KR101673019B1 - Photographing apparatus and auto focus adjusting apparatus - Google Patents

Abstract

The present invention relates to a photographing apparatus and an auto-focus adjusting apparatus, and more particularly to a photographing apparatus and an auto-focus adjusting apparatus which are capable of performing multi-division focus detection in a plurality of focus detection regions obtained by dividing at least a partial region of an image- An image pickup apparatus comprising: focus detection means; and control means for driving the focus lens in accordance with the focus detection result, wherein an area of each of the plurality of focus detection regions of the multi-segmental focus detection for moving images is a plurality The focus detection area being larger than the area of each focus detection area of the main focus detection area.

Description

[0001] The present invention relates to a photographing apparatus and an auto focus adjusting apparatus,

The present invention relates to a photographing apparatus and an autofocusing apparatus.

In order to capture a clear still image or a moving image in a photographing apparatus such as a camera or a camcorder, it is necessary to accurately focus on the subject. For this purpose, focus adjustment is performed on the AF area set in the image.

1 is a view showing an AF area.

Referring to Fig. 1 (a), the AF area is divided into a plurality of focus detection areas. This multi-segment focus detection area is advantageous for AF control of a still image that captures various compositional images. That is, the AF control is possible regardless of the position of the main subject. However, the reason for segmenting the AF area is as follows. When the size of the imaging device is increased, the depth of field becomes shallow. This means that the range of focus in the image becomes shorter. Therefore, the AF area is subdivided in order to closely correspond to the distance distribution of the subject. Then, a portion determined to have a subject is selected from among the subdivided regions, and AF adjustment is performed on the selected region.

However, the stability of the AF operation is emphasized when shooting motion pictures. In the case of photographing a moving image using a refined focus detection area as shown in FIG. 1 (a), the focus position is changed even if the subject moves a little, and the AF adjustment is frequently performed. Therefore, the video which is very inconvenient to watch is taken. In order to solve the above problem, a large area is used as an AF area as shown in FIG.

Referring to FIG. 1 (b), in the large AF area, a flower located at a close distance, a person located at a medium distance, and a mountain located at a remote location are simultaneously included. At this time, it is possible to perform stable AF adjustment because the subject is out of the AF area, a new subject enters the AF area, and the like. However, since the subjects located at various distances are located in the AF area at the same time, the focus position does not match any object.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photographing apparatus and an automatic focus adjusting apparatus capable of photographing an image focused on a main subject when photographing moving images.

According to an aspect of the present invention, there is provided an image pickup apparatus including a focus lens, driving means for driving the focus lens, and focus detection means for performing multi-division focus detection in a plurality of focus detection regions And a control unit for driving the focus lens in accordance with the result of focus detection, wherein the area of each of the plurality of focus detection areas of the multi-divisional focus detection for moving images is the same as that of the still image multi-divisional focus detection Is larger than the area of each of the plurality of focus detection areas of the focus detection area.

According to another aspect of the present embodiment, the total area of the plurality of focus detection areas of the multi-segmented focus detection for moving images can be equal to or larger than the total area of the plurality of focus detection areas of the still image multi-segmentation focus detection.

According to still another aspect of the present embodiment, there is provided an image pickup apparatus including a switch of a two-stage input system, wherein the control means performs multi-segment focus detection for stationary mode in response to a first- It is possible to switch to multi-divisional focus detection for moving images.

According to still another aspect of the present embodiment, moving picture shooting can be started in response to the two-stage input signal of the switch.

According to another aspect of the present embodiment, the control means controls the focus lens to be driven at a high speed corresponding to the one-stage input signal of the switch, and controls the focus lens to be driven at low speed in accordance with the two- have.

According to another aspect of the present invention, there is provided an imaging apparatus including an imaging device for imaging a light passing through an imaging lens to generate a video signal, a focus detection evaluation value calculation unit for performing focus detection using a video signal, A position detection section for detecting the position of the focus lens, and an optimum position calculating section for calculating an optimum position of the focus detection evaluation value using the position of the focus lens and the focus detection evaluation value, And a control section for controlling the focus lens to drive the focus lens to the calculated optimum position, wherein the area of each of the plurality of focus detection areas of the multi-segmentation focus detection for moving images is determined by a plurality of respective focus detection And the area of the area is larger than the area of the area.

According to another aspect of the present invention, there is provided an image pickup apparatus including a switch of a two-stage input system, performing multi-split focus detection for a still image corresponding to a first-stage input signal of a switch, It is possible to switch to multi-division focus detection.

According to still another aspect of the present invention, there is provided an image pickup apparatus including a first switch and a second switch, performing multi-split focus detection for a still image corresponding to an input signal of the first switch, It is possible to perform multi-segment focus detection.

According to another feature of this embodiment, the imaging lens may be an interchangeable lens.

With the above-described structure, the photographing apparatus and the automatic focus adjusting apparatus according to the present invention can photograph an image focused on the main subject at the time of moving picture photographing.

1 is a view showing an AF area.
2 to 5 are views showing an AF area for a moving picture according to an embodiment of the present invention.
6 is a diagram illustrating a camera system according to an embodiment of the present invention.
7 is a view showing a camera control unit of the camera system according to FIG.
8 is a diagram for explaining the peak value detection of the AF evaluation value in the contrast AF method.
9 to 12 are flowcharts showing a method of controlling a camera system according to an embodiment of the present invention.
13 is a diagram illustrating a camera system according to another embodiment of the present invention.
14 is a diagram illustrating a camera system according to another embodiment of the present invention.
15 to 18 are flowcharts showing a method of controlling a camera system according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In order to solve the problem caused by the focus adjustment in the AF area as shown in FIG. 1, the present invention provides various multi-segmented focus detection areas as shown in FIGS. 2 to 5 so that the photographing apparatus and the focus adjustment apparatus are stable, .

FIGS. 2 to 5 are views showing an AF area for moving images according to various embodiments of the present invention.

Referring to FIG. 2, the moving image AF area according to the present embodiment divides the center portion of the image into 15 equal areas from e1 to e15 as shown in FIG. However, the size of each divided area and the entire AF area is larger than the size of each area and the entire AF area in FIG. 1 (a).

Referring to FIG. 3 (a), the moving image AF area according to the present embodiment divides the entire AF area into three areas. As shown in FIG. 3 (b), if the AF area is divided into three as shown in FIG. 1 (b), the focus adjustment position for each subject is obtained in each AF area. It is possible to perform AF adjustment by selecting one of the areas.

Referring to FIG. 4, in the moving image AF area according to the present embodiment, the entire AF area is divided into three areas, and a part of the areas is overlapped with each other.

Referring to FIG. 5, the moving image AF area according to the present embodiment includes two areas, and one area is included in another area.

2 to 5, the size of each divided area and the entire AF area may be equal to or larger than the size of each area of the still image AF area and the size of the total AF area as shown in FIG. 1 (a). In addition, the moving image AF areas may be set in combination with several still image commercial AF areas or may be set separately from the still image commercial AF areas.

Hereinafter, various embodiments for capturing an image using the various AF areas shown above will be described.

{First Embodiment}

[Configuration of Camera System]

6 is a diagram showing a camera system 1 according to an embodiment of the present invention.

Referring to FIG. 6, the camera system 1 according to the present embodiment includes an exchangeable lens 100 and a main body 200. In this embodiment, the main body 200 is provided with a focus detection function, and the interchangeable lens 100 is provided with a function of driving the focus lens 104.

The interchangeable lens 100 includes a focusing optical system 101, a zoom lens position detection sensor 103, a lens driving actuator 105, a focus lens position detection sensor 106, a diaphragm driving actuator 108, a lens control unit 110, and a lens mount 109.

The focusing optical system 101 includes a zoom lens 102 for zoom adjustment, a focus lens 104 for changing the focus position, and a diaphragm 107. In the following description, the term " imaging lens " is used in the concept including the zoom lens 102 and thephorsus lens 104. [

The zoom lens position detection sensor 103 and the focus lens position detection sensor 106 sense the positions of the zoom lens 102 and the focus lens 104, respectively. The timing for sensing the position of the focus lens 104 may be set by the lens control unit 110 or a camera control unit 209 to be described later. For example, the timing for sensing the position of the focus lens 104 may be a timing for performing AF detection from a video signal. The focus lens position detection sensor 106 may be an example of the position detection unit.

The lens driving actuator 105 and the diaphragm driving actuator 108 are controlled by the lens control unit 110 to drive the focus lens 104 and the diaphragm 107, respectively. In particular, the lens driving actuator 105 drives the focus lens 104 in the optical axis direction. The lens driving actuator 105 may be an example of a focus lens driving unit.

The lens control unit 110 includes a timer 111 and a lens memory 112 for time measurement. Also, the lens controller 110 transmits position information of the detected focus lens 104 to the main body 200.

The lens mount 109 has a lens-side communication pin and meshes with a camera-side communication pin, which will be described later, and is used as a transmission path for data, a control signal, and the like.

Next, the configuration of the main body 200 will be described.

The main body unit 200 includes a viewfinder (EVF) 201, a shutter 203, an imaging element 204, an imaging element control section 205, a display section 206, an operation button 207, a camera control section 209, And a camera mount 208.

The viewfinder 201 may have a built-in liquid crystal display unit 202 and can view a captured image in real time.

The shutter 203 determines the time that light is applied to the image sensing element 204, that is, the exposure time.

The image pickup element 204 picks up image light that has passed through the imaging optical system 101 and generates a video signal. A charge coupled device (CCD) sensor, a complementary metal oxide semiconductor (CMOS) sensor, or the like may be used as the image sensing element 204.

The imaging element control unit 205 generates a timing signal and controls the imaging element 204 to capture the image in synchronization with the timing signal. Further, the image pickup element control unit 205 sequentially reads the horizontal direction video signals when the charge accumulation in each scanning line ends. The read horizontal direction video signal is used for AF detection in the camera controller 209.

The display unit 206 displays various images and information. The display unit 207 may be a liquid crystal display (LCD), an organic light emitting diode (OLED) display, or the like.

The operation button 207 is a part for inputting various commands from the user for the operation of the camera system 1. [ The operation buttons 207 may include various buttons such as a main switch SM, a shutter release button, a mode dial, and a menu button. The shutter release button may be a switch of a two-stage input method, in which the switch corresponding to the first depression is denoted by S1, and the switch corresponding to the depression of the second depression is denoted by S2.

The camera control unit 209 performs AF detection on a video signal generated by the imaging device 204 to calculate a focus detection evaluation value (hereinafter, referred to as an AF evaluation value). Further, the AF evaluation value at each AF detection time according to the timing signal generated by the imaging element control unit 205 is stored, and the optimum position of the focus lens is calculated using the lens position information transmitted from the lens 100 and the stored AF evaluation value Position, that is, a focus position. The calculation result of the optimum position is transmitted to the lens 100. That is, the camera controller 209 may be an example of a focus adjustment evaluation value calculator and an optimum position calculator.

The camera mount 208 has a camera-side communication pin.

Hereinafter, the schematic operation of the lens 100 and the main body 200 will be described.

When the subject is photographed, the camera system 1 starts its operation by turning on the main switch SM included in the operation button 207. [ The camera system 1 performs live view display once as follows.

The image light of the subject that has passed through the imaging optical system 101 is incident on the imaging element 204. [ At this time, the shutter 203 is in the open state. The incident object light is converted into an electric signal by the image pickup element 204, thereby generating a video signal. The image pickup element 204 operates by the timing signal generated by the image pickup element controller 205. [ The generated image signal of the subject is converted into displayable data in the camera control unit 209 and outputted to the viewfinder 201 and the display unit 206. [ This operation is a live view display, and the live view image displayed by the live view display is continuously displayed as a moving image.

After the live view display is performed, when the shutter release button, which is one of the operation buttons 207, is half-pressed and S1 is turned on, the camera system 1 starts the AF operation. The AF operation is performed using the image signal generated by the image pickup element 204. In the contrast AF method, the focus position of the focus lens is calculated from the AF evaluation value related to the contrast value, and based on the calculation result, . The AF evaluation value is calculated by the camera control unit 209. The camera control unit 209 calculates information for controlling the focus lens 104 from the AF evaluation value and transmits the information for controlling the focus lens 104 to the lens control unit 110 via the communication pin provided on the lens mount 109 and the camera mount 208. [ ).

The lens control unit 110 controls the lens driving actuator 105 based on the received information to drive the focus lens 104 in the optical axis direction to perform AF. The position of the focus lens 104 is monitored by the focus lens position detection sensor 106 and feedback control is performed.

The position of the zoom lens 102 is detected by the zoom lens position detection sensor 103 and the lens control unit 110 detects the position of the AF control parameter of the focus lens 104 And AF is performed again. The AF control parameters can be stored in the lens memory 112 as the intrinsic information of the interchangeable lens 100. [ When the position of the zoom lens 102 is changed, the conversion coefficient of the focus lens shift amount and the focus shift amount is changed, but this conversion coefficient is also one of the unique parameters storing.

When the camera system 1 is in the still image shooting mode when the shutter release button is fully depressed and the S2 is turned on when the subject image is in focus as described above, Exposure is performed. At this time, the camera control unit 209 once closes the shutter completely and transmits the photometric information obtained so far to the lens control unit 110 as iris control information. The lens control unit 110 controls the diaphragm drive actuator 108 based on the diaphragm control information and tightens the diaphragm 107 to an appropriate diaphragm value. The camera control unit 209 controls the shutter 203 based on the photometric information, opens the shutter 204 for an appropriate exposure time, and captures the photographed subject image.

On the other hand, when the camera system 1 is in the moving image shooting mode, the camera system 1 performs moving image exposure, that is, moving image shooting. When shooting a movie, movie shooting ends when the shutter release button is fully pressed again and S2 turns from On to Off.

The still image capture image is subjected to image signal processing and compression processing and stored in the memory card 212. At the same time, a captured image is output to the viewfinder 201 and the display unit 206, which display the subject. This image is called a quickview image. A series of photographing operations is completed by the above process. In the case of moving picture shooting, moving picture compression processing is performed at the same time as shooting, and the moving picture is stored in the memory card 212. When taking a movie, you may not provide a quickview.

[Configuration of camera control unit and camera operation]

FIG. 7 is a diagram showing a camera control unit 209 of the camera system according to FIG.

7, the camera control unit 209 according to the present embodiment includes a preprocessing unit 220, a signal processing unit 221, a compression expansion unit 222, a display controller 223, a CPU 224, a memory controller 225, an audio controller 226, a card controller 227, a main bus 230, and the like.

The camera control unit 209 transmits various instructions and data to the respective parts through the main bus 230.

The preprocessor 220 receives an image signal generated by the image sensing element 204 and performs arithmetic operations of AWB (Auto White Balance), AE (Auto Exposure), and AF (Auto Focus). That is, the AF evaluation value for the automatic focus control, the AE evaluation value for the exposure control, and the AWB evaluation value for the white balance control are calculated.

The signal processing unit 221 performs a series of video signal processing such as gamma correction to produce a live view image or a captured image that can be displayed on the display unit.

The compression expansion unit 222 compresses and decompresses the image signal subjected to the image signal processing. In the case of compression, the image signal is compressed in a compression format such as JPEG compression format or H.264 compression format. The image file including the image data generated by the compression process is transferred to the memory card 212 and stored.

The display controller 223 controls the video output of the viewfinder 201 to the display screen such as the LCD 202 and the display unit 206. [

The CPU 224 controls the operation of each part as a whole. Also, in the case of the camera system 1 according to Fig. 6, the CPU 224 performs communication with the lens 110. Fig.

The memory controller 225 controls the memory 210 for temporarily storing captured image data such as captured images and association information, and the audio controller 226 controls the microphone or the speaker 211. The card controller 227 also controls the memory card 212 that stores the turned-on image.

Hereinafter, a schematic operation of the camera control unit 209 will be described.

When the CPU 224 detects that the main switch SM is turned on, the CPU 224 operates the imaging element control section 205 through the preprocessing section 220. The imaging element control section 205 outputs a timing signal to operate the imaging element 204. [ When a video signal is input from the image pickup element 204 to the preprocessing unit 220, AWB and AE operations are performed. The results of the AWB and AE operations are fed back to the image pickup element control unit 205 so that a proper color output and an image signal of an appropriate exposure are obtained from the image pickup element.

On the other hand, when the operation of the camera system 1 is started, a live view display is performed. The camera control unit 209 inputs the video signal photographed with proper exposure to the preprocessing unit 221 to calculate the AE evaluation value and the like. The live view display video signal is directly applied to the signal processing unit 221 without passing through the main bus 230 and performs video signal processing such as interpolation processing of pixels. The video signal on which the video signal processing is performed is displayed on the LCD 202, the display unit 206, and the like via the main bus 230 and the display controller 223. The live view display is basically updated at a cycle of 60 fps (frame per second), but the present invention is not limited thereto and may be updated at a cycle of 30 fps, 120 fps, 240 fps, and the like. The update speed may be set by the CPU 224 based on the photometry result, the AF condition, or the like, and may be performed by changing the timing signal in the image pickup element controller 205. [

When the shutter release button is half-pressed and S1 is turned on, the CPU 224 senses an On input of the half-press signal S1 and transmits the ON signal to the lens control unit (not shown) via a communication pin provided on the camera mount 208 and the lens mount 109 110 to start driving the focus lens 104 for AF operation.

The CPU 224 acquires a video signal from the imaging device 204, and the preprocessing unit 220 calculates an AF evaluation value. The AF evaluation value is calculated in accordance with the movement of the focus lens 104. [ The position of the focus lens 104 (the position at which the AF evaluation value becomes maximum) at which the contrast of the subject image becomes the maximum is calculated from the change of the AF evaluation value, and the focus lens 104 is moved to the calculated position. The above series of operations is the AF operation, and the display of the live view image is continuously performed even during the AF operation. The video signal used for the live view video and the video signal used for calculating the AF evaluation value are the same video signal.

6, in the case of the camera system 1 using the interchangeable lens 100 shown in FIG. 6, the camera mount 208 and the lens mount 109 ) Is used as the communication pin.

When the shutter release button is fully depressed and S2 is turned on, the AF operation is stopped in the still image shooting mode, the AF operation is maintained in the moving image shooting mode, and the AF operation is repeated continuously after the focus is set. This AF operation is called continuous AF. However, in such a case, the focus lens 104 is driven at a low speed so as to minimize the influence of sound or angle of view change at the time of moving picture shooting.

[Detection of peak]

A method of detecting the peak value of the AF evaluation value in the AF operation will be described below.

8 is a diagram for explaining the peak value detection of the AF evaluation value in the contrast AF method. The detection of the in-focus position in the contrast AF method is to detect the peak value of the AF evaluation value. The horizontal axis in FIG. 8 indicates the position of the focus lens at the AF detection time, and the vertical axis indicates the AF evaluation value. The AF detection time point means an intermediate time point between the charge accumulation start time and the charge accumulation end time in the AF area of the image pickup device.

Since the AF evaluation values are discrete, the actual peak value can be calculated by interpolating the AF evaluation values. The actual peak is a point PK where the AF evaluation value is Vpk when the focus lens position is LVpk. Here, the interpolation calculation for detecting the peak value can be performed using three pieces of data, for example, LV3, LV4, LV5 and corresponding AF evaluation values s3, s4, s5.

When the peak value of the AF evaluation value is calculated, the position of the focus lens at the timing having the peak value is determined. This makes it possible to drive the focus lens 104 to a focused target position.

[Control method of camera system]

The operation of the camera system 1 will be described with reference to Figs. 9 to 12. Fig.

The operation A1 in Fig. 9 is an operation at the start of operation of the camera system 1. Fig. When the main switch SM of the camera system 1 is turned on and the camera system 1 is started, the operation of the operation button is detected (S101). At this time, the state of the mode dial is also detected. According to the state of the mode dial, either a still image or a moving image is selected (S102).

The camera control unit 209 receives the lens information necessary for the camera operation from the interchangeable lens 100 (S103). The lens information is information necessary for AF, AE, AWB, and image quality control with each lens-specific parameter stored in the lens memory 112. The image pickup element 204 periodically captures an image to generate a video signal (S104). In addition, the preprocessing unit 220 performs the AE calculation and the AWB calculation according to the photometric result (S105). Then, live view display is performed (S106). The steps S104 through S106 are sequentially performed, but the steps are simultaneously performed while receiving the video signal from the image sensing element 204. [ Then, it is determined whether the main switch SM is off (S107). If the main switch SM is not off, the process returns to S101 and the live view operation is repeated. On the other hand, if the main switch SM is off, the camera system 1 is stopped (S108) and the operation A1 of the camera system 1 is ended.

Next, a case in which the shutter release button is half-pressed during the live view display will be described.

10 is a flowchart showing an interrupt operation when the shutter release button is half-pressed.

Referring to FIG. 10, if the shutter release button is half-depressed while S1 is ON while the live view is displayed, the operation A2 is started. When the operation A2 is started, a high-speed driving command is transmitted to the interchangeable lens 100 for high-speed driving of the focus lens 104 (S110). The lens control unit 110 drives the focus lens 104 at a constant speed in accordance with the command to perform contrast AF.

When the focus lens 104 starts to be driven, a photographing timing signal is input to the CPU 224 (S111). The photographing timing signal is a signal indicating the timing of starting AF detection. The signal is generated corresponding to the set AF detection area. The CPU 224 counts the driving signals generated by the imaging element control unit 205, and determines that the AF detection starts when the predetermined number of times is counted. That is, the timing corresponds to the focus detection area position delayed by a predetermined time from the accumulation start point.

When the photographing timing signal is inputted, the AF detection circuit of the preprocessing unit 220 inputs the image signal of the AF area to perform AF detection (S112), sets the area 1 of the AF area of FIG. 1 as areaS, The AF evaluation values L1 to L15 are calculated for each area of the area (S113). The size of the total AF area is set to a high probability of a sum of seconds.

When the AF evaluation value is calculated, the conversion coefficient KL of the current focal distance from the lens 100, the position of the focus lens 104 at the AF detection timing, the drive amount of the current focus lens 104 and the amount of focus misalignment is obtained and is calculated And stored as a set with one AF evaluation value (S114).

Then, it is determined whether the focus lens 104 has been driven to one end (S115). If it is not driven to the end, it is determined whether all the AF evaluation values L1 to L15 have exceeded the peak (S116). If all of the AF evaluation values do not pass the peak, the process returns to step S111. On the other hand, the focus lens 104 may be driven to one end before all the peak values are calculated during the AF operation. Accordingly, if the focus lens 104 is driven to one end, the process proceeds to step S124, and it is determined whether the AF evaluation value exceeds a peak in at least one area (S124). If at least one of the AF evaluation values exceeds the peak, the process proceeds to step S117. On the other hand, if there is no area beyond the peak of the AF evaluation value, it is determined that the AF adjustment has failed and the drive stop command of the focus lens 104 is transmitted to the lens 100 (S125). Then, after the AF failure is displayed (S126), the process returns to the step A1 of FIG. 9 to repeat the live view display.

If the AF operation is to be continuously performed, the subject is determined by the multi-point algorithm using the AF evaluation values calculated in step S113 (S117). Here, the multi-point algorithm can be assumed to be performed for all of the fifteen divided areas and only for the area in which the peak value is detected, but this is the same in both methods. Generally, the region in which the peak position is determined to be closest to the camera is selected. However, when the magnification is larger than the predetermined magnification, if the central region is selected, an algorithm with a high inference probability is obtained. For example, the predetermined magnification may be 1/50 or 1/60 times for APS-C format (Advanced Photo System type-C format). Hereinafter, the above-described multipoint algorithm will be described.

11 is a flow chart of the multipoint algorithm operation. The subroutine of FIG. 11 assumes that a region other than the low contrast region is extracted in the multi-segment AF region, and the detection of the peak position is completed for each extracted region.

First, it is determined whether or not the magnification of the subject detected in the AF area in the center part of the multi-division AF area exists (S301). The center magnification can not be obtained when the peak position is not detected due to the low center of the central portion. Here, the magnification can be calculated by knowing the focal distance of the lens and the position of the focus lens. If it is determined that the magnification is greater than 1/60 (S302), it is determined that there is a higher probability that the main subject exists in the center, and it is determined that AF is adjusted for the center area (S303). On the other hand, when there is no central magnification or the central magnification is 1/60 or less, the area determined to be the closest to the peak position is determined as the area to be AF-adjusted (S304).

When one of the AF areas is selected by the multipoint algorithm operation, the peak value (Vpk) of the AF evaluation value and the focus lens position (LVpk) at the position where the peak value is calculated in the selected area are interpolated (S118). It is determined whether the calculated peak value Vpk is larger than the reference value PKT (S119). If Vpk is larger than the reference value, it is determined that AF adjustment is possible. Therefore, the correction coefficient for correction is applied from the lens 100, and the lens position error is corrected according to the position of the selected region (S120). The error of the lens position is caused by the difference between the imaging lens and the AF detection frequency, and this error also varies depending on the position of the focus detection area. Therefore, the lens position error is corrected in consideration of the error DELTA IBoff caused by the position of the focus detection area in the error DELTA IB caused by the difference between the imaging lens and the AF detection frequency. Here, [Delta] IBoff is a value determined according to the selected focus detection area.

Since the unit of the lens position correction value is um, it is changed to the drive amount of the focus lens (S121). This can be obtained by ΔLVpk × KL. At this time, KL uses the KL nearest to LVpk.

Subsequently, the driving amount of the focus lens, the backward driving command of the focus lens 100, and the high-speed driving command of the focus lens 100 to the target position are transmitted to the lens 100 (S122). The lens 100 accordingly starts the reverse drive of the focus lens 104 to drive the focus lens 104 to the target position.

Thus, if the focus adjustment is successful, AF success is displayed (S123), and the operation returns to A1 in FIG. 11 to repeat the live view display.

Next, a case in which the shutter release button is fully depressed during the live view display will be described.

12 is a flowchart showing an interrupt operation when the shutter release button is fully depressed.

Referring to FIG. 12, when the shutter release button is fully depressed while S2 is turned on while the live view is displayed, the operation A3 is started. When the operation A3 is started, it is determined whether the camera is in the moving image shooting mode (S131). When the camera system 1 is in the still image capturing mode, the process of focusing, capturing a still image, and displaying a quick view image is performed according to a conventional still image capturing method (S132 to S134).

On the other hand, if the camera system 1 is in the moving image shooting mode, the moving image is exposed and the moving image capturing is started (S141). This video exposure continues until S2 is turned on and off. When capturing a moving image is started, it is determined whether the lens is in focus (S142). If the focus is correct, the next AF adjustment is performed after a predetermined time Tw elapses (S143). This is based on the assumption that continuous AF is performed during moving picture shooting. In order to smoothly perform continuous AF, a new AF adjustment is performed after a predetermined time elapses even after in-focus. For example, Tw is a number such as 500 ms or 1 s. If it is not in ineffected in step S142, it does not perform waiting for a predetermined time as in step S143.

Next, a low-speed drive command of the focus lens 104 is transmitted to start the low-speed drive of the focus lens 104 (S144). This is because it is easier to appreciate that the focus lens 104 is driven at a low speed when capturing a moving image.

Then, the multi-segmentation AF areaM is switched to the multi-segmentation AF areaM for each moving image having a larger size by comparing the multi-segmentation focus detection area with the static AF for the commercial application at step S1 (S145). In the present embodiment, the AF area area 3 shown in FIG. 3 (a) is taken as areaM.

When the AF area is switched, a photographing timing signal is input to the CPU 224 (S146), and AF detection is performed (S147). AF evaluation values L16 to L18 are calculated for each area of area M by AF detection (S148). The AF area in FIG. 3 includes a center portion and is divided into three areas. The size of the entire AF area is the same as the size of the entire AF area in Fig. The reason for making the size of the entire area the same is to prevent the case where the focus pocus is lost or newly generated when the focus detection area is switched.

After the calculation of the AF evaluation value, the conversion coefficient KL of the current focal distance from the lens 100, the position of the focus lens 104 at the AF detection timing, the drive amount of the current focus lens 104 and the amount of focus misalignment is obtained And stored as a set with the calculated AF evaluation values (S149).

Then, it is determined whether the focus lens 104 has been driven to one end (S150). If it is not driven to the end, it is determined whether all the AF evaluation values L16 to L18 have exceeded the peak (S151). If all the AF evaluation values do not pass the peak, the process returns to step S145. On the other hand, if the focus lens 104 is driven to one end before all the peak values are calculated during the AF operation, the process proceeds to step S161 to determine whether the AF evaluation value has exceeded the peak in at least one area (S161). If at least one of the AF evaluation values exceeds the peak, the process proceeds to step S152. On the other hand, if there is no region beyond the peak of the AF evaluation value, it is determined that the AF adjustment has failed with a low contrast, and the drive stop instruction of the focus lens 104 is transmitted to the lens 100 (S162). Then, return to S142 of A4 and repeat AF adjustment.

On the other hand, if the process proceeds to step S152, the subject is determined by the multi-point algorithm using the calculated AF evaluation values (S152). Here, the multipoint algorithm can be performed by the subroutine described in FIG.

When one of the AF areas is selected by the multipoint algorithm operation, the peak value (Vpk) of the AF evaluation value and the focus lens position (LVpk) at the position where the peak value is calculated in the selected area are calculated through interpolation S153). It is determined whether the calculated peak value Vpk exceeds the reference value PKT (S154). If Vpk is larger than the reference value, it is determined that AF adjustment is possible. Accordingly, the correction coefficient for correction is applied from the lens 100, and the lens position error is corrected according to the position of the selected area (S155). The correction is the same as the correction by S1.

Then, the lens position correction value is changed to the drive amount of the focus lens (S156). Then, the drive amount of the focus lens 100, the backward drive command of the focus lens 100, (S157).

S2 is again turned on or off (S158). If the shutter release button has not been operated, the flow advances to step S142 of A4 to continuously perform moving picture capture and continuous AF. On the other hand, if the shutter release button is fully depressed again, the movie shooting is ended (S159). Then, the process returns to the A1 operation of FIG. 11 to repeat the live view display.

{Second Embodiment}

13 is a diagram showing a camera system 2 according to another embodiment of the present invention. Since the camera system 2 according to the present embodiment has a similar configuration and function to the camera system 1 according to Fig. 6, only differences will be described.

The camera system 2 according to the present embodiment includes a lens driving actuator 414 for driving a focus lens 304, a focus lens position detecting sensor 415, and a coupler for transmitting driving force to the lens 300 413 on the body 400 side. It is also possible to use the lens information stored in the main body memory 416 when the main body memory 416 is provided in the camera control unit 409 and the lens 300 is spherical so that the lens information is insufficient. In addition, the main memory 416 may store lens specific information or? IB,? IBoff.

The operation of the camera system 2 according to the present embodiment is almost the same as the operation according to the first embodiment described with reference to Figs. Since the focus lens 304 is directly driven by the main body 400, the driving amount of the focus lens 304, the direction switching command, and the high-speed drive command of the focus lens 304 are transmitted to the lens 300 no need. In addition, the moving image AF area M can be set to area 4 shown in FIG.

{Third Embodiment}

14 is a view showing a camera system 3 according to another embodiment of the present invention. The camera system 3 according to the present embodiment has a configuration in which the lens and the body portion are integrally formed. The operation of the camera system 3 is the same as the operation of the camera system 1 according to FIG. 6, but the camera control unit 509 performs the role of the lens control unit 110.

Hereinafter, a control method of the camera system 3 will be described with reference to Figs. 15 to 18. Fig.

The operation B1 in Fig. 15 is an operation at the start of operation of the camera system 3. Fig. When the main switch SM of the camera system 1 is turned on and the camera system 3 is started, the operation of the operation button is detected (S201). At this time, the state of the mode dial is also detected. Depending on the state of the mode dial, either a still image or a moving image is selected (S202). Since the camera system 3 of the present embodiment stores the lens information in the main body memory 528, it is not necessary to receive the information necessary for the operation of the camera.

Since steps S204 to S208 are the same as those in the first embodiment, description thereof will be omitted.

Next, a case in which the shutter release button is half-pressed during the live view display will be described.

16 is a flowchart showing an interrupt operation when the shutter release button is half-pressed.

The operation of Fig. 16 is almost the same as that of Fig. However, since the camera system 3 according to the present embodiment directly controls the focus lens 514, the camera control unit 509 can directly control the focus lens 514 without needing to transmit information or commands to the lens in steps S210, S214, S222, .

17 is a flowchart showing an interrupt operation when the shutter release button is fully depressed.

The operation of Fig. 17 is almost the same as the operation of Fig. However, since the camera system 3 also directly controls the focus lens 514, the camera control unit 509 performs direct control in S244, S249, and S257 without transmitting information or commands to the lens.

On the other hand, area 5 shown in FIG. 5 is used as a multi-segment AF area for moving images in this embodiment. That is, area 5 is set to areaM. In step S246, a photographing timing signal is applied to the area 5.

In addition, in step S252, an area for performing AF adjustment is determined by the multipoint algorithm operation shown in FIG. As for the multi-point algorithm according to the present embodiment, all of the multi-segment AF areas include the center portion, but the sizes are different from each other. Referring to FIG. 18, it is determined whether contrast is detected in a small area in the center (S401). If contrast is detected in the small area, it is determined in step S402 to adjust AF for the small area. On the other hand, if the contrast is not detected in the small area, it is determined to adjust the AF for the large area located in the outer area (S403).

{Fourth Embodiment}

The present embodiment is a case where a multi-segment AF area as shown in FIG. 2 is used as a multi-segment AF area for moving images. In the case of FIG. 2, the entire AF area and each divided focus detection area are enlarged in comparison with FIG. 1 (a). In this case, in order to alleviate the problem caused by the change of the size of the entire AF area when the AF area is switched by S2 on, one area of the AF area for moving images including the same coordinates as the coordinates selected in the static AF area . Then, the AF operation is stopped for a while from the start of moving image shooting, and then the multi-point algorithm using the AF area for moving images is operated to perform the continuous AF operation.

The photographing apparatus or the auto-focus adjusting apparatus according to the present invention may be applied to various apparatuses such as a processor, a memory chip for storing and executing program data, a card memory such as an SD card, a communication apparatus for communicating with an external apparatus, a touch panel, a key, User interface devices, and the like. Methods implemented with software modules or algorithms may be stored on a processor readable recording medium as executable code or program instructions on the processor. Here, a semiconductor recording medium (for example, a flash memory) can be used as a recording medium readable by a processor. The medium is readable by a processor and may be executed in the processor.

In order to facilitate understanding of the present invention, reference will be made to the preferred embodiments shown in the drawings, and specific terminology is used to describe the embodiments. However, the present invention is not limited to the specific terminology, Lt; / RTI > may include all components that are commonly conceivable to those skilled in the art.

The present invention may be represented by functional block configurations and various processing steps. These functional blocks may be implemented in a wide variety of hardware and / or software configurations that perform particular functions. For example, the present invention may include integrated circuit configurations, such as memory, processing, logic, look-up tables, etc., that may perform various functions by control of one or more microprocessors or other control devices Can be adopted. Similar to the components of the present invention that may be implemented with software programming or software components, the present invention may be implemented as a combination of C, C ++, and C ++, including various algorithms implemented with data structures, processes, routines, , Java (Java), assembler, and the like. Functional aspects may be implemented with algorithms running on one or more processors. The present invention may also employ conventional techniques for electronic configuration, signal processing, and / or data processing. Terms such as "mechanism", "element", "means", "configuration" may be used broadly and are not limited to mechanical and physical configurations. The term may include the meaning of a series of routines of software in conjunction with a processor or the like.

The specific acts described in the present invention are, by way of example, not intended to limit the scope of the invention in any way. For brevity of description, descriptions of conventional electronic configurations, control systems, software, and other functional aspects of such systems may be omitted. Also, the connections or connecting members of the lines between the components shown in the figures are illustrative of functional connections and / or physical or circuit connections, which may be replaced or additionally provided by a variety of functional connections, Connection, or circuit connections. Also, unless explicitly mentioned, such as "essential "," importantly ", etc., it may not be a necessary component for application of the present invention.

The use of the terms "above" and similar indication words in the specification of the present invention (particularly in the claims) may refer to both singular and plural. In addition, in the present invention, when a range is described, it includes the invention to which the individual values belonging to the above range are applied (unless there is contradiction thereto), and each individual value constituting the above range is described in the detailed description of the invention The same. Finally, if there is no explicit description or contradiction to the ordering of dodges constituting the method according to the invention, the steps can be performed in the proper order. The present invention is not necessarily limited to the order of the steps described above. The use of all examples or exemplary language (e.g., etc.) in this invention is for the purpose of describing the present invention only in detail and is not intended to be limited by the scope of the claims, But is not limited thereto. It will also be appreciated by those skilled in the art that various modifications, combinations, and alterations may be made depending on design criteria and factors within the scope of the appended claims or equivalents thereof.

Claims (9)

Focus lens;
Driving means for driving the focus lens;
Multi-division focus detection means for performing multi-division focus detection in a plurality of focus detection regions obtained by dividing at least a partial region of an image pickup screen;
Control means for driving the focus lens in accordance with the focus detection result; And
A two-stage input type switch,
The area of each of the plurality of focus detection areas of the multi-segmented focus detection for moving images used in the moving image shooting mode is larger than the area of each of the plurality of focus detection areas of the still image multi-segmentation focus detection used in the still image shooting mode,
Wherein,
Performs multi-segmented focus detection for still images corresponding to the one-stage input signal of the switch, and switches to multi-segment focus detection for moving images in accordance with the two-stage input signal of the switch. The method according to claim 1,
Wherein the total area of the plurality of focus detection areas of the motion image multi-segmentation focus detection is equal to or larger than the total area of the plurality of focus detection areas of the still image multi-segmentation focus detection. delete The method according to claim 1,
And starts shooting the moving picture corresponding to the two-stage input signal of the switch. 5. The method of claim 4,
Wherein the control means controls the focus lens to be driven at a high speed corresponding to a first stage input signal of the switch and controls the focus lens to be driven at a low speed in accordance with a two stage input signal of the switch Device. An imaging device for imaging a light passing through the imaging lens to generate a video signal;
A focus detection evaluation value calculation unit for performing focus detection using the image signal;
A focus lens driver for driving a focus lens of the imaging lens;
A position detector for detecting a position of the focus lens;
An optimum position calculating unit for calculating an optimum position of the focus detection evaluation value using the position of the focus lens and the focus detection evaluation value;
A control unit for controlling the focus lens to be driven to the calculated optimum position; And
A two-stage input type switch,
The area of each of the plurality of focus detection areas of the multi-segmented focus detection for moving images used in the moving image shooting mode is larger than the area of each of the plurality of focus detection areas of the still image multi-segmentation focus detection used in the still image shooting mode,
Wherein the multi-divisional focus detection unit performs the multi-divisional focus detection for the still image corresponding to the one-stage input signal of the switch, and switches to the multi-split focus detection for the moving image corresponding to the two-stage input signal of the switch. delete The method according to claim 6,
Further comprising a first switch and a second switch,
And performs multi-segment focus detection for the still image corresponding to the input signal of the first switch, and performs multi-segment focus detection for the image corresponding to the input signal of the second switch. 9. The method of claim 8,
Wherein the imaging lens is an interchangeable lens.

Images