JP2001209085A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera which does not necessitate a large electric power for rapid operation of a diaphragm in a moving picture photographing mode and with which each image flame can be photographed on appropriate exposure conditions as a still picture even in a usual diaphragm operation. SOLUTION: For maintaining the quality of the still picture, only the image flame photographed at the period overlapping the operation of a diaphragm part is deleted, and subsequent image flames are moved forward. Thereby the image quality is not adversely affected even when a turret type diaphragm which requires a mechanical operation is adopted as a diaphragm part. In the case of taking a photograph in the quality as a moving picture, the photograph is taken by using a preset vertical synchronizing signal for still picture photographing alternately. Thereby, the photographing period and the operating period of the diaphragm part cannot overlap at all, and the diaphragm part can be operated by usual control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital camera capable of photographing a subject as a digital image.

[0002]

2. Description of the Related Art With the advent of digital cameras in the photographic industry with the development of digital technology, CC cameras have been replaced by ordinary cameras that take pictures by exposing them to silver halide films.
The use of digital cameras that capture an image of a subject using a solid-state imaging device such as D and store the captured digital image data in a memory is increasing.

[0003] The original digital camera is a so-called still image (1).
(Image frames) only, but with the increase in memory, a plurality of continuous image frames can be stored, and so-called moving image shooting has become possible.

Here, a general digital video camera mainly shoots a moving image, so that a iris diaphragm mechanism is employed to adjust the exposure amount, and the adjustment is performed slowly and sufficiently for a sufficient time. . In this case, an appropriate exposure amount may not be obtained in a specific one image frame.

In this case, in a digital video camera, 1
This is not a major problem because it is rare to handle image frames, but if a similar mechanism is used as a digital camera, some of the image frames shot as moving images should be handled as still images. Because there are many
An image with an inappropriate exposure amount may be picked up.

In order to solve this problem, the image shooting time (C
It has been proposed to quickly operate the aperture mechanism during a period other than the CD (corresponding to the imaging accumulation time) (for example, see JP-A-9-102905).

[0007] According to this, all image frames are photographed under appropriate exposure conditions, and all image frames can be adopted as still images.

[0008]

However, digital cameras are devices that handle digital image data.
For the purpose of positioning the digital video camera at low cost and easy handling, complicated aperture mechanisms such as an iris aperture mechanism are not common, and are usually turret type, that is, a disc provided with a plurality of openings. Since one of the openings is arranged on the optical path by rotating the plate, the light is blocked by the plate between the openings when there is a switching operation. For this reason, an image frame with lower image quality than the iris diaphragm mechanism is formed.

[0009] In any case of the iris diaphragm mechanism and the turret type diaphragm mechanism, rapid operation requires large power. This is against power saving and miniaturization of digital cameras.

In consideration of the above facts, the present invention does not require a large amount of power for the rapid operation of the aperture mechanism in the moving image shooting mode, and each image frame is a still image even when the aperture mechanism is operating normally. It is an object of the present invention to obtain a digital camera capable of shooting under appropriate exposure conditions.

[0011]

According to the first aspect of the present invention,
A digital camera capable of photographing a subject as a digital image, wherein, when photographing the digital image, either a still image mode in which one image is photographed and stored in a memory, or a moving image mode in which a plurality of images are continuously photographed A photographing mode selecting means for selecting such a photographing mode, an aperture mechanism section disposed on the photographing optical path and changing the aperture in a stepwise manner, and the light amount at the time of photographing the digital image, automatically When the aperture mechanism is operated to change the aperture amount, an aperture amount control unit that executes the operation while avoiding at least the exposure period of each image is provided.

According to the first aspect of the present invention, when the moving image mode is selected by the photographing mode selecting means, the diaphragm amount controlling means avoids at least the photographing time of each image when changing the diaphragm amount. As a result, the aperture amount does not change during shooting of each image of the moving image. For this reason, there is no image having a defect in the exposure amount at the time of shooting, and there is no problem in selecting any image as a still image.

According to a second aspect of the present invention, there is provided a digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory. A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

According to the second aspect of the present invention, the aperture operation is performed during the time only for storing the image in the memory after capturing each image, thereby completely operating the aperture mechanism during the image capturing time. Since this is not performed, a photographing failure due to a change in light amount during switching does not occur.

That is, each time an image is shot one frame,
There is provided a fixed time for storing one frame in the memory, whereas the shooting time varies depending on the situation of the subject. For this reason, when there is a time that is applied only to the memory, by executing the aperture operation during the time only for storing in the memory, the aperture can be changed without affecting the image.

According to a third aspect of the present invention, there is provided a digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory. A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

According to the third aspect of the present invention, the diaphragm operation by the diaphragm amount control means is performed immediately before the start of moving image shooting, for example,
By keeping the shutter button in the state immediately before the operation of the shutter button and prohibiting the aperture operation during shooting, image defects in each image unit constituting a moving image unless there is a large change in the density (brightness and darkness) of the shooting subject Can be eliminated.

That is, when a moving image is photographed, a standby state exists, and from this state, the moving image is actually photographed in response to, for example, operation of a shutter button. For this reason, the normal aperture operation is performed until immediately before the transition from the standby state to the moving image shooting, and during the actual operation shooting time, the immediately previous aperture state is held. Thereby, it is possible to avoid the aperture operation during the operation shooting.

In one movie shooting, since the subject is usually in the same situation, there is not much conversion of the aperture. That is, if the aperture needs to be changed, such as day or night, indoor / outdoor, backlight, etc. Since most of the operations are performed after the standby state, if the aperture in the state immediately before shooting of the moving image is held, the image quality of almost all moving images will not be reduced.

According to a fourth aspect of the present invention, there is provided a digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory. A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

According to a fifth aspect of the present invention, there is provided a digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory. A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

According to the fourth aspect of the present invention, it is necessary to operate the aperture mechanism to change the aperture during the operation photographing. If there is not enough time to store the data, an image overlapping the operation of the aperture mechanism unit is stored in the memory, and then the adjacent image is overwritten.

The image to be overwritten is an image frame taken next, and if the taken image is moved forward by one frame thereafter, a time loss (the same address on the memory) will occur. There is no time loss for rewriting the image, and the photographing can be performed (one frame is reduced as a result).

According to a sixth aspect of the present invention, there is provided a digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory, A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

According to a seventh aspect of the present invention, there is provided a digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory, A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

According to the sixth and seventh aspects of the present invention, conditions for executing the inventions of the first to fifth aspects in a combined manner are shown.

That is, when ts ≧ tm is satisfied when the moving image mode is selected by the photographing mode selecting means, the image stored in the memory overlapping with the aperture switching operation time is deleted from the moving image group. Alternatively, storage in the memory is not performed from the beginning (execution of the inventions of claims 4 and 5). When ts <tm is satisfied, the aperture switching operation is executed during the time tm only for storing in the memory (execution of claims 2 and 3).

The invention according to claim 8 is a digital camera capable of photographing a subject as a digital image, wherein, when photographing the digital image, a still image mode in which one image is photographed and stored in a memory. A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

A ninth aspect of the present invention is characterized in that, in the eighth aspect of the present invention, the thinning is performed at a constant period.

According to the eighth and ninth aspects of the present invention, when photographing an operation, a moving image is photographed by appropriately thinning out the number of images that can be photographed per unit time of photographing.
Thereby, sufficient operation time of the aperture mechanism can be secured. In order to ensure image quality (continuity of moving images, etc.), for example, by setting every other image, uniform image quality can be obtained as a whole.
There is no loss of continuity.

According to a tenth aspect of the present invention, there is provided a digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory, A photographing mode selecting means for selecting any one of a moving image mode of a moving image mode for continuously photographing the image, an aperture mechanism section provided on a photographing optical path and changing an aperture in a stepwise manner, An aperture control means for automatically operating the aperture mechanism in accordance with the amount of light at the time of photographing and changing the aperture in order to avoid at least the exposure period of each image. .

According to the tenth aspect of the present invention, a so-called turret type diaphragm mechanism is assumed, and in a digital camera to which such a diaphragm mechanism requiring a mechanical operation is applied. The effects of the inventions of claims to 9 are more remarkable. In other words, a digital camera that has a function that mainly shoots still images and can optionally perform operation shooting (usually for several seconds to several minutes) has a simple configuration (reducing the number of parts and controlling This is advantageous when simplifying the system and reducing the cost).

[0033]

FIG. 1 shows a digital camera 10 according to an embodiment of the present invention.

As shown in FIGS. 1A and 1B, the main body 12 of the digital camera 10 is substantially box-shaped, and a projection (gripping portion) for facilitating the grip of the main body 12 is provided on the left side when viewed from the front. )
Is formed. A lens 14 is attached to the center of the front side of the main body 12. Above the lens 14 of the main body 12, an optical viewfinder 16 for a user to visually check a photographing range and the like is provided. A strobe 18 for emitting auxiliary light is attached.

On the upper surface of the main body 12, a power switch 20 is provided on the right side when viewed from the front, and a shutter button 22 is provided on the left side (position corresponding to the grip portion). The right side is provided with a slot 24 in which a memory card (not shown) can be inserted.

Further, below the strobe 18, there is an AC adapter connection port 28 connected to obtain power from an AC power supply.
Is provided so that power can be supplied to the digital camera 10 from an AC power supply.

Further, as shown in FIG.
A color display 26 (which may be a monochrome display) made of a transmissive liquid crystal (which may be a transflective liquid crystal) is provided on the back surface of the device. It is provided with a configuration. The display 26 has the function of the finder 16.

On the rear side of the main body 12, on the left side as viewed, a menu (MENU) switch 36, an execution / screen switch (E
X / VIEW CHG) switch 38 and selection (S
An ELECT) switch 42 is provided, and a cancel (CANCEL) is provided above the display 26.
A switch 64 is provided. The selection switch 4
Reference numeral 2 denotes a switch for selecting a mode such as a menu screen displayed by pressing the menu switch 36, and an execution / screen switch 38 is a switch for executing the selected mode or the like. The switch 64 is a switch for canceling various modes and the like.

FIG. 2 shows the configuration of the electric system of the digital camera 10. Specifically, the lens 14 is a zoom lens (variable focal length lens) having an autofocus (AF) mechanism. The AF mechanism and the zoom mechanism of the lens 14 are driven by a drive circuit 44. Instead of the zoom lens, a focal length component lens having only an AF mechanism may be used as the lens 14.

At a position corresponding to the focal position of the lens 14 inside the main body 12, an image pickup device 46 composed of an area CCD sensor or the like is arranged. An image is formed on the light receiving surface of the imaging device 46. The imaging device 46 includes the driving circuit 4
4 and 45 are driven at a timing synchronized with a timing signal generated by a built-in timing generation circuit (not shown), and each of the image signals (each of a large number of photoelectric conversion cells arranged in a matrix on a light receiving surface). ) Is output.

A shutter 48 and a diaphragm 49 are arranged between the lens 14 and the imaging device 46. The shutter 48 and the aperture 49 are driven by drive circuits 44 and 45. The shutter is for preventing the occurrence of smear due to light entering the light receiving surface of the imaging device 46 when an image signal is output from the imaging device 46, and is omitted depending on the configuration of the imaging device 46. It is possible. Further, the aperture may be configured by a single aperture capable of continuously changing the aperture amount, or may be configured to switch a plurality of apertures having different aperture amounts. The strobe 18 is further connected to the drive circuit 44. When the strobe 18 is detected to have low illuminance or when light emission is instructed by the user, light emission is controlled.

An analog signal processing unit 50, an A / D converter 52, a digital signal processing unit 54, and a memory 56 are sequentially connected to a signal output terminal of the imaging device 46. The analog signal processing unit 50 amplifies the image signal output from the imaging device 46 and performs correction such as white balance on the amplified image signal. The image signal output from the analog signal processing unit 50 is converted into digital image data by the A / D converter 52 and input to the digital signal processing unit 54. The digital signal processor 54 performs color correction, γ correction, Y correction on the input image data.
Various processing such as / C conversion is performed. Digital signal processing unit 54
Is temporarily stored in a memory 56 such as a RAM.

The driving circuit 44, the analog signal processing unit 50,
A / D converter 52, digital signal processing unit 54, memory 5
6 and a compression / expansion unit 58 (to be described later) are connected to a bus 60 to which a microcomputer 62 is connected, and a power switch 20, a menu switch 36, an execution / screen switch 38, and the like. Switches 40 and a shutter switch 34 that is turned on / off by operating the shutter button 22 are connected to each other. Although not shown, the microcomputer 6
Reference numeral 2 includes peripheral circuits such as a CPU, a ROM, a RAM, and input / output ports.

The display 26 and the compression / expansion unit 58 are connected to the memory 56, respectively. When displaying an image on the display 26, the microcomputer 62
Is displayed on the display 26 after performing a predetermined process on the image data selected by operating the selection switch 42 from the plurality of image data temporarily stored in the memory 56.
Transfer to Thus, an image represented by the image data temporarily stored in the memory 56 is displayed on the display 26.

When the shutter button 22 is operated and the shutter switch 34 is turned on, the slot 2
4 is instructed to store image data in the memory card loaded in
Is read out and transferred to the compression / decompression unit 58. Thus, the image data is stored in the memory card after being compressed by the compression / decompression unit 58. The image data may be stored in the memory card without being compressed depending on the shooting mode or the like.

Reproduction (display) of an image represented by image data stored in a memory card loaded in a slot.
Is instructed, the image data is read from the memory card, and the read image data is
And then temporarily stored in the memory 56.
Then, display (reproduction) of the image on the display 26 is performed using the image data temporarily stored in the memory 56.

The microcomputer 62 further includes functions such as a clock and a calendar, brightness adjustment of the display 26,
Control such as color temperature control using the calendar is performed. The information stored in the memory 56, the date and time stored in the microcomputer 62, and the control performed by the microcomputer 62 are controlled by a main battery or backup The information is stored using a battery as a power source.

It should be noted that the digital camera 10 can shoot a moving image in addition to a still image. The shooting of a moving image is selected by operating the selection switch 42. Basically, when shooting a moving image, shooting of a still image is continuously performed. However, a limited frame memory is prepared in advance, and shooting of a moving image for a time corresponding to the capacity of the frame memory can be performed. It is possible. Normal moving image shooting time ranges from several seconds to several minutes.

Here, as shown in FIG. 3, the diaphragm 49 in the present embodiment is constituted by a so-called turret type diaphragm mechanism 104.

The diaphragm mechanism 104 is provided with a fan-shaped plate 10.
0 and a motor 102 having a rotating shaft 102A mounted near the sharp portion 100A of the fan-shaped plate 100 and rotating forward and backward. The driving circuit 45 controls the rotation and rotation direction of the motor 102. Is controlled.

The plate 100 is provided with two openings 106 and 108 having different opening areas in the vicinity of the arc portion 100B, and these two openings 106 and 108 are selectively arranged on the optical axis L. Thus, the aperture is changed. In this embodiment, the aperture values F are F2.8 and F8.

In the case of photographing a still image, by pressing the shutter 48 halfway, the amount of light incident on the image pickup device is measured, and by controlling the driving of the motor 102, an appropriate aperture (apertures 106, 108) can be obtained. ) Is selected. afterwards,
By pressing the shutter 48 fully, a still image is taken.

On the other hand, in the case of shooting a moving image, a half-pressed state does not exist because continuous frames need to be shot. For this reason, in the present embodiment, the operation of the aperture mechanism is appropriately controlled under the following conditions.

That is, according to various photographing conditions, a photographed frame is deleted (overwritten) (overwrite control), or a photographable image frame is thinned out in advance to secure the operation time of the aperture mechanism (thinning control). The aperture operation is avoided during actual shooting (exposure) of a moving image. (Overwrite control) Normally, as shown in FIG. 4, one image frame (No. 0 in FIG.
-No. 5) is described, and the respective exposure times differ depending on the conditions of the photographing subject. Further, the photographed image is stored in the memory 56 with a shift of one vertical synchronization. The storage time in the memory 56 is one vertical synchronizing signal pitch, and the exposed images are sequentially stored in the memory 56. By the way, during the storage time, the shooting of the next image frame is performed. Therefore, the storage time includes a time for storing only and a time for storing and shooting in parallel. Therefore, the time tm for storing only, that is, the non-exposure time tm changes depending on the shooting time of the next image frame.

On the other hand, the aperture operation is performed in synchronization with the vertical synchronizing signal. When it is determined that the aperture must be switched when capturing the second image, N
o. The plate 100 starts moving after the photographing of one image is completed, and the openings 106 and 108 are switched. This switching operation time ts is about 10 msec in the present embodiment.

First, under the above-mentioned photographing conditions, if the time required for switching the aperture mechanism 104 is ts and the time only for storage in the memory 56 is tm, if ts <tm, this memory 56 The aperture switching operation is performed during the time tm when only the data is stored.

This corresponds to the image frame No. in FIG.
1 corresponds to the storage time in the memory 56. That is, the image frame No. 1 during the storage time of the next image frame No. 1 in the memory 56. Since the photographing (exposure) time of No. 2 is short, it does not overlap with the operation time ts of the aperture mechanism unit 104. For this reason, since the aperture operation does not affect the photographed image, there is no problem of continuing photographing as it is.

On the other hand, under photographing conditions as shown in FIG.
If the time required for switching the aperture mechanism 104 is ts and the time only for storage (non-exposure time) is tm, ts ≧
When tm is satisfied, the aperture operation is performed while the image frame stored in the memory overlaps with the aperture switching operation time (in FIG. 4, the aperture operation is performed while the image frame No. 3 is being stored. Delete the image frame No. 4) from the moving image frame group (store it temporarily in the memory 56, but overwrite the next image frame as No. 4) or store it in the memory from the beginning Absent.

This will be described with reference to the address of the memory 56 as shown in FIG. 5. After the fourth frame (image frame No. 4) is stored at a predetermined address, the fifth frame (image frame No. 4) is stored. The image data to be stored as 5) is overwritten on the fourth frame. Hereinafter, by moving up each frame and storing it, only the frame that overlaps with the aperture operation is skipped and stored in the memory 56. For a moving image, even if one image frame is deleted, the actual image quality is not significantly affected, and the quality can be maintained as a continuous image.

The operation of storing the image frame in the memory 56 that overlaps with the above-described aperture operation need not be actually performed. (Thinning-out control) As shown in FIG.
This is a method in which shooting is performed every vertical synchronization signal. In an area where shooting is performed (vertical synchronization signal period width), the operation of the aperture mechanism unit 104 is not performed at all, and the shooting is performed in an area where shooting is not performed. As a result, the operation of the aperture mechanism 104 and the photographing (exposure) do not overlap at all, and the image quality is not adversely affected. In this decimation control method, there is a concern that the number of frames to be shot is reduced by half, but since the vertical synchronization signal period itself is set based on still image shooting,
It is over-quality for video shooting and does not actually cause slow motion frame advance, so there is no effect on quality. (Aperture Fixed Control) This aperture fixed control is a so-called standby state before the operation of the shutter 22 when the selection switch 42 is operated and the moving image mode is set. In this standby state, there is no problem even if the aperture mechanism 104 is operated normally.

Here, when the shutter 22 is operated, the operation shifts to actual shooting. In this case, while the shutter 22 is being operated, that is, during shooting, by maintaining the aperture state immediately before the shutter operation, it is possible to prohibit the change of the aperture during shooting, and to avoid a decrease in image quality due to the aperture operation.

The operation of this embodiment will be described below.

In the control method of the aperture operation, the thinning control and the fixed aperture control do not overlap the photographing time (exposure time) at all even if the conventional aperture operation is performed without any change.

On the other hand, in the overwriting control, the memory 5
A new control is required for storing data in the memory 6 and the like. Hereinafter, the overwrite control will be described in detail with reference to the flowchart of FIG.

In step 200, it is determined whether or not the mode is the moving image shooting mode. If the determination is negative, this routine is passed. If an affirmative determination is made in step 200, it is determined that the current mode is the moving image shooting mode, and the flow shifts to step 202 where the image frame No. Is cleared (0), and the routine proceeds to step 204.

In step 204, it is determined whether or not shooting has been started (shutter operation). If an affirmative determination is made, it is determined in step 206 whether n = 0. That is, it is determined whether or not the first image frame has been photographed. If the determination is affirmative, the storage control (described later) in the memory 56 is passed. If a negative determination is made in step 206, it is determined that image data that has been photographed (exposed) already exists,
Proceeding to step 208, the memory 5 of the (n-1) th frame
6. The storage control to 6 starts. The storage control in step 208 will be described later.

In the next step 210, the photographing time (exposure time) of one image frame is determined. In step 212, photographing (exposure) is performed based on the vertical synchronizing signal (see FIG. 4).
It is determined whether it is time to start. Here, if an affirmative determination is made, the process proceeds to step 214 to start photographing (exposure). This photographing (exposure) is performed continuously while the shutter 48 is operated.

In the next step 216, it is determined whether the storage of the image data of the (n-1) th image frame in the memory 56 has been completed and whether the photographing (exposure) of the nth image frame has been completed. Then, the process proceeds to step 218, where it is determined whether or not an aperture operation has been performed during shooting.
If it is determined that the aperture operation has been performed, step 22 is executed.
If 0, the flag F is set (1). If it is determined that there is no aperture operation, the flag F is reset (0) in step 222, and the process proceeds to step 224.

In step 224, it is determined whether or not the photographing (exposure) has been completed. If the determination is affirmative, the process proceeds to step 226 to write the final image frame into the memory 56, and then ends this routine. If a negative determination is made in step 224,
The process proceeds to step 228, and it is determined whether or not the moving image photographable time has come (time up). In the case of time-up, since it is impossible to take any more images, the process forcibly proceeds to step 226. If a negative determination is made in step 228, the variable Nn is incremented in step 230, and the process returns to step 200 to repeat the above steps.

Next, according to the flowchart of FIG.
The storage control subroutine for storing the (n-1) th image frame in step 208 and the final image frame image frame in step 226 in the memory 56 will be described.

In step 250, the address on the memory 56 is determined, and then in step 252, the image frame No. stored in the memory 56 last time. It is determined whether the flag F corresponding to (n-2) is set (1) or not. It is determined that the diaphragm operation has been performed during the photographing of the (n-2) -th image frame, and the process proceeds to step 254. The address is changed to the previous address which is the address corresponding to n-2, the process proceeds to step 256, and the address changed in step 254 is changed to No. n-1
Write the image frame of.

If the determination in step 252 is negative, It is determined that the diaphragm operation has not been performed during the photographing of the (n-2) -th image frame.
o. Write n-1 image frames.

As described above, in the present embodiment, in order to maintain the quality of a still image, only the image frames shot at the same time as the operation of the aperture mechanism unit 104 are deleted, and the subsequent image frames are deleted. Even if the turret type aperture mechanism 104 requiring mechanical operation is adopted as the aperture, the image quality is not adversely affected.
In addition, in the case of shooting with the quality as a moving image, if the shooting is performed using every other vertical synchronization signal for shooting a still image, the shooting timing and the aperture mechanism 104
The operation timing does not overlap at all, and the aperture mechanism 104 can be operated by normal control.

When the overwrite control and the thinning-out control are mounted on an actual digital camera, they may be used together with a single digital camera 10, or one of them may be selected depending on the type of digital camera. It may be.

[0075]

As described above, the digital camera according to the present invention does not require a large amount of electric power for the rapid operation of the aperture mechanism in the moving image shooting mode, and can operate each image even when the ordinary aperture mechanism operates. This has an excellent effect that a frame can be photographed as a still image under appropriate exposure conditions.

[Brief description of the drawings]

FIG. 1 is a digital camera according to an embodiment,
(A) is a perspective view seen from the front, (B) is a perspective view seen from the back.

FIG. 2 is a control block diagram of the digital camera according to the present embodiment.

FIG. 3 is a perspective view schematically showing a diaphragm mechanism.

FIG. 4 is a timing chart of shooting and storage in overwriting control.

FIG. 5 is a schematic diagram showing addresses on a memory in overwriting control.

FIG. 6 is a timing chart of shooting and storage in thinning control.

FIG. 7 is a flowchart of a shooting and storage control routine in overwrite control.

FIG. 8 is a flowchart showing a subroutine for storing in a memory.

[Explanation of symbols]

 Reference Signs List 10 digital camera 42 selection switch 45 drive circuit 49 aperture 62 microcomputer 100 plate 102 motor 104 drive mechanism 106, 108 opening

Claims (10)

[Claims] 1. A digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory, or a plurality of images are continuously photographed A photographing mode selecting means for selecting any one of the photographing modes of the moving image mode, a diaphragm mechanism section disposed on the photographing optical path and changing the diaphragm in a stepwise manner, and a light amount at the time of photographing the digital image. And a diaphragm amount control unit that automatically operates the diaphragm mechanism to change the diaphragm amount while avoiding at least the exposure period of each image. 2. The digital camera according to claim 1, wherein an aperture operation by said aperture amount control means is performed during a period of recording each image in a memory. 3. The digital camera according to claim 1, wherein the aperture operation by the aperture amount control means is maintained in a state immediately before the start of moving image shooting, and is operated during a period other than the moving image shooting period. 4. When the avoidance by the aperture control means is impossible, the image is replaced with a corresponding image stored in a memory.
2. The method according to claim 1, wherein an adjacent image is overwritten.
The digital camera according to claim 3. 5. The digital camera according to claim 4, wherein the image to be overwritten is an image captured next. 6. A digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, one image is photographed and stored in a memory, or a plurality of images are continuously photographed. A photographing mode selecting means for selecting any one of the photographing modes of the moving image mode to be switched; and a diaphragm mechanism disposed on the photographing optical path, the diaphragm is changed stepwise, and the time required for this switching is set to ts. An aperture control means for automatically operating the aperture mechanism and changing the aperture in accordance with the amount of light at the time of capturing the digital image, wherein a video mode is selected by the capture mode selection means. When the time required for switching the aperture mechanism section ts ≧ the period tm other than the exposure (ts ≧ tm), the image frames stored in the memory overlap with the aperture switching operation timing. Wherein the digital camera is deleted from the moving image frame group or is not stored in the memory from the beginning. 7. A digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory, or a plurality of images are continuously photographed. A photographing mode selecting means for selecting any one of the photographing modes of the moving image mode to be switched; and a diaphragm mechanism disposed on the photographing optical path, the diaphragm is changed stepwise, and the time required for this switching is set to ts. An aperture control means for automatically operating the aperture mechanism and changing the aperture in accordance with the amount of light at the time of capturing the digital image, wherein a video mode is selected by the capture mode selection means. In this case, when the time required for switching the aperture mechanism section ts <the period tm other than the exposure is satisfied (ts <tm), the aperture switching operation is performed during the storage time tm in the memory. Digital camera according to claim. 8. A digital camera capable of photographing a subject as a digital image, wherein when photographing the digital image, a still image mode in which one image is photographed and stored in a memory, or a plurality of images are continuously photographed. A photographing mode selecting means for selecting any one of the photographing modes of the moving image mode, a diaphragm mechanism disposed on a photographing optical path, and a diaphragm being changed in a stepwise manner; An aperture control unit for automatically operating the aperture mechanism to change the aperture, and an image that can be captured per unit time when the video mode is selected by the capture mode selection unit. For numbers,
While taking a moving image by appropriately thinning out, executing the aperture switching operation during the time obtained by thinning out,
A digital camera. 9. The digital camera according to claim 8, wherein the thinning is performed at a fixed period (for example, every other image). 10. The diaphragm mechanism section selects one of the openings on an optical path by mechanically operating the plate on which a plurality of openings having different opening areas are discretely formed in advance. The digital camera according to any one of claims 1 to 9, further comprising: a driving unit that is arranged in a fixed manner.