JP2017022542A - Imaging apparatus, and control method for imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus which decreases performance reduction during half pressing or full pressing of a shutter button, by suppressing a waiting time that is generated when operating an ND filter, to a minimum requirement.SOLUTION: The imaging apparatus comprises: imaging means; photographing means which performs photographing processing in response to a photographing instruction of a user; ND filter control means for controlling ON/OFF of the ND filter during the photographing processing; camera shake correction control means for controlling camera shake correction during the photographing processing; and control means which performs control so as to generate waiting for a predetermined time from the ON/OFF control of the ND filter to imaging in accordance with a resolution of a captured image that is obtained by the imaging means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus and an imaging apparatus control method, and more particularly to an imaging apparatus including an image stabilization mechanism and an ND filter, and control of the imaging apparatus.

  2. Description of the Related Art Conventionally, an imaging apparatus that includes an ND filter in order to improve the convenience of exposure control is known. By using the ND filter, it is possible to shoot with a wide aperture even in a bright scene or shoot with long-second exposure, and the range of expression can be expanded. In such an imaging apparatus, the ND filter operates as necessary at the timing of a half-press or full-press of the shutter button by the user.

  Here, consider the case where the ND filter control unit is energized in order to operate the ND filter. When the ND filter control unit is energized, there may be a case where a magnetic field is exerted on the surroundings, for example, the Hall element for detecting the position information of the camera shake correction lens. Further, when the ND filter operates, the camera shake correction lens may be shaken by the vibration. Therefore, when the ND filter operates at the timing of the half-press or full-press of the shutter button, the camera shake correction lens is shaken and unstable due to the above-described factors, and a blurred image is acquired.

  On the other hand, when the ND filter is operating, it is necessary to acquire an image after waiting for a predetermined time until the camera shake correction lens is stabilized. However, this leads to performance degradation when the shutter button is pressed halfway or fully.

  Patent Document 1 proposes an imaging apparatus that acquires an image with less discomfort by determining whether or not to operate an ND filter based on a predetermined condition during moving image shooting. According to this, if the ND filter is operated between each frame when the frame rate is long, it is possible to prevent the image stabilization lens from acquiring an image during an unstable period.

  Patent Document 2 proposes an imaging apparatus that performs camera shake correction control based on whether or not to save a captured image.

JP 2013-157688 A JP2013-33184A

  However, Patent Document 1 does not provide a means for preventing performance degradation when the ND filter is operated during still image shooting. Further, in Patent Document 2, camera shake correction control is performed based on whether or not a captured image is stored. However, when the camera shake correction control itself cannot be normally performed due to the operation of the ND filter, a blur image is prevented from being acquired. I can't.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an imaging apparatus that reduces the performance degradation when the shutter button is half-pressed or fully pressed by minimizing the waiting time that occurs when the ND filter is operated. is there.

  In order to achieve the above object, an imaging apparatus according to the present invention includes an imaging unit, an imaging unit that performs an imaging process in accordance with a user's imaging instruction, and an ND filter that controls ON / OFF of the ND filter in the imaging process. A waiting time of a predetermined time is generated between the ON / OFF control of the ND filter and the imaging according to the control means, the camera shake correction control means for controlling the camera shake correction in the photographing process, and the resolution of the captured image obtained by the imaging means. And control means for controlling the operation.

  According to the present invention, it is possible to provide an imaging apparatus that can reduce a decrease in performance when the shutter button is half-pressed or fully pressed by minimizing the waiting time that occurs when the ND filter is operated.

It is a flowchart which shows the operation | movement at the time of ND filter control of a present Example. It is a block diagram which shows the imaging device of a present Example. It is a flowchart which shows the operation | movement of ND filter control determination of a present Example. It is a flowchart which shows the operation | movement of ND filter control determination of a present Example. It is a flowchart which shows the operation | movement at the time of the 2nd ND filter control of a present Example.

  Hereinafter, examples of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. The embodiments of the present invention show preferred modes of the invention and do not limit the scope of the invention.

[Example]
In this embodiment, an image pickup apparatus including a camera shake correction mechanism and an ND filter will be described. In the imaging apparatus according to the present exemplary embodiment, the ND filter operates as necessary at the timing of the user's half-press or full-press of the shutter button. Hereinafter, the imaging apparatus of the present embodiment will be described.

  Hereinafter, the main configuration of the imaging apparatus 100 according to the present embodiment will be described with reference to FIG. In FIG. 2, reference numeral 100 denotes an imaging device. The system control unit 101 includes, for example, a CPU (MPU), a memory (DRAM, SRAM), and the like, and executes various processes (programs) to control each block of the image capturing apparatus 100 and transfer data between the blocks. To control. In addition, the system control unit 101 controls each block of the imaging apparatus 100 according to an operation signal from the operation unit 102 that receives an operation from the user.

  The operation unit 102 includes switches for inputting various operations related to photographing such as a power button, a shutter button, and a zoom lever. Further, it includes a menu display button, a determination button, other cursor keys, a pointing device, a touch panel, and the like. When these keys and buttons are operated by the user, an operation signal is transmitted to the control unit 101. The bus 103 is a general-purpose bus for sending various data, control signals, instruction signals, and the like to each block of the imaging apparatus 100.

  The zoom lens 104 is a lens that can optically change the focal length. The zoom control unit 105 drives the zoom lens 104 to change the focal length in order to change the zoom magnification of the captured image. The focus lens 106 is a lens for performing focusing. The focus control unit 107 drives the focus lens 106 so as to focus the subject imaged on the imaging unit 115.

  The camera shake correction lens 108 is a lens for correcting a shake of a captured image due to a user's camera shake. The Hall element 109 is an element for detecting the magnetic field and acquiring positional information of the camera shake correction lens 108. The camera shake correction control unit 110 acquires the position information of the camera shake correction lens 108 by the hall element 109 and drives the camera shake correction lens 108 so as to cancel the blur of the captured image caused by the user's camera shake.

  The ND filter 111 is a filter that reduces the amount of light taken into the imaging unit 115. The ND filter 111 enables shooting with a wide aperture and shooting with long second exposure even in a bright scene, and can broaden the range of expression. The ND filter control unit 112 controls the ND filter 111 to be taken in and out of the light path to the imaging unit 115 as necessary at the timing of an operation such as half-pressing or full-pressing the shutter button. At this time, energization to the ND filter control unit 112 is performed, but the magnetic field around the ND filter control unit 112 may change due to energization to the ND filter control unit 112.

  If the Hall element 109 is affected by the change in the magnetic field, the position information of the camera shake correction lens 108 may not be acquired correctly. Further, when the ND filter 111 is operated, the camera shake correction lens 108 may be shaken by the vibration. Therefore, when the ND filter 111 is operated at the timing of half-pressing or full-pressing the shutter button, the camera shake correction lens 108 is shaken and unstable due to the above-described factors, and a blurred image is acquired.

  On the other hand, when the ND filter 111 is operating, it is necessary to obtain an image after waiting for a predetermined time until the camera shake correction lens 108 is stabilized. However, this leads to performance degradation when the shutter button is pressed halfway or fully. The diaphragm 113 adjusts the amount of light taken into the imaging unit 115. The aperture control unit 114 controls the aperture 113 so that the captured image has an optimal exposure. The imaging unit 115 converts the optical image of the subject captured by the lens into an image signal by an imaging element such as a CCD sensor or a CMOS sensor, performs analog-digital conversion, and transmits the image signal to the image processing unit 116.

  The resolution (number of pixels) of the image signal generated by the imaging unit 115 varies depending on the state of the imaging device 100. For example, when a through image is displayed on the display unit 118 described later, an image signal having a size sufficient for the resolution of the display device may be generated. When contrast detection is performed using an image signal for focusing, an image signal having a size sufficient for focusing may be generated. In addition, when a still image is recorded on a recording medium 120 described later, it is preferable to generate an image signal having a maximum size that can be output by the imaging unit 115. As described above, the system control unit 101 changes the resolution of the image signal generated by the imaging unit 115 according to the state of the imaging device 100 as needed.

  The image processing unit 116 performs image quality adjustment processing for adjusting white balance, color, brightness, and the like on the input digital image signal based on setting values. Then, the image signal processed by the image processing unit 116 is transmitted by the system control unit 101 to the display control unit 117 described later. Further, the image processing unit 116 encodes the image signal and generates a compressed image signal. The system control unit 101 transmits the compressed image signal to a recording unit 119 described later.

  The display control unit 117 causes the display unit 118 to display a video based on the image signal transmitted from the image processing unit 115, an operation screen (menu screen) for operating the imaging apparatus 100, and the like. The display unit 118 may be any display device such as a liquid crystal display, an organic EL display, or electronic paper. The recording unit 119 records the compressed image signal generated by the image processing unit 116 and other control data related to photographing on the recording medium 120.

  The recording medium 120 may be a recording medium built in the imaging apparatus or a removable recording medium, as long as the compressed image signal generated by the imaging apparatus 100 and various data can be recorded. For example, the recording medium 120 includes all types of recording media such as a hard disk, an optical disk, a magneto-optical disk, a CD-R, a DVD-R, a magnetic tape, a nonvolatile semiconductor memory, and a flash memory.

  Next, a characteristic operation of the imaging apparatus 100 of the present embodiment will be described. The image pickup apparatus 100 according to the present exemplary embodiment performs a characteristic operation of reducing the performance degradation when the shutter button is half-pressed or fully pressed by minimizing the waiting time generated when the ND filter is operated. Can be executed.

  The operation when controlling the ND filter 111 of this embodiment will be described below with reference to FIG.

  When the shutter button included in the operation unit 102 is half-pressed or fully pressed by the user, the system control unit 101 controls the ND filter 111 through the ND filter control unit 112 as necessary. A method for determining whether to control the ND filter 111 will be described later. In S200, energization to the ND filter control unit 112 is started to operate the ND filter 111, and the ND filter 111 is inserted (ON) on the light path to the imaging unit 115 or removed from the path (OFF). ).

  In S201, it is determined whether or not the resolution of the image signal generated by the imaging unit 115 is greater than or equal to a predetermined value in the current state of the imaging device 100. If not greater than the predetermined value, the process proceeds to S202. For example, when the state of the imaging apparatus 100 is a state in which a through image is displayed on the display unit 118 or a state in which contrast detection is performed using an image signal for focusing, an image signal generated by the imaging unit 115 It can be determined that the resolution of is not higher than a predetermined resolution. On the other hand, when the state of the imaging apparatus 100 is a state of recording a still image on the recording medium 120, it can be determined that the resolution of the image signal generated by the imaging unit 115 is equal to or higher than a predetermined value.

  In S202, the image signal generated by the imaging unit 115 is acquired and the process ends. In S203, a predetermined time is waited until the camera shake correction lens 108 is stabilized, and the process proceeds to S202.

  According to the present embodiment, when recording a still image, the image is acquired after waiting for a predetermined time until the camera shake correction lens 108 is stabilized, so that an image without blur can be obtained. Further, when displaying a through image or performing focusing, since the resolution of the image signal to be used is not at a level that is affected by the shaking of the camera shake correction lens 108, unnecessary waiting can be avoided. .

  Next, a method for determining whether or not to control the ND filter 111 of the present embodiment will be described with reference to FIGS. FIG. 3A shows the flow of processing when the user presses the shutter button halfway (SW1), follows the exposure for a while, and then presses the shutter button fully (SW2). It is assumed that the ND filter 111 starts from the OFF state.

  In S300, it is determined whether or not SW1 has been operated. If not, the process returns to S300, and if operated, the process proceeds to S301. In S301, SW1AF (focusing) processing described later is executed. In S302, SW1AE (exposure control) processing described later is executed. In S303, an image signal is acquired by the imaging unit 115 and the current brightness is measured. In S304, the focus lens 106 is controlled to keep the subject in focus. Further, in order to keep the exposure of the subject optimal, the aperture 113 is controlled based on the brightness obtained in S303, the shutter time (exposure time of the imaging unit 115) is adjusted, and the image processing unit 116 is used. Perform the image quality adjustment process.

  In S305, it is determined whether or not SW2 has been operated. If not, the process returns to S303, and if operated, the process proceeds to S306. In S306, SW2 processing described later is executed.

  Next, the SW1AF process will be described. In S310, in order to obtain the optimum exposure for focusing, an image signal is acquired by the imaging unit 115 and the brightness is measured. In S311, it is determined whether or not the brightness obtained in S310 is greater than or equal to a predetermined value. If not, the process proceeds to S312 and if it is greater than or equal to the predetermined value, the process proceeds to S313. In step S312, the focus lens 106 is controlled to focus on the subject.

  In S313, the ND filter 111 is turned on. Thereby, even in a bright scene, the amount of light taken into the imaging unit 115 can be reduced and focusing can be performed with optimal exposure. Here, since the imaging apparatus 100 is in a state of focusing, the resolution of the image signal generated by the imaging unit 115 is equal to or lower than a predetermined value. Accordingly, in S313, the stabilization of the camera shake correction lens 108 is not performed after the control of the ND filter 111.

  Next, the SW1AE process will be described. In S320, an image signal is acquired by the imaging unit 115 and the current brightness is measured. In S321, it is determined whether or not the brightness obtained in S320 is greater than or equal to a predetermined value. If not, the process proceeds to S322, and if it is greater than or equal to the predetermined value, the process proceeds to S323. In S322, when the current state of the ND filter 111 is ON, OFF control is performed. Thereby, in a dark scene, it is possible to display a through image with an optimal exposure without reducing the amount of light taken into the imaging unit 115.

  In S323, in order to optimize the exposure of the subject, the aperture 113 is controlled based on the obtained brightness, the shutter time (exposure time of the imaging unit 115) is adjusted, and the image quality adjustment by the image processing unit 116 is performed. Process. In S324, when the current state of the ND filter 111 is OFF, ON control is performed. Thereby, in a bright scene, the amount of light captured by the imaging unit 115 can be reduced, and a through image can be displayed with an optimum exposure. Here, since the imaging apparatus 100 is in a state of displaying a through image, the resolution of the image signal generated by the imaging unit 115 is a predetermined value or less. Therefore, in S322 and S324, the stabilization of the camera shake correction lens 108 is not performed after the control of the ND filter 111.

  Next, the SW2 process will be described. In S330, it is determined whether or not the current brightness is equal to or greater than a predetermined result as a result of the previous photometry and AE tracking. If not, the process proceeds to S331, and if it is equal to or greater than the predetermined brightness, the process proceeds to S333. In S331, when the current state of the ND filter 111 is ON, OFF control is performed. As a result, when the scene changes to a dark scene as a result of AE tracking, the amount of light captured by the imaging unit 115 is not reduced, and a still image can be recorded with an optimal exposure. In S332, a still image shooting process is executed.

  In S333, if the current state of the ND filter 111 is OFF, ON control is performed. As a result, when the scene changes to a bright scene as a result of AE tracking, the amount of light captured by the imaging unit 115 can be reduced, and a still image can be recorded with an optimal exposure. Here, since the imaging apparatus 100 is in a state of recording a still image, the resolution of the image signal generated by the imaging unit 115 is equal to or higher than a predetermined value. Therefore, in S331 and S333, after the control of the ND filter 111, the stabilization of the camera shake correction lens 108 is performed.

  FIG. 3B shows a flow of processing when SW1 is performed by the user and flicker reduction processing is performed when flicker (flickering generated under a light source such as a fluorescent lamp) is detected, and then SW2 is performed. Yes. It is assumed that the ND filter 111 starts from the OFF state.

  In S400, it is determined whether or not SW1 has been operated. If not, the process returns to S400, and if it has been operated, the process proceeds to S401. In S401, the above-described SW1AF (focusing) process is executed. In S402, a SW1AE (exposure control) process for detecting flicker described later is executed. In S403, it is determined whether or not SW2 has been operated. If not, the process returns to S403, and if it has been operated, the process proceeds to S404. In S404, SW2 processing for flicker detection described later is executed.

  Next, the SW1AE process for flicker detection will be described. In S410, an image signal is acquired by the imaging unit 115 to measure the current brightness and detect flicker. Hereinafter, a case where flicker is detected will be considered. In S411, it is determined whether or not the brightness obtained in S410 is greater than or equal to a predetermined value. If not, the process proceeds to S412. If it is greater than or equal to the predetermined value, the process proceeds to S413. In step S412, it is stored that the ND filter 111 is turned off during still image shooting. Here, the ND filter 111 is not controlled.

  In S413, the fact that the ND filter 111 is turned on at the time of still image shooting is stored. Here, the ND filter 111 is not controlled. In S414, when the current state of the ND filter 111 is ON, OFF control is performed. In S415, in order to set a shutter time that is not affected by flicker (exposure time of the imaging unit 115) and optimize the exposure of the subject, the aperture 113 is controlled based on the obtained brightness, Image quality adjustment processing by the processing unit 116 is performed.

  Here, since the imaging apparatus 100 is in a state of displaying a through image, the resolution of the image signal generated by the imaging unit 115 is a predetermined value or less. Therefore, in S414, the stabilization of the camera shake correction lens 108 is not performed after the control of the ND filter 111. In the flicker detection SW1AE process, the ND filter 111 is always in the OFF state when performing the flicker reduction process, so that the flicker reduction process can be simplified.

  Next, the SW2 process for flicker detection will be described. In S420, it is determined whether or not the state of the ND filter 111 stored in S412 or S413 is ON. If it is OFF, the process proceeds to S421, and if it is ON, the process proceeds to S422. In S421, a still image shooting process is executed.

  In S422, the ND filter 111 is ON-controlled. Thereby, even in a bright scene, the amount of light taken into the imaging unit 115 can be reduced, and a still image can be recorded with an optimum exposure. Here, since the imaging apparatus 100 is in a state of recording a still image, the resolution of the image signal generated by the imaging unit 115 is equal to or higher than a predetermined value. Accordingly, in S422, after the ND filter 111 is controlled, the stabilization of the camera shake correction lens 108 is waited.

  Next, a second embodiment will be described with reference to FIG. 4 regarding processing at the time of still image shooting in the imaging apparatus 100 of the present embodiment. FIG. 4 shows the flow of processing when the shutter button is fully pressed (SW2) by the user. In S500, it is determined whether or not the ND filter 111 should be controlled. If the ND filter 111 is not controlled, the process proceeds to S510, and if the ND filter 111 is controlled, the process proceeds to S502.

  In step S501, exposure by the imaging unit 115 is started to record a still image. In S502, energization to the ND filter control unit 112 is started to operate the ND filter 111, and the ND filter 111 is inserted (ON) on the light path to the imaging unit 115 or removed from the path (OFF). ). In S503, the setting mode of the imaging apparatus 100 is checked to determine whether the camera shake correction setting is “ON” or “OFF”. If “OFF”, the process proceeds to S501. If “OFF”, S504 is determined. Proceed to In S504, a predetermined time is waited until the camera shake correction lens 108 is stabilized, and the process proceeds to S501.

  According to the present exemplary embodiment, when a still image is recorded with the camera shake correction setting “ON”, the image is acquired after waiting for a predetermined time until the camera shake correction lens 108 is stabilized, so that an image without blur can be obtained. . In addition, when a still image is recorded with the camera shake correction setting “OFF”, if the camera shake correction lens 108 is always fixed, the camera shake correction lens 108 will not be shaken even if the ND filter 111 is operated. Therefore, in that case, unnecessary waiting can be avoided.

  In this embodiment, after the control of the ND filter 111, the camera waits for a predetermined time until the camera shake correction lens 108 is stabilized. You may make it get out of the wait. As a result, the waiting time that occurs can be minimized.

  In addition, the influence of blurring on the captured image due to shaking of the camera shake correction lens 108 varies depending on the zoom magnification. The smaller the zoom magnification, the smaller the blur of the captured image due to the shake of the camera shake correction lens 108, and the greater the zoom magnification, the greater the blur of the captured image due to the shake of the camera shake correction lens 108. Therefore, when the focal length by the zoom lens 104 is short, the waiting time may be set short, and when the focal length by the zoom lens 104 is long, the waiting time may be set long. As a result, the waiting time that occurs can be minimized.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

100 imaging device, 101 system control unit, 102 operation unit, 103 bus,
104 zoom lens, 105 zoom control unit, 106 focus lens,
107 focus control unit, 108 camera shake correction lens, 109 Hall element,
110 camera shake correction control unit, 111 ND filter, 112 ND filter control unit,
113 aperture, 114 aperture control unit, 115 imaging unit, 116 image processing unit,
117 display control unit, 118 display unit, 119 recording unit, 120 recording medium

Claims (8)

Imaging means;
Photographing means for performing photographing processing according to a user's photographing instruction;
ND filter control means for controlling ON / OFF of the ND filter in the photographing process;
Camera shake correction control means for controlling camera shake correction in the photographing process;
An image pickup apparatus comprising: control means for controlling to wait for a predetermined time between ON / OFF control of the ND filter and image pickup according to the resolution of the picked-up image obtained by the image pickup means. The imaging apparatus according to claim 1, wherein when the resolution of the captured image is a resolution for AF, the waiting for the predetermined time is not generated. The imaging apparatus according to claim 1, wherein when the resolution of the captured image is a resolution for a through image, the waiting for the predetermined time is not generated. 4. The imaging apparatus according to claim 1, wherein when the camera shake correction control unit is set to be invalid, the waiting for the predetermined time is not generated. 5. The imaging apparatus according to claim 1, wherein the waiting for the predetermined time is generated when servo AF / AE is set. The imaging apparatus according to claim 1, wherein the waiting of the predetermined time is generated when flicker is detected. The imaging apparatus according to claim 1, wherein the predetermined time is changed according to a state of the camera shake correction control unit. The imaging apparatus according to any one of claims 1 to 7, wherein the predetermined time is changed according to a focal length.