JP2003348437A - Image pickup unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup unit for processing automatic focus control at high speed while displaying an object image. <P>SOLUTION: A CCD 21 of the image pickup unit has a first thinning out mode wherein longitudinal pixels of image data are thinned out to 1/8 at output of the image data and a second thinning out mode wherein longitudinal pixels of image data are thinned out to 1/16 at output of the image data. In the first thinning out mode, a first thinned out image can be outputted for a period of 1/30 seconds and in the second thinning out mode, a second thinned out image can be outputted for a period of 1/60 seconds. The number of longitudinal pixels of the second thinning out image is the number of longitudinal pixels of a liquid crystal monitor or below. In the case of automatic focus control, the second thinning out mode is selected and since a focus evaluation value FV is derived by 1/60 seconds each, the automatic focus is processed at high speed. On the other hand, the longitudinal pixels of the second thinning out image is interpolated to produce display image data ILV the number of longitudinal pixels of which is coincident with the number of longitudinal pixels of the liquid crystal monitor. Thus, the object image can be displayed on the liquid crystal monitor. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a technique for displaying a subject image in an image pickup apparatus.

[0002]

2. Description of the Related Art In an image pickup apparatus such as a digital still camera (hereinafter simply referred to as a "digital camera") provided with a display means such as a liquid crystal monitor, image data is acquired at regular intervals in a photographing standby state. A live view display for displaying a subject image on a display means based on the obtained image data is performed. With such a live view display, the user can perform framing while checking a subject image having no parallax.

[0003] In an image pickup apparatus for obtaining image data using image pickup means such as a CCD, a so-called contrast method (or a hill-climbing method) is applied to auto-focus control.
The contrast method is a method in which the contrast of image data obtained in each driving stage is acquired as an evaluation value while driving the focusing lens, and the lens position having the highest evaluation value is set as the focus position.

When this contrast method is applied, the speed of autofocus control can be improved by increasing the number of image data obtained per unit time (frame rate) for obtaining an evaluation value. For this reason, conventionally, in order to acquire image data at a relatively high frame rate, image data is thinned out at a predetermined ratio and read, and the thinned image data is output from an imaging unit.

[0005]

By the way, by increasing the degree of thinning when reading image data, the frame rate can be increased, and further improvement in the speed of the autofocus control can be expected.

However, at the time of autofocus control, the resolution of the image data output from the imaging means needs to be higher than the resolution of the display means in order to allow the live view display on the display means to coexist. That is, the amount of image data output from the imaging unit is
The data amount required for displaying the subject image on the display means is restricted. Therefore, there has been a problem that the frame rate cannot be increased, and the speed of the auto focus control cannot be further improved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and displays an object image on a display unit even when the image pickup unit outputs image data having no data amount necessary for displaying the object image. It is an object to provide a possible imaging device.

[0008]

According to a first aspect of the present invention, there is provided an imaging apparatus for obtaining image data of a subject via an optical system, and the image processing apparatus comprising: An imaging apparatus comprising: a focus control unit that performs focus control of an optical system; and a display unit that displays a subject image based on image data from the imaging unit, wherein the imaging unit outputs acquired image data. The output mode includes a first output mode for outputting first image data having a data amount necessary for both the focus control and the display of the subject image, and a data amount necessary for the focus control. And a second output mode for outputting second image data not having a data amount necessary for displaying the subject image, wherein the imaging apparatus includes:
When the output mode of the imaging unit is the second output mode, the image processing unit includes: an image generation unit that generates display image data for displaying the subject image on the display unit based on the second image data. ing.

According to a second aspect of the present invention, in the imaging device according to the first aspect, when the output mode is the second output mode, the imaging means is configured by a two-dimensional array of a plurality of pixels. Outputting, as the second image data, image data obtained by thinning out pixels in the one-dimensional direction of the two-dimensional array from the acquired image data, and the image generation unit outputs the second image data In the method, at least a part of the display image data is generated by supplementing the pixels decimated in the generation process by interpolation of the second image data.

According to a third aspect of the present invention, in the imaging apparatus according to the first aspect, the first image output from the imaging means when the output mode of the imaging means is the first output mode. A storage unit for storing and holding data, wherein the imaging unit is configured to set the output mode to the second mode.
When in the output mode, image data including at least a focusing target area used for the focus control in the acquired image data is output as the second image data, and the image generation unit is stored and held in the storage unit. Said the first
The display image data is generated based on image data and the second image data.

According to a fourth aspect of the present invention, in the imaging apparatus according to the second or third aspect, the image capturing apparatus further includes a receiving unit that receives an instruction to start focus control of the optical system from a user. The output mode is set to the second output mode in response to receiving a focus control start instruction.

According to a fifth aspect of the present invention, in the imaging apparatus according to the second or third aspect, a receiving unit for receiving an instruction to acquire image data for recording by the imaging unit from a user is further provided. Is characterized by setting the output mode to the second output mode in response to receiving an instruction to acquire the image data for recording.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following description, a digital camera will be described as an example of the imaging apparatus.

<1. First Embodiment><1-1. Configuration of Digital Camera> First, the configuration of the digital camera 1 will be described. Figure 1 shows a digital camera 1
FIG. 2 is a diagram showing a configuration of the back side of the digital camera 1.

As shown in FIG. 1, a photographing lens 3, a flash 23 and an objective window of an optical finder 22 are provided on the front side of the digital camera 1. Shooting lens 3
Has a plurality of lens groups including a focusing lens 31 (see FIG. 3) for determining the in-focus state of the subject image. In addition, a CCD 21 that is an image pickup device that acquires image data (hereinafter, also simply referred to as “image”) of a subject via a lens group is provided at an appropriate position inside the digital camera 1 behind the photographing lens 3. ing.

On the upper surface side of the digital camera 1, a shutter button 25 and a main switch 24 for switching power on and off are arranged. Shutter button 2
Reference numeral 5 denotes a button for accepting an instruction for starting autofocus control or photographing from the user, and is a two-stage switch capable of detecting a half-pressed state (S1 state) and a fully-pressed state (S2 state). A card slot 26 for mounting a memory card 9 as a recording medium for recording image data and the like is formed on a side surface of the digital camera 1.
The memory card 9 is detachable.

On the other hand, as shown in FIG. 2, on the rear side of the digital camera 1, an eyepiece window of the optical viewfinder 22, a mode switching lever 27 for switching operation modes, a liquid crystal monitor 28 for performing various displays, and various operations are provided. A button group 29 for performing the operation is provided.

The digital camera 1 has, as its operation modes, a “photographing mode” for acquiring image data of a subject,
There is a “playback mode” for playing back and displaying the recorded image data, and these operation modes are switched by operating the mode switching lever 27.

The liquid crystal monitor 28 displays the acquired image data and the image data recorded on the memory card 9 and also displays a menu screen for making various settings of the digital camera 1.

In the photographing standby state, the liquid crystal monitor 2
8, a live view display is performed in which image data obtained by the CCD 21 is displayed continuously at regular intervals, so that the user can perform framing while checking the displayed subject image. Has been. At the time of the live view display, a frame 28a indicating a predetermined focus area which is a focusing target area is displayed. The user can bring the desired subject image into a focused state by performing framing so that the desired subject image is arranged in the frame 28a.

The button group 29 includes a display switching button 29
a, a left button 29b, a right button 29c, and a menu button 29d. The display switching button 29a is
A button for setting whether or not to display the liquid crystal monitor 28 in the shooting standby state. Each time the button is pressed, the state of the liquid crystal monitor 28 is switched between display and non-display.

The left button 29b, right button 29c, and menu button 29d are buttons for mainly performing various settings of the digital camera 1. Menu button 29
By pressing d, a menu screen is displayed on the liquid crystal monitor 28, and while checking this menu screen, the left button 29b
Various settings can be made by operating the right button 29c.

<1-2. Next, the internal configuration of the digital camera 1 will be described. FIG. 3 is a diagram showing a main internal configuration of the digital camera 1 as functional blocks.

The CCD 21 includes a light receiving section for storing signal charges by exposure, a vertical transfer section for transferring and outputting signal charges, a horizontal transfer section and an output section. The light receiving unit is composed of a plurality of pixels to which any one of R (red), G (green), and B (blue) color filters is attached, and is configured to transmit a light image of a subject formed by the lens group of the photographing lens 3. Photoelectric conversion into signal charges (image data). In addition,
As the color filter attached to the light receiving section, a complementary color filter composed of a combination of C (cyan), M (magenta), and Y (yellow) may be adopted.

FIG. 4 is a diagram showing an example of a pixel array of the light receiving section of the CCD 21. As shown in FIG. 4, the pixel array of the light receiving unit is a two-dimensional array of 2560 × 1920 pixels. The arrangement of the color filters (color components) attached to each pixel is a Bayer arrangement, and two pixels of the G filter, one pixel of the R filter, and pixels of the B filter are arranged in the four neighboring pixel regions 21a. One is included.

The signal charges stored in each pixel of the light receiving section are read out, temporarily transferred to a vertical transfer section, and thereafter, in one horizontal pixel row (horizontal pixel row: hereinafter also referred to as “line”). Is transferred to the horizontal transfer unit and output from the output unit sequentially.

The CCD 21 not only outputs all the pixels of the image data but also reads out the lines by thinning out the lines at a predetermined ratio, and can output the image data in which the pixels in the vertical direction are thinned out. Various output methods of such image data are set in advance as the output mode of the CCD 21. As the output mode, the CCD 21 of the present embodiment includes a “normal mode” for outputting all pixels of image data, a “first thinning mode” and a “second thinning mode” for outputting thinned image data. Have.

FIG. 5 is a diagram for explaining image data output from the CCD 21. The light receiving unit of the CCD 21 acquires image data D1 (hereinafter, referred to as “acquired image data”) D1 composed of a two-dimensional array of 2560 × 1920 pixels. In the acquired image data D1, an area FA1 of 1280 (horizontal) × 240 pixels (vertical) at the center thereof is set as a focus area.

The output mode of the CCD 21 is the "normal mode"
Is set, all the pixels of the acquired image data D1 are read, and a normal image D2 having 2560 × 1920 pixels is output.

On the other hand, when the output mode is set to the "first thinning mode", the lines of the acquired image data D1 are thinned and read at a rate of 1/8. As a result, 2560 horizontal × 240 vertical pixels in which the vertical pixels are thinned out to 1/8.
A first thinned image D3 having pixels is output. When the output mode is set to the “second thinning mode”, the lines of the acquired image data D1 are thinned out and read at a ratio of 1/16, and the pixels in the vertical direction are reduced to 1/16. A second thinned image D4 having 2560 horizontal × 120 vertical pixels is output.

FIG. 6 is a diagram showing a partial area of the acquired image data D1, and reference numerals L0 to L32 indicate lines of the acquired image data D1, respectively. The line L0 corresponds to the upper end line of the acquired image data D1, and is hereinafter referred to as the upper end line L0 to the zeroth line L0, the first line L1,.

In the "first thinning mode" or the "second thinning mode", the intervals between the lines read out are not constant, and the arrangement of the color components of the pixels in the first thinned image D3 and the second thinned image D4 as well. Are read out so as to have a Bayer array. More specifically, in the case of the “first thinning mode”, the 0th line L0, the ninth line L9, the 16th line L16, the 25th line L25,... . On the other hand, in the case of the “second thinning mode”, the 0th line L0, the 17th line L17, the 32nd line
The line L32, the 49th line,..., And the line indicated by reference numeral B in the figure are read.

When the output mode is set to "first thinning mode" or "second thinning mode", "normal mode"
, The number of lines to be output is smaller. Accordingly, image data for each frame can be output at high speed, and the number of image data to be output per unit time, that is, the frame rate (unit: fps) can be increased. Since the number of lines to be output is smaller in the “second thinning mode” than in the “first thinning mode”, the frame rate can be further increased (image data can be output even faster). In the CCD 21 of the present embodiment, the frame rate is 30 fps (1/30 second cycle) in the “first thinning mode”,
In the “second thinning mode”, the frame rate is 60 fp
s (1/60 second cycle). That is, in the “second thinning mode”, the number of image data to be output per unit time can be doubled as compared with the “first thinning mode”.

The output mode of the CCD 21 is set by a signal from the timing generator 201 (see FIG. 3). This timing generator 201
Is a CCD based on a signal input from the overall control unit 40.
21 for transmitting various drive control signals to the CC.
In addition to a signal for setting the output mode of D21, a timing pulse for determining the start and end of exposure of the CCD 21 and the like are transmitted. This timing pulse is also input to other processing units, whereby output of image data from the CCD 21 and
The image data is synchronized with various processes.

Returning to FIG. 3, the signal processing circuit 202
A predetermined analog signal processing is performed on the image data output from D21. The signal processing circuit 202 has a CDS (correlated double sampling) circuit and an AGC (auto gain control) circuit therein, reduces noise of image data by the CDS circuit, and adjusts the level of the image data by the AGC circuit. I do.

The A / D converter 203 is a signal processing circuit 20
2. The image data of the analog signal output from 2 is converted into a digital signal. Further, the image processing unit 204 performs various image processing on the image data converted into the digital signal. Specifically, color component interpolation processing for interpolating the color components of the Bayer array so that each pixel has all the RGB data, white balance correction for correcting the influence of the illumination light source on the subject, and correction of the gradation characteristics of the image Γ correction and contrast correction for correcting the contrast are performed.

The image memory 205 is a memory for temporarily storing image data output from the image processing unit 204, and has a storage capacity capable of storing at least one frame of the normal image D2.

The display image generation unit 210 is provided with the image memory 20
5, the image data stored in the LCD monitor 2 is read out.
8 to generate display image data to be displayed on the display screen. The resolution of the liquid crystal monitor 28 of the present embodiment is 3
Since there are 20 × 240 vertical pixels, the display image generating unit 210 generates display image data having the same resolution as this.

The VRAM 211 includes a display image generation unit 210
Is a buffer memory for storing the display image data generated by. The display image data stored in the VRAM 211 is read out according to the refresh rate of the liquid crystal monitor 28 (the number of times the display screen is rewritten per unit time) and displayed on the liquid crystal monitor 28. The refresh rate of the liquid crystal monitor 28 is set to 30 fps, and the display image data stored in the VRAM 211 is displayed on the liquid crystal monitor 28 every 1/30 second.

The image data output from the A / D converter 203 in the photographing standby state is transmitted to the AF operation unit 207.
The luminance signal is also input to the luminance calculation unit 208 and used for exposure control and focus control.

The AF calculation unit 207 derives a focus evaluation value used for focus control from the input image data. Specifically, an area corresponding to the focus area in the image data (hereinafter simply referred to as “focus area”)
That. A contrast value is obtained from the pixel of ()) and is used as a focus evaluation value. The obtained focus evaluation value is input to the overall control unit 40.

On the other hand, the luminance calculator 208 derives a luminance value of the subject used for exposure control from the input image data. Specifically, the luminance component value of each pixel in the image data is obtained, and the average value of these luminance component values is used as the luminance value of the subject. The obtained brightness value of the subject is input to the overall control unit 40.

The lens drive unit 209 drives the focusing lens 31 in the photographing lens 3, the diaphragm in the photographing lens 3 for determining the amount of incident light, and the like. Lens drive unit 209
Are electrically connected to the overall control unit 40,
The focusing lens 31 and the like in the photographing lens 3 are driven based on the signal input from 0.

The card I / F 206 is a card slot 2
The recording of image data on the memory card 9 mounted on the memory card 6 and the reading of image data from the memory card 9 are performed. The card I / F 206 is also electrically connected to the general control unit 40, and performs recording and reading of image data based on a signal from the general control unit 40.

The operation input unit 20 shows an operation member including the above-described shutter button 25, main switch 24, mode switching lever 27, button group 29, and the like as one functional block. The operation of the operation input unit 20 is input to the overall control unit 40 as a signal.

The overall control unit 40 controls the operation of each of the above-described members of the digital camera 1 as a whole, and includes a CPU 41 for performing various types of arithmetic processing, a RAM 42 as a work area for performing arithmetic operations, and a control unit. A ROM 43 in which programs and the like are stored.

Various functions of the overall control unit 40 are stored in the ROM 4
3 is realized by the CPU 41 performing arithmetic processing according to the control program stored in the control program 3. Such a control program is stored in the ROM 43 in advance, but a new control program can be stored in the ROM 43 by reading it out from the memory card 9 or the like. In FIG. 3, the exposure control unit 51, the display control unit 52, and the AF control unit 53 schematically represent, as functional blocks, some of the functions realized by the CPU 41 performing arithmetic operations according to a control program.

The exposure controller 51 controls the exposure. Specifically, a shutter speed (corresponding to the exposure time of the CCD 21) and a diaphragm value (corresponding to the aperture diameter of the diaphragm) are determined based on the luminance value of the subject input from the luminance calculator 208 and a predetermined program chart. Then, a signal is transmitted to the timing generator 201 and the lens driving unit 209 so that the shutter speed and the aperture value are determined. If the subject is underexposed due to low brightness, the signal processing circuit 202 adjusts the level of the image data output from the CCD 21 to correct improper exposure due to insufficient exposure.

The display control section 52 controls the display on the liquid crystal monitor 28. The display image data stored in the VRAM 211 is read by the display control unit 52 in accordance with the refresh rate of the liquid crystal monitor 28, and
It is converted into a video signal and displayed on the liquid crystal monitor 28.
Also, it controls a generation method and the like when the display image generation unit 210 generates display image data.

The AF controller 53 monitors the focus evaluation value input from the AF calculator 207, and focuses the focusing lens in the photographing lens 3 so that the subject image in the focus area in the image data is in focus. Auto focus control for driving the motor 31 is performed. AF control unit 5
Reference numeral 3 controls the driving of the focusing lens 31 by transmitting a predetermined signal to the lens driving unit 209.

FIG. 7 is a diagram showing an example of the relationship between the lens position (the position of the focusing lens 31) and the focus evaluation value (contrast). As shown in the figure,
The focus evaluation value changes according to the lens position, and reaches a maximum value at any one of the lens positions. AF control unit 5
In step 3, the lens position at which the evaluation value becomes the maximum value is determined as the focus position FP, and the focusing lens 31 is moved to the focus position FP.

More specifically, assuming that the lens position before the autofocus control (hereinafter, referred to as an “initial position”) is the position indicated by the reference numeral IP, first, the focusing lens 31 is minutely driven from the initial position IP. (Arrow AR
1) The magnitude of the evaluation value obtained at each of the plurality of positions of the focusing lens 31 is determined. The driving direction of the focusing lens 31 is determined based on the evaluation value determination result, and the focusing lens 31 is driven in the determined driving direction (the direction of the arrow AR2). Then, the evaluation values sequentially obtained during the driving are monitored, and it is determined whether or not the monitored evaluation value decreases.

When the evaluation value decreases (arrow AR3),
It is determined that the lens position has passed the focusing position FP, and the driving direction of the focusing lens 31 is reversed (arrow AR4).
), And the focusing lens 31 is driven. Then, such a focusing lens 31
While switching the driving direction of the arrow (AR
5) The change of the focus evaluation value is monitored, and the focusing lens 31 is moved to the focusing position FP where the evaluation value finally reaches a maximum value.

<1-3. Overview of Digital Camera Operation>
Next, an outline of the operation of the digital camera 1 in the shooting mode will be described. FIG. 8 is a diagram schematically illustrating the operation of the digital camera 1 in the shooting mode.

When the digital camera 1 is set to the photographing mode, the digital camera 1 enters a photographing standby state, and performs a live view display in which image data repeatedly acquired by the CCD 21 is displayed on the liquid crystal monitor 28.

That is, first, image data for live view display is obtained by the CCD 21 (step ST1).
1). At this time, the output mode of the CCD 21 is set to the “first thinning mode” by the timing generator 201, and the first thinned image D3 is output from the CCD 21.
The output first thinned image D3 is output from the signal processing circuits 202 to
Predetermined processing is performed by the image processing unit 204 and stored in the image memory 205. Then, display image data is generated from the first thinned image D3 by the display image generation unit 210, and the generated display image data is displayed on the liquid crystal monitor 28. Thus, a live view display in which the subject image is displayed on the liquid crystal monitor 28 is performed (step ST1).
2).

FIG. 9 is a diagram for explaining a method of generating display image data used for live view display from the first thinned image D3. As described above, the first thinned image D
3 has 2560 horizontal pixels by 240 vertical pixels, the display image data D31 of 320 horizontal pixels by 240 vertical pixels that match the resolution of the liquid crystal monitor 28 is generated by simply thinning out the horizontal pixels by 1/8. You.

While such live view display is performed, the first thinned image D3 is also input to the luminance calculator 208, and the luminance value of the subject is derived. The derived brightness value of the subject is input to the overall control unit 40, and the shutter speed and the aperture value are determined by the exposure control unit 51 based on the brightness value (step ST13).

The series of operations in steps ST11 to ST13 are repeated until the shutter button 25 is half-pressed (while No in step ST14). CC
When the output mode of D21 is the “first thinning mode”, the frame rate is 30 fps, and thus a series of these operations is repeated at a cycle of 1/30 seconds. In addition,
In the digital camera 1 according to the present embodiment, the auto focus control is not performed during the series of operations, and therefore, the operations in steps ST11 to ST13 are referred to as “single live view operations” in the following description.

In the live view alone operation, when the shutter button 25 is half-pressed (S1) (Yes in step ST14), the shutter button 25
Is pressed as a focus control start instruction, and in response to this, the AF control unit 53 performs first autofocus control (step ST15).

Further, when the shutter button 25 is fully pressed (S
2) When this is done (Yes in step ST16), the full press of the shutter button 25 is accepted as an instruction to acquire image data for recording. In response to this, image data for recording is obtained, but prior to this, A
The second autofocus control is performed by the F control unit 53 (step ST17). The second autofocus control is a continuous control when the lens position cannot be driven to the focus position by the first autofocus control.
Alternatively, the adjustment is performed as the final adjustment of the lens position.

When the second auto focus control is completed,
Exposure is performed by the CCD 21 at the set shutter speed, and image data for recording is obtained (step S).
T18). At this time, the output mode of the CCD 21 is set to the “normal mode” by the timing generator 201, and the normal image D2 is output from the CCD 21. The output normal image D2 is subjected to predetermined processing in the signal processing circuit 202 to the image processing unit 204, stored in the image memory 205, and then compressed in a compression format such as JPEG and recorded on the memory card 9. (Step ST19).

After the image data for recording has been recorded, or after the shutter button 25 has been half-pressed, and the shutter button 25 has not been fully pressed (No in step ST16), the process returns to step ST11 again to perform live A view-only operation is performed.

<1-4. Auto Focus Control> In the digital camera 1, even during the auto focus control,
Display of subject image on LCD monitor 28 (live view display)
It is supposed to do. Hereinafter, the operation during the autofocus control will be described in detail. Note that, in the present embodiment, the same operation is performed in both the first and second autofocus control (steps ST15 and ST17).

In the digital camera 1, the method of autofocus control is made different depending on the brightness of the subject. Therefore, as shown in FIG. 10, in performing the auto focus control, the AF control unit 5 determines whether or not the brightness value of the subject input from the brightness calculation unit 208 is equal to or greater than a predetermined reference value.
3 (step ST31). If the brightness value of the subject is equal to or greater than the predetermined reference value, high-speed control is performed (step ST32), and if it is less than the predetermined reference value, normal control (step ST32) is performed.

When the luminance value of the subject is relatively low, a relatively long shutter speed is required. This shutter speed depends on the output cycle of the image data of the CCD 21. In the high-speed control (step ST33), the output mode of the CCD 21 is set to a “second thinning mode” in which image data is output at a 1/60 second cycle (details will be described later). For this reason, the output cycle of the image data becomes relatively short, resulting in insufficient exposure, and there is a possibility that an effective focus evaluation value cannot be obtained. Further, if the level of the image data is adjusted by the signal processing circuit 202 or the like in order to solve this, noise in the image data increases, and as a result, the accuracy of the evaluation value decreases. For this reason, high-speed control is performed only when the luminance value of the subject is equal to or greater than a predetermined reference value, so that highly accurate autofocus control can be performed.

<1-4-1. Normal Control> First, the normal control (step ST33) will be described. FIG. 11 is a timing chart showing the auto focus control operation in the normal control. In FIG.
PT12 indicates a time point. Time point P
T3 is a point in time when the shutter button 25 is half-pressed in the live view alone operation (S1), and the exposure EP immediately after that is pressed.
, The first auto focus control is performed from the start time PT4.

As described above, in the live view alone operation (time points PT1 to PT4), the output mode of the CCD 21 is set to the "first thinning mode", so that the exposure EP is repeated at a period of 1/30 second and acquired. The first thinned image D3 is output by 1/8 thinning-out reading of the image data D1. Then, in the same 1/30 second cycle, the generation LV of the display image data from the first thinned image D3 by the method shown in FIG. 9 is performed. Thus, the subject image displayed on the liquid crystal monitor 28 is updated every 1/30 seconds.

When the shutter button 25 is half-pressed (at time point PT)
3) Then, the process shifts to the auto focus control (time point PT4), but in the normal control, the output mode of the CCD 21 is set to the “first thinning mode” as it is. Therefore, after shifting to the auto focus control (at time points PT4 to PT
T12 ...) is also exposed EP at 1/30 second cycle, and
Reading of image data is repeated. Then, in the generation LV of the display image data, the same processing as the live view alone operation is repeated at a 1/30 second cycle. As a result, even during the auto focus control, the liquid crystal monitor 2
The subject image displayed at 8 is updated every 1/30 seconds, and the live view display is performed.

After the shift to the auto focus control (time points PT4 to PT12...), The focus area FA3 (1280 horizontal × 3 vertical) in the output first thinned image D3 is output.
Based on the 0 pixel: see FIG. 9), the AF calculation unit 207 derives a focus evaluation value FV, and the focusing lens 31 is driven based on the focus evaluation value. Since the first thinned image D3 is output at a period of 1/30 second, the derivation FV of the focus evaluation value is also 1/30.
It is performed in a second cycle. Then, such an operation is repeated, and finally the focusing lens 31 is moved to the in-focus position.

<1-4-2. High Speed Control> Next, the high speed control (step ST32) will be described. FIG. 12 is a timing chart showing the auto focus control operation in the high-speed control. In FIG. 12 as well as in FIG. 11, the shutter button 25 is half-pressed at time point PT3, and autofocus control is performed from time point PT4.
The live view alone operation (time points PT1 to PT4) is similar to the normal control.

When the shutter button 25 is half-pressed (at time point PT)
3) When the shutter button 25 is half-pressed, the operation shifts to the auto-focus control (time point PT4).
1 causes the output mode of the CCD 21 to be "second thinning mode"
Is changed to Therefore, after the shift to the autofocus control (time points PT4 to PT12,...), 1/16 thinning-out reading is performed on the acquired image data D1, and 1 /
The exposure EP is repeated at a cycle of 60 seconds. That is, the second thinned image D4 is repeatedly output from the CCD 21 at a period of 1/60 second.

Then, after the time point PT6, the display image generation unit 210 performs the generation ILV of the display image data from the second thinned image D4. FIG. 13 is a diagram for explaining a method of generating display image data from the second thinned image D4. As described above, the second thinned image D4 has 2560 × 120 pixels. For this reason, if pixels in the horizontal direction are simply thinned out to 1/8, image data D41 of 320 × 120 pixels is generated, and the resolution (320 × 240) required for display on the liquid crystal monitor 28 is obtained.
Image data having pixels) cannot be obtained. That is, the first thinned image D3 is image data having a data amount necessary for displaying the subject image, whereas the second thinned image D4 is image data having no data amount necessary for displaying the subject image. You can say that.

For this reason, the display image generation section 210 interpolates the vertical pixels of the image data D41 by a factor of 2 to obtain a horizontal 320 ×
The display image data D42 having 240 pixels vertically is generated. As the pixel interpolation method, for example, in addition to the bilinear method of performing linear interpolation from a plurality of neighboring pixel values, an interpolation method such as a nearest neighbor method or a bicubic method can be used. May be adopted. The display image data D42 generated from the second thinned image D4 in this way has a slightly lower image quality than the display image data D31 (see FIG. 9) generated from the first thinned image D3. The image quality is practically sufficient to grasp the state of the subject image.

Returning to FIG. 12, such a second thinned image D
Generation of display image data by interpolation from
This is called "interpolation generation". 3.) ILV is performed in a 1/30 second cycle in accordance with the refresh rate of the liquid crystal monitor 28. In other words, the interpolation generation ILV of the display image data is performed at a rate of one for every two exposures EP (and for the reading thereof).
Will be performed. Therefore, even during the high-speed control autofocus control, the subject image displayed on the liquid crystal monitor 28 is updated every 1/30 second, and the live view display is made smooth.

The interpolation generation ILV of the display image data is performed.
May be performed every 1/60 second in accordance with the output cycle of the second thinned image D4. In particular, in the case of an image pickup apparatus including a liquid crystal monitor whose refresh rate can be changed, by changing the refresh rate of the liquid crystal monitor to 60 fps, the live view display can be further smoothly performed and the change of the subject image can be easily grasped. .

The focus evaluation value is calculated based on the focus area FA4 (horizontal 12) in the output second thinned image D4.
80 pixels × 15 vertical pixels: refer to FIG. The second thinned image D4 is 1 /
Since the focus evaluation value is output at a cycle of 1/60 second, the output is performed at a cycle of 1/60 second. Therefore,
The derivation FV of the focus evaluation value is, for example, from time point PT4 to time point PT4.
It is performed four times in 1/15 second of PT8. On the other hand, during the same period PT4 to P4 in the normal control in FIG.
At T8, the derivation FV of the focus evaluation value is performed only twice. That is, by setting the output mode of the CCD 21 to the “second thinning mode”, the number of times of derivation FV of the focus evaluation value per unit time is doubled. Since this corresponds to an increase in the number of times of grasping the change of the evaluation value per unit time, it is possible to increase the driving speed of the focusing lens 31 without reducing the accuracy in determining the lens position. is there. Further, since the change in the evaluation value due to the lens position can be grasped precisely, the speed can be improved also in determining the lens position. Therefore, the auto-focus control can be performed quickly and with high accuracy.

Although the first embodiment has been described above, the digital camera 1 thins out the acquired image data D1 below the resolution required for display on the liquid crystal monitor 28 in order to quickly perform autofocus control. Even in this case, the interpolation of the thinned pixels is performed by the display image generation unit 210, so that the subject image can be appropriately displayed on the liquid crystal monitor 28.

In the digital camera 1, high-speed auto-focus control is performed in response to receiving an instruction to start auto-focus control. That is,
High-speed control is performed in both the first and second autofocus control, and high-speed control is performed throughout the entire autofocus control, so that autofocus control can be performed quickly.

<2. Second Embodiment> Next, a second embodiment of the present invention will be described. The CCD 21 of the digital camera 1 according to the first embodiment has only an output mode for thinning out the entire area of the acquired image data D1 as an output mode capable of outputting image data at high speed. The CCD 21 of the camera 1 has an output mode for outputting only a part of the acquired image data D1. Since the configuration of the digital camera 1 according to the present embodiment is the same as that shown in FIGS.
The following description focuses on the differences from the above embodiment.

FIG. 14 is a diagram for explaining image data output from the CCD 21 of the present embodiment. CC
D21 includes, as output modes, a “normal mode” for outputting a normal image D2 similar to that of the first embodiment, a “first thinning mode” for outputting a first thinned image D3, and a focus area. A "region limited mode" for outputting only a limited region including at least is provided.

As in the first embodiment, an area FA1 of 1280 (horizontal) × 240 (vertical) pixels at the center of the acquired image data D1 is set as a focus area.
When the output mode of the CCD 21 is set to the “area limited mode”, the horizontal 2560 including the focus area FA1 is set.
× Lines of only the limited area D11 having 240 pixels vertically are thinned out and read out at a rate of 1/2. This allows
An area limited image D5 having 2560 horizontal × 120 vertical pixels in which the pixels in the vertical direction of the limited area D11 are thinned out to １ ／ is output.

In the "region limited mode", the lines are read out so that the color components of the pixels are arranged in a Bayer arrangement. Specifically, the line L0 shown in FIG.
1, the 0th line L0, the third line L3, the fourth line L4, and the seventh line L
7 and the line indicated by reference symbol C in the figure is read. Since the number of lines to be output in the “area limited mode” is 120 lines, the frame rate is 60 fps (1/60 second cycle) as in the “second thinning mode” in the first embodiment. Become. That is, the number of image data to be output per unit time can be doubled in the “area limited mode” compared to the “first thinning mode”.

The area-limited image D5 output in the “area-limited mode” is not an image relating to the entire area of the acquired image data D1, and therefore does not include the entire subject image. That is, it can be said that the region limited image D5 is image data that does not have the data amount necessary for displaying the subject image.

The outline of the operation of the digital camera 1 of the present embodiment in the photographing mode is the same as that shown in FIG. 8, but in the first autofocus control (step ST15), the normal control (see FIG. 11) is always performed. Done. Then, the brightness value of the subject in FIG. 10 is determined only during the second autofocus control (step ST17), and when the brightness value of the subject is equal to or higher than a predetermined reference value, high-speed control is performed.

FIG. 15 is a timing chart showing the auto focus control operation in the high speed control according to the present embodiment. In FIG. 15, reference numerals PT21 to PT32 indicate time points, respectively. The time point PT23 is a time point when the shutter button 25 is fully pressed in the first autofocus control (S2), and the second autofocus control is performed immediately after the start time PT24 of the exposure EP.

As described in the first embodiment, the first auto focus control (time P
In T21 to PT24), since the output mode of the CCD 21 is set to the "first thinning mode", the output of the first thinned image D3 by the exposure EP and the 1/8 thinning is repeated in a 1/30 second cycle. . Then, in the same period as this, the generation LV of the display image data and the derivation FV of the focus evaluation value are performed.

When the shutter button 25 is fully pressed (at time PT2)
3) Then, the process shifts to the second autofocus control (time point PT24). In response to the full depression of the shutter button 25, in the high-speed control, the output mode of the CCD 21 is changed to the “region limited mode” by the timing generator 201. Is changed to. Therefore, after the shift to the second autofocus control (time points PT24 to PT32,...), １ ／ of the limited area D11 of the acquired image data D1 is obtained.
Thinning-out reading (hereinafter also referred to as “limited reading”)
LA is performed, and the exposure EP is repeated at a period of 1/60 second. In other words, the area limited image D5 is repeatedly output from the CCD 21 at a period of 1/60 second.

On the other hand, at the time point PT24 when the operation shifts to the second auto focus, the first thinned image D3 output by the nearest 1/8 thinning readout R1 is stored and held in the image memory 205 (reference HO). ). Then, after the time point PT26, the first thinned image D stored and held
3 and the generation CLV of the display image data based on the periodically output area limited image D5 is performed by the display image generation unit 210.
It is performed by

FIG. 16 is a diagram for explaining a method of generating display image data based on the first thinned image D3 and the area limited image D5. First, the horizontal pixel of the first thinned image D3 held in the image memory 205 is 1/8
, Image data D31 having 320 × 240 pixels is generated. On the other hand, the area limited image D
5 focus area FA5 (1280 horizontal × 120 vertical)
1/8) of the horizontal pixel only for the pixel), and
The vertical pixels are thinned out by 1/4 to generate image data D51 having 160 horizontal pixels × 30 vertical pixels. Then, the image data D51 is directly embedded in an area corresponding to the focus area of the image data D31. This allows
The two pieces of image data D51 and D31 are aligned and combined with each other while being adjusted to the same resolution (reduction ratio), thereby generating display image data D53.

Returning to FIG. 15, such a first thinned image D
3 (hereinafter referred to as “synthesis generation”) CLV
Is 1 according to the refresh rate of the LCD monitor 28.
/ 30 second cycle. That is, the exposure EP (and
That is, the combination generation CLV of the display image data is performed at a rate of once per two readings. Therefore, the subject image displayed on the liquid crystal monitor 28 is updated every 1/30 second even during the high-speed auto focus control of the present embodiment.

However, the display image data D53 is composed of pixels of the area limited image D5 for the focus area, and is composed of pixels of the first thinned image D3 for the peripheral area outside the focus area. As the area limited image D5, a newly obtained image is used in sequence, but the first thinned image D5 is used.
3 is stored and held in the image memory 205. Therefore, in the display image data D53, the peripheral area is not updated, and only the focus area is sequentially updated. As shown in FIG. 17, only the subject image in the focus area is focused. ,
The degree of focusing can be clearly understood.

The focus evaluation value is derived by the AF calculation unit 207 based on the focus area FA5 (see FIG. 16) in the area limited image D5. Since the region limited image D5 is output at a 1/60 second cycle, the derivation FV of the focus evaluation value is also performed at a 1/60 second cycle.
Therefore, the derivation FV of the focus evaluation value is performed, for example, four times in 1/15 seconds from the time points PT24 to PT26. On the other hand, time points PT21 to PT24 at which the normal control is performed
The derivation of the evaluation value is performed only twice in 1/15 second. Therefore, even in the high-speed control of the present embodiment, the derivation of the focus evaluation value per unit time F
The number of times of V is twice as large as that of the normal control, and the auto focus control can be performed quickly and with high accuracy.

Although the second embodiment has been described above, the present embodiment outputs an area-limited image D5 that is an area including at least a focus area, so that autofocus control can be performed quickly. . On the other hand, the display image data is generated by synthesizing the first thinned image D3 relating to the entire area and the area limited image D5, so that the subject image can be appropriately displayed on the liquid crystal monitor 28.

Further, compared with the first embodiment, since the thinning out of the focus area itself is あ り and the ratio of the thinning out is small, a highly accurate focus evaluation value can be obtained. At the same time, no pixel interpolation is performed in the display image data, so that an image with a high resolution is obtained.

The focus area in the first thinned image D3 is 1280 × 30 pixels, and the focus area in the area limited image D5 is 1280 × 12.
0 pixels. As a result, it can be seen that the data amount necessary for the autofocus control is secured even if the thinning rate is increased when acquiring the area limited image D5. Therefore, the degree of thinning when acquiring the area limited image D5 may be increased. According to this, the frame rate can be further increased, and more rapid autofocus control can be performed.

In the present embodiment, autofocus control of high-speed control is performed in response to receiving an instruction to acquire image data for recording. Therefore, since the image data for recording can be quickly acquired after the acquisition instruction, it is possible to prevent missing a photo opportunity.

<3. Third Embodiment> Next, a third embodiment of the present invention will be described. In the second embodiment, the subject image in the peripheral area in the display image data is not updated. However, in the present embodiment, the subject image in the peripheral area is updated. The configuration of the digital camera 1 according to the present embodiment is the same as that shown in FIGS.
Reference numeral 21 denotes the output mode of the CC of the second embodiment.
As in the case of D, a “normal mode”, a “first thinning mode”, and a “region limited mode” are provided. The outline of the operation in the photographing mode is the same as that shown in FIG.
As in the embodiment, normal control is performed in the first autofocus control (step ST15), and high-speed control is performed when the luminance value of the subject is equal to or more than a predetermined reference value in the second autofocus control (step ST17). It has become.

FIG. 18 is a timing chart showing the auto focus control operation in the high speed control according to the present embodiment. As in FIG. 15, in FIG.
3, the shutter button 25 is fully pressed, and the
, The second autofocus control is performed.

When the shutter button 25 is fully pressed (at time PT2)
3) Then, the process shifts to the second autofocus control (time point PT24). In response to the full depression of the shutter button 25, in the high-speed control, the output mode of the CCD 21 is changed to the “region limited mode” by the timing generator 201. Is changed to.

As a result, the limited readout LA of only the limited area D11 of the acquired image data D1 is performed, and the limited readout LA of the acquired image data D1 is performed.
Is performed twice (time points PT24 to PT26), the CCD
The output mode 21 is set to the “first thinning mode”, and 1/8 thinning reading of the acquired image data D1 is performed (time points PT26 to PT28). Thereafter, in the same cycle, C is switched between the “area limited mode” and the “first thinning mode”.
The output mode of the CD 21 is switched. That is, 1 /
The output mode of the CCD 21 is switched every 30 seconds,
The area-limited image D5 is output at a rate of two out of three readings, and the first thinned image D3 is output at a rate of one out of three readings. This also allows the exposure EP of the CCD 21 to be performed twice in the 1/60 second cycle and once in the exposure EP.
One exposure at a cycle of / 30 seconds is periodically repeated.

On the other hand, the point in time when the first thinned image is output from the CCD 21 (the point in time PT24 when shifting to the second autofocus, and the point in time when the "first thinning mode" is switched to the "area limited mode") PT28 ...)
The nearest 1/8 thinning-out reading (R1, R2, R3
..) Is output from the image memory 2
05 (reference HO). That is, the first thinned image D3 stored and held in the image memory 205 is “first
It is updated every time the first thinned image D3 in the “thinning mode” is output.

Then, based on the first thinned image D3 and the region limited image D5, a 1/30 second period (time point PT2
4, PT26, PT28, PT30 ...), display image data is generated, but this generation method differs depending on the most recently output image data. That is, when the most recently output image data is the first thinned image D3 (time points PT24, PT28 ...), the generation LV of the display image data shown in FIG. 9 is performed, and the most recently output image data is output. Is the region limited image D5 (time points PT26, PT30 ...)
Is configured to perform the synthesis generation CLV of the display image data shown in FIG. As described above, since the first thinned image D3 in the image memory 205 is sequentially updated, even when the display image data is generated by the method shown in FIG. 16, the peripheral area of the display image data is updated. Will be done. Therefore, in the present embodiment, it is possible to update the entire area of the display image data.

When the most recently output image data is the first thinned image D3 (at time points PT24, PT25, PT28, PT29 ...), the focus evaluation value is determined as the focus area in the first thinned image D3. When the image data derived based on FA3 (see FIG. 9) and output most recently is the area-limited image D5 (time points PT26, PT30,...)
The focus area FA5 in the area limited image D5 (FIG. 16)
Reference). Time point PT24 to PT28
Since image data is output three times from the CCD 21 in 1/15 second of the above, the focus evaluation value derivation FV
Is also performed three times. Thereafter, the same three derivation FVs of the evaluation value are repeated in a 1/15 second cycle. On the other hand, at time points PT21 to PT24 when normal control is performed, 1/15
In a second, the derivation of the evaluation value is performed only twice. Therefore, in the high-speed control of the present embodiment,
The number of times of deriving FV for deriving the focus evaluation value per unit time is 1.5 times that of the normal control, and the autofocus control can be performed quickly and with high accuracy.

Although the third embodiment has been described above, in the present embodiment, the output mode is switched between "first thinning mode" and "area limited mode" at a predetermined cycle. Therefore, it is possible to perform high-speed focus control while updating the entire area of the display image data.

<4. Modifications> While the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-discussed preferred embodiments, but allows various modifications.

For example, in the above-described first embodiment, high-speed control is performed in both the first and second autofocus control. However, as in the second and third embodiments, the second autofocus control is performed. High-speed control may be performed only in focus control. Conversely, in the second and third embodiments, high-speed control is performed only in the second autofocus control, but high-speed control may be performed in both the first and second autofocus controls. Good.

As described above, if high-speed control is performed in both the first and second auto-focus control, high-speed control is performed throughout the entire auto-focus control, and the auto-focus control can be performed quickly. However, in consideration of operability, it is more likely that framing is performed in the first autofocus, so that it is preferable to relatively emphasize the display of the subject image. On the other hand, in the second autofocus control, Is after the instruction to acquire the image data for recording,
It is preferable to place emphasis on speeding up the autofocus control. Therefore, operability can be improved by performing high-speed control only by the second autofocus control.

The high-speed control method in each of the above embodiments may be switched according to the operation stage. For example, in the first autofocus control, the high-speed control method of the first embodiment may be used, and in the second autofocus control, the high-speed control method of the second embodiment may be used. Since the high-speed control method according to the first embodiment can update the entire subject image, it can be said that, when compared with the high-speed control according to the second embodiment, the control method emphasizes the display of the subject image. . On the other hand, the high-speed control method according to the second embodiment can further increase the frame rate as described above, and therefore, is more important for speeding up the auto-focus control than the high-speed control according to the first embodiment. It can be said that it is a method that puts in. Therefore, by performing the above, it is possible to change the manner of weighting in displaying the subject image and increasing the speed of the autofocus control according to the necessity in the operation stage,
Operability can be improved.

The method of generating the display image data is not limited to the method in the above embodiment, but may be generated by another method. For example, in the second thinned image D4 in the first embodiment, the number of vertical pixels is 1 with respect to the resolution required for display on the liquid crystal monitor 28.
/ 2 image. For this reason, the display image data may be generated by combining the two second thinned images D4 that are continuously acquired. Specifically, one of the second
By inserting the data of the horizontal pixel line of the other second thinned image D4 between the data of the horizontal pixel line of the thinned image D4, both horizontal pixel lines are arranged alternately (alternately). Then, two second thinned images D4 are combined. Even in this case, since the second thinned image D4 is obtained at a 1/60 second cycle, the display image data can be generated at a 1/30 second cycle. According to this, display image data can be generated without performing interpolation, and an image with a high resolution is obtained. In such a case, in order to improve the image quality of the display image data, the readout line for outputting the second thinned image D4 from the CCD 21 must be placed between the two second thinned images D4 to be synthesized. It is preferable to make them different.

In the above embodiment, the CCD
When the output mode of No. 21 is the “region limited mode”, the region limited image D5 to be output is image data of a region including a horizontal pixel row including the focus area, but the region limited image D5 has at least the focus area. As long as it is included, for example, the image data of only the focus area may be used as the area limited image D5.

In the above embodiment, the brightness value of the subject is obtained from the image data output from the CCD 21. However, the brightness value of the subject may be detected using a brightness sensor or the like. .

Further, in the above-described embodiment, it has been described that various functions are realized by the CPU performing arithmetic processing according to a program. However, all or a part of these functions may be realized by a dedicated electric circuit. Good. In particular, a high-speed operation can be realized by constructing a portion where a repetitive operation is performed by a logic circuit. Conversely, all or some of the functions realized by the electric circuit are C
It may be realized by the PU performing arithmetic processing according to a program.

◎ The specific embodiments described above include inventions having the following configurations.

(1) In the image pickup apparatus according to claim 3, when the focus control means performs focus control, the image pickup means switches the output mode between the first output mode and the second output mode. Wherein the storage means updates the first image data stored and held each time the output mode of the imaging means changes to the first output mode.

According to this, the whole area of the display image data to be displayed on the display means can be updated.

(2) The image pickup apparatus according to any one of claims 4 and 5, and (1), further comprising a detecting means for detecting the luminance of the object, wherein the image pickup means detects the luminance of the object. An imaging apparatus, wherein the output mode is set to the second output mode only when the output mode is equal to or more than a predetermined reference value.

According to this, it is possible to prevent a decrease in the accuracy of focus control when the subject has low luminance.

[0119]

As described above, according to the first aspect of the present invention, even when the imaging means outputs the second image data which does not have the data amount necessary for displaying the subject image, the second means can be used. Since display image data is generated from the image data,
The subject image can be displayed on the display means.

Further, according to the second aspect of the present invention, the focus control is performed by using the second image data on which the pixels are thinned out, while the display image data is obtained by using the pixels on which the second image data is thinned out. Since the image is generated by interpolation, the subject image can be appropriately displayed on the display means while performing focus control quickly.

According to the third aspect of the present invention, the second image data including at least the focusing target area is used for the focus control, while the display image data is the first image data and the second image data. Therefore, the subject image can be appropriately displayed on the display means while performing focus control quickly.

According to the fourth aspect of the present invention, since the optical system can be driven at a high speed from the start of the focus control, the focus control can be performed more quickly.

According to the fifth aspect of the present invention, in response to receiving an instruction to acquire image data for recording, the output mode of the imaging means is set to the second output mode in which focus control can be quickly performed. Thus, after the acquisition instruction, the image data for recording can be quickly acquired.

[Brief description of the drawings]

FIG. 1 is a perspective view of a digital camera as an imaging device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a back side of the digital camera.

FIG. 3 is a diagram illustrating a main internal configuration of the digital camera as functional blocks.

FIG. 4 is a diagram illustrating an example of a pixel array of a light receiving unit of a CCD.

FIG. 5 is a diagram for explaining image data output from a CCD according to the first embodiment.

FIG. 6 is a diagram for explaining a read line of acquired image data.

FIG. 7 is a diagram illustrating an example of a relationship between a lens position and a focus evaluation value.

FIG. 8 is a diagram illustrating an outline of an operation in a shooting mode of the digital camera.

FIG. 9 is a diagram for explaining a method of generating display image data from a first thinned image.

FIG. 10 is a diagram showing a flow of processing for selecting one of normal control and high-speed control.

FIG. 11 is a diagram illustrating an autofocus control operation in normal control.

FIG. 12 is a diagram illustrating an auto-focus control operation in high-speed control according to the first embodiment.

FIG. 13 is a diagram for explaining a method of generating display image data from a second thinned image.

FIG. 14 is a diagram for explaining image data output from a CCD according to the second embodiment.

FIG. 15 is a diagram illustrating an autofocus control operation in high-speed control according to the second embodiment.

FIG. 16 is a diagram illustrating a first thinned image and an area-limited image,
FIG. 5 is a diagram for explaining a method of generating display image data.

FIG. 17 is a diagram illustrating an example of display image data generated in the second embodiment.

FIG. 18 is a diagram illustrating an autofocus control operation in high-speed control according to the third embodiment.

[Explanation of symbols]

1 Digital camera 3 Shooting lens 21 CCD 25 Shutter button 28 LCD monitor 31 Focusing Lens 52 Display control unit 53 AF control unit 201 Timing Generator 205 Image memory 210 display image generation unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 17/18 G02B 7/11 D H04N 9/07 G03B 3/00 A (72) Inventor Noriyuki Okisu Osaka Osaka International Building Minolta Co., Ltd. (72) Inventor Toshihiro Hamamura 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka Metropolitan Building Minolta Co., Ltd. (72) ) Inventor Shinichi Fujii Osaka International Building Minamita Co., Ltd. 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi Inventor Tsutomu Honda 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Co., Ltd. F term (reference) 2H011 AA03 BA31 BB04 CA21 DA05 2H051 AA00 BA47 CE01 CE14 DA01 FA48 GA03 GA13 2H102 AA44 BA12 CA34 5C022 AB26 AC42 5C065 BB11 DD02 EE05 EE06

Claims (5)

[Claims] An imaging unit that acquires image data of a subject via an optical system; a focus control unit that performs focus control of the optical system based on image data from the imaging unit; and an image from the imaging unit. A display unit for displaying a subject image based on data, wherein the imaging unit includes an output mode for outputting the acquired image data, wherein both the focus control and the display of the subject image are performed. A first output mode for outputting first image data having a necessary data amount, and a first output mode having a data amount necessary for the focus control and not having a data amount necessary for displaying the subject image. A second output mode for outputting two image data, wherein the imaging device is configured to output the second image data when the output mode of the imaging unit is the second output mode. Imaging device that, the image generating means for generating display image data for displaying the object image on the display unit, comprising: a based on. 2. The image capturing apparatus according to claim 1, wherein the image capturing unit is configured to, when the output mode is the second output mode, apply to the acquired image data including a two-dimensional array of a plurality of pixels. The image data obtained by thinning out pixels in one of the two-dimensional arrays in the two-dimensional array
Output as image data, wherein the image generating means generates at least a part of the display image data by supplementing pixels decimated in the process of generating the second image data by interpolation of the second image data. An imaging device, comprising: 3. The storage device according to claim 1, wherein the first image data output from the imaging unit is stored when the output mode of the imaging unit is the first output mode. The imaging means, when the output mode is the second output mode, the image data including at least a focusing target area used for the focus control in the acquired image data, the second image data An image pickup apparatus, wherein the image generating unit generates the display image data based on the first image data and the second image data stored and held in the storage unit. 4. The imaging apparatus according to claim 2, further comprising: a receiving unit that receives an instruction to start focus control of the optical system from a user, wherein the imaging unit receives the instruction to start focus control. The output mode is set to the second output mode in response to the request. 5. The image capturing apparatus according to claim 2, further comprising: a receiving unit configured to receive an instruction to acquire image data for recording by the image capturing unit from a user, wherein the image capturing unit includes the image for recording. In response to receiving the data acquisition instruction, the output mode is changed to the second mode.
An imaging device, which is set to an output mode.