JPH11341313A - Digital camera and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a digital camera, in which a control time required for displaying a photographic image by a displaying part does not prevent from shortening a fixed interval in consecutive photographing. SOLUTION: A flag 'Burst', that shows whether or not it is in the middle of photographing, is adopted, and whether or not live view processing is performed in accordance with its value. When the flag 'Burst' is '1', it is decided as being in the middle of photographing, and consecutive photographing processing is performed at a step S709 on the condition that a shutter button is pressed down at a step S708. Also, when the flag 'Burst' is '1', it is decided as being not in the middle of photographing, and if the shutter button is not pressed down, live view processing of steps S703 and S704 is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera, and more particularly, to a digital camera having both a continuous shooting function and a live view function.

[0002]

2. Description of the Related Art An image photoelectrically converted by an image pickup device such as a CCD (Charge Coupled Device) is converted to an LCD (Liquid Cryst).
A digital camera having a so-called live view finder function for displaying on a display unit such as an Al Display is known. In addition, there is a digital camera having a so-called continuous shooting function of continuously taking images at a constant interval.
In such a digital camera, an image being captured is displayed on the display unit even during continuous shooting.

[0003]

Accordingly, the control time required for the display unit to display a photographed image must be shorter than the above-mentioned fixed interval in continuous shooting. However, the data amount of the captured image is very large, and there is a problem in that the control time required for display limits shortening of the fixed interval in continuous shooting.

[0004] In view of the above problems, the present invention provides a digital camera control method in which the continuous shooting function is prioritized over the live viewfinder function.

[0005]

Means for Solving the Problems Claim 1 of the present invention
An image sensor that converts an optical image of a subject into an image signal, a shutter button, a plurality of storage elements that sequentially store the image signals by pressing the shutter button, and the shutter button is pressed. A display unit that performs live view processing for updating the image signal at a predetermined cycle to display the latest image signal when there is no such button, and does not perform the live view processing when the shutter button is pressed. It is a digital camera.

[0006] The invention according to claim 2 is as follows:
A method for controlling a digital camera including an imaging element that converts an optical image of a subject into an image signal, a shutter button, a plurality of storage elements that sequentially store the image signals by pressing the shutter button, and a display unit. So,
When the shutter button is not pressed, the display unit performs a live view process of updating the image signal at the predetermined cycle and displaying the latest image signal, and when the shutter button is pressed. The present invention is a control method for a digital camera, wherein the display unit does not perform the live view processing.

According to the third aspect of the present invention,
3. The control method for a digital camera according to claim 2, wherein the number of the plurality of storage elements is N (N is an integer of 2 or more), and a flag is adopted. (A) When the flag takes the first value, (a-1) the flag is set to the first value without performing the live view processing on condition that the shutter button is pressed. Second different from the value
(A-2) storing the image signal in the first storage element and performing the live view processing on condition that the shutter button is not pressed; When the flag takes the second value,
(B-1) storing the image signals sequentially in the second to N-th storage elements without performing the live view processing on condition that the shutter button is pressed; Setting the flag to the first value on condition that the shutter button is not pressed.

According to a fourth aspect of the present invention,
4. The digital camera control method according to claim 3, wherein in the live view processing, the image signal is stored in the first storage element while being updated at the predetermined cycle. 5.

[0009] According to a fifth aspect of the present invention,
4. The control method for a digital camera according to claim 3, wherein in the steps (a-1) and (b-1), the display unit displays a blue screen.

[0010] The invention according to claim 6 is as follows:
6. The control method for a digital camera according to claim 5, wherein in the steps (a-1) and (b-1), the display unit continuously changes the order of the image signals sequentially stored in the storage element. Show.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Basic Structure Example of Digital Camera to Which the Present Invention is Applied: FIGS. 1 to 3 show a basic structure of a digital camera 1 to which a control method according to the present invention is applied. 1 corresponds to a front view, FIG. 2 corresponds to a rear view, and FIG. 3 corresponds to a bottom view, but does not necessarily conform to the triangular projection, but merely conceptually illustrates the basic structure of the digital camera 1.

The digital camera 1 has a structure roughly divided into a substantially rectangular parallelepiped camera main body 2 and a substantially cylindrical imaging unit 3. 2 is detachably attached to the right side surface in FIG. 1 and is rotatably mounted in a plane parallel to the right side surface.

The imaging unit 3 includes a macro zoom lens 301 serving as a photographing lens and a color area sensor (hereinafter, simply referred to as a "CCD") which is a photoelectric conversion element such as a CCD; hidden behind the macro zoom lens 301 and shown in FIGS. (Not shown in FIG. 3). The optical image of the subject is C
Each pixel of the CD is photoelectrically converted, and the captured image is converted into a charge signal. In addition, a dimming sensor 305 that receives reflected light of the flash light from the subject is provided at an appropriate position of the imaging unit 3.

The camera body 2 has a card loading section 1 for loading a memory card 8 for storing a photographed image as a recorded image.
7 and a battery loading unit 18 for loading, for example, four AA batteries
And built-in. The digital camera 1 is driven entirely by a battery loaded in the battery loading section 18 with the exception of a clock circuit described later. When attaching and detaching the memory card 8 and the battery, the bottom cover 15 is opened and closed. The power is turned on / off by a power switch PS provided on the back of the camera body 2.

On the front surface of the camera body 2, a grip 4 is provided at an appropriate position on the left side, and a built-in flash 5 is provided at an appropriate position on the upper right.
Are provided respectively. In addition, a display unit 10 composed of an LCD is provided at an appropriate position on the left side of the back surface.

A flash mode setting switch 11 is provided above and to the left of the display unit 10 to switch the light emission mode of the built-in flash 5. As the light emission mode, for example, an automatic light emission mode in which light emission / non-light emission of the built-in flash 5 is automatically controlled according to the subject brightness, a forced light emission mode in which the built-in flash 5 is forcibly fired regardless of the subject brightness, There is a flash inhibition mode in which the built-in flash 5 is not forcibly emitted regardless of the luminance of the subject. Each of these modes is sequentially switched and set each time the flash mode setting switch 11 is pressed.

Above the right side of the display unit 10, a two-contact slide-type photographing / reproduction mode setting switch 14 is provided to switch between a photographing mode and a reproduction mode. The shooting mode is a mode for shooting a subject, and the display unit 10 performs monitor display (corresponding to a viewfinder function). The reproduction mode is a mode in which an image recorded on the memory card 8 is reproduced and displayed on the display unit 10. For example, sliding to the right sets the playback mode, and sliding to the left sets the shooting mode.

Below the display unit 10, a slide type compression ratio changeover switch 12 is provided to select a compression ratio of image data to be stored in the memory card 8. In the upper surface of the camera body 2, switches 6 and 7 for frame advance are provided substantially at the center, and these switches are used to replace the recorded images already stored in the memory card 8 with the frame numbers assigned to each of the recorded images. Play in order. Each time the switch 6 is pressed, the recorded images are sequentially updated and reproduced on the display unit 10 in the order of increasing frame numbers (in the order of shooting). Each time the switch 7 is pressed, the recorded images are sequentially updated in the order of decreasing frame numbers and reproduced on the display unit 10. A shutter button 9 is provided on the upper surface of the camera body 2 on the right side, and an erase switch D for erasing a recorded image stored in the memory card 8 is provided on the left side.

A connection terminal 13 is provided on the right side of the camera body so that a computer can be connected from outside the digital camera 1.

B. Description of the functional blocks of the digital camera to which the present invention is applied: (b-1) Functional blocks of the imaging unit 3. FIG. 4 is a block diagram illustrating the configuration of the digital camera 1 from the viewpoint of its functions. The imaging unit 3 includes a macro zoom lens 301,
CCD 303, signal processing circuit 3 in addition to the light control sensor 305
13, timing generator 314, dimming circuit 304
It has. The CCD 303 is a macro zoom lens 3
The optical image of the subject formed in step 01 is photoelectrically converted into an image signal of RGB color components and output. The image signal is C
This is a signal composed of a column of pixel signals obtained by receiving light at each pixel of the CD 303. Timing generator 314 is C
Various timing pulses for controlling the driving of the CD 303 are generated. For example, the timing of starting and ending the charge integration of the CCD 303 (charge storage time; equivalent to shutter speed) and the timing of reading control of each pixel signal (horizontal synchronization signal, vertical synchronization signal, transfer signal, etc.) are controlled. .

The signal processing circuit 313 performs predetermined analog signal processing on the analog image signal obtained from the CCD 303. For example, CDS (correlated double sampling)
Processing and AGC (auto gain control) processing are performed. The former process reduces the noise of the image signal, and the latter process adjusts the level of the image signal.

The level adjustment of the image signal is performed in relation to the shutter speed. Since the aperture of the imaging unit 3 is fixed, exposure control is performed by adjusting the exposure amount of the CCD 303, that is, the charge accumulation time by the timing generator 314. However, if the subject brightness is low and the shutter speed is high, the exposure will be insufficient. To correct this, the signal processing circuit 313 adjusts the level of the image signal.

A reference clock is given to the timing generator 314 and the signal processing circuit 313 from the timing control circuit 202 provided in the camera body 2.

The light control circuit 304 is used to control the amount of light emission when flash photography is performed using the built-in flash 5. At the time of flash photographing, the amount of reflected light of the flash light from the subject is detected by the light control sensor 305, and when this reaches a predetermined level, a light emission stop signal STP is given to a flash control circuit 214 to be described later. The light emission amount of the flash 5 is controlled to be equal to or less than a predetermined light emission amount.

(B-2) Functional block of the camera body 2.
The camera body 2 includes a built-in flash 5, a display unit 10, a connection terminal 13, a card loading unit 17, and a general control unit 211 which includes a CPU and integrally controls driving of each unit of the digital camera 1 in relation to each other. , Timing control circuit 2
02, A / D converter 205, black level correction circuit 206,
White balance circuit 207, γ correction circuit 208, image memories 209 _{1 to} 209 ₆ , VRAM 210, operation unit 2
50, card interface 212, communication interface 213, flash control circuit 214, clock circuit 21
9 is provided.

The flash control circuit 214 is a general control unit 2
Under the control of 11, the light emitting operation of the built-in flash 5 is controlled. However, when the light emission stop signal STP is given from the dimming circuit 304, the built-in flash 5 does not emit light as described above.

The communication interface 213 is, for example, U
It conforms to the SB (Universal Serial Bus) standard, and interfaces data between a computer externally connected via the connection terminal 13 and the overall control unit 211. The card interface 212 performs data interface between the memory card 8 loaded into the camera body 2 via the card loading unit 17 and the overall control unit 211. Specifically, storage of the recorded image in the memory card 8 and reading of the recorded image from the memory card 8 are performed.

A clock circuit 219 is a clock for managing the photographing date and time, and is driven by an independent power supply.

The operation unit 250 includes switches 6 and 7, a shutter button 9, a flash mode setting switch 11, a compression ratio changeover switch 12, and a photographing / playback mode setting switch 14. 1 to request control of each section.

The image signal that has been subjected to the predetermined analog signal processing by the signal processing circuit 313 has an A / A signal for each pixel signal.
The signal is converted into a 10-bit digital signal in the D converter 205. This analog-to-digital conversion is performed by supplying a clock for analog-to-digital conversion from the timing control circuit 202.

The image signal converted into a digital signal is supplied to a black level correction circuit 206, a white balance circuit 207,
The γ correction circuit 208 corrects the black level,
Adjustment of white balance and gamma correction are performed.

The display unit 10 displays the contents captured by the CCD 303.
In the shooting mode, image data that has been subjected to black level correction, white balance adjustment, and γ correction are stored in an image memory 2 having a storage capacity for one frame.
09 is _{1 to 209 6} temporarily stored. Image memory 2
09 _{1-209 6,} the captured image CCD303 is imaged at a time, stores an association with pixel data and the pixel position.

[0033] when the shutter a shooting mode is not turned off, in other words capturing standby state, only the image memory ₂₀₉₁ is used at all times. And the image memory 20
9 ₁ content was analyzed in the overall control unit 211, such as color and brightness of the photographed image, setting a level conversion table for white balance based on the shooting conditions.
The level conversion table has conversion coefficients (gradients of characteristics) of RGB color components. Based on the conversion coefficients, the white balance circuit 207 converts the level of data of each color component of the pixel signal to adjust the white balance. Similarly, γ
Correction of the correction table are also based on the photographing conditions that were analyzed from the contents of the image memory _2091, for example, selected from six correction table. Then, the pixel signal data is corrected in the γ correction circuit 208.

[0034] Only the image memory ₂₀₉₁ is in the photographing standby state as described above is used at all times, serving as a buffer number of pixels is converted by the overall controller 211 the contents of V
The data is transferred to the display unit 10 via the RAM 210. Since the captured image captured by the imaging unit 3 every 1/30 second is displayed on the display unit 10, the photographer can visually recognize the subject image. For example, the number of pixels of the CCD 303 is 640.
× 480, and the number of pixels of the display unit 10 is 320 × 240.
In this case, 1/4 thinning-out processing is performed as conversion of the number of pixels. The VRAM 210 may have a storage capacity corresponding to the number of pixels of the display unit 10. The normal photography (hereinafter, "single shot" and referred) not called continuous even image memory 209 ₁ only to the image signal is stored.

However, when photographing is performed by operating the continuous photographing function, the continuously photographed images are sequentially stored in the image memories 209 ₁ to 209 ₁ .
209 is stored to _6. Specifically image data of the first to sixth frame is stored in the image memory 209 _{1-209 6} respectively If you continue pressing the shutter button 9. If you release the shutter button 9 within a predetermined time image signals only in the image memory ₂₀₉₁ becomes single shooting is stored.

When the photographing is instructed by the shutter button 9 in the photographing mode in the photographing mode,
For photographed image taken in the image memory ₂₀₉₁ after shooting instruction to generate a thumbnail image. If necessary, the photographed image is compressed using, for example, the JPEG method. Then, tag information (for example, frame number, exposure value, shutter speed, presence / absence of compression, shooting date / time, presence / absence of flash emission, scene information, judgment result of image quality, etc.) regarding the shot image is added, and the thumbnail image and the shot image are added. (Or a compressed captured image) is stored in the memory card 8 via the card interface 212 as a recorded image.

FIG. 5 is a memory map of the memory card 8. Memory areas _{8 1, 8 2, 8 3} , ..., 8 n, is ... in are stored data about the captured image of it one frame, tag, data of the photographed image data of the thumbnail image becomes collectively I have.

[0038] especially when performing shooting exercising Ren'utsushiren shooting function, compared the image stored in the image memory 209 _{1-209 6} is also added information indicating the order of the continuous shooting as part of the tag, respectively You. For example, if the 24th to 29th frames of the recorded image are consecutively shot in 6 frames, "a" for the 24th frame, "b" for the 25th frame, ... for the 29th frame The information “f” indicating the continuous shooting and the order of the continuous shooting is added as a part of the tag.

When the recorded image is read out from the memory card 8 and reproduced, the data of the recorded image is given to the overall control unit 211 via the card interface 212, and, for example, signal processing for matching the number of pixels is performed. . Thereafter, the image is provided from the overall control unit 211 to the display unit 10 via the VRAM 210 as a reproduced image, and reproduced and displayed.

C. Relationship between continuous shooting function, storage of recorded image, and display: FIG. 6 is a flowchart showing a characteristic portion of a control method of a digital camera according to the present invention. The portion relating to the display control at 10 is extracted and shown. These processes are executed under the control of the overall control unit 211. In this operation, a flag Burst that takes a value of “1” or “0” is adopted depending on whether or not shooting is being performed.

First, in step S701, the flag Bur
The value of st is examined. If “1”, it is determined that the image is being captured, and the process proceeds to step S708. If “0”, it is determined that the image is not being captured, and the process proceeds to step S702.

In step S702, it is determined whether the camera is in a shooting standby state or whether the first frame of single or continuous shooting is being shot. If the shutter button 9 is off, it is determined that the camera is in the photographing standby state, and step S703,
Step S704 is executed. If the shutter button 9 is turned on, it is determined that the first frame of single shooting or continuous shooting is being shot, and the flow advances to step S705.

[0043] In the shooting standby state, only the image memory ₂₀₉₁ is used at all times as described above, the imaging unit 3 1/3
The process is performed on the captured image captured every 0 seconds. In other words, although not shown in detail in the flowchart, even if the interval of branching via steps S701 and S702 is 1/30 second or less, steps S703 and S702 are executed.
Step 704 is executed every 1/30 second. This process is a process for performing the live view function (live view process).

In step S703, the image memory 209 ₁
By thinning out the data of
The number of 640 × 480 pixels obtained from the CD 303 is converted into the number of 320 × 240 pixels that can be displayed on the display unit 10. Then, the image signal converted in step S704 is transferred to VRAM 210. Step S704
Returns to the main routine after the
If only the start timing of execution of step 704 is set, the process returns to the main routine without waiting for steps S703 and S704 to be actually executed. In other words, back up time of the main routine from being determined to be shooting standby state in step S702, does not necessarily depend on the 1/30 second is an interval of the data processing in the image memory 209 _1.

In step S702, when it is determined that the first frame of the single or continuous shooting is being shot, the shutter button 9 is pressed and the first shooting is performed. 1 is set, and the parameter k is set to 1. The auxiliary variable k specifies the image memory 209 _k . In the flowchart, an arrow indicates that the content on the right side is set in the variable on the left side.

In step S706, the image memory 209 _k
, A process of recording an image signal of the captured image. As described above, in continuous shooting, both the image signal of the first frame and the image signal of single shooting are stored in the image memory 209 _1.
At step S705, the parameter k
Is set to 1. Thus subjected to the recording process at step S706 is actually an image memory 209 _1.

Thereafter, the flow advances to step S707. At the stage of step S705, there is a possibility that the shutter button 9 will be released afterward and a single shooting will be performed, and further, there is a possibility that the shutter button 9 will be continuously pressed and the second and subsequent frames of continuous shooting will be taken. Thus, the value of the auxiliary variable k is increased by one. Specifically, the value “2” is adopted. Then, the process returns to the main routine.

If it is determined in step S701 that the flag Burst takes the value "1", the process proceeds to step S708.
Then, it is determined whether or not continuous shooting is performed irrespective of single shooting or continuous shooting. That proceeds to step S709 if continued shutter button 9 is pressed, and records a new captured image in the image memory 209 _k. Auxiliary variable k at this time is increased by 1 at step S707 to be executed, the image signal of the k-th frame in response to the continuous shooting is stored in the image memory 209 _k before step S708 is executed .

If it is determined in step S709 that the image memory 2
If 09 of the storage processing on the ₆ has been performed, the image signal already 6 frame of continuously are stored, can not be any more continuous shooting. Therefore, the process advances to step S710 to determine whether or not k = 6. If k = 6, the process advances to step S711 to flag that continuous shooting is not continued.
Set the value “0” to Burst. Also, the value of the auxiliary variable k is set to "1". Then, the process returns to the main routine.

Alternatively, in step S710, the auxiliary variable k is not 6 (k> 6 by the processing in step S711).
Since k ≦ 5, the flow advances to step S707 to increase the value of the auxiliary variable k by 1 and then returns to the main routine so that continuous shooting can be continued.

If the shutter button 9 has not been depressed in step S708, no subsequent photographing is performed, and the process returns to the main routine after receiving the processing in step S711.

As described above, during photographing, step S70
4 is not executed. Therefore, the display state of the display unit 10 during shooting is displayed without being updated before continuous shooting, and the time required for processing such as data conversion for display is reduced.
There is no restriction on shortening the interval between consecutive shots.

As soon as the photographing is completed, step S702 is performed.
Since the shooting standby state is set in steps S703 to S703, the display is a live view. Processing shown in step S703,
That is, the image signal to be processed in the shooting standby state is
Be other than those stored in the image memory ₂₀₉₁ may be. That image signal to be subjected to the live view in the photographing standby state can also be specified in any of the image memory 209 _{2-209 6.} However, many useful as a newly captured image in continuous shooting by using the image memory ₂₀₉₁ corresponding to the oldest image recorded on a live view, the contents of the image memory 209 _{2-209 6,} communication It is desirable that the data can be stored in the memory card 8 after the photographing.

Of course, the upper limit of the number of continuous shootings is not limited to six frames, and the upper limit of the number of continuous shootings can be increased by increasing the number of image memories.
At 10, the value of k will be compared to the number of image memories.

Further, when performing continuous shooting, single shooting and continuous shooting may be switched by a switch, or continuous shooting may be performed by pressing a shutter button dedicated to continuous shooting.

The display on the display unit 10 during continuous shooting may be displayed in a so-called blue background (all blue). Then, the value of the auxiliary variable k may be displayed. This makes it possible to visually recognize the number of frames being shot during continuous shooting. Since the time required for such display control is very short, it does not prevent shortening the interval between continuous shootings.

FIG. 7 shows a part of a flow chart adopted in the above case. In the flow chart of FIG. 6, steps S712 and S707, and steps S708 and S709 are performed in steps S712 and S712, respectively. , S713. In both steps S712 and S713, the display unit 10 displays a blue screen together with the value of the auxiliary variable k.

[0058]

According to the digital camera according to the first aspect of the present invention and the digital camera control method according to the second aspect, the continuous shooting function is prioritized over the live viewfinder function, so that data conversion for display is performed. The time required for such processing does not impose a restriction on shortening the interval between continuous shootings.

According to the control method of the digital camera according to the third aspect of the present invention, the digital camera is controlled by employing the flag indicating whether or not the photographing is being performed. If the live view processing is not performed when the digital camera is present, the digital camera control method according to claim 2 can be realized.

According to the digital camera control method of the present invention, the live view processing is performed using the storage element for storing the oldest photographed image in the continuous shooting, which is useful in the continuous shooting. The new image, which is often present, is not damaged.

According to the control method of the digital camera according to the fifth aspect of the present invention, the time required for displaying the blue screen is very short, so that it is not prevented to shorten the interval between continuous shootings.

According to the control method of the digital camera according to the sixth aspect of the present invention, it is possible to visually recognize which frame is being photographed during continuous shooting.

[Brief description of the drawings]

FIG. 1 is a front view showing a basic structure of a digital camera according to the present invention.

FIG. 2 is a rear view showing a basic structure of the digital camera according to the present invention.

FIG. 3 is a bottom view showing a basic structure of the digital camera according to the present invention.

FIG. 4 is a block diagram illustrating a configuration of a digital camera according to the present invention.

FIG. 5 is a diagram of a memory map of a memory card of the digital camera according to the present invention.

FIG. 6 is a flowchart illustrating a digital camera control method according to the present invention.

FIG. 7 is a flowchart illustrating a digital camera control method according to the present invention.

[Explanation of symbols]

9 shutter button, 303 CCD, 211 overall control unit, 209 _{1 to} 209 ₆ image memory

Claims (6)

[Claims] An imaging device for converting an optical image of a subject into an image signal; a shutter button; a plurality of storage devices for sequentially storing the image signals by pressing the shutter button; and the shutter button being pressed. A display unit that performs live view processing for updating the image signal at a predetermined cycle to display the latest image signal when there is no such button, and does not perform the live view processing when the shutter button is pressed. Digital camera. 2. A digital camera comprising: an image sensor for converting an optical image of a subject into an image signal; a shutter button; a plurality of memory elements for sequentially storing the image signal by pressing the shutter button; and a display unit. In the method of controlling, when the shutter button is not pressed, the display unit performs a live view process of updating the image signal at the predetermined cycle and displaying the latest image signal, The control method of a digital camera, wherein the display unit does not perform the live view process when the shutter button is pressed. 3. The method according to claim 1, wherein the number of the plurality of storage elements is N (N is an integer of 2 or more), and a flag is adopted. (A) When the flag takes a first value, (a-1) On condition that the shutter button is pressed, without performing the live view processing, a flag is set to a second value different from the first value, and the image signal is stored in the first storage element. (A-2) a process of performing the live view processing on condition that the shutter button is not pressed; and (b) when the flag takes the second value, 1) On the condition that the shutter button is pressed, the image signals are sequentially stored in the second to N-th storage elements without performing the live view processing. Provided that it is not pressed And a step of setting the flag to the first value, control method according to claim 2 digital camera according. 4. The digital camera control method according to claim 3, wherein in said live view processing, said image signal is stored in said first storage element while being updated at said predetermined cycle. 5. The display unit displays a blue screen in the steps (a-1) and (b-1).
The control method of the digital camera described in the above. 6. The digital camera according to claim 5, wherein in the steps (a-1) and (b-1), the display unit indicates the order of the image signals sequentially stored in the storage element. Control method.