JP2003121731A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a digital camera capable of accurately performing photographing intended by a photographer concerning focusing as a digital camera capable of setting a focusing position to an optional spot. SOLUTION: When the position of an AF cursor CR is designated on the screen of an LCD 10 by the photographer, an AF area AR1 is set with center at a position CR1 corresponding to the position of the cursor CR on a photographic image. Simultaneously, eight positions CR2 to CR9 are regulated near the periphery of the position CR1, and AF areas AR2 to AR9 with center at the respective positions CR2 to CR9 are respectively set. When a shutter button 8 is half-depressed (S1), the focusing positions concerning the respective AF areas ARj (j=1 to 9) are successively detected and data on the respective focusing positions is preserved. Thereafter, when the shutter button 8 is fully depressed (S2), photographing (recording processing) is successively performed by nine times in all based on the data on the preserved focusing position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera having a function of setting a focus position on a subject at a position other than the center of the screen.

[0002]

2. Description of the Related Art In recent years, due to the demand for image quality of photographed images, the number of pixels of image pickup elements of digital cameras has increased
On a display screen such as a viewfinder, there is a limitation due to the camera size, etc., and it cannot be expected that the number of pixels is as high as that of the image sensor.

To give an example, horizontal 1600 × vertical 1200
The number of display pixels is 400 ×
There is a digital camera whose height is suppressed to 300. In this digital camera, the number of display pixels with respect to the number of image pickup pixels becomes 1/4 in the horizontal and vertical directions.

By the way, in Japanese Patent Laid-Open No. 3-187580 and Japanese Patent Laid-Open No. 11-196301, a photographer moves a focus frame by a key operation so that a position to be focused on an object other than the center of the screen is set. A conventional digital camera that can be designated at a location is disclosed.

[0005]

However, in the conventional digital camera disclosed in the above publication, the focus frame is simply moved to specify the in-focus position, and the result as intended by the photographer cannot be obtained. I'm afraid.

That is, when the focus position is designated, even if the movement accuracy of the focus frame is maximized, the movement of the display screen in pixel units is limited. When the number of pixels is 1/4 in the horizontal and vertical directions, the uncertainty of the position designation of 4 × 4 pixels remains in the captured image. That is, the conventional digital camera disclosed in the above publication has a problem that a situation in which actual focusing is not performed at the focusing position designated by the photographer is likely to occur.

The present invention has been made to solve such a problem, and in a digital camera having a function of setting a focus position on a subject to a position other than the center of the screen, the photographer's intention regarding the focus is set. The purpose of the present invention is to obtain a digital camera capable of performing accurate street photography.

[0008]

[Means for Solving the Problems] Claim 1 of the present invention
The digital camera described in (1) above has a display unit having a screen for displaying an image of a subject, a designation unit for designating a focus designated position on the subject within the screen based on an operation input, and the focusing unit within the screen. Setting means for setting a first focus area corresponding to the focus designated position and setting a plurality of second focus areas in the vicinity of the first focus area; A detection unit that detects each in-focus position in each of the first and second in-focus areas based on each image data in the two in-focus areas. It is characterized in that the lens is sequentially driven to each of the in-focus positions so that photographing is performed at each position.

The digital camera according to a second aspect of the present invention is the digital camera according to the first aspect, wherein the number of the second focus areas is changeable. It is a thing.

The digital camera according to a third aspect of the present invention is the digital camera according to the second aspect, wherein the setting means determines the number of the second focus areas according to a photographing condition. It is characterized by changing it.

A fourth aspect of the present invention is the digital camera according to the first aspect, wherein the position of the second focusing area with respect to the position of the first focusing area. Is changeable.

According to a fifth aspect of the present invention, in the digital camera according to the fifth aspect, a display means having a screen for displaying an image of a subject, and based on an operation input, within the screen,
The designation means for designating a designated focus position on the subject and the first lens position for focusing at a location on the subject corresponding to the designated focus position are defined as the first lens position. A plurality of different second lens positions are set, and the lenses are sequentially driven to the first and second lens positions, and shooting is performed at each position.

According to a sixth aspect of the present invention, the digital camera according to the fifth aspect is characterized in that the number of the second lens positions can be changed. Is.

The digital camera according to a seventh aspect of the present invention is the digital camera according to the sixth aspect, wherein the setting means determines the number of the second lens positions according to photographing conditions. It is characterized by changing.

According to a eighth aspect of the present invention, the digital camera according to the eighth aspect has a display unit having a screen for displaying an image of a subject, and based on an operation input, within the screen,
Designating means for designating a designated focus position on the subject, evaluation value acquisition means for obtaining a focusing evaluation value at at least three lens positions while driving the lens, and on the subject corresponding to the designated focus position. A first lens position for focusing at a position is determined based on each focus evaluation value at the at least three lens positions, and a plurality of second lens positions different from the first lens position are determined.
Lens position determining means for determining the lens position of
With respect to the positions of the first and the plurality of second lenses, the lenses are sequentially driven in a predetermined order so that imaging is performed at each position.

The digital camera according to a ninth aspect of the present invention is the digital camera according to the eighth aspect, wherein the first camera corresponds to a position of the designated focus position in the screen. The focus area is set and the first
Focusing area setting means for setting a plurality of second focusing areas in the vicinity of the focusing area, and the evaluation value acquiring means includes a first focusing evaluation corresponding to the first focusing area. A value and a plurality of second focus evaluation values corresponding to each of the plurality of second focus areas are collectively obtained for each lens position for each of the at least three lens positions. The lens position determining means determines the first lens position based on the first focus position at each of the at least three lens positions, and the plurality of second focus positions at the at least three lens positions. It is characterized in that a plurality of second lens positions for focusing at a location of the subject corresponding to the plurality of second focus areas are respectively determined based on the focus evaluation value.

According to a tenth aspect of the present invention, the digital camera according to the eighth aspect is the digital camera according to the eighth aspect, wherein the lens is driven to the first and the plurality of second lens positions. The lenses are driven in the order in which the total driving distance of the lenses is the shortest.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Main Configuration of Digital Camera> FIGS. 1 to 4 are a front view, a rear view, a side view and a bottom view showing an external structure of a digital camera 1 according to an embodiment of the present invention. Yes, FIG. 5 is a block diagram showing the internal configuration of the digital camera 1.

The digital camera 1, as shown in FIG.
It is composed of a box-shaped camera body 2 and a rectangular parallelepiped image pickup unit 3 (shown by thick lines in FIGS. 1, 2 and 4). The image pickup unit 3 has a zoom lens 301 with a macro function, which is a photographing lens, and, like a lens shutter camera using a silver salt film (hereinafter, referred to as “silver salt camera”), reflects light of flash light from a subject. It has a light control sensor 305 for receiving light and an optical finder 31. This zoom lens 301 has a focal length of 35 mm to 70 m when converted to a silver halide camera using a 35 mm film.
It is possible to zoom up to m.

The image pickup unit 3 includes a zoom lens 301.
A CCD 303 (see FIG. 5), which is a CCD color area sensor that functions as an image pickup unit, is built in at the rear position of the CCD, and the CCD 303 is a part of the image pickup circuit 302. The CCD 303 has a number of pixels of 1600 horizontal × 1200 vertical.

As shown in FIG. 1, on the front surface of the camera body 2, a grip portion 4 is provided at the left end, a built-in flash 5 is provided at the upper center, and a shutter button 8 is provided at the upper surface. There is.

On the other hand, as shown in FIG.
An LCD 10 for displaying a captured image on a monitor (corresponding to a viewfinder), reproducing and displaying a recorded image, and the like is provided in a substantially central portion on the back surface of the. This LCD 10 is
It has a display screen in which the number of pixels is 400 horizontal × 300 vertical.
Below the LCD 10, key switch groups 221 to 226 for operating the digital camera 1 and a power switch 227 are provided. The key switch 224 functions as an enlarged display button. The key switch 225 is used for the AF cursor C for designating the in-focus position on the subject.
It functions as an AF cursor button for displaying R (focus designation display) on the LCD 10. The key switch 226 is
Functions as a menu button. On the left side of the power switch 227, an LED 228 that lights up when the power is on
And LED22 that lights up when accessing the memory card
9 and 9 are arranged.

Further, on the rear surface of the camera body 2, a mode setting switch 14 for switching the mode among "shooting mode", "playback mode" and "preference mode".
Are provided (see FIG. 3). The shooting mode is for taking pictures, and the playback mode is for the memory card 91.
This is a mode for reproducing and displaying the photographed image recorded on the LCD 10. Also, the preference mode is LCD
In this mode, various settings are made by selecting from the display items (setting items) displayed in 10. In the preference mode, it is possible to set focus bracket shooting described later.

The mode setting switch 14 is a three-contact slide switch. When it is set to the lower side in FIG. 2, it is set to the photographing mode, when it is set to the center, it is set to the reproduction mode, and when it is set to the upper side, it is set to the preference mode. It

A quad switch 230 is provided on the right side of the rear surface of the camera. Button 2 in shooting mode
Pressing 31 or 232 changes the focal length of the zoom lens 301, zooming for changing the zoom magnification can be performed, and exposure correction can be manually performed by pressing the buttons 233 or 234. Further, in the shooting standby state of the shooting mode (a live view display of a moving image is displayed on the LCD 10, which is also referred to as a “preview state”), by operating the quad switch 230, the AF operation is performed.
The cursor CR can be moved vertically and horizontally.

On the back surface of the image pickup section 3, as shown in FIG.
LCD button 32 for turning on / off the LCD 10.
1 and a macro button 322 are provided. LCD
When the button 321 is pressed, the LCD display is switched on / off. For example, when shooting only using the optical viewfinder 31, the LCD display is turned off for the purpose of power saving. When the macro button 322 is pressed during macro shooting, the AF motor 308 (see FIG. 5) is driven and the zoom lens 301 is ready for macro shooting.

A DC input terminal 235 is provided on the side surface of the camera body 2 as shown in FIG.

As shown in FIG. 4, a battery loading chamber 18 and one card loading chamber 17 (card slot portion) are provided on the bottom surface of the camera body 2. Card loading room 1
A memory card 91 or the like can be loaded in the card 7. The card filling chamber 17 can be opened and closed by a clamshell type lid 15. The lid 15 has an opening 15a.

The digital camera 1 uses a power supply battery 236 (see FIG. 5) formed by loading four AA dry batteries in the battery loading chamber 18 and connecting them in series. Of course, it is also possible to supply and use the power from the adapter from the DC input terminal 235 shown in FIG.

Next, the internal structure of the image pickup section 3 will be described in order with reference to FIG.

The image pickup circuit 302 uses the zoom lens 301 to form an optical image of the object formed on the CCD 303 by the CCD.
Photoelectric conversion using 303, R (red), G (green), B
It is output as an image signal of a (blue) color component (a signal consisting of a signal sequence of pixel signals received by each pixel).

In the digital camera 1, the aperture value can be set in several steps by the key operation of the photographer. The exposure control in the image pickup unit 3 is performed by adjusting the exposure amount of the CCD 303 (charge accumulation time of the CCD 303 corresponding to the shutter speed). If the proper shutter speed cannot be set when the subject brightness is low, C
Improper exposure due to insufficient exposure is corrected by adjusting the level of the image signal output from the CD 303. That is, at low brightness, exposure control is performed by combining shutter speed and gain adjustment. The level adjustment of the image signal is performed by the AGC in the signal processing circuit 313 described later.
(Auto gain control) circuit. The photometry in this automatic exposure (AE) will be described in detail later.

The timing generator 314 generates a drive control signal for the CCD 303 based on the clock transmitted from the timing control circuit 202 in the camera body 2. The timing generator 314 generates, for example, a clock signal such as a timing signal of integration start / end (that is, exposure start / end) and a read control signal (horizontal synchronization signal, vertical synchronization signal, transfer signal, etc.) of a light reception signal of each pixel. And outputs it to the CCD 303.

The signal processing circuit 313 subjects the image signal (analog signal) output from the image pickup circuit 302 to predetermined analog signal processing. The signal processing circuit 313 is
Although not shown, it has a CDS (correlated double sampling) circuit and an AGC circuit therein, the noise of the image signal is reduced by the CDS circuit, and the level of the image signal is adjusted by adjusting the gain of the AGC circuit. Make adjustments.

The dimming circuit 304 controls the light emission amount of the built-in flash 5 during flash photography to a predetermined light emission amount set by the overall control unit 211 of the camera body 2. In flash photography, the reflected light of the flash light from the subject is started at the same time as the exposure is started.
When the received light amount reaches a predetermined light emission amount, the light control circuit 304 outputs a light emission stop signal to the flash control circuit 214 of the camera body 2 via the overall control unit 211. The flash control circuit 214 forcibly stops the light emission of the built-in flash 5 in response to the light emission stop signal, whereby the light emission amount of the built-in flash 5 is controlled to a predetermined light emission amount.

Further, inside the image pickup section 3, there is a zoom motor 307 for changing the zoom ratio of the zoom lens 301 and for moving the lens between the accommodation position and the photographing position, and an AF (for focusing). Autofocus) motors 308 are provided respectively. The AF control will be described later in detail.

Next, the internal structure of the camera body 2 will be described.

The overall control unit 211 mainly comprises a CPU,
The shooting operation of the digital camera 1 is comprehensively controlled by controlling the driving of each peripheral configuration in the image pickup unit 3 and the camera body unit 2 which are connected by an address bus, a data bus, and a control bus.

Note that the flow of image data in FIG. 5 (and FIG. 6 described later) is also indicated by arrows between peripheral components for the sake of convenience.
11 for each peripheral configuration. The overall control unit 211 includes a work RAM 211 including a DRAM.
a and a flash ROM for storing the program
211b is built in.

Next, a configuration relating to image signal processing and image display inside the camera body 2 will be described.

The analog image signal output from the signal processing circuit 313 of the image pickup section 3 is input to the image processing section 200 in the camera body section 2 and various image processing is performed in the image processing section 200. FIG. 6 is a block diagram showing the configuration of the image processing unit 200. First, the analog image signal sent to the image processing unit 200 is converted into a 10-bit digital signal for each pixel in the A / D converter 205. The A / D converter 205 is a timing control circuit 202.
Each pixel signal (analog signal) is converted into a 10-bit digital signal on the basis of the A / D conversion clock input from.

The timing control circuit 202 generates a reference clock and a clock for the timing generator 314 and the A / D converter 205 under the control of the overall control unit 211.

The black level correction circuit 206 corrects the black level of the A / D converted pixel signal (hereinafter referred to as "pixel data") to a reference black level. Also, W
The B circuit 207 converts the level of pixel data of each of the R, G, and B color components, and performs automatic white balance adjustment (AWB) in consideration of γ correction in the subsequent process. The white balance is adjusted from the overall control unit 211 to the WB circuit 2.
This is performed using the level conversion table (correctly, its data) input to 07, and the conversion coefficient (characteristic inclination) of each color component of the level conversion table is set for each captured image by the overall control unit 211.

The γ correction circuit 208 corrects the γ characteristic of pixel data. The output from the γ correction circuit 208 is sent to the image memory 209 as shown in FIG.

The image memory 209 is a memory for storing pixel data output from the image processing section 200, and has a storage capacity of at least one frame of an image. That is, when the CCD 303 has pixels arranged in a 1600 × 1200 matrix, the image memory 20
Reference numeral 9 has a storage capacity of pixel data of 1600 × 1200 pixels, and each pixel data is stored in a corresponding storage area (address).

The VRAM 210 is an LCD for the playback mode.
10 is a buffer memory for image data displayed on the screen 10.
The VRAM 210 has a storage capacity of image data corresponding to 400 × 300 pixels of the LCD 10, that is, a capacity of 400 × 300 pixels.

With such a configuration, in the image pickup standby state in the image pickup mode, each pixel data of the image picked up by the image pickup section 3 at predetermined intervals is processed by the image processing section 200 and stored in the image memory 209. And transferred to the VRAM 210 via the overall control unit 211,
It is displayed on the LCD 10. As a result, live view display can be performed in which the image of the subject before shooting is displayed on the LCD 10 as a moving image.

That is, in the live view display, as shown in FIG. 7, the image data of 1600 × 1200 pixels is 1 / horizontal 1 /
VRAM 210 of 400 × 300 pixels thinned out to 4
Will be transferred to.

Further, when the enlargement display button 224 is pressed here, image data of 400 × 300 pixels in the image memory 209 is cut out and transferred to the VRAM 210 to be enlarged and displayed 4 times vertically and horizontally. To be done. In this way, by pressing the enlargement display button 224, the photographer can easily switch the photographed image acquired by the CCD 303 and the enlarged image on the LCD 10.

In the reproduction mode, the image read from the memory card 91 is subjected to predetermined signal processing by the overall control unit 211, then transferred to the VRAM 210 and reproduced and displayed on the LCD 10. Note that when displaying an image on the LCD 10, the backlight 16 is turned on under the control of the overall control unit 211.

Next, the other components in the camera body 2 will be described in order.

The card I / F 212 is provided in the card filling chamber 17
This is an interface for exchanging signals with the memory card 91 loaded in the. Specifically, writing of image data to the memory card 91 and reading of image data from the memory card 91 are performed.

The flash control circuit 214 is a circuit for controlling the light emission of the built-in flash 5 as described above. The flash control circuit 214 controls the presence / absence of light emission, the amount of light emission, the light emission timing, etc. of the built-in flash 5 based on the control signal of the overall control unit 211, and based on the light emission stop signal input from the dimming circuit 304, the flash control circuit 214 Control the amount of light emission.

The clock circuit 219 is a clock circuit for managing the shooting date and time. It is driven by another power source (not shown).

Further, in the camera body 2, a zoom motor drive circuit 215 for driving the zoom motor 307 is provided.
And an AF motor drive circuit 216 for driving the AF motor 308. These circuits function according to the operation of the shutter button 8 and other various switches and buttons described above and the operation unit 250.

For example, the shutter button 8 is a two-step switch that can detect a half-pressed state (S1) and a pressed-in state (S2) as used in a silver halide camera. When the button 8 is pressed halfway down, the AF motor drive circuit 216 drives the AF motor 308 to move the zoom lens 301 to the in-focus position.

When the buttons 231 and 232 are pressed, signals from these buttons are sent to the overall control section 211, and the zoom motor drive circuit 215 drives the zoom motor 307 to zoom by the instruction of the overall control section 211. Optical zooming is performed by moving the lens.

Although the respective components in the camera body 2 have been described above, the overall controller 211 performs various functions by software in addition to data transfer with the peripheral components and timing control.

For example, the overall control unit 211 has a filtering processing function, a recorded image generating function, and a reproduced image generating function in order to perform the recording processing of the photographed image.

The filtering processing function is to correct the high frequency component of the image to be recorded by the digital filter to correct the image quality relating to the contour.

The recorded image generation function reads pixel data from the image memory 209 and generates thumbnail images and compressed images to be recorded in the memory card 91. Specifically, while scanning in the raster scanning direction from the image memory 209, pixel data is read every 8 pixels in both the horizontal and vertical directions and sequentially transferred to the memory card 91 to generate thumbnail images. Memory card 91
To record. Further, when recording the compressed image data in the memory card 91, all pixel data are read from the image memory 209, and these pixel data are subjected to a predetermined compression process by the JPEG method such as two-dimensional DCT conversion and Huffman coding, and the memory card. Record at 91.

As a specific operation, in the shooting mode, when shooting is instructed by the shutter button 8, the image is compressed by the JPEG method according to the thumbnail image of the image captured in the image memory 209 after the shooting instruction and the set compression rate. The compressed compressed image is generated and tag information related to the captured image (frame number, exposure value, shutter speed, compression rate, shooting date, flash on / off data at the time of shooting, scene information, image determination results, etc. Information) and both images are stored in the memory card 91.

The reproduced image generation function is a function of decompressing the compressed image recorded in the memory card to generate a reproduced image. As a specific operation, when the mode setting switch 14 is set to the reproduction mode, the image data with the largest frame number in the memory card is read, the data is expanded, and the data is transferred to the VRAM 210. This allows
The LCD 10 displays the image with the largest frame number, that is, the image captured most recently.

<About AF> In the digital camera 1,
The AF cursor CR for designating the in-focus position on the subject will be displayed on the screen of the LCD 10.
This will be explained below.

FIG. 8 is a partial block diagram of the digital camera 1.

The overall control unit 211 has a cursor generation unit 21.
1f, a cursor display position control unit 211g, a resolution conversion unit 211h, an image synthesis unit 211i, a focus area setting unit 211j, and an evaluation value calculation unit 211k.

The cursor generation unit 211f reads the cursor data for displaying the AF cursor CR on the screen of the LCD 10 from the flash ROM 211b and transfers it to the cursor display position control unit 211g. The AF cursor CR has a cross shape, and its size is
It has a size of 16 × 16 pixels on the screen of the LCD 10.

The cursor display position control unit 211g changes the position of the AF cursor CR displayed on the screen of the LCD 10 based on the operation input to the operation unit 250 (quad switch 230) by the photographer. AF cursor C
The R is discretely moved on the screen of the LCD 10 with a movement width of 25 pixels in the horizontal direction and 20 pixels in the vertical direction. In the image captured by the CCD 10 (hereinafter referred to as “captured image”), as shown in FIG.
4 times the moving width of D10 on the screen, that is, 100 in the horizontal direction.
Pixels (16 steps), 80 pixels vertically (1
The AF cursor CR is discretely moved within a movement width of 5 steps).

As described above, the resolution conversion section 211h sends an image obtained by thinning out a captured image to 1/4 in the normal display state to the image synthesizing section 211i, but does not thin out in the enlarged display state. Then, part of the captured image is directly transferred to the image synthesizing unit 211i.

The image synthesizing section 211i includes a resolution converting section 21.
The image input from 1h and the cursor display position control unit 2
The image of the AF cursor CR input from 11g is combined, and the combined image is transmitted to the VRAM 210. By this combining operation, the AF cursor C on the screen of the LCD 10
The size of R is a constant size regardless of the thinning rate in the resolution conversion unit 211h. This also applies to the electronic zoom.

The focus area setting section 211j is used for the LCD 10
The AF area AR is set in the captured image in correspondence with the position of the AF cursor CR on the screen. The AF area AR is an area of 200 pixels × 80 pixels in the captured image of 1600 × 1200 pixels. The AF process is performed using the data of the pixels included in the AF area AR. When the AF area AR is virtually represented on the screen of the LCD 10 (in this case, the size of the AF area AR is 50
X vertical 20), as shown in FIG. 9, the AF area AR
And the center position of the AF cursor CR coincide with each other.

The evaluation value calculation unit 211k is an AF evaluation value (focus evaluation value) E for performing contrast AF when the shutter button 8 is half pressed (S1).
Perform the operation of. Hereinafter, the AF evaluation value is simply referred to as “evaluation value”.
Call. Specifically, the image data in the AF area AR is used to calculate the evaluation value E, which is the sum of the absolute values of the differences between the adjacent pixels. 7 steps of lens (ai: i =
1 to 7), the evaluation value E (i) is calculated at each lens position, and the focus position (that is, the lens position for obtaining the focus) is determined based on the result. Then, by driving the zoom lens 301 to the determined focusing position, focusing on the main subject or the like is realized. It should be noted that the seven stages are for convenience of description, and the focus position is determined by a larger number of stages for actual focus evaluation.

<About AE> For AE, LCD
AE based on center-weighted photometry is performed based on the position of the AF cursor CR displayed on the screen of 10. In other words, the AF cursor CR also functions as an AE cursor corresponding to the photometric point. In this example, the photometric area for AE is set corresponding to the AF cursor CR, but an AE cursor indicating the center of the photometric area, which is a photometric point, may be displayed separately from the AF cursor CR.

In this photometry, as shown in FIG.
Image data acquired by the CCD 303 with the ellipse Ea and the ellipse Eb acting as the photometric areas centered on the cursor CR, the inside of the ellipse Ea set as a weighting factor of 8, and the region from the ellipse Ea to the ellipse Eb set as a weighting factor of 2, for example. Perform photometric calculation for. As a result, it is possible to perform appropriate photometry aiming at the main subject.

<Regarding Focus Bracket Shooting Function> The digital camera 1 according to the present invention has a focus bracket shooting function, and this function will be described below. With reference to FIG. 12, when the position of the AF cursor CR is designated on the screen of the LCD 10 by the photographer, the position CR corresponding to the position of the AF cursor CR in the captured image.
An AF area AR1 is set around 1. Along with this, there are eight position CRs around the position CR1.
2 to CR9 are defined, and AF areas AR2 to AR9 centered on the respective positions CR2 to CR9 are set.
The positions CR1 to CR9 adjacent to each other are 2 in the lateral direction.
5 pixels, 20 pixels apart in the vertical direction. The size of the AF areas AR2 to AR9 is 200 pixels horizontally × 80 pixels vertically, as in the AF area AR1.

When the shutter button 8 is pressed halfway (S1) by the photographer, each AF area ARj (j =
The in-focus positions regarding 1 to 9) are sequentially detected, and the data (lens position and lens movement amount) regarding each in-focus position is stored. The order of detecting the in-focus position is, for example, AR1 →
The order is AR2 → ... → AR9. After that, when the shutter button 8 is fully pressed (S2) by the photographer, a total of 9 times of photographing (recording processing) are sequentially performed based on the stored data regarding each in-focus position.
The order of shooting is, for example, the in-focus position of AR1, the in-focus position of AR2, ..., The in-focus position of AR9.

Whether or not to execute the focus bracket photographing is arbitrarily determined depending on whether or not the bracket photographing menu (FIG. 13) is displayed in the preference mode and the item "focus bracket photographing" is selected. Can be set. When focus bracket shooting is not executed, only the in-focus position and shooting for the AF area AR1 are performed in the above example.

Further, in the above example, the total number of times of photographing in the focus bracket photographing is 9, but it may be set to, for example, 5 times according to the selection of the photographer in order to speed up the photographing process. As a subordinate menu of the “focus bracket shooting” menu shown in FIG. 13, the “focus bracket shooting frequency” item shown in FIG. 14 is provided.
The photographer may be allowed to select a desired one from “5 times” and “9 times”. When "5 times" is selected, the five AF areas AR1, AR3 shown in FIG. 12 are selected.
Focus bracket shooting is performed using AR5, AR7, and AR9.

Further, the total number of times of photographing may be automatically changed depending on the photographing condition. For example, it is set to 9 times when shooting at high resolution and 5 times when shooting at low resolution.
Alternatively, when shooting under shooting conditions in which the depth of field is shallow due to the relationship with the focal length and aperture value of the zoom lens 301, 9
5 times when shooting under deep shooting conditions.
The rule of the total number of times of photographing is stored in advance in the flash ROM 211b in a table manner, and the total control unit 211 refers to the table and determines the total number of times of photographing every time photographing is performed.

The number of AF areas ARj can be changed by
AF areas AR2 to AR with respect to the position of F area AR1
It can also be regarded as a change in the position of 9. That is, it can be regarded as a change in the additional positions of the AF areas AR2 to AR9 to be added in addition to the AF area AR1.

<Operation of Digital Camera According to First Embodiment> The outline of the focus bracket photographing function has already been described, but in the following, the operation of the digital camera 1 when performing the focus bracket photographing (total photographing number 9 times). Will be specifically described. This operation is performed by the overall control unit 211.
Is automatically executed by.

FIG. 15 is a flow chart for specifically explaining the operation of the digital camera according to the first embodiment of the present invention. First, in step SP101, the photographer operates the quad switch 230 to set L
The AF cursor CR is moved within the screen of the CD 10. As a result, the position on the subject to be focused (focus designated position) is designated.

Next, in step SP102, it is determined whether or not the shutter button 8 has been pressed halfway (S1) by the photographer. When the result of the determination in step SP102 is "NO", the process returns to the start. On the other hand, if the result of the determination in step SP102 is "YES", then the operation proceeds to step SP103, and as described in the above <Regarding the focus bracket photographing function>, the focus for each AF area ARj (j = 1 to 9) is achieved. The positions are detected in order and the data for each in-focus position is saved.

Next, in step SP104, AF
The zoom lens 30 is placed at the in-focus position with respect to the area AR1.
1 is driven. Next, in step SP105,
The shutter button 8 is fully pressed by the photographer (S
It is determined whether or not it is set to 2). Step SP105
If the result of the determination in step 1 is "NO", the process returns to start. On the other hand, if the result of the determination in step SP105 is "YES", then the processing proceeds to step SP107,
"1" is assigned to the counter j as an initial value.

Next, in step SP107, AF
The recording process in the area ARj is performed. That is, the image of the subject focused at the focus position with respect to the AF area ARj is captured by the CCD 303, and the image memory 209
Will be recorded in.

Next, at step SP108, it is judged if the value of the counter j is "9". Step S
When the result of the determination in P108 is "YES", the process returns to the start. On the other hand, when the result of the determination in step SP108 is "NO", step SP10
In step 9, "1" is added to the value of the counter j. Next, in step SP110, the zoom lens 301 is driven to the in-focus position with respect to the AF area ARj.
The driving of the zoom lens 301 is performed based on the data regarding each in-focus position stored in step SP104. The operations of steps SP107 to SP110 are repeated until "YES" is determined in step SP108. As a result, finally, the AF area AR1
A total of nine subject images focused at each focusing position with respect to AR9 are captured by the CCD 303.

Focusing only on the operation of the zoom lens 301 and capturing the above operation, the zoom lens 301 determines a lens position (focus on the AF area AR1) for focusing on a position on the subject corresponding to the AF cursor CR. Different lens positions (AF areas AR2 to AR9)
Drive to each focusing position). In this case, the AF areas AR2 to AR
9 need not be added, and the lens position may be changed in several steps within a predetermined width before and after the in-focus position with respect to the AF area AR1, and shooting may be performed sequentially at each of these lens positions.

In step SP104, AF area A
Instead of driving the lens to the focus position of R1, when driving the zoom lens 301 to all the focus positions related to the AF areas AR1 to AR9 starting from the current lens position, the total drive distance of the zoom lens 301 is the shortest. It is also possible to determine the following shooting order (lens driving order). The shooting order can be calculated based on the data regarding each in-focus position stored in step SP103.
In this case, in steps SP106 to SP110, the zoom lens 301 is driven according to the lens driving order determined in step SP104. That is, "j" in FIG. 15 when such control is performed means the shooting order determined in step SP104.

With respect to this point, preferably, a series of photographing can be performed in one of the following sequences.

(1) If all of the series of in-focus positions exist in only one direction as seen from the current position (initial position) of the lens at the start of shooting, while moving the lens in that one direction. , The shooting is performed sequentially from the in-focus position close to the initial position.

(2) When a series of in-focus positions are divided in both directions when viewed from the initial position of the lens, there are the following two preferable sequences.

(2-1: First Sequence Example) First, while moving the lens in one direction (hereinafter referred to as "plus direction") from the initial position, shooting is performed sequentially from the focus position close to the initial position. The in-focus positions of the lens farthest from the initial position in both directions of the initial position are a (max1) and a (max2)
In this case (neither is shown), it is preferable to adopt, as the plus direction, the direction in which the in-focus position closer to the initial position exists among these two in-focus positions a (max1) and a (max2). In the following, the case where the focus position a (max1) is closer to the lens initial position than the focus position a (max2) is taken as an example.

The lens position is at the in-focus position a (max1) at the time when the photographing at each in-focus position in the plus direction is completed, but the direction of lens movement is reversed at this position to reverse the plus direction. Run the lens in the direction (hereinafter referred to as "minus direction") and return to the initial position. Then, the lens movement in the minus direction is continued, and shooting is performed in order from the focus position that reaches first in the lens movement in the minus direction among the remaining focus positions.

The advantage of this first sequence example is that since the first photographing starts relatively early after the shutter button is fully pressed (S2), the photographer is informed that "a series of photographing has been started". It is easy to recognize.

(2-2: Second Sequence Example) The lens is idled in the plus direction from the initial position without taking a picture.
The preferred plus direction here is the same as in the first sequence example. When the lens position reaches the farthest focusing position a (max1) in the plus direction, the lens is temporarily stopped at that position. Then, starting from shooting at the focus position a (max1), while moving the lens position in the negative direction,
Shooting is performed in order from the focus position that reaches first among the focus positions. Then, when the focus position a (max2) is reached, a series of photographing ends.

The advantage of the second sequence example is that once shooting at a series of in-focus positions is started, the lens does not run idle during the shooting, so "shooting interruptions" occur during the series of shootings. It means that the photographer is not given the impression that "" has occurred.

As described above, the digital camera according to the embodiment of the present invention is provided with the focus bracket photographing function, and when the position of the AF cursor CR is designated by the photographer, the AF cursor CR is displayed in the captured image. Not only the AF area AR1 centered on the position CR1 corresponding to the position, but also a plurality of positions CR2 to CR9 near the periphery of the position CR1.
AF areas AR2 to AR9 centered at
Is set. Then, a single image capturing operation (S2) by the photographer captures a plurality of images focused at the respective focusing positions with respect to the AF areas AR1 to AR9.

Therefore, the situation where the actual focus is not achieved at the position where the focus is designated by the photographer is unlikely to occur, and it is possible to accurately perform the photographing as intended by the photographer.

<First Example of Detecting Method of Focused Position>
Step SP103 in the flowchart of FIG.
That is, the first example of the method of detecting the in-focus position for each AF area ARj (j = 1 to 9) will be specifically described.

16 and 17 are flowcharts for specifically explaining the first example of the method for detecting the in-focus position. First, in step SP201, "1" is assigned to the counter j as an initial value. Next, step SP
At 202, the focusing area is set to the AF area ARj corresponding to the value of the counter j. Next, "1" is assigned to the counter i as an initial value. Next, in step SP204, the lens position is moved to the lens position ai corresponding to the value of the counter i, and in that state, image data of the subject is acquired from the CCD 303. As shown in FIG. 18, the lens position can be set in seven stages of a1 to a7 (that is, i = 1 to 7).

Next, in step SP205, the evaluation value E (i, j) is calculated by using the image data in the AF area ARj at the lens position ai. Next, in step SP206, the counter i is "7".
Is determined. If the result of the determination in step SP206 is "NO", the flow proceeds to step SP207, "1" is added to the value of the counter i, and the zoom lens 301 is moved to the next lens position ai + 1. Until “YES” is determined in step SP206,
The operations of steps SP204 to SP207 are repeated. It is determined to be “YES” in step SP206, which means that a total of 7 evaluation values E (i, j) regarding the seven types of lens positions a1 to a7 are prepared for the AF area ARj set at that time. That's what it means.

If the result of the determination in step SP206 is "YES", the flow proceeds to step SP208 and it is determined whether the value of the counter j is "9". If the result of the determination in step SP208 is "NO", the flow proceeds to step SP209, "1" is added to the value of the counter j, and the flow shifts to the next AF area ARj + 1. Until “YES” is determined in step SP208,
The operations of steps SP202 to SP209 are repeated. The determination of “YES” in step SP208 means that there are seven types of lens positions a1 to a7 and 9
This means that all 63 evaluation values E (i, j) regarding the AF areas AR1 to AR9 of all types are prepared.

If the result of the determination in step SP208 is "YES", the flow proceeds to step SP210 and the value of the counter j is set to "1". Next, step S
In P211, the evaluation value E (i,
Based on j), the focus position for the AF area ARj is detected. Next, in step SP212, it is determined whether the value of the counter j is "9". When the result of the determination in step SP212 is "NO", the flow proceeds to step SP213, "1" is added to the value of the counter j, and the flow shifts to the next AF area ARj + 1. Until "YES" is determined in step SP212,
The operations of steps SP211 to SP213 are repeated. The determination of “YES” in step SP212 means that all the in-focus positions for all the AF areas AR1 to AR9 are aligned.

A method of detecting the in-focus position based on the evaluation value E (i, j) in step SP211 will be described below. With reference to FIG. 18, a curve Fa is a curve obtained by connecting the evaluation values E (i, 1) calculated at the lens positions a1 to a7 with respect to the AF area AR1.
The lens position aa that gives the maximum value Ea of the evaluation values E on this curve Fa is detected as the in-focus position with respect to the AF area AR1. Such a focus position detection method is also referred to as “mountain climbing focus detection”.

The curve Fb is the evaluation value E calculated at each lens position a1 to a7 for the AF area AR2.
(I, 2) is connected in a curved shape. This curve Fb
The lens position bb that gives the maximum value Eb of the evaluation value E above is
It is detected as the in-focus position with respect to the AF area AR2.

By creating curves similar to the curves Fa and Fb for the other AF areas AR3 to AR9, it is possible to obtain the in-focus positions for the respective AF areas AR3 to AR9.

As described above, according to the first example of the focus position detecting method, by adopting the hill-climbing focus detection as the focus detection method, each focus position of the AF areas AR1 to AR9 is accurately measured. It can be detected well.

<Second Example of Focusing Position Detection Method> Next,
Step SP103 in the flowchart of FIG.
That is, the second example of the method of detecting the in-focus position for each AF area ARj (j = 1 to 9) will be specifically described.

FIG. 19 is a flowchart for specifically explaining the second example of the method of detecting the in-focus position. First, in step SP301, "1" is assigned to the counter i as an initial value. Next, step SP302
At, the lens position is moved to the lens position ai corresponding to the value of the counter i. Next, step SP303
In, the counter j is assigned "1" as the initial value. Next, in step SP304, the focus area is set to the AF area ARj corresponding to the value of the counter j, and the image data of the subject is acquired from the CCD 303 in that state.

Next, in step SP305, the evaluation value E (i, j) is calculated by using the image data in the AF area ARj at the lens position ai. Next, in step SP306, the counter j is "9".
Is determined. If the result of the determination in step SP306 is "NO", the flow proceeds to step SP307, "1" is added to the value of the counter j, and the next AF is performed.
Move to area ARj + 1. Until it is determined to be "YES" in step SP306, step SP304-
The operation of SP307 is repeated. Step SP306
Is determined to be “YES”, it means that there are nine types of AF areas A with respect to the lens position ai at that time.
This means that a total of nine evaluation values E (i, j) regarding R1 to AR9 are prepared.

If the result of the determination in step SP306 is "YES", the flow proceeds to step SP308 and it is determined whether the value of the counter i is "7". If the result of the determination in step SP308 is "NO", the flow proceeds to step SP309, "1" is added to the value of the counter i, and the zoom lens 301 moves the next lens position ai +.
Moved to 1. In step SP308, "YE
Until it is determined as "S", steps SP302 to SP30
The operation of 9 is repeated. The determination of “YES” in step SP308 means that seven types of lens positions a1 to a7 and nine types of AF areas AR1 to AR9.
It means that a total of 63 evaluation values E (i, j) regarding the above have been prepared.

If the result of the judgment in step SP208 is "YES", step SP2 shown in FIG.
Then, the procedure proceeds to 10, and thereafter, as in the first example, the in-focus positions for all the AF areas AR1 to AR9 are detected.

As described above, according to the second example of the focus position detecting method, by adopting the hill-climbing focus detection as the focus detection method, the focus positions of the AF areas AR1 to AR9 are accurately determined. It can be detected well.

Further, instead of individually changing the lens position over a plurality of times for each AF area AR1 to AR9, all the AF areas AR for one lens position ai are changed.
Since the evaluation values E of 1 to AR9 are collectively obtained, the number of times of changing the lens position is significantly reduced as compared with the first example of the above detection method.

[0115]

According to the first aspect of the present invention, since the lens is driven in sequence to the respective focus positions of the first and second focus areas to carry out the bracket photographing, the focusing is performed. It is possible to accurately perform shooting as intended by the photographer.

According to the second aspect of the present invention, since the number of the second focusing areas can be changed, the operability of the photographer is improved.

Further, according to the third aspect of the present invention, it is possible to perform the appropriate bracket photographing according to the photographing condition.

According to the fourth aspect of the present invention, since the position of the second focus area can be changed, the operability of the photographer is improved.

According to the fifth aspect of the present invention, the lenses are sequentially driven to the first and second lens positions to perform the bracket photographing, so that the focusing is performed as intended by the photographer. The shooting can be performed accurately.

According to the sixth aspect of the present invention, since the number of the second lens positions can be changed, the operability of the photographer is improved.

Further, according to the seventh aspect of the present invention, it is possible to carry out an appropriate bracket photographing according to the photographing condition.

According to the eighth aspect of the present invention, since the lenses are sequentially driven to the first and second lens positions to perform the bracket photographing, the focusing is performed according to the photographer's intention. Can be taken accurately.

According to the ninth aspect of the present invention, instead of individually changing the lens position a plurality of times for each focusing area, a plurality of focusing positions can be obtained for one lens position. To obtain the focus evaluation value of the area at once,
The number of times the lens position is changed is greatly reduced.

According to the tenth aspect of the present invention, since the lenses are driven in the order in which the total driving distance becomes the shortest, the time required to complete the bracket photographing can be shortened.

[Brief description of drawings]

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

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

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

FIG. 4 is a bottom view showing the structure of the digital camera according to the embodiment of the present invention.

FIG. 5 is a block diagram showing an internal configuration of the digital camera according to the embodiment of the present invention.

FIG. 6 is a block diagram specifically showing a part of the internal configuration of the digital camera according to the embodiment of the present invention.

FIG. 7 is a conceptual diagram for explaining live view display.

FIG. 8 is a block diagram specifically showing a part of the internal configuration of the digital camera according to the embodiment of the present invention.

FIG. 9 is a schematic diagram showing an example of a screen of an LCD on which an AF cursor is displayed.

FIG. 10 is a schematic diagram for explaining movement of an AF cursor.

FIG. 11 is a schematic diagram for explaining photometry in a digital camera.

FIG. 12 is a schematic diagram for explaining the concept of focus bracket shooting.

FIG. 13 is a schematic diagram for explaining the concept of focus bracket shooting.

FIG. 14 is a schematic diagram for explaining the concept of focus bracket shooting.

FIG. 15 is a flowchart for specifically explaining the operation of the digital camera according to the embodiment of the present invention.

FIG. 16 is a flowchart for specifically explaining a first example of a focus position detection method.

FIG. 17 is a flowchart for specifically explaining a first example of a focus position detection method.

FIG. 18 is a diagram showing a relationship between a lens position and an AF evaluation value in each AF area.

FIG. 19 is a flowchart for specifically explaining the second example of the method for detecting the in-focus position.

[Explanation of symbols]

1 digital camera 10 LCD 209 image memory 210 VRAM 211 Overall control unit 225 AF cursor button 303 CCD AR AF area CR AF cursor

Continued front page    (72) Inventor Katsuhito Shinkawa             2-3-3 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Prefecture               Osaka International Building Minolta Co., Ltd. F-term (reference) 2H051 DA07 EA09                 5C022 AA13 AB26 AB30 AC03 AC31                       AC42 AC69

Claims (10)

[Claims] 1. A display unit having a screen for displaying an image of a subject, a designation unit for designating a designated focus position on the subject within the screen based on an operation input, and a focus designation within the screen. Setting means for setting a first focusing area corresponding to the position of the position and setting a plurality of second focusing areas in the vicinity of the first focusing area, and the first and second A detection unit that detects each in-focus position in each of the first and second in-focus areas based on each image data in the in-focus area, each of the first and second in-focus areas A digital camera characterized in that a lens is sequentially driven to a focus position to take an image at each position. 2. The digital camera according to claim 1, wherein the number of the second focus areas is changeable. 3. The digital camera according to claim 2, wherein the setting unit changes the number of the second focus areas according to shooting conditions. 4. The position of the second focusing area with respect to the position of the first focusing area is changeable.
Digital camera described in. 5. A display unit having a screen for displaying an image of a subject, a designation unit for designating a designated focus position on the subject in the screen based on an operation input, and a designation unit corresponding to the designated focus position. A setting unit configured to set a first lens position for focusing at a location on the subject and set a plurality of second lens positions different from the first lens position; The digital camera is characterized in that the lens is sequentially driven to the second lens position and shooting is performed at each position. 6. The digital camera according to claim 5, wherein the number of the second lens positions is changeable. 7. The digital camera according to claim 6, wherein the setting unit changes the number of the second lens positions according to shooting conditions. 8. A display unit having a screen for displaying an image of a subject, a designating unit for designating a focus designated position on the subject in the screen based on an operation input, and at least 3 while driving a lens. An evaluation value acquisition unit that obtains a focus evaluation value at each of the three lens positions, and a first lens position for focusing at a position on the subject that corresponds to the designated focus position is provided for each of the at least three lens positions. A lens position determining means for determining a plurality of second lens positions different from the first lens position, the lens position determining means determining the focus lens based on the focus evaluation value; A digital camera characterized in that the lenses are sequentially driven in a predetermined order to take an image at each position. 9. A first focus area is set in correspondence with the position of the designated focus position in the screen, and
A focus area setting unit that sets a plurality of second focus areas in the vicinity of the first focus area is further provided, and the evaluation value acquisition unit is a first focus area corresponding to the first focus area. A focus evaluation value and a plurality of second focus evaluation values corresponding to each of the plurality of second focus areas are collectively obtained for each lens position for each of the at least three lens positions. The lens position determining means determines the first lens position based on the first focus position at each of the at least three lens positions, and the plurality of first lens positions at the at least three lens positions. 9. The plurality of second lens positions for focusing at the location of the subject corresponding to the plurality of second focus areas are respectively determined based on the focus evaluation values of 2. Digital camera. 10. When driving the lens to the first and plurality of second lens positions, the lenses are driven in the order in which the total driving distance of the lenses is the shortest.
The digital camera according to claim 8.