element, the exposure value calculation time 930 and the drive time 940 of the aperture is required, the continuous shooting speed is slowed down. The technique disclosed in this specification can solve such a problem and realize the high speed of continuous shooting.

Hereinafter, specific embodiments will be described in detail with reference to the drawings.

<1st embodiment>

1 is a block diagram schematically illustrating an image capturing apparatus according to an exemplary embodiment. Referring to FIG. 1, the imaging apparatus 100 may include a photographing unit 110, a controller 120, and a storage 130. The controller 120 may control the photographing unit 110 and the storage 130.

The photographing unit 110 may include an aperture, a shutter, and an imaging device. In one embodiment, the photographing unit 110 may further include a mirror. In the present specification, the photographing unit 110 refers to a photographing unit 110 capable of continuous shooting.

The storage unit 130 may be a buffer, a main memory or an auxiliary memory. In an embodiment, the storage unit 130 may be a buffer that temporarily stores a parameter required for photographing. In this specification, the parameter may include at least one of a brightness of an object, an exposure value of an imaging device, an aperture value, a shutter speed, and a gain.

The controller 120 may obtain a parameter stored in the storage 130. The controller 120 may control the photographing unit 110 to perform photographing based on the parameter obtained from the storage 130. For example, the controller 120 may adjust the aperture and the shutter based on the aperture value and the shutter speed obtained from the storage 130. In addition, the controller 120 may control to amplify the image signal obtained from the photographing unit 110 based on the gain obtained from the storage 130. The controller 120 may acquire a parameter for later capturing based on the image signal acquired from the capturing unit 110. The controller 120 may control to store the obtained parameter in the storage 130. The parameter acquired by the controller 120 may be used for photographing after the next photographing.

2 is a block diagram showing the configuration of the imaging device according to the first embodiment. As shown in FIG. 2, the imaging device 100 according to the first embodiment includes an imaging optical system 10, an imaging device 20, a front end portion 21, an image signal processing circuit 22, and a photometric calculation unit ( 23), operation unit 30, central processing unit (CPU) 31, synchronous dynamic random access memory (SDRAM) 40, on-screen display (OSD) synthesis circuit 41, video random access memory (VRAM) (42), liquid crystal display (LCD) driver 43, LCD 44, media controller 45, recording medium 46, timing generator 50, aperture driver 51, lens driver 52, and The shutter driver 53 may be included.

The imaging optical system 10 and the imaging device 20 of FIG. 2 may correspond to the imaging unit 110 of FIG. 1. The CPU 31 and the photometric calculator 23 of FIG. 2 may correspond to the controller 120 of FIG. 1. The SDRAM 40 and the VRAM 42 of FIG. 2 may correspond to the storage 130 of FIG. 1.

The imaging optical system 10 includes a zoom lens 11, an aperture 12, a focus lens 13, and a mechanical shutter 14. The imaging optical system 10 is arranged in order of the zoom lens 11, the aperture 12, the focus lens 13, and the mechanical shutter 14 along the optical axis. The imaging optical system 10 may form an image on the imaging device 20 by transmitting light from a subject.

The zoom lens 11 may be disposed at a position opposite to the subject to guide the light from the subject to the imaging device 20. The aperture 12 adjusts the amount of light incident on the image pickup device by adjusting the amount of light transmitted (light amount). The focus lens 13 moves along the optical axis to focus the subject image on the imaging surface of the imaging device 20. The mechanical shutter 14 can function as a light shield blade.

In addition, the imaging optical system 10 includes an aperture driving motor 15, a lens driving motor 16, and a shutter driving motor 17. The aperture driving motor 15 is connected to the aperture 12. The aperture 12 controls the exposure amount by changing the aperture value by the aperture drive motor 15. The lens drive motor 16 is connected to the focus lens 13. The focus lens 13 is moved along the optical axis by the lens drive motor 16.

The shutter drive motor 17 is connected to the mechanical shutter 14. The mechanical shutter 14 is in a closed state so as to cut off the light at the time of non-photographing, and in an open state so that light is shined on the imaging device 20 only at the time of shooting, thereby controlling the exposure time. The mechanical shutter 14 is controlled by an operation unit 30 such as a shutter button connected to the CPU 31.

An imaging device 20 is disposed behind the focus lens 13. The imaging device 20 changes the subject image formed by the imaging optical system 10 into an electrical signal. As the imaging device 20, an image sensor of, for example, a charge coupled device (CCD) type or a complementary metal oxide semiconductor (CMOS) type may be used.

The timing generator (TG) 50 is connected to the imaging element 20. The timing generator 50 generates a timing signal for controlling the operation of the imaging device 20. Photocharges accumulate as light from the subject enters within the time period in which each pixel of the imaging device 20 is driven in accordance with the timing signal. In addition, the charge accumulated in the imaging device 20 can be read out by the timing signal from the timing generator 50.

In addition, the aperture 12, the focus lens 13, and the mechanical shutter 14 are respectively provided through the aperture driver 51, the lens driver 52, and the shutter driver 53, and the imaging device 20 is the timing generator 50. It is controlled by the CPU 31 through.

The output signal output from the imaging element 20 is input to the front end portion 21. The front end 21 includes a pre-process circuit 24 and an amplifier circuit 25. The preprocessing circuit 24 performs preprocessing on the output signal of the imaging element 20 to generate an image signal capable of image processing in the image signal processing circuit 22. The amplifying circuit 25 amplifies the input image signal using the gain calculated by the CPU 31.

The image signal amplified by the amplifying circuit 25 is input to the image signal processing circuit 22 and the photometric calculating unit 23. The image signal processing circuit 22 performs various image processing such as noise reduction, white balance correction, gamma correction, and generates image data such as a live view image and still image. Image data subjected to image processing is temporarily stored in the VRAM 42 which is an image display memory. In the example shown in FIG. 2, the VRAM 42 includes two storage areas, a storage area A and a storage area B. FIG. Each image data stored in the VRAM 42 is updated at predetermined intervals.

The OSD synthesizing circuit 41 performs a process for displaying a through image for the LCD 44 in accordance with the image data stored in the VRAM 42. In addition, the OSD synthesizing circuit 41 can display various types of information such as a shutter speed and a remaining battery level on the preview image on the LCD 44. The LCD driver 43 is a display driver that receives image data from the OSD synthesizing circuit 41 and displays an image on the LCD 44.

As an example of the display unit provided in the main body of the imaging device 100, the LCD 44 displays, for example, a live view display before shooting, various setting screens, images captured and recorded, and the like read out from the VRAM 42. The display unit is not limited to the LCD 44, and an organic EL display or the like can also be used.

The SDRAM 40 temporarily stores image data of a captured image. The SDRAM 40 has a storage capacity capable of storing a plurality of image data. The SDRAM 40 also has a function of sequentially storing image signals during focus control or an operation program of the CPU 31.

The media controller 45 controls the recording of the image data on the recording medium 46 such as a memory card or the reading of the image data recorded on the recording medium 46 or the like. As the recording medium 46, for example, an optical disc (CD, DVD, Blu-ray (registered trademark) Disc, etc.), an optical magnetic disc, a semiconductor storage medium, or the like can be used.

The CPU 31 can collectively control the overall operation of the imaging apparatus 100. The CPU 31 may include an exposure calculator 32 and an exposure controller 33. The operation unit 30, the timing generator 50, the aperture driver 51, the lens driver 52, and the shutter driver 53 described above are connected to the CPU 31.

The operation unit 30 may include, for example, a shutter button, a power switch, a cross key, a mode dial, and the like installed in the imaging apparatus 100. The operation unit 30 sends an operation signal to the CPU 31 in accordance with the user's operation. The shutter button can be pressed halfway, fully pressed or released by the user. When the shutter button is pressed halfway, an operation signal of focus control start can be output. In addition, when the shutter button is pressed completely, an operation signal of shooting start may be output. The imaging device 100 can continuously perform shooting while the shutter button is pressed.

The photometric calculating section 23 calculates the subject luminance using the image signal input from the front end section 21. For example, the photometric calculating section 23 accumulates the output signal from the pixel of the imaging device 20 for each predetermined region and calculates the luminance. The exposure calculating unit 32 calculates a parameter for performing exposure control necessary for photographing an aperture value, a shutter speed, a gain, and the like according to the subject brightness calculated by the photometric calculating unit 23.

The shutter speed determined by the exposure calculating section 32 is used for controlling the mechanical shutter 14 through the shutter driver 53. In addition, the aperture value determined by the exposure calculation unit 32 is used for controlling the aperture 12 through the lens driver 52. The gain determined by the exposure calculating section 32 is used for the control of the amplifying circuit 25. The exposure control unit 33 controls the gain of the aperture 12, the mechanical shutter 14, and the amplifying circuit 25 based on the parameters calculated by the exposure calculating unit 32, and adjusts the exposure amount.

The exposure controller 33 transmits control signals to the aperture driver 51, the lens driver 52, and the shutter driver 53, respectively. The aperture driver 51 generates a drive signal according to the control signal received from the exposure controller 33, and drives the aperture drive motor 15. Similarly, the lens driver 52 generates a drive signal according to the control signal received from the exposure controller 33, and drives the lens drive motor 16. In addition, the shutter driver 53 generates a drive signal according to the control signal received from the exposure controller 33 and drives the shutter drive motor 17.

3 is a flowchart schematically illustrating an image pickup method, according to an exemplary embodiment. In FIG. 3, the imaging apparatus 100 may perform continuous shooting, including first shooting, second shooting, and third shooting.

In operation 310, the imaging apparatus 100 may perform first imaging. In one embodiment, the first shooting may be the first shooting of the continuous shooting. In another embodiment, the first shooting may not be the first shooting of the continuous shooting.

In operation 320, the imaging apparatus 100 may obtain a first parameter for second photographing. When the first shooting is the first shooting of the continuous shooting, the first parameter may be the same parameter as the parameter used for the first shooting. If the first shot is not the first shot of the continuous shooting, the first parameter may be a parameter obtained based on an output signal corresponding to one of the previous shots of the first shot.

In operation 330, the imaging apparatus 100 may perform second imaging. The imaging apparatus 100 may perform the adjustment for the second imaging by using the parameter acquired in operation 320 as the first parameter. For example, when the first shooting is the first shooting of the continuous shooting, the imaging apparatus 100 may use the aperture value, the shutter speed, and the gain used in the first shooting as it is. If the first photographing is not the first photographing of the continuous shooting, the imaging apparatus 100 may perform adjustment for the second photographing using the stored parameter as the first parameter.

In operation 340, the imaging apparatus 100 may obtain a second parameter based on an output signal corresponding to the result of the second imaging. For example, the imaging apparatus 100 may determine an exposure value by measuring the luminance of the subject of the second photographing. The imaging apparatus 100 may determine the aperture value, the shutter speed, and the gain based on the determined exposure value. The imaging apparatus 100 may store the second parameter.

In operation 350, the imaging apparatus 100 may perform third imaging. The parameter used for the third imaging may be a parameter obtained based on an output signal of the first imaging. In another embodiment, the imaging apparatus 100 may perform third imaging by using a parameter obtained based on an output signal corresponding to one of previous imagings of the first imaging.

4 is a diagram illustrating an example of a continuous shooting method according to an exemplary embodiment. Referring to FIG. 4, a part of the continuous shooting photographing process including the first photographing 400 and the second photographing 410 is illustrated in chronological order. In the first image 400, the aperture adjustment may be performed first in step 401. The aperture value required for adjusting the aperture may be a value stored in the imaging apparatus 100 or may be a value acquired by the imaging apparatus 100 based on the brightness of the subject.

When the aperture adjustment is completed, the imaging apparatus 100 may open the shutter to perform exposure in step 402. Exposure is a process of obtaining an image by exposing the imaging device 20 to external light. The imaging apparatus 100 may end the exposure by closing the shutter after a time set in the shutter speed.

After the step 402 is finished, the imaging apparatus 100 may perform step 403. In operation 403, the imaging apparatus 100 may transmit the acquired image as an output signal. In addition, the imaging apparatus 100 may perform a shutter charging operation for driving the shutter again. The transmission and shutter charge of the output signal can be performed simultaneously. Therefore, the period from the operation which is started first to the operation which is terminated late among the two operations can be referred to as a shooting preparation period for the next shooting.

In addition, when the step 402 is finished, the imaging apparatus 100 may start preparation for the second imaging 410. In operation 411, the imaging apparatus 100 may acquire a parameter for the second imaging 410. The parameter for the second imaging 410 may be a parameter stored in the imaging apparatus 100.

In operation 412, the imaging apparatus 100 may perform aperture adjustment. In this embodiment, in order to perform continuous shooting at a uniform time interval, the time required for adjusting the aperture may need to be shorter than the shooting preparation period of step 403. Therefore, the imaging apparatus 100 may limit the range of the aperture value so that the time required for the aperture adjustment may be set shorter than the shooting preparation period. The imaging apparatus 100 may compensate for the problem that the range of the aperture value is limited by adjusting the gain and the shutter speed.

In operation 404, the imaging apparatus 100 may calculate an exposure value for subsequent imaging based on the output signal of the first imaging 400. The exposure value may be calculated based on the brightness of the subject. In addition, the imaging apparatus 100 may set a parameter including an aperture value, a shutter speed, and a gain necessary for photographing later based on the exposure value. As mentioned in step 412, the aperture value may be limited to be set within a range in which the aperture can be adjusted in the shooting preparation period.

In operation 405, the imaging apparatus 100 may store a parameter. In this case, the stored parameter may include at least one of a brightness of an object, an exposure value of an imaging device, an aperture value, a shutter speed, and a gain.

In operation 413, the imaging apparatus 100 may open the shutter to start exposing the second image. The exposure value calculation of step 404 and the exposure of step 413 may proceed simultaneously. Using this method, the imaging apparatus 100 can perform a fast and uniform continuous shutter operation.

In the first embodiment, the imaging device 100 can apply each parameter calculated at the time of continuous shooting to immediately following shooting after shooting. Hereinafter, the imaging method according to the first embodiment will be described with reference to FIG. 5. 5 is a diagram illustrating a procedure during continuous shooting of the imaging device according to the first embodiment. In FIG. 5, an example in which four shots from the first shot 1 to the fourth shot 4 are continuously performed is illustrated.

In Fig. 5, "transmission time" 531 to 534 indicates the transmission time of the output signal from the image pickup device 20, and "exposure calculations" 541 to 544 indicate the time according to the calculation. That is, the lengths of the bands representing “exposure time” (511 to 514), “aperture drive time” (521 to 523), “transmission time” (531 to 534), and “exposure operation” (541 to 544) are time. The length of is shown. The time represented by the parallelograms 551 to 554 of the "mechanical shutter" indicates that the mechanical shutter 14 is in an open state. In other words, the exposure time is the time when the bands of the “exposure time” 511 to 514 and the parallelograms 551 to 554 of the “mechanical shutter” overlap.

In addition, in Fig. 5, the “calculation result” 560 indicates the exposure calculation result (each parameter on the image) obtained by the exposure calculation in the exposure calculation section 32, and the “calculation result buffer” 570 indicates the buffer. Shows the parameters on the image stored in the.

In one embodiment, when the shutter button is pressed for a long time, burst shooting may be started. First, in the first photographing 1, photographing is performed using a predetermined aperture value, shutter speed, and gain. When the imaging element 20 is in the driving state, exposure is performed while the mechanical shutter 14 is in the open state.

After the mechanical shutter 14 is in the closed state, the output signal from the imaging device 20 exposed in the first imaging 1 is transmitted. After the transmission of the output signal is completed, the photometric calculation is performed by the photometric calculation unit 23 using the output signal, and the exposure calculation unit 32 performs the exposure calculation according to the photometric calculation result.

Here, the exposure calculation result (aperture value, shutter speed, gain parameters) calculated according to the output signal of the first photographing 1 is not applied to the second photographing 2 immediately after the first photographing 1, It applies after 3rd imaging | photography 3 after 2nd imaging | photography (2).

In the example shown in FIG. 5, the exposure calculation result calculated according to the output signal of the first photographing 1 is applied to the third photographing 3. That is, in FIG. 5, the exposure calculation result by the 1st imaging | photography 1 shown by the oblique line at the lower right is applied to the setting of the aperture, shutter speed, and gain of the 3rd imaging | photography 3. In FIG. For this reason, it is possible to set the aperture 12 for the third imaging 3 during the transmission of the output signal of the imaging device 20 exposed in the second imaging 2.

As shown in FIG. 5, the transmission of the output signal from the imaging device 20 exposed in the second imaging 2 during the operation of the aperture 12 for the third imaging 3 is completed, and the output signal is transmitted to the corresponding output signal. According to the exposure operation. Accordingly, the exposure calculation result by the first imaging 1 is updated with the exposure calculation result by the second imaging 2.

For this reason, the exposure calculation result by the 1st imaging | photography 1 is buffered. Then, the shutter speed and the gain in the third shooting 3 are set using the result of the exposure calculation by the buffered first shooting 1.

In addition, the exposure calculation result calculated according to the output signal of the second photographing 2 is not applied to the third photographing 3 immediately after the second photographing 2, and the fourth photographing following the third photographing 3 ( Applies to 4). That is, in FIG. 5, the exposure calculation result by the 2nd imaging | photography 2 shown by the oblique grating | lattice is applied to the setting of the aperture, shutter speed, and gain of the 4th imaging | photography 4. In FIG.

Therefore, it is possible to set the aperture 12 for the fourth imaging 4 during the transmission of the output signal of the imaging device 20 exposed in the third imaging 3. Then, the shutter speed and the gain in the fourth photographing 4 are set using the result of the exposure calculation by the buffered second photographing 2.

As described above, the photometric calculating section 23 accumulates the output signals from all the pixels of the imaging device 20 to calculate the subject luminance. Therefore, in the example shown in FIG. 9, after the output signal transmission from all the pixels of the imaging element 20 at the time of the last photographing is completed, the exposure calculation part 32 enables exposure calculation. In order to drive the aperture for the next imaging by using the exposure calculation result, it takes time to add the transmission time of the output signal from the telephone station of the imaging device 20 and the drive time of the aperture. Therefore, there may be a limitation in speeding up the continuous shooting speed.

In contrast, in the first embodiment, the aperture of the next imaging can be driven while the output signal of the previous imaging is transmitted. Accordingly, parameters such as an aperture value, a shutter speed, and a gain can be changed in conjunction with a change in luminance of the subject without sacrificing the shooting speed.

Here, each parameter in the 2nd imaging | photography 2 immediately after the 1st 1st imaging 1 of continuous shooting is demonstrated. In the 2nd imaging | photography 2, as shown by the dot in FIG. 5, the same parameter as the 1st 1st imaging | photography 1 of continuous shooting photography can be used. That is, exposure of the 1st imaging | photography 1 and exposure of the 2nd imaging | photography 2 can be made the same. The interval between the first photographing 1 and the second photographing 2 is short, and in general, the subject luminance rarely changes in the meantime, and therefore, there is no particular problem in photographing.

The aperture value in the second imaging 2 is the same as the aperture value in the first imaging 1, and the aperture is not driven in the second imaging 2. Accordingly, since the time for driving the aperture is not required between the first photographing 1 and the second photographing 2, the continuous shooting speed can be prevented from slowing down.

In the second photographing 2, only the aperture value may be the same as the first photographing 1. The shutter speed and the gain of the second photographing 2 can be set using the exposure calculation result calculated using the output signal from the first photographing 1 under the same condition as the aperture of the first photographing 1. . As a result, the exposure amount can be changed in accordance with the luminance of the subject without slowing down the continuous shooting speed even in the second photographing 2.

In addition, in the above-mentioned example, although each parameter computed according to the output signal of the 1st imaging | photography 1 was applied to the 3rd imaging | photography 3, it can also apply to imaging | photography after 3rd imaging | photography 3.

In continuous shooting, it is also important to keep the continuous shooting interval constant. If the luminance change is large or small during continuous shooting, the change amount of the aperture may become uneven. When the change amount of the iris is large, the iris driving time becomes a bottleneck, and there is a problem that the interval of continuous shooting is longer as long as the coma.

Therefore, in 1st Embodiment, after exposure by the imaging element 20 at the time of continuous shooting is completed, it is within the range which drive of the aperture 12 is completed in the imaging | photography preparation period which prepares to start next exposure. Calculate the aperture value in. An imaging preparation period for driving the aperture 12 will be described with reference to FIG. 6.

As shown in FIG. 6, the imaging device 20 starts to transmit the output signal when the mechanical shutter 14 is in the closed state (shielding state) 610. In addition, the mechanical shutter 14 starts a preparation operation (charging operation) for changing to the open state 620 for the next shooting while maintaining the closed state when the previous shooting is finished. In order to start the next shooting, both the transmission of the output signal from the imaging element 20 and the charging operation of the mechanical shutter 14 need to be completed. That is, even if the aperture 12 is driven until such an operation is completed, it does not affect the burst interval.

Therefore, the shooting preparation period 660 includes the transmission period 630 of the output signal from the imaging device 20 and the charge period 640 for driving the mechanical shutter 14 to a charge state capable of opening / closing the next shooting. ) From the period which is started first to the period which is later terminated. This shooting preparation period is uniquely determined by the mechanical shutter 14 and the imaging device 20. For example, the photographing preparation period can be uniquely determined based on the charge period of the mechanical shutter 14 and the transmission period of the output signal from the imaging element 20.

In this embodiment, the photographing preparation period 660 is set as the setting period 650 of the aperture 12 so that the continuous shooting interval is not lengthened by the driving of the aperture. That is, the aperture value is limited so that the driving of the aperture 12 is completed within the shooting preparation period during the previous shooting and the next shooting.

The time required for driving the aperture 12 between the arbitrary aperture values can be calculated in advance. The exposure calculating unit 32 calculates a limit aperture value capable of completing the driving of the aperture 12 within the shooting preparation period from the current aperture value.

As described above, the exposure calculation unit 32 calculates the aperture value, the shutter speed, and the gain by using the subject luminance calculated by the photometric calculation unit 23. When the result exceeds the limit aperture value, the aperture value is limited. Limit to the aperture value. When the limit aperture value is used, the desired exposure amount can be realized by changing the shutter speed and the gain. As a result, even when the subject brightness fluctuates greatly during continuous shooting, each parameter can be changed in conjunction with the subject brightness without lowering the continuous shooting speed.

For example, in the exposure calculating section 32, the exposure value is EV = 11 (ISO100), the aperture value is AV = 5 (F5.6), the shutter speed is TV = 7 (1 / 128s), and the gain is SV = 6. It is calculated by (ISO200). Here, the current aperture value is AV = 2 (F2.0), and the limit aperture value is AV = 4 (F4.0).

In this case, the exposure calculating unit 32 limits the aperture value to AV = 4 (F4.0) of the limit aperture value, and changes the gain to SV = 5 (ISO100), for example. Thereby, EV (ISO100) = AV + TV + 5-SV = 4 + 7 + 5--5 = 11, and even if an aperture value is restrict | limited, it can expose with the same exposure value.

In this way, by limiting the aperture value so that the driving of the aperture for performing the next imaging is completed within the shooting preparation period, the continuous shooting interval can be kept constant.

<2nd embodiment>

The imaging device according to the second embodiment applies the technique disclosed herein to a digital single-lens reflex (DSLR) camera having a mirror. In addition, since the structure of the imaging device which concerns on 2nd Embodiment is the same as the structure shown in FIG. 2 except for including the finder optical system containing a quick return mirror, a finder screen, a penta prism, an eyepiece optical system, etc., it overlaps. The description will be omitted.

The quick return mirror is disposed between the focus lens 13 and the mechanical shutter 14. The optical path on the subject collected by the focus lens 13 is bent toward the finder screen by the quick return mirror. The quick return mirror is operably provided in the imaging optical system 10. The quick return mirror is retracted to a position which does not prevent the incident light from entering the image pickup device 20 by the operation of the shutter button.

The finder screen forms an image of the subject reflected by the quick return mirror. The penta prism guides the image formed on the finder screen to the eyepiece optics as an erect image. The eyepiece optical system is an optical system for magnifying and observing a subject image that has been stipulated by a penta prism. In addition, the structure of a finder optical system is not limited to this example.

An imaging method according to the second embodiment will be described with reference to FIG. 7. 7 shows the procedure at the time of continuous shooting of the imaging device according to the second embodiment. In FIG. 7, an example in which four shots from the first shot 1 to the fourth shot 4 are continuously performed is illustrated. Since "mechanical shutter", "exposure time", "aperture drive time", "transmission time", "exposure operation", "operation result", and "operation result buffer" in FIG. 7 are the same as those described with reference to FIG. The description will be omitted.

In Fig. 7, “mirror” indicates the state of the quick return mirror. "Mirror up" 710 represents a state in which the quick return mirror has been retracted to a position which does not prevent the incident light from entering the imaging element 20. "Mirror down" 720 indicates a state where the quick return mirror is disposed between the focus lens 13 and the mechanical shutter 14.

When the shutter button is pressed for a long time, continuous shooting is started. First, in the 1st imaging | photography 1, it is mirrored up and image | photographs using a predetermined aperture value, shutter speed, and gain. When the imaging element 20 is in the driving state, exposure is performed while the mechanical shutter 14 is in the open state.

The exposure calculation result calculated according to the output signal of the first photographing 1 is not applied to the second photographing 2 immediately after the first photographing 1, but the third photographing 3 following the second photographing 2. Apply afterwards. In the example shown in FIG. 7, the exposure calculation result calculated according to the output signal of the first photographing 1 is applied to the third photographing 3. In addition, the exposure calculation result calculated according to the output signal of the second photographing 2 is not applied to the third photographing 3 immediately after the second photographing 2, and the fourth photographing following the third photographing 3 ( Applies to 4).

As in the example shown in Fig. 8, when performing light metering using the light metering element mounted on the optical finder side, the exposure operation cannot be performed until the mirror down is completed and the metering value is acquired, and the aperture for the next shooting is performed. Cannot start driving.

In contrast, according to the second embodiment, the driving of the aperture for the next imaging can be started before the mirror down is completed. That is, even if the technique disclosed herein is applied to a digital single-lens reflex camera having a mirror, the continuous shooting time can be shortened.

As described above, in the second shooting 2 immediately after the first first shooting 1 of continuous shooting, the same parameters as the first first shooting 1 of continuous shooting can be used. In addition, in the 2nd imaging | photography 2, only an aperture value can be made the same as the 1st imaging | photography 1. The shutter speed and the gain of the second photographing 2 can be set using the exposure calculation result calculated using the output signal from the first photographing 1 under the same condition that the aperture value is the same as that of the first photographing 1. .

Also in the second embodiment, as shown in FIG. 6, the aperture value can be limited so that the driving of the aperture 12 is completed within the shooting preparation period during the immediately preceding shooting and the next shooting.

As described above, according to the embodiment, in the imaging device which performs the photometric calculation using the output signal of the imaging element, the exposure calculation can be performed in conjunction with the subject brightness change without lowering the continuous shooting speed. In addition, the continuous shooting interval can be kept constant regardless of the magnitude of the subject brightness change.

In addition, the technique disclosed in this specification is not limited to embodiment and can be suitably changed in the range which does not deviate from the meaning.

In addition, although the above-mentioned embodiment mainly explained the structure of hardware, it is not limited to this, It can also implement | achieve arbitrary processes by running a computer program in a CPU. In this case, the computer program may be stored using various types of non-transitory computer readable medium and supplied to the computer. Non-transitory computer-readable media includes tangible storage media having various types of entities.

Examples of non-transitory computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, optical magnetic disks), CD-ROMs (Read Only Memory), CD-R, CD-R / W, semiconductor memory (e.g., mask ROM, programmable ROM (PROM), erasable PROM (EPROM), flash ROM, random access memory (RAM)). In addition, the program may be supplied to the computer by various types of temporary computer readable medium. Examples of temporarily readable media on a computer include electric signals, optical signals, and electromagnetic waves. Temporarily readable media from a computer can supply a program to a computer through a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

Claims

A photographing unit which performs continuous shooting including a second photographing and a third photographing;

Storage unit; And

Acquire a first parameter stored in the storage unit, control the photographing unit to perform the second photographing based on the first parameter, and set a second parameter based on an output signal corresponding to a result of the second photographing; A control unit which acquires and controls to store the second parameter in the storage unit; Including,

And the second parameter is used for photographing after the third photographing.
The method of claim 1, wherein the continuous shooting further comprises a first shooting before the second shooting,

The photographing unit performs the first photographing,

When the first shooting is the first shooting of the continuous shooting,

And the first parameter is the same as at least one of the parameters used for the first imaging.
The method of claim 2, wherein when the first shooting is not the first shooting of the continuous shooting,

And the first parameter is a parameter obtained based on an output signal corresponding to one of previous photographs of the first photographing.
The method of claim 1, wherein the first parameter and the second parameter,

And at least one of a brightness of a subject, an exposure value of the imaging device, an aperture value, a shutter speed, and a gain.
The method of claim 4, wherein the photographing unit comprises an aperture, a shutter and an image pickup device,

The control unit calculates the aperture value within a range in which the driving of the aperture is completed in a shooting preparation period in which preparation for starting the next exposure is completed after exposure by the imaging device is completed. Imaging device.
The method of claim 5, wherein the shooting preparation period,

A period required to transmit the output signal,

An image pickup apparatus, characterized in that it is from a period beginning first to a period ending late among charge periods for driving the shutter to a charge state capable of opening / closing a next shooting operation.
In the method for performing continuous shooting including the second shooting and the third shooting by using the imaging device,

Acquiring a first parameter stored in the imaging device;

Performing the second imaging based on the first parameter;

Obtaining a second parameter based on an output signal corresponding to the result of the second imaging;

Storing the second parameter in the imaging device; And

Performing the third imaging; Including,

And the second parameter is used for photographing after the third photographing.
The method of claim 7, wherein the continuous shooting further comprises a first shooting before the second shooting,

The method includes performing the first imaging; More,

When the first shooting is the first shooting of the continuous shooting,

The first parameter is equal to at least one of the parameters used for the first imaging.
The method of claim 8, wherein when the first shooting is not the first shooting of the continuous shooting,

The first parameter is a parameter obtained based on an output signal corresponding to one of the previous shots of the first shot.
The method of claim 7, wherein the first parameter and the second parameter,

And at least one of a brightness of a subject, an exposure value of the imaging device, an aperture value, a shutter speed, and a gain.
The method of claim 10, wherein the aperture value,

And after the exposure by the imaging device is completed, in a shooting preparation period in which preparation for starting the next exposure is performed, within the range in which driving of the aperture included in the imaging device is completed.
The method of claim 11, wherein the shooting preparation period,

A period required to transmit the output signal,

And a period in which the shutter included in the imaging device is driven in a charge state capable of opening / closing a next photographing period from a first starting period to a later ending period.
A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 7 to 12.