JP5790011B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus.

  2. Description of the Related Art Conventionally, there has been known an imaging device that records a moving image by repeatedly capturing an image using an imaging element. As such an imaging apparatus, for example, when performing a wobbling operation in which the focus adjustment lens is finely reciprocated along the optical axis direction from a predetermined reference position, the quality of the moving image due to a change in imaging magnification due to the wobbling operation is improved. In order to suppress the decrease, a method of recording a moving image only when the focus adjustment lens is at a predetermined reference position is known (for example, Patent Document 1).

JP 2010-113291 A

  However, in Patent Document 1, a moving image is recorded only when the focus adjustment lens is at a predetermined reference position. Therefore, in order to perform focus adjustment, the focus adjustment lens is moved from a predetermined reference position. When driving to the focus adjustment position, there has been a problem that a change in the quality of a moving image due to a change in photographing magnification cannot be suppressed.

  The problem to be solved by the present invention is to provide an imaging apparatus capable of obtaining a good captured image.

  The present invention solves the above problems by the following means. In the following description, the reference numerals corresponding to the drawings showing the embodiments of the present invention are used for explanation, but these reference numerals are only for facilitating the understanding of the present invention and are not intended to limit the invention. Absent.

[1] The imaging apparatus of the present invention repeatedly captures an image by an optical system at a predetermined frame rate, and outputs a captured image signal corresponding to the captured image, and a focus adjustment lens (12). Is driven in the optical axis direction to adjust the focus state of the optical system, and the zoom lens changing unit is configured to change the zoom magnification by driving the zoom lens (13) in the optical axis direction. 51), a storage unit (70) that stores the relationship between the amount of change in the photographing magnification of the optical system with respect to the driving amount of the focus adjustment lens, and the focus adjustment in the case of moving the focus adjustment lens in the in-focus direction. A determination unit that determines whether the lens is driven in a direction in which the imaging magnification of the optical system is increased or a direction in which the imaging magnification of the optical system is decreased, and the focus is determined based on a determination result of the determination unit. Adjustment lens , If the imaging magnification of the optical system is determined to have drive in the direction of increasing, as imaging magnification of the optical system becomes smaller than the before starting the driving of the focusing lens, said focusing on the basis of the amount of change in the relationship of the photographing magnification of the optical system with respect to the drive amount of the lens, the control unit for controlling the zoom magnification changing unit so as to drive the zoom lens in the optical axis direction (70), the determination When it is determined that the focus adjustment lens is driven in a direction in which the imaging magnification of the optical system is reduced according to the determination result of the optical unit, the imaging magnification of the optical system is greater than before the drive of the focus adjustment lens is started. And an image processing unit (70) for cutting out a part of the area from the image based on the captured image signal and generating a cut-out image.

  [2] In the image pickup apparatus of the present invention, the control unit (70) causes the zoom magnification so that the photographing magnification of the optical system is smaller than that before the focus adjustment lens (12) starts to be driven. When the lens (13) is driven in the optical axis direction, the zoom lens can be driven stepwise.

  [3] In the imaging apparatus of the present invention, the image processing unit (70) causes the clipped image so that the image magnification of the clipped image is the same as the image magnification before starting the driving of the focus adjustment lens. Can be configured to generate.

  [4] In the imaging apparatus of the present invention, the focus adjustment unit (70a) causes the focus adjustment lens (12) to wobble in a direction in which the imaging magnification of the optical system decreases, and the result of the wobbling drive is obtained. The driving direction of the focus adjustment lens may be determined based on the determination result.

  [5] The imaging apparatus of the present invention further includes a calculation unit (70a) for calculating a focus evaluation value based on the captured image signal, and the image processing unit (70) is configured to evaluate the focus evaluation of the captured image signal. It is determined whether the value is equal to or greater than a predetermined value, and the generation method for generating the cut-out image is different between the case where the focus evaluation value is equal to or greater than the predetermined value and the case where the value is less than the predetermined value. Can be configured.

  According to the imaging apparatus of the present invention, a good captured image can be obtained.

FIG. 1 is a block diagram showing a digital camera 1 according to this embodiment. FIG. 2 is a flowchart showing an operation example of the camera according to the present embodiment. FIG. 3 is a diagram illustrating an example of a scene to which the present embodiment is applied. FIGS. 4A to 4C are diagrams illustrating an example of a change in photographing magnification by driving the focus lens. FIG. 5A to FIG. 5C are diagrams for explaining the crop processing in the present embodiment. FIG. 6 is a diagram illustrating an example of a scene to which the present embodiment is applied. FIG. 7 is a diagram illustrating changes in the focus lens position, zoom lens position, and image magnification in the scene example shown in FIG.

  An embodiment in which the present invention is applied to a digital camera will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a digital camera 1 according to the present embodiment, and illustration and description of a general configuration of the camera other than the configuration related to the imaging apparatus of the present invention are partially omitted.

  The digital camera 1 (hereinafter simply referred to as the camera 1) of the present embodiment includes a lens system 10, an aperture 21, an aperture drive control unit 22, an image sensor 31, an analog signal processing circuit 41, an A / D conversion unit 42, and lens drive. A control unit 51, a memory 60, a camera control unit 70, an operation unit 80, and a display unit 90 are provided.

  The lens system 10 includes a plurality of lenses 11, 12, and 13 including a focus lens 12 for adjusting the focus and a zoom lens 13 for changing the zoom magnification, and constitutes a photographing optical system together with the diaphragm 21.

  The focus lens 12 is provided so as to be movable along the optical axis L <b> 1, and its position or amount of movement is detected by a focus lens encoder (not shown), and its position is adjusted by the focus lens drive motor 52. The current position information of the focus lens 12 detected by the focus lens encoder is transmitted to the camera control unit 70 via the lens drive control unit 51, and the camera control unit 70 refers to this information to focus. The focus adjustment position of the lens 12 is calculated, and a lens drive signal is transmitted to the focus lens drive motor 52 via the lens drive control unit 51.

  The zoom lens 13 is provided so as to be movable along the optical axis L <b> 1, and its position or amount of movement is detected by a zoom lens encoder (not shown), and its position is adjusted by the zoom lens driving motor 53. The position of the zoom lens 13 is adjusted by operating a zoom button provided on the operation unit 80 or by a zoom lens drive command sent from the camera control unit 70 via the lens drive control unit 51.

  The diaphragm 21 is configured such that the aperture diameter around the optical axis L1 can be adjusted in order to limit the amount of the light beam L1 that passes through the lens system 10 and reaches the image sensor 31 and adjust the amount of blur. . For example, in the automatic exposure mode, the camera control unit 70 calculates a target aperture diameter based on the light flux reaching the image pickup device 31, and an aperture drive signal corresponding to the calculated aperture diameter is generated by the camera control unit 70. Is transmitted to the aperture drive unit 23 via the aperture drive control unit 22 to adjust the aperture diameter by the aperture 21. The aperture diameter is also adjusted by manually operating the operation unit 80 provided in the camera 1, and the aperture diameter set by the operation unit 80 is changed from the camera control unit 70 via the aperture drive control unit 22. Input to the aperture drive unit 23. The aperture diameter of the diaphragm 21 is detected by a diaphragm aperture sensor (not shown), and the current aperture diameter is recognized by the camera control unit 70.

  The image pickup device 31 is disposed on the optical axis L1 from the subject of the camera 1 and at a position that is a planned focal plane of the lens system 10. The imaging element 31 is a two-dimensional array of a plurality of photoelectric conversion elements, and can be constituted by a two-dimensional CCD image sensor, a MOS sensor, a CID (charge injection device), or the like. Note that the image sensor 31 has an electronic shutter function for controlling the accumulation time of charges accumulated in each pixel, that is, the shutter speed by a shutter gate pulse.

  In addition, color filters corresponding to red (R), green (G), and blue (B) are arranged in the effective pixel area on the imaging surface of the imaging device 31, and the subject image received on the imaging surface is RGB. It is converted into the image signal. Examples of such a color filter array include, but are not limited to, a Bayer Arrangement.

  When a subject image is projected onto the imaging surface of the image sensor 31, it is photoelectrically converted into a signal charge of an amount corresponding to the amount of incident light, and sequentially read out as an imaging output signal. The photoelectrically converted analog image signal is output to the analog signal processing unit 41.

  The analog signal processing unit 41 includes a CDS circuit that performs correlated double sampling (CDS), a gain circuit that amplifies the output of the analog image signal, and a color separation circuit. In the analog signal processing unit 41, output gain values relating to output of pixels corresponding to RGB colors can be set independently.

  The A / D conversion unit 42 converts the analog image signal output from the analog signal processing unit 41 into a digital image signal. The image signal digitized by the A / D conversion unit 42 is output to the camera control unit 70.

  The operation unit 80 includes a main power switch for activating the camera 1, a shutter release button, a zoom switch for driving the zoom lens 13 to perform a zoom operation, and a photographer selecting various operation modes of the camera 1. It has an input switch for setting. The photographer can switch the moving image shooting mode / still image shooting mode, the automatic exposure mode / manual exposure mode, the auto focus mode / manual focus mode, and the like via the operation unit 80. It is like that. The operation by the operation unit 80 and various set modes are transmitted to the camera control unit 70.

  The camera control unit 70 is composed of peripheral components such as a microprocessor and a memory, and performs operations for controlling each unit constituting the camera 1. Based on the calculation result, the camera control unit 70 adjusts the opening diameter of the diaphragm 21 and sets the gain of the analog signal processing unit 41.

  In addition, the camera control unit 70 acquires the image signal digitized by the A / D conversion unit 42, performs digital processing on the acquired image signal, outputs it to the memory 60 and the display unit 90, and saves it in the memory 60. In addition, the display unit 90 displays an image based on the image signal.

  Furthermore, the camera control unit 70 includes an AF processing unit 70a that controls the autofocus operation. The AF processing unit 70 a drives the focus lens drive motor 52 via the lens drive control unit 51 to cause the image pickup device 31 to pick up the subject image while moving the focus lens 12, thereby moving the focus lens 12. A digital image signal corresponding to each movement position is acquired. A high frequency component is extracted from the image signal used for focus detection from the acquired digital image signal, and a focus evaluation value is calculated. Specifically, the image signal is passed through a bandpass filter, a signal corresponding to a frequency component of a predetermined band is extracted from the image signal, and the absolute value of the extracted signal is integrated to obtain a focus evaluation value for the subject image. obtain. Then, the AF processing unit 70a drives the focus lens drive motor 52 via the lens drive control unit 51 based on the calculated focus evaluation value, thereby bringing the focus lens 12 into a predetermined lens adjustment position. Move.

  Further, when the moving image shooting mode is selected, the AF processing unit 70a performs a wobbling operation for minutely driving the focus lens 12 in the vicinity of the current position before executing the autofocus operation. Further, based on the calculated focus evaluation value, the driving direction of the focus lens 12 when performing the autofocus operation is determined. In the present embodiment, the wobbling operation is executed by repeating the operation of causing the focus lens 12 to be finely driven from the current lens position in a direction in which the photographing magnification decreases, and then returning to the original lens position. .

  In addition, the camera control unit 70 stores in advance a table indicating the relationship between the lens driving amount of the focus lens 12 and the amount of change in the image magnification of the captured image picked up by the image pickup device 31, and this table is used. Then, the AF processing unit 70a performs an operation of correcting a change in the image magnification of the photographed image while the focus lens 12 is being driven when the autofocus operation is being performed. The operation for correcting the change in the image magnification of the captured image will be described later.

  The display unit 90 is configured with a liquid crystal display or the like, and functions as an electronic viewfinder that sequentially displays images captured by the image sensor 31. The photographer performs a shooting operation while observing the subject displayed on the display unit 90. Can be done.

  Next, an operation example of the camera 1 according to this embodiment will be described. FIG. 2 is a flowchart showing the operation of the camera 1 according to this embodiment. In the following, the operation in a scene where the moving image shooting mode is selected will be described.

  First, in step S <b> 101, when the camera 1 is turned on, the imaging element 31 starts capturing a subject image. In the present embodiment, imaging of a subject image by the image sensor 31 is repeatedly performed at a predetermined frame rate.

  Next, in step S <b> 102, the camera control unit 70 acquires an image signal of an image captured by the image sensor 31. In the present embodiment, the camera control unit 70 converts the image signal of the image captured by the image sensor 31 by the analog signal processing unit 41 and the A / D conversion unit 42 and obtains it as a digitized signal.

  Next, in step S103, the camera control unit 70 performs processing for storing the captured image based on the image signal acquired in step S102 in the memory 60.

  In step S104, a focus evaluation value is calculated based on the image signal acquired in step S102 by the AF processing unit 70a of the camera control unit 70. The calculated focus evaluation value is stored in a memory provided in the camera control unit 70 together with information on the position of the focus lens 12.

  In step S105, it is determined whether or not a wobbling operation is being performed. The wobbling operation is an operation for minutely driving the focus lens 12 in the vicinity of the current position before executing the autofocus operation, and is controlled by the AF processing unit 70a provided in the camera control unit 70. If it is determined that the wobbling operation is not executed, the process proceeds to step S106. On the other hand, if it is determined that the wobbling operation is being executed, the process proceeds to step S113.

  In step S106, it is determined whether or not the driving operation of the focus lens 12 (continuous driving operation in one direction different from the wobbling operation) is being performed by the camera control unit 70 in order to perform the autofocus operation. Is done. If it is determined that the drive operation of the focus lens 12 is being performed, the process proceeds to step S107. On the other hand, if it is determined that the drive operation of the focus lens 12 is not performed, the process proceeds to step S112. The driving operation of the focus lens 12 is controlled by an AF processing unit 70 a provided in the camera control unit 70. In the present embodiment, for example, when it is determined that it is necessary to detect a new in-focus position based on the result of the wobbling operation, or when the photographing brightness changes greatly, the focus calculated during the previous process is further changed. When the value changes by a predetermined value or more as compared with the evaluation value, the autofocus operation is executed by the AF processing unit 70a.

  In step S107, the focus lens 12 is in a direction in which the photographing magnification decreases (that is, the angle of view becomes wider) than when the drive of the focus lens 12 is started (that is, when the autofocus operation is started). It is determined whether or not it is moving in the direction). If it is determined that the focus lens 12 has moved in a direction in which the photographing magnification is decreased as compared with the time when the drive of the focus lens 12 is started, the process proceeds to step S108. On the other hand, when it is determined that the focus lens 12 is moved in a direction in which the photographing magnification is increased (that is, a direction in which the angle of view is narrowed) compared to the time when the drive of the focus lens 12 is started. The process proceeds to step S111.

Here, FIG. 3 shows an example of a scene to which the present embodiment is applied. FIG. 3A shows a change in the lens position of the focus lens 12 in the example of the scene, and FIG. B) shows a change in image magnification of an image captured by the image sensor 31 and a change in image magnification of a moving image stored in the memory 60 in one scene example. In FIG. 3A, the acquisition timing of the image signal from the image sensor 31 is indicated by a black circle. That is, in FIG. 3 (A), the intervals of time T _alpha, imaging is performed by the image pickup device 31, at intervals of time T _alpha, based by the AF processing section 70a, the image signal captured by the image pickup device 31 In this example, the focus evaluation value is calculated. In FIG. 3A, when the focus lens 12 is at the position P1 at time t1, the autofocus operation is started at time t2, and the focus lens 12 is driven in a direction in which the photographing magnification decreases. The scene where the focus evaluation value is calculated and the focus lens 12 is moved to the position P2 which is the focus position at time t3 based on the calculated focus evaluation value is shown.

  In the example shown in FIG. 3A, during the time t2 to t3, the focus lens 12 is compared with the position P1 of the focus lens 12 when the drive of the focus lens 12 is started. In this case, the process proceeds to step S108.

  As described above, when it is determined that the focus lens 12 is moved in the direction in which the photographing magnification is decreased as compared with the time when the drive of the focus lens 12 is started, the process proceeds to step S108, and step S108. Then, the camera control unit 70 performs a crop process for cutting out a part of the captured image based on the image signal obtained in step S102. Here, when the focus lens 12 is driven in a direction in which the photographing magnification decreases, the obtained photographed image changes in the angle of view from the image shown in FIG. 4A to the image shown in FIG. It will end up. On the other hand, in this embodiment, cropping processing is performed to prevent such a change in the angle of view. Specifically, as shown in FIG. 5A, a cutout area for cutting out an image is selected from the obtained captured image, and then the size of the cutout area is shown in FIG. 5B. However, a process for enlarging the captured image is performed so that the size corresponds to the size of the captured image. Then, as shown in FIG. 5C, a cropped image is obtained by performing a process of cutting out the cutout region. In this embodiment, when a crop image is obtained, the image is cut out so that the obtained crop image has the same image magnification as that before the focus lens 12 is driven. Specifically, based on a table indicating the relationship between the lens position of the focus lens 12 stored in advance in the camera control unit 70 and the image magnification of the captured image captured by the image sensor 31 at each lens position, The image is cut out so that the obtained crop image has the same image magnification as that before driving the focus lens 12.

  In the present embodiment, when processing for enlarging the captured image shown in FIG. 5B is performed, a different processing method is selected by the AF processing unit 70a depending on the calculated focus evaluation value. This may be a good response. Specifically, when it is determined that the focus evaluation value is less than a predetermined value and the amount of blur of the captured image captured by the image sensor 31 is relatively large, a method with a relatively low computational load And the focus evaluation value is equal to or greater than a predetermined value, and the blur amount of the captured image captured by the image sensor 31 is determined to be relatively small, a method for obtaining a high-resolution image Can be used. For example, when the focus evaluation value is less than a predetermined value, as a method with a relatively low calculation load, for example, a method of obtaining an enlarged image by performing pixel interpolation at the pixel level by linear interpolation, etc. Can be used. On the other hand, when the focus evaluation value is equal to or greater than a predetermined value, as a method for obtaining a high-resolution image, for example, a bicubic method or a plurality of images captured in a plurality of consecutive frames are used. A method for obtaining an enlarged image by performing super-resolution processing that performs pixel interpolation can be used. Note that the predetermined value in this case can be set to a value by which it can be determined, for example, whether the captured image captured by the image sensor 31 is an image near the in-focus position.

  Next, in step S109, the camera control unit 70 performs processing for storing the cropped image obtained in step S108 in the memory 60 as a moving image.

  Next, in step S110, the cropped image obtained in step S108 is output from the camera control unit 70 to the display unit 90, and the cropped image is output by the display unit 90.

  As described above, in this embodiment, when a crop image is obtained, the image is cut out so that the obtained crop image has the same image magnification as that before driving the focus lens 12. is there. Therefore, for example, by driving the focus lens 12 at time t2 to t3 shown in FIG. 3 (A), the angle of view of the captured image is shown in FIG. 4 (C) from the image shown in FIG. 4 (A). Even when the image has changed like the image, a crop image obtained by performing the crop processing as shown in FIGS. 5A to 5C is obtained and stored as a moving image. Thus, it is possible to prevent a change in the angle of view in the obtained moving image.

  Then, according to the present embodiment, as shown in FIG. 3B, when the focus lens 12 is driven, the image magnification (FIG. 3 (B), even when the solid line changes), a moving image for obtaining a cropped image and storing the obtained cropped image in the memory 60 as described in step S107 above. By doing so, the image magnification (indicated by a broken line in FIG. 3B) of the obtained moving image is maintained at the image magnification α1 before the focus lens 12 is driven. In the present embodiment, a mode in which a cropped image is obtained even after time t3 when driving of the focus lens 12 is stopped, and the obtained cropped image is used as a moving image to be stored in the memory 60. Although illustrated, it is not particularly limited to this. For example, the cropping ratio of the cropped image is gradually decreased, and the image magnification of the moving image is gradually brought closer to the photographed image captured by the image sensor 31. Any processing may be performed.

  On the other hand, in step S107, it is determined that the focus lens 12 has moved in the direction in which the photographing magnification is increased (that is, the direction in which the angle of view is narrowed) compared to the time when the drive of the focus lens 12 is started. If YES in step S111, the flow advances to step S111. In step S111, processing for driving the zoom lens 13 is started in response to driving of the focus lens 12. Here, when the focus lens 12 is driven in a direction in which the shooting magnification increases, the obtained shot image changes in angle of view from the image shown in FIG. 4 (A) to the image shown in FIG. 4 (B). It will end up. On the other hand, in this embodiment, in order to prevent such a change in the angle of view, when it is determined that the focus lens 12 is moving in a direction in which the photographing magnification is increased, the focus lens 12 The zoom lens 13 is driven according to the drive.

  Here, FIG. 6 shows another scene example to which the present embodiment is applied. 6A shows a change in the lens position of the focus lens 12 in another example of the scene, and FIG. 6B shows an image captured by the image sensor 31 in the other example of the scene. A change in image magnification and a change in image magnification of a moving image stored in the memory 60 are shown. In FIG. 6A as well, the acquisition timing of the image signal from the image sensor 31 is indicated by a black circle, as in FIG. 3A. In FIG. 6A, when the focus lens 12 is at the position P3 at time t11, the autofocus operation is started at time t12, and the focus lens 12 is driven in the direction in which the photographing magnification increases. In this case, the focus evaluation value is calculated while the focus lens 12 is moved to the focus position P4 at time t16 based on the calculated focus evaluation value.

  In such a case, in this embodiment, as shown in FIGS. 7A and 7B, at time t12, the focus lens 12 starts to be driven in the direction in which the photographing magnification increases. Accordingly, the zoom lens 13 is driven in the direction in which the photographing magnification decreases (position P5 → P6) from time t12 to t13, and further, the zoom lens 13 is moved in the direction in which the photographing magnification decreases from time t14 to t15. It is driven to (position P6 → P7). As a result, as shown in FIG. 7C, even when the focus lens 12 is driven in a direction in which the shooting magnification is increased, the image magnification of the shot image picked up by the image pickup device 31 is the same as that of the focus lens 12. Control is performed so that the image magnification α3 is smaller than that before driving. In FIG. 7C, when the zoom lens 13 is driven, the image magnification of the captured image picked up by the image pickup device 31 is a solid line, and the image pickup is performed by the image pickup device 31 when the zoom lens 13 is not driven. The image magnifications of the captured images are shown by broken lines.

  7A to 7C show an example in which the zoom lens 13 is driven stepwise as the focus lens 12 is driven. However, the present invention is not limited to such an example. A configuration in which the lens 12 is continuously driven as the lens 12 is driven may be employed. The driving amount of the zoom lens 13 when the zoom lens 13 is driven in accordance with the driving of the focus lens 12 is the lens driving amount of the focus lens 12 stored in advance and a photographed image captured by the image sensor 31. It is possible to calculate based on this table using a table showing the relationship with the amount of change in image magnification. The driving amount of the zoom lens 13 is such that the lower limit image magnification α5 (see FIG. 7C) after driving the zoom lens 13 is the image magnification α3 before driving the focus lens 12 (see FIG. 7C). On the other hand, it is desirable from the viewpoint of maintaining good image quality of the obtained cropped image that the enlargement ratio when obtaining an enlarged image by the cropping process described later is within about 1.2 times. If the photometric value or the histogram of the image changes relatively greatly, it is determined that the composition has been changed, and the zoom lens 13 exceeds the lower limit image magnification α5, and the zoom lens 13 has a lower photographing magnification. You may drive in the direction.

  Further, in the present embodiment, when executing the process of driving the zoom lens 13 with the driving of the focus lens 12, for example, the image magnification of the captured image obtained by the image sensor 31 is the upper limit image magnification α4 (FIG. 7). (See (C)) and the lower limit image magnification α5 (see FIG. 7C). For example, in FIGS. 7A to 7C, when the upper limit image magnification α4 is reached, the zoom lens 13 is driven in a direction in which the photographing magnification decreases, and the zoom lens 13 is driven. When α5 is reached, the control for stopping the zoom lens 13 is repeatedly performed.

  Therefore, in this embodiment, in step S111, when the zoom lens 13 is driven, it is determined whether or not the lower limit image magnification α5 has been reached, and if the lower limit image magnification α5 has been reached. Then, processing for stopping the driving of the zoom lens 13 is performed. On the other hand, when the zoom lens 13 is stopped, it is determined whether or not the upper limit image magnification α4 has been reached. When the upper limit image magnification α4 has been reached, the zoom lens 13 has a lower shooting magnification. A process of driving in a certain direction is performed. The upper limit image magnification α4 is not particularly limited as long as it is smaller than the image magnification α3 before the focus lens 12 is driven.

  Then, when the process for driving the zoom lens 13 is executed along with the driving of the focus lens 12, the process proceeds to step S108, and the cropped image is subjected to the cropping process in the same manner as described above, and the image before the focus lens 12 is driven. A crop image having the same image magnification as the magnification is obtained. Then, in step S109, the obtained crop image is stored in the memory 60 as a moving image. In step S110, the crop image is displayed on the display unit 90. The process of displaying on is performed.

  Here, as described above, in the present embodiment, when a crop image is obtained, the image is clipped so that the obtained crop image has the same image magnification as that before driving the focus lens 12. To do. Therefore, for example, at time t12 to t16 shown in FIG. 6A, the zoom lens 13 is driven in accordance with the driving of the focus lens 12, so that the angle of view of the captured image is changed from the image shown in FIG. 4C, and the cropped image obtained by performing the cropping process as shown in FIGS. 5A to 5C is obtained, and this is converted into a moving image. As a result, it is possible to prevent a change in the angle of view in the obtained moving image.

  Then, according to the present embodiment, as shown in FIG. 6A, even when the focus lens 12 is driven in a direction in which the photographing magnification increases from t12 to t16, as shown in FIG. The zoom lens 13 is driven, whereby the image magnification (shown by a solid line in FIG. 6B) of the captured image captured by the image sensor 31 is set to the image magnification α3 before the focus lens 12 is driven. By obtaining a cropped image as described in step S107 described above from the obtained captured image, and making the obtained cropped image a moving image for storing in the memory 60, The image magnification (indicated by a broken line in FIG. 3B) of the obtained moving image is maintained at the image magnification α3 before the focus lens 12 is driven.

  On the other hand, if it is determined in step S106 described above that the driving operation of the focus lens 12 has not been performed, the process proceeds to step S112, and the image captured by the image sensor 31 stored in the memory 60 in step S103. A process of storing the image as a moving image is performed, and a process of displaying the captured image on the display unit 90 is performed.

  If it is determined in step S105 described above that the focus lens 12 is in the wobbling drive, the process proceeds to step S113. As described above, in the present embodiment, the wobbling operation repeats the operation of causing the focus lens 12 to be finely driven from the current lens position in a direction in which the photographing magnification decreases, and then returning to the original lens position. Is executed. Therefore, in step S113, whether the focus lens 12 is at the lens position before the wobbling operation is performed, or whether the photographing magnification is smaller than the lens position before the wobbling operation is performed. A determination is made. If it is determined that the lens position is before the wobbling operation, the process proceeds to step S112, and the captured image captured by the image sensor 31 stored in the memory 60 is stored as a moving image in step S103. Processing is performed, and processing for displaying the captured image on the display unit 90 is performed.

  On the other hand, if it is determined that the focus lens 12 is located in a direction in which the photographing magnification is smaller than the lens position before the wobbling operation is performed, the process proceeds to step S108, and the photographed image is similar to the above. To obtain a cropped image having the same image magnification as that before executing the wobbling operation, and then storing the obtained cropped image in the memory 60 as a moving image in step S109. In step S110, a process for displaying the cropped image on the display unit 90 is performed.

  As described above, the camera 1 according to this embodiment operates.

  In the present embodiment, the focus lens 12 has a direction in which the photographing magnification is increased (that is, the angle of view is larger than the time when the drive of the focus lens 12 is started (that is, the time when the autofocus operation is started). When the focus lens 12 moves in the direction of narrowing, the focus lens 12 is driven by driving the zoom lens 13 as the focus lens 12 is driven, as shown in FIGS. As compared with the previous case, control is performed so that the shooting magnification of the image captured by the image sensor 31 is reduced, and a crop process for cutting out a part of the obtained captured image is performed. The video is saved as a moving image. Therefore, according to this embodiment, even when the focus lens 12 moves in the direction in which the shooting magnification increases, the change in the angle of view of the obtained moving image can be suppressed. It can be made favorable with little change in the angle of view.

  Further, according to the present embodiment, the focus lens 12 has a direction in which the photographing magnification decreases (that is, when the focus lens 12 starts to be driven (that is, when the autofocus operation is started)). When the image is moved in the direction in which the angle of view is widened, a cropping process for cutting out a part of the captured image captured by the image sensor 31 is performed, and the obtained crop image is stored as a moving image. Therefore, according to the present embodiment, in addition to the case where the focus lens 12 is moved in the direction in which the photographing magnification is increased, the change in the angle of view of the obtained moving image is performed even when the focus lens 12 is moved in the direction in which the photographing magnification is decreased. Accordingly, the obtained moving image can be improved with little change in the angle of view.

  Furthermore, according to the present embodiment, the wobbling operation is performed by repeating the operation of minutely driving the focus lens 12 from the current lens position in a direction in which the photographing magnification decreases, and then returning to the original lens position. At the same time, when the focus lens 12 is positioned in a direction in which the photographing magnification is smaller than the lens position before the wobbling operation is performed, a crop image having the same image magnification as that before the wobbling operation is obtained. The obtained crop image is saved as a moving image. Therefore, according to the present embodiment, even when the shooting magnification changes due to the wobbling operation, it is possible to suppress the change in the angle of view of the obtained moving image, and thereby the obtained moving image has less change in the angle of view. It can be good.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the above-described embodiment, an example in which the AF processing unit 70a performs the autofocus operation by the contrast method is illustrated. However, the embodiment is not particularly limited to the contrast method, and for example, the autofocus operation is performed by the phase difference method. It is good.

  In the above-described embodiment, the lens-integrated digital camera 1 has been described as an example. However, the present invention can also be applied to a lens interchangeable digital camera, a small camera module built in a mobile phone, or the like. .

DESCRIPTION OF SYMBOLS 1 ... Digital camera 10 ... Lens system 12 ... Focus lens 13 ... Zoom lens 21 ... Diaphragm 22 ... Diaphragm drive control part 31 ... Imaging element 41 ... Analog signal processing circuit 42 ... A / D conversion part 51 ... Lens drive control part 60 ... Memory 70 ... Camera control unit 80 ... Operation unit 90 ... Display unit

Claims (5)

An imaging unit that repeatedly captures an image of the optical system at a predetermined frame rate and outputs a captured image signal corresponding to the captured image;
A focus adjustment unit that drives the focus adjustment lens in the optical axis direction to adjust the focus state of the optical system;
A zoom magnification change unit for changing the zoom magnification by driving the zoom lens in the optical axis direction;
A storage unit that stores a relationship of a change amount of the imaging magnification of the optical system with respect to a driving amount of the focus adjustment lens;
When moving the focus adjustment lens in the in-focus direction, whether the focus adjustment lens is driven in a direction in which the imaging magnification of the optical system is increased, or is driven in a direction in which the imaging magnification of the optical system is reduced, A determination unit for determining
When it is determined by the determination result of the determination unit that the focus adjustment lens is driven in a direction in which the imaging magnification of the optical system is increased, the imaging magnification of the optical system starts driving the focus adjustment lens. The zoom magnification changing unit is configured to drive the zoom lens in the optical axis direction based on the relationship of the change amount of the photographing magnification of the optical system with respect to the drive amount of the focus adjustment lens so as to be smaller than before. A control unit for controlling
When it is determined by the determination result of the determination unit that the focus adjustment lens is driven in a direction in which the imaging magnification of the optical system decreases , a part of the region is cut out from the image based on the captured image signal, An image processing apparatus comprising: an image processing unit that generates a cut-out image. The imaging device according to claim 1,
When the zoom lens is driven in the optical axis direction so that the photographing magnification of the optical system is smaller than that before starting the driving of the focus adjustment lens, An imaging device characterized in that driving is performed in stages. The imaging device according to claim 1 or 2,
The image processing unit generates the clipped image so that an image magnification of the clipped image is the same as an image magnification before starting the driving of the focus adjustment lens. In the imaging device in any one of Claims 1-3,
The focus adjustment unit drives the focus adjustment lens in a direction in which a photographing magnification of the optical system decreases, and determines a drive direction of the focus adjustment lens based on a result of the wobbling drive. An imaging device. In the imaging device according to any one of claims 1 to 4,
A calculation unit for calculating a focus evaluation value based on the captured image signal;
The image processing unit determines whether or not the focus evaluation value of the captured image signal is greater than or equal to a predetermined value, and the focus evaluation value is greater than or equal to the predetermined value and less than the predetermined value. Thus, the imaging device is characterized in that the generation method for generating the cut-out image is different.

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