JP6539114B2 - Imaging device, control method therefor, and program - Google Patents

Description

  The present invention relates to an imaging device, a control method therefor, and a program.

  Conventionally, an imaging element (hereinafter, simply referred to as a variable-curvature sensor) capable of controlling a curvature of a concave curved surface by arranging a photoelectric conversion element on the concave curved surface side of a curved imaging surface is known. In addition, in a digital camera equipped with such a variable curvature sensor and an optical zoom, the focus of the entire imaging surface is improved by controlling the curvature of the variable curvature sensor according to the focal length changed by the optical zoom. What is known is.

  In such a digital camera, when the lens is close to the imaging surface with a wide-angle lens, the curvature radius (reciprocal of curvature with the curvature radius) of the concave surface of the sensor is reduced, while the lens is far from the imaging surface with a telephoto lens In some cases, the radius of curvature of the concave surface of the sensor is increased. In this way, the curvature of the concave surface can be controlled to minimize the curvature of field aberration of the lens, so that an image in which the entire imaging surface is in focus can be generated regardless of the lens position. . Patent Document 1 proposes a technique of changing the curvature of a sensor using a change in magnetic force by an electromagnet, a volumetric contraction rate by heat, or a degree of vacuum by a suction force.

JP 2012-182194 A

  On the other hand, digital cameras and video cameras are becoming more common as they have a live view display function and a moving image shooting function in addition to the still image shooting function. In particular, in moving image shooting, the processing becomes much more complicated than still image shooting, and power consumption may increase. On the other hand, with the demand for downsizing of these cameras, it is desirable to reduce the maximum amount of power from the viewpoint of heat generation and the like.

  A digital camera using the above-described variable curvature sensor requires additional power to change the curvature according to the magnification (focal length) of the optical zoom and to maintain the changed curvature. In particular, in live view display and moving image shooting, it is necessary to maintain the curvature according to the set magnification of the optical zoom over the shooting period, and measures to reduce power consumption are desired.

  The present invention has been made in view of the above-described problems of the prior art, and an imaging device capable of reducing power consumption when using an imaging device capable of controlling the curvature of a curved imaging surface, and the imaging device It aims to provide a control method and a program.

In order to solve this problem, for example, the imaging device of the present invention has the following configuration. That is, the image pickup optical system, the image pickup means configured to be able to bend the image pickup surface, the drive means to bend the image pickup surface of the image pickup means, and the subject surface of the image pickup surface The subject brightness is controlled to reduce the curvature of field produced in the focal length of the image pickup optical system to a first curvature that does not satisfy a predetermined power consumption condition, and the subject brightness is controlled. If the curvature of the imaging surface is smaller than the first curvature and the power consumption is lower than the predetermined luminance value, the second power consumption satisfies the predetermined power consumption state. And controlling means for controlling the driving means so as to have a curvature .

  According to the present invention, it is possible to reduce the power consumption of the imaging device when using an imaging element capable of controlling the curvature of the curved imaging surface.

A block diagram showing an example of a functional configuration of a digital camera as an example of an imaging apparatus according to an embodiment of the present invention Flowchart showing a series of operations of curvature control processing according to the first embodiment Block diagram showing an example of the functional configuration of the digital camera according to the second embodiment Flowchart showing a series of operations of curvature control processing according to the second embodiment Flowchart showing a series of operations of curvature control processing according to the third embodiment The figure explaining the outline of the curvature control processing in each embodiment

(Embodiment 1)
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In the following, an example in which the present invention is applied to an arbitrary digital camera provided with an imaging element capable of controlling the curvature of the imaging surface will be described as an example of the imaging apparatus. However, the present invention is applicable not only to digital cameras but also to any electronic device capable of controlling the curvature of the imaging surface of the imaging device. These devices may include information terminals (for example, mobile phones, game machines, tablet terminals, personal computers, watch-type or glasses-type terminals, etc.), on-vehicle devices, monitoring devices, robots, and the like.

(Configuration of digital camera 100)
FIG. 1 is a block diagram showing an example of the functional configuration of a digital camera 100 as an example of an imaging device according to this embodiment. Note that one or more of the functional blocks shown in FIG. 1 may be realized by hardware such as an ASIC or programmable logic array (PLA), or realized by a programmable processor such as a CPU or MPU executing software. May be Also, it may be realized by a combination of software and hardware. Therefore, in the following description, even when different functional blocks are described as an action subject, the same hardware can be realized as the subject.

  The imaging optical system 101 includes a lens group including a focus lens and a zoom lens, and an aperture, and moves the zoom lens in the optical axis direction according to an instruction from the imaging optical system drive unit 106 to perform zoom magnification (or focal length ) Can be changed. Further, the aperture diameter of the diaphragm can also be changed in accordance with an instruction from the imaging optical system drive unit 106.

  The imaging device 102 is an imaging device in which the imaging surface can be curved and the photoelectric conversion element is disposed on the concave surface side to control the curvature of the imaging surface having the concave surface. The imaging element 102 has a configuration in which a plurality of pixels having photoelectric conversion elements are two-dimensionally arrayed on the concave surface side. The imaging device 102 may be, for example, an imaging device such as a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. An object optical image formed by the imaging optical system 101 is photoelectrically converted by each pixel, and further analog / digital converted by an A / D conversion circuit (not shown) to output a digital signal (image data) in pixel units. Further, for example, image data in which one frame is 1920 pixels wide × 1080 pixels high can be output at a predetermined frame rate (for example, 30 frames per second). Note that a plurality of independent photoelectric conversion elements may be provided in each pixel of the image sensor, and a plurality of image data having a phase difference may be output.

  In addition, the imaging device 102 is an imaging device (also referred to as a variable curvature sensor) having a drive unit for changing and maintaining the curvature of the imaging surface, and changes the curvature of the imaging surface to maintain the curvature. Power or control signals are provided. In the present embodiment, for example, the curvature control unit 107 supplies power to control the curvature of the imaging surface.

  The imaging system signal processing unit 103 performs image signal processing such as various correction processing on image data or video data (hereinafter, also simply referred to as image data) output from the imaging element 102, and processes the processed image data. The signal is output to the recording / reproducing system signal processing unit 104. The recording / reproduction signal processing unit 104 encodes the input image data according to, for example, a predetermined encoding method, compresses the amount of information, and converts the data into data suitable for recording. The data processed by the recording / reproducing system signal processing unit 104 is recorded on the recording medium 109. The recording medium 109 is a recording medium such as a memory card for recording the image data output from the recording and reproduction signal processing unit 104, and includes a semiconductor memory, a magnetic disk, and the like.

  The display unit 105 includes, for example, a monitor such as a touch panel, and the image data output from the recording and reproduction signal processing unit 104, the video data for live view display, or the operation screen for operating the digital camera 100 (menu screen ) Etc. are displayed. The display unit 105 may be anything as long as it is a display device such as a liquid crystal display, an organic EL display, electronic paper or the like.

  The imaging optical system drive unit 106 includes a drive device that drives the imaging optical system 101 to a predetermined position, and operates according to an instruction of the control unit 113, for example.

  The curvature control unit 107 includes a control circuit or control module, and the photographing conditions (for example, subject brightness, F number, movement amount of the subject) detected by the detection unit 108 and the photographing optical system drive unit 106 The curvature of the imaging surface of the imaging device 102 is controlled based on information (focal length information and aperture information) indicating the state of the system (curvature control processing).

  The detection unit 108 receives image data output from the imaging system signal processing unit 103 or acquires information on the aperture set from the imaging optical system drive unit 106 to detect the imaging condition of the digital camera 100. .

  The changeover switch 110 includes, for example, a mechanical switch for selecting a moving image shooting mode and a still image shooting mode. The zoom switch 111 is a switch for setting an optical zoom magnification, and the trigger switch 112 operates start and stop of moving image recording.

  The control unit 113 is, for example, a CPU or an MPU, and controls the entire digital camera 100 by developing a program stored in the ROM in a work area of the RAM and executing the program. Signals from the changeover switch 110, the zoom switch 111, and the trigger switch 112 are received, and each unit is controlled in accordance with the contents of each operation. Although the curvature control unit 107 and the detection unit 108 are described as being independent of the control unit 113 in the present embodiment, the control unit 113 may realize these functions.

(Outline of Curvature Control Processing According to the Present Invention)
When control information or a control command according to the state of the zoom switch 111 is input from the control unit 113, the imaging optical system drive unit 106 drives and controls the zoom lens of the imaging optical system 101 to the wide angle side or the telephoto side. The imaging optical system drive unit 106 also supplies focal length information of the zoom lens of the imaging optical system 101 to the curvature control unit 107. The imaging optical system drive unit 106 controls the aperture of the imaging optical system 101 to open and close in accordance with the brightness of the subject and the depth of field desired by the user, and drives the focus lens of the imaging optical system 101 to The imaging position of the optical image in the optical axis direction is controlled.

  When focusing on the entire imaging surface, the curvature control unit 107 minimizes or reduces the field curvature aberration based on the focal distance information of the lens supplied from the imaging optical system drive unit 106 (ie, based on the angle of view The curvature of the imaging surface of the imaging element 102 is controlled so as to reduce the difference in the condensing position). For the optimum curvature of the imaging surface corresponding to the focal length, for example, a predetermined curvature value is stored as a table in the memory of the control unit 113, and the curvature control unit 107 can calculate all or all of the curvature values in this table. A part is acquired at a predetermined timing (via the control unit 113).

  For example, when the image sensor 102 has a drive unit that controls the radius of curvature by stress, stress is applied to the image sensor to control the radius of curvature to be small. At this time, the imaging element 102 consumes power for generating stress (ie, power for controlling curvature). In addition, when the curvature of the imaging surface is, for example, an optimal curvature (that is, in a stressed state), the imaging element 102 consumes power for maintaining the curvature. This optimal curvature is maintained, for example, until the position of the zoom lens of the imaging optical system 101 is changed, or until the moving image shooting is completed. Therefore, the longer the time for the maintenance, the more power is consumed.

  As described above, if the stress is controlled, the distance between the center of the imaging surface and the imaging optical system 101 fluctuates, so that the focus position shifts. However, in general, when focusing is constantly monitored by contrast AF or the like at the time of moving image shooting, a shift in focus due to a change in curvature of the imaging surface can be absorbed by this normal AF operation.

  On the other hand, when the imaging element 102 does not apply stress, for example, the imaging surface changes from concave to nearly flat. In this state, power for controlling the curvature of the imaging surface is not consumed, or power consumption is lower than a predetermined value (hereinafter, the state of the imaging surface is referred to as an initial state or a non-energized state). That is, when the imaging device 102 is in the initial state, the power supplied to the imaging device 102 can be unnecessary or reduced, and thus the power consumption by the imaging device 102 can be reduced.

  In the present embodiment, it is focused on that, even if the imaging device 102 is in the initial state and out of focus, the out of focus condition may be permitted depending on the shooting conditions. For example, in a scene in which the brightness of the detected subject is low and the curvature of field aberration is not noticeable, the image sensor 102 is put into the above-described initial state to prioritize power consumption reduction.

  More specifically, the subject brightness of the image data output from the imaging system signal processing unit 103 is detected, and the curvature is controlled according to the detected subject brightness (that is, the imaging condition) and the focal length of the imaging optical system 101. In the present embodiment, as shown in FIG. 6A, when the luminance value is smaller than a predetermined luminance value, the curvature of the image pickup device 102 is set to the initial state (or the state of small curvature), while the luminance is in advance. If it is equal to or greater than the predetermined value, the curvature is controlled according to the focal length of the imaging optical system 101. By doing this, it is possible to effectively reduce the power consumption of the image pickup element and hence the power consumption of the image pickup apparatus within the range where the influence of the curvature of field aberration is not noticeable during use.

  In the digital camera 100 according to the present embodiment, for example, the detection unit 108 detects the brightness of the subject based on the image data output from the imaging system signal processing unit 103. If the detected luminance value is smaller than a predetermined luminance value, the detection unit 108 supplies a detection signal for the luminance to the curvature control unit 107. That is, the detection unit 108 detects the case where the luminance of the subject is low and notifies the curvature control unit 107, and the curvature control unit 107 detects the detection signal from the detection unit 108. The power supplied to maintain the curvature is stopped or reduced (hereinafter, also referred to as cancellation of the curvature control). Then, the imaging surface of the imaging element 102 is in an initial state.

  On the other hand, the detection unit 108 does not supply a detection signal when the detected luminance of the subject is equal to or greater than a predetermined value. For this reason, the curvature control unit 107 supplies power to change or maintain the curvature of the imaging device 102, whereby the imaging device 102 changes the curvature of the imaging surface so as to minimize curvature of field aberration or maintain.

(A series of operations related to curvature control processing of the imaging surface)
Next, with reference to FIG. 2, a series of operations related to the curvature control process of the imaging surface will be described. Note that this process is started when, for example, the digital camera 100 is in a standby state for moving image shooting, for example, when there is a user operation on a switch such as the zoom switch 111 or the changeover switch 110. The control unit 113 loads the program stored in the ROM into a work area of the RAM and executes the program. Further, each step described below is executed by the control unit 113 unless otherwise described.

  In step S201, the control unit 113 determines whether to perform a zoom operation. Specifically, the control unit 113 determines the presence or absence of the input signal from the zoom switch 111, and proceeds to step S202 to determine the zoom position when determining that the input signal is present. On the other hand, when the control unit 113 determines that there is no input signal from the zoom switch 111, the process proceeds to step S203.

  In step S203, the control unit 113 determines the optimal curvature of the imaging surface according to the zoom position. When the zoom operation is not performed in S201, the control unit 113 determines the optimum curvature of the imaging surface corresponding to the initial position of the lens. For example, if a table indicating the set of the zoom position, the focal length and the optimum curvature of the imaging surface is stored in advance in a memory or the like, the optimum curvature of the imaging surface can be obtained from the obtained zoom position (or focal length). it can. The control unit 113 stores the obtained value of the optimum curvature in the memory area.

  In S204, the control unit 113 determines whether to start moving image recording. For example, when detecting that the user operates the trigger switch 112, the control unit 113 determines that moving image recording is to be started, and advances the process to S205. At this time, the control unit 113 separately starts moving image recording. If not, the process returns to S204.

  In S205, the detection unit 108 detects subject brightness. As described above, the detection unit 108 acquires the image data output from the imaging system signal processing unit 103, and calculates, for example, the luminance value of the entire or a part of the image (such as the periphery of the image), Detect subject brightness.

  In step S206, the control unit 113 determines whether moving image recording is continuing, and advances the process to step S207 when continuing, and ends the series of processes when not continuing.

  In S207, the detection unit 108 determines whether the subject brightness is equal to or more than a predetermined value. If the detection unit 108 determines that the subject brightness is smaller than the predetermined value, the control unit 113 returns the process to S205 again and repeats the processes of S205 to S207. If the detection unit 108 determines that the subject brightness is equal to or more than the predetermined value, the control unit 113 proceeds to the process of S208. In S208, the curvature control unit 107 acquires the value of the curvature obtained in S203 from the control unit 113, and controls the curvature of the imaging surface of the imaging element 102.

  In S209, the detection unit 108 detects subject brightness. In step S210, the control unit 113 determines whether moving image recording is continuing. If moving image recording is continuing, the process proceeds to step S211. If not, the process proceeds to step S213 to cancel curvature control of the imaging element 102. And complete the series of operations.

  In S211, the detection unit 108 determines whether the subject brightness is equal to or more than a predetermined value. If the detection unit 108 determines that the subject brightness is equal to or higher than the predetermined value, the control unit 113 returns the process to S209. If the subject brightness is lower than the predetermined value, the process proceeds to S212. In step S <b> 212, the control unit 113 cancels the curvature control of the imaging element 102 (i.e., sets the initial state). When the curvature control is released and the curvature of the imaging surface is changed as described above, the distance between the center of the imaging surface and the lens is changed to cause defocus. However, in the present embodiment, since this control is performed when the luminance of the photographed image is low, the movement or shift of the focus is less noticeable as compared with the case of a normal bright image. For this reason, it is possible to effectively reduce power consumption in a range in which the influence of the curvature of field aberration is not noticeable during use.

  In step S214, the control unit 113 determines whether moving image recording is continuing. If it is determined that the moving image recording is continuing, the process returns to step S205 again to repeat the detection of the subject brightness. On the other hand, if it is determined that the moving image recording is not continuing, the series of operations of the present process is ended.

  In the present embodiment, in the cancellation of the curvature control, an example in which the imaging surface is in the initial state and the curvature is controlled to the power consumption lower than the predetermined value has been described. However, even if the imaging surface is not in the initial state, it is obvious that the effect of the present invention can be obtained at any curvature as long as the power consumption is reduced from the power consumption required for the optimum curvature, for example.

  Further, in the present embodiment, the imaging element having a structure in which the curvature of the imaging surface is controlled by applying stress is described as an example, but the curvature of the imaging surface may be controlled and the control may involve power consumption. For example, it is not limited to this. For example, power may be supplied to control the curvature of the imaging surface by the change of the magnetic force by the electromagnet, the volumetric contraction rate by heat, or the attraction force.

  Further, in the present embodiment, the curvature control unit 107 controls the supply of power to the imaging element 102 to control the curvature of the imaging surface. However, the curvature control unit 107 may output a control signal to the imaging element 102, and the imaging element 102 may control the imaging surface according to the control signal. Even in this case, power consumption can be reduced as a result of control of the imaging surface.

  As described above, in the present embodiment, the curvature of the imaging surface is controlled in accordance with the detected luminance in the imaging device configured to reduce the curvature of field aberration based on the state of the imaging optical system. . In particular, when the luminance of the detected image data is smaller than a predetermined luminance value, the curvature of the imaging element 102 is set to the initial state to suppress the power consumption for changing or maintaining the curvature. That is, in the case of a dark screen, power consumption can be effectively reduced by utilizing the case where the influence of the curvature of field aberration is not noticeable. In addition, when the detected subject brightness is equal to or greater than a predetermined brightness value, the optimal curvature can be maintained, so that the merit of the variable curvature sensor can be used in a scene where the influence of the curvature of field aberration can be noticeable .

Second Embodiment
Next, the second embodiment will be described. In the first embodiment, the subject brightness is detected as the shooting condition. However, in the second embodiment, the curvature of the imaging surface is controlled based on the state of the aperture of the imaging optical system 101. In the configuration of the digital camera 100 according to the present embodiment, the imaging optical system drive unit 106 supplies the state of the diaphragm of the imaging optical system 101 to the detection unit 108, and the detection unit 108 and the curvature control unit 107 perform curvature according to the state of the diaphragm. Differs in that it controls In addition, since the other structure is the same as that of Embodiment 1, the same code | symbol is attached | subjected about the same structure, the overlapping description is abbreviate | omitted, and a difference is mainly demonstrated.

  FIG. 3 shows an example of a functional configuration showing the digital camera 100 according to the present embodiment. The difference from the first embodiment is that the imaging optical system drive unit 106 and the detection unit 108 are connected, and the imaging optical system drive unit 106 transmits to the detection unit 108 information indicating the state (for example, F value) of the aperture of the imaging optical system 101. It is a point to be output.

  More specifically, as shown in FIG. 6B, the curvature of the imaging surface is controlled to the curvature in the initial state or the focal length of the imaging optical system 101 according to the F value. Ru.

  The detection unit 108 detects the state (F value) of the aperture of the imaging optical system 101 supplied from the imaging optical system drive unit 106. The detection unit 108 supplies a detection signal to the curvature control unit 107 when the detected F value is smaller than a predetermined value.

  In response to the detection signal from the detection unit 108 being received, the power supplied to maintain the curvature of the imaging element 102 is stopped or reduced (that is, the curvature of the imaging element 102 is set to the initial state). ). In other words, when the f-number is small, the depth of field becomes shallow, so it is possible to take a picture with a blurred area around the subject as in portrait photography, and the area around the subject is blurred. It may be less noticeable.

  On the other hand, when the F value detected by the detection unit 108 is equal to or greater than a predetermined value, the detection signal is not supplied as in the first embodiment. Therefore, the curvature control unit 107 continues the power supply to maintain the curvature of the imaging surface of the imaging device 102, whereby the imaging device 102 has the curvature of the imaging surface so as to minimize the curvature of field. Change or maintain.

  Next, a series of operations of the curvature control process according to the present embodiment will be described with reference to the flowchart shown in FIG. Also in the present embodiment, as in the first embodiment, when the digital camera 100 is in a standby state for moving image shooting, for example, this process is started when there is a user operation on a switch such as the zoom switch 111 or the changeover switch 110. The control unit 113 loads the program stored in the ROM into a work area of the RAM and executes the program. Further, each step described below is executed by the control unit 113 unless otherwise described.

  The control unit 113 performs each process of S201 to S204.

  In S401, the detection unit 108 detects the F value of the imaging optical system 101. If the control unit 113 determines in S206 that the moving image recording has not ended, the detection unit 108 determines whether the F value of the imaging optical system 101 is equal to or more than a predetermined value in S402. If the F value is equal to or greater than the predetermined value, the control unit 113 advances the process to S403, and returns the process to S401 if the F value is lower than the predetermined value.

  In step S403, the curvature control unit 107 controls the curvature curvature of the imaging element 102 to the value obtained in step S203 because the F value is equal to or greater than a predetermined value. When the F-number is large, the depth of field becomes deep, and it is possible to capture an image in focus at the corner of the screen regardless of the distance to the subject. As described above, when the F-number is large, the influence of the curvature of field aberration is easily noticeable, so the curvature of the imaging surface is controlled in accordance with the curvature of field aberration.

  In S404, the detection unit 108 detects the F value of the imaging optical system 101 again. If it is determined in S210 that the moving image recording is not completed, then in S405, the detection unit 108 determines whether the F value of the imaging optical system 101 is equal to or more than a predetermined value. If the detection unit 108 determines that the F value of the imaging optical system 101 is smaller than the predetermined value, the control unit 113 advances the process to S212 and cancels the curvature control of the imaging element 102. When the curvature control of the imaging element 102 is released, the imaging surface of the imaging element 102 is in an initial state.

  If the detection unit 108 determines in step S405 that the F value of the imaging optical system 101 is equal to or greater than a predetermined value, the control unit 113 returns the process to step S404 and continues detecting the F value of the imaging optical system 101. If the control unit 113 determines that the moving image recording has ended in S210, the curvature control of the imaging element 102 is canceled in S213.

  As described above, according to this embodiment, the curvature of the imaging surface is controlled in accordance with the detected state of the diaphragm in the imaging device configured to reduce the curvature of field aberration based on the state of the imaging optical system. It was made to do. In particular, when the detected F-number is smaller than a predetermined aperture value, the curvature of the imaging element 102 is set to the initial state to suppress the power consumption for changing or maintaining the curvature. That is, power consumption can be effectively reduced by utilizing the fact that the influence of curvature of field aberration is not noticeable when the depth of field is shallow. Further, when the detected f-number is equal to or more than a predetermined f-number, the optimum curvature can be maintained, so that the merit of the variable-curvature sensor can be utilized in the scene where the influence of the curvature of field aberration is noticeable.

(Embodiment 3)
Furthermore, Embodiment 3 will be described. In the first embodiment, the subject brightness is detected as the shooting condition, but in the third embodiment, the detection unit 108 detects the amount of movement of the subject, and the curvature control unit 107 controls the curvature of the imaging surface based on the detection result. The configuration of the digital camera 100 according to the present embodiment is the same as that of the functional configuration example shown in FIG. 1 and, therefore, the same symbols are attached to the same components and redundant description is omitted. explain.

  The difference from the first embodiment is that, as described above, the detection unit 108 obtains the amount of movement of the subject from a plurality of image data (video data) output from the imaging system signal processing unit 103, and performs imaging according to the movement amount. The point is to control the curvature of the element. More specifically, as shown in FIG. 6C, the curvature of the image sensor 102 is controlled to the initial state or the curvature according to the focal length of the imaging optical system 101 according to the detected amount of movement.

  In the present embodiment, the detection unit 108 detects the amount of movement of the subject based on the video data output from the imaging system signal processing unit 103, and the curvature control unit 107 detects the amount of movement detected. Supply a detection signal. The curvature control unit 107 stops or reduces the power supplied to maintain the curvature of the imaging device 102 in response to the reception of the detection signal from the detection unit 108 (that is, the curvature control unit 107 The curvature is made an initial state). Generally, the user pays attention to the movement of the subject when there is a movement of the subject, so it is difficult to notice the influence of the curvature of field aberration compared to a still image, and also the image plane when the entire screen shakes like camera shake. It is hard to notice the influence of curvature aberration. That is, when the subject has motion, the motion of the subject or the screen may make it difficult to recognize the influence of the curvature of field aberration.

  On the other hand, when the motion amount detected by the detection unit 108 is equal to or less than the predetermined value, the detection signal is not supplied as in the first embodiment. Therefore, the curvature control unit 107 continues the power supply to maintain the curvature of the imaging surface of the imaging device 102, whereby the imaging device 102 has the curvature of the imaging surface so as to minimize the curvature of field. Change or maintain.

  Next, a series of operations of the curvature control process according to the present embodiment will be described with reference to the flowchart shown in FIG. Also in the present embodiment, as in the first embodiment, when the digital camera 100 is in a standby state for moving image shooting, for example, this process is started when there is a user operation on a switch such as the zoom switch 111 or the changeover switch 110. The control unit 113 loads the program stored in the ROM into a work area of the RAM and executes the program. Further, each step described below is executed by the control unit 113 unless otherwise described.

  The control unit 113 performs each process of S201 to S204.

  In S501, the detection unit 108 detects the movement of the subject in the video data. In addition, the detection method of a to-be-photographed object can use the detection method of a well-known motion vector, for example. If the control unit 113 determines in S206 that moving image recording is continuing, in S502 the detection unit 108 determines whether the detected amount of movement of the subject is equal to or more than a predetermined value. If the movement amount is equal to or less than the predetermined value, the control unit 113 advances the process to step S503. If the movement amount is larger than the predetermined value, the control unit 113 returns the process to step S501 to continue moving image shooting.

  In step S503, the curvature control unit 107 controls the curvature curvature of the imaging element 102 to the value obtained in step S203. When the amount of movement is small, blurring due to the movement is small and the influence of the curvature of field aberration is easily noticeable. Therefore, the curvature of the imaging surface is controlled according to the curvature of field curvature.

  In S504, the detection unit 108 detects the amount of movement of the subject. Next, when it is determined in S210 that moving image recording is continuing, in S505, the detection unit 108 determines whether the detected amount of movement of the subject is equal to or less than a predetermined value. If the detection unit 108 determines that the amount of movement of the subject is larger than the predetermined value, the control unit 113 advances the process to step S212 and cancels the curvature control of the imaging element 102. When the curvature control of the imaging element 102 is released, the imaging surface of the imaging element 102 is in an initial state.

  In step S505, when the detection unit 108 determines that the amount of movement of the subject is equal to or less than the predetermined value, the control unit 113 returns the process to step S504 and continues detecting the amount of movement of the subject. If the control unit 113 determines that the moving image recording has ended in S210, the curvature control of the imaging element 102 is canceled in S213.

  As described above, according to the present embodiment, in the imaging device configured to reduce the curvature of field aberration based on the state of the imaging optical system, the curvature of the imaging surface is adjusted according to the amount of movement of the detected object. I made it to control. In particular, when the detected amount of movement of the subject is larger than the predetermined amount of movement, the curvature of the imaging device 102 is set to the initial state to suppress power consumption for changing or maintaining the curvature. That is, power consumption can be effectively reduced by making it difficult to recognize the influence of the curvature of field due to the movement of the subject or the screen. Also, if the detected amount of movement of the subject is less than or equal to a predetermined amount of movement, in order to maintain the optimum curvature, take advantage of the merits of the variable-curvature sensor in scenes where the effects of curvature of field are noticeable Can.

  Although the curvature control of the imaging device during moving image recording has been described in the above-described embodiment, the same power reduction effect can be obtained even when the present invention is applied to the standby mode for photographing in the still image mode. In particular, when live view display is performed, the image pickup element 102 generates image data as needed as in the case of moving image recording, so that the same effect as that of moving image recording can be obtained.

  Further, in order to prevent destruction of the imaging sensor, a means for detecting the amount of bending of the imaging sensor may be provided, and control of the curvature may be limited so as not to be a predetermined curvature or more.

(Other embodiments)
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

DESCRIPTION OF SYMBOLS 101 ... Imaging optical system, 102 ... Imaging element, 106 ... Imaging optical system drive part, 107 ... Curvature control part 108 ... Detection part, 113 ... Control part

Claims (10)

An imaging optical system,
An imaging unit configured to be able to bend an imaging surface;
Driving means for curving an imaging surface of the imaging means;
When the subject brightness is equal to or greater than a predetermined brightness value, the curvature of the imaging surface is a curvature that reduces the curvature of field aberration generated at the focal length of the imaging optical system, and satisfies a predetermined power consumption condition. The drive means is controlled to have a first curvature, and when the subject brightness is lower than the predetermined brightness value, the curvature of the imaging surface is smaller than the first curvature and the power consumption is lower. A control unit configured to control the drive unit to have a low curvature and a second curvature satisfying the predetermined power consumption state ;
An imaging apparatus characterized by having: An imaging optical system having an aperture;
An imaging unit configured to be able to bend an imaging surface;
Driving means for curving an imaging surface of the imaging means;
The curvature of the imaging surface is a curvature that reduces the curvature of field aberration generated at the focal length of the imaging optical system when the diaphragm value of the diaphragm is equal to or greater than a predetermined diaphragm value, and the predetermined power consumption is The drive means is controlled so as to obtain a first curvature not satisfying the state, and when the aperture value of the aperture is smaller than the predetermined aperture value, the curvature of the imaging surface is greater than the first curvature. Control means for controlling the driving means so as to have a second curvature which satisfies the condition of the predetermined power consumption .
An imaging apparatus characterized by having: An imaging optical system and an imaging unit configured to be able to bend an imaging surface;
Driving means for curving an imaging surface of the imaging means;
If the amount of movement of the subject imaged by the imaging means or the amount of movement of the entire screen is equal to or less than a predetermined movement amount, the curvature of the imaging surface produces a curvature of field aberration that occurs in the focal distance of the imaging optical system. The driving means is controlled to have a curvature to be reduced and a first curvature not satisfying a predetermined power consumption state, and the curvature of the imaging surface is controlled when the movement amount is larger than the predetermined movement amount A control means for controlling the drive means to have a curvature smaller than the first curvature and lower in power consumption and to a second curvature satisfying the predetermined power consumption state ;
An imaging apparatus characterized by having: The said control means controls the curvature of the said imaging surface by supplying the electric power for driving the said drive means to the said drive means, The control method is described in any one of the Claims 1 thru | or 3 characterized by the above-mentioned. Imaging device. The imaging unit outputs video data imaged using the curvature of the imaging surface controlled by the control unit,
The image pickup apparatus according to any one of claims 1 to 4 , further comprising recording means for recording the output video data. The imaging unit outputs video data imaged using the curvature of the imaging surface controlled by the control unit,
The image pickup apparatus according to any one of claims 1 to 4 , further comprising display means for displaying the output video data. A method for controlling an imaging apparatus including an imaging optical system and an imaging means for imaging surface configured to be bent,
A driving step of driving means for curving an imaging surface of the imaging means;
When the control means is such that the curvature of the image pickup surface reduces the curvature of field aberration generated at the focal length of the image pickup optical system when the subject luminance is equal to or greater than a predetermined luminance value, the predetermined power consumption The drive means is controlled such that the first curvature does not satisfy the condition of b. If the subject brightness is lower than the predetermined brightness value, the curvature of the imaging surface is smaller than the first curvature. And a control step of controlling the driving means so as to have a second curvature satisfying the predetermined power consumption state with a low power consumption .
And a control method of an imaging apparatus. A control method of an imaging apparatus, comprising: an imaging optical system having an aperture; and an imaging unit configured to be capable of bending an imaging surface,
A driving step of driving means for curving an imaging surface of the imaging means;
The control means is a curvature that reduces the curvature of field aberration that occurs at the focal length of the imaging optical system when the control unit has a stop value of the stop that is equal to or greater than a predetermined stop value. Controlling the driving means to achieve a first curvature that does not satisfy the state of power consumption, and when the diaphragm stop value of the diaphragm is smaller than the predetermined diaphragm value, the curvature of the imaging surface is the first curvature. A control step of controlling the drive means so as to have a curvature smaller than the curvature and lower in power consumption, and to have a second curvature satisfying the predetermined power consumption state;
And a control method of an imaging apparatus. A control method of an imaging apparatus, comprising: an imaging optical system; and an imaging unit configured to be capable of bending an imaging surface,
A driving step of driving means for curving an imaging surface of the imaging means;
When the control means is such that the amount of movement of the subject imaged by the imaging means or the amount of movement of the entire screen is equal to or less than a predetermined movement amount, The driving unit is controlled to have a curvature that reduces a surface curvature aberration and does not satisfy a predetermined power consumption state, and the movement amount is larger than the predetermined movement amount. A control step of controlling the drive means such that the curvature of the imaging surface is a curvature smaller than the first curvature and lower in power consumption, and is a second curvature satisfying the predetermined power consumption state; ,
And a control method of an imaging apparatus. The computer program for executing the respective steps of the control method of the imaging apparatus according to any one of claims 7 to 9.

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