Imaging system and control method for the same and program

Abstract

To reduce a time lag from an instruction to start moving image recording to the start of the moving image recording, in an imaging system in which a control body of a diaphragm can be switched.SOLUTION: An imaging system 1 has: a diaphragm driving ring 208 that sets a first diaphragm value according to a user operation to a diaphragm 202; a lens control unit 205 that performs drive control of the diaphragm 202; and a camera control unit 104 that sets a second diaphragm value to the diaphragm 202 on the basis of a photometric value, and controls the drive of the diaphragm 202 through the lens control unit 205. When switching from an automatic diaphragm mode in which the camera control unit 104 performs drive control of the diaphragm 202 to the second diaphragm value through the lens control unit 205, to a manual diaphragm mode in which the lens control unit 205 performs drive control of the diaphragm 202 to the first diaphragm value, the camera control unit 104 switches a control body of the diaphragm 202 to the lens control unit 205 after performing drive control of the diaphragm 202 to the first diaphragm value.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an imaging system capable of selectively controlling the aperture value of an aperture provided in a lens device by the lens device and the imaging device, and a control method and program for the imaging system. [Background technology]

[0002] As an imaging device that takes pictures using an image sensor, those that have a still image shooting mode in which a subject is shot singly and a video shooting mode in which the subject is shot as a video (image) composed of successive frame images are widely used. Also, an imaging system is known in which the aperture value of an aperture equipped in a lens device (interchangeable lens) that can be attached to the imaging device can be selectively controlled by the lens device side or the imaging device side (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-76807 Summary of the Invention [Problem to be solved by the invention]

[0004] In video shooting mode, in order to record the process of scene transitions, it is desirable that the lens device immediately controls the aperture in response to a change in aperture value setting by the user, whereas in still image shooting mode, in which images are recorded one-off, it is desirable that the lens device controls the aperture based on an aperture drive instruction from the imaging device.

[0005] In some cases, a user may press the movie recording button while the camera is in still image capture mode to start movie recording. In this case, it is necessary to switch from still image capture mode to movie capture mode, which requires communication between the image capture device and the lens device to switch the aperture control entity from the image capture device to the lens device. As a result, there is a time lag between pressing the movie recording button and starting movie recording.

[0006] An object of the present invention is to provide an imaging system that can switch the control entity of the aperture, and that can shorten the time lag from when a start instruction for moving image recording is given until the moving image recording starts. [Means for solving the problem]

[0007] The imaging system of the present invention is an imaging system having a lens device and an imaging device, wherein the lens device comprises an aperture, a first setting means for setting the aperture to a first aperture value in response to a user operation, and a first control means for controlling the driving of the aperture, and the imaging device comprises a second setting means for setting the aperture to a second aperture value based on a photometric value, a second control means for controlling the driving of the aperture via the first control means, and a switching means for switching between a first mode in which the first control means controls the driving of the aperture to the first aperture value and a second mode in which the second control means controls the driving of the aperture to the second aperture value, and is characterized in that when switching from the second mode to the first mode, the second control means controls the driving of the aperture to the first aperture value via the first control means, and then the switching means switches the control entity of the aperture from the second control means to the first control means. [Effects of the Invention]

[0008] According to the present invention, in an imaging system in which the control entity for controlling the aperture can be switched, it is possible to reduce the time lag from when a start instruction for moving image recording is given until the recording starts. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a schematic configuration of an imaging system according to an embodiment. [Figure 2] FIG. 2 is a perspective view of the appearance of a lens unit that constitutes the imaging system. [Figure 3] FIG. 2 is a schematic diagram illustrating a live view operation of the imaging system. [Figure 4] 10 is a flowchart of an aperture control process executed during a live view operation of the imaging system. [Figure 5] Fig. 5 shows the aperture drive speed table in manual aperture mode. [Figure 6] 10 is a flowchart of the aperture control subject determination process in step S404. [Figure 7] 10 is a timing chart according to an embodiment of a process for switching the subject of aperture control from a camera control unit to a lens control unit. [Figure 8] 10 is a timing chart relating to a reference example of processing for switching the subject of aperture control from a camera control unit to a lens control unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 is a block diagram showing a schematic configuration of an imaging system 1 according to the embodiment. The imaging system 1 includes an imaging device 100 (hereinafter referred to as "camera 100") and a lens device 200 (hereinafter referred to as "lens unit 200").

[0011] The camera 100 includes a shutter 101, an image sensor 102, an analog signal processing unit 103, a camera control unit 104, a shutter control unit 111, a timing generation unit 112, a communication terminal 113, an image display unit 114, a memory control unit 115, a memory 116, and an operation unit 117. The lens unit 200 includes a lens 201, an aperture 202, a focus driving unit 203, an aperture driving unit 204, a lens control unit 205, a communication terminal 206, and an aperture position acquisition unit 207.

[0012] First, the configuration of camera 100 will be described. Here, camera 100 is assumed to be a mirrorless single-lens camera. In this embodiment, shutter 101 is configured as a mechanical shutter that controls the exposure time of the light beam that has passed through lens unit 200 to image sensor 102 by mechanically moving a front curtain and a rear curtain, and is normally in an open state. Driving of shutter 101 is controlled by camera control unit 104 via shutter control unit 111.

[0013] The image sensor 102 is a so-called image sensor such as a CMOS sensor or a CCD sensor. A subject light beam incident on the lens unit 200 forms an image on the imaging surface of the image sensor 102, which converts the optical image of the subject into an analog electrical signal by photoelectric conversion and outputs it to the analog signal processing unit 103. In addition to the imaging pixels, the image sensor 102 also has a plurality of focus detection pixels that photoelectrically convert an image formed by split light beams from the lens unit 200.

[0014] Under the control of the camera control unit 104, the timing generation unit 112 generates signals that control the timing of resetting and signal readout in the image sensor 102 and supplies the signals to the image sensor 102. The timing generation unit 112 also realizes a so-called electronic shutter function that sets the time at which a subject light beam is incident on the image sensor 102. The analog signal processing unit 103 converts an analog electrical signal transmitted from the image sensor 102 into a digital signal (image signal) by A / D conversion and outputs the digital signal to the camera control unit 104. The analog signal processing unit 103 may be built into the image sensor 102, which is a sensor.

[0015] The camera control unit 104 is a microcomputer composed of a CPU, ROM, RAM, etc., and by executing programs stored in the ROM, it performs various data processing and performs overall control of not only the camera 100 but also the imaging system 1. Note that various setting values ​​set by the user to control the operation of the camera 100 are stored in a storage medium, such as an EEPROM provided in the camera control unit 104, whose memory contents can be rewritten.

[0016] The operation unit 117 is composed of buttons, switches, a touch panel, etc. that accept user operations, and notifies the camera control unit 104 of user input operations. The operation unit 117 includes, for example, a power switch, an AF instruction button, a mode setting dial, a release button, a video button, a flicker detection instruction button, etc. The communication terminal 113 is connected to a communication terminal 206 of the lens unit 200, thereby enabling communication between the camera control unit 104 and the lens control unit 205. In the following description, unless otherwise specified, communication between the camera control unit 104 and the lens control unit 205 is assumed to be performed by a communication connection via the communication terminals 113 and 206.

[0017] The image display unit 114 is specifically a rear monitor or EVF configured using a liquid crystal panel or the like, and displays various information such as the captured image and imaging conditions. The memory control unit 115 stores image data of the captured image (still image, video) in the memory 116, and conversely, reads out image data stored in the memory 116 and provides it to the camera control unit 104. The memory 116 is, for example, a memory card or the like that is detachable from the camera 100, and mainly stores image data of the captured image (still image, video).

[0018] Next, we will explain the functional units (software configuration) of the camera control unit 104. The camera control unit 104 has a digital gain unit 105, an image processing unit 106, a photometry processing unit 107, an exposure control unit 108, a focus detection processing unit 109, and a flicker detection processing unit 110 as functional units that execute various types of data processing.

[0019] The digital gain unit 105 adds a digital gain to the digital signal transmitted from the analog signal processing unit 103 and outputs the result to the image processing unit 106 .

[0020] The image processing unit 106 generates image data by performing, for example, WB processing, pixel interpolation processing, color conversion processing, compression / expansion processing, etc. on the digital signal output from the digital gain unit 105. The generated image data is stored in the memory 116 via the memory control unit 115. The image processing unit 106 also performs D / A conversion on the image data transmitted from the memory control unit 115 to generate an image signal to be displayed on the image display unit 114.

[0021] The photometry processing unit 107 calculates the luminance value (photometric value) of the subject image from the digital signal output from the digital gain unit 105, and outputs the calculated luminance value to the exposure control unit .

[0022] The exposure control unit 108 calculates exposure control values ​​including an aperture value Av, a shutter speed Tv, and a gain amount Sv based on the brightness value transmitted from the photometry processing unit 107. The aperture value Av is a control value for the aperture 202 of the lens unit 200. The shutter speed Tv is a value that controls the time of incidence of a light beam on the image sensor 102 using an electronic shutter function or a mechanical shutter function. The gain amount Sv represents the magnitude of the gain added by the analog signal processing unit 103 or the digital gain unit 105.

[0023] The focus detection processing unit 109 detects the phase difference between the pair of images based on the digital signals of the focus detection pixels output from the analog signal processing unit 103, and performs focus detection processing of the imaging optical system based on the detected phase difference.

[0024] The flicker detection processing unit 110 performs processing to detect the frequency of a flickering light source using data of frame images, which are digital signals that are continuously captured and output from the analog signal processing unit 103 .

[0025] In the following, the camera control unit 104 will be described as performing various controls and processes other than the processes performed by the above-mentioned digital gain unit 105, image processing unit 106, photometry processing unit 107, exposure control unit 108, focus detection processing unit 109, and flicker detection processing unit 110.

[0026] Next, the lens unit 200 will be described. The lens unit 200 is a so-called interchangeable lens that is detachable from the camera 100. Note that the lens unit 200 may be integrated (non-detachable) with the camera 100. In this case, the functions of the lens control unit 205 are generally integrated into the camera control unit 104, but in this embodiment, the lens control unit 205 and the camera control unit 104 coexist because it is necessary to enable switching between the camera control unit 104 and the lens control unit 205 as the main control entity for the aperture 202.

[0027] The lens 201 is composed of multiple lenses such as a zoom lens, a focus lens, and an image stabilization lens, and focuses incident light from the subject field onto the imaging plane of the image sensor 102. The diaphragm 202 adjusts the amount of incident light guided to the image sensor 102 (the amount of light received by the image sensor 102) by adjusting the aperture diameter. The diaphragm driver 204 drives the diaphragm 202 in accordance with a control signal from the lens controller 205.

[0028] The focus driving unit 203 adjusts the position of the focus lens constituting the lens 201 in the optical axis direction in accordance with a control signal from the lens control unit 205, thereby performing a focusing operation on the subject. The communication terminal 206 is connected to the communication terminal 113 of the camera 100, thereby enabling communication between the lens control unit 205 and the camera control unit 104. The aperture position acquisition unit 207 detects information on the actual position (aperture diameter) of the aperture 202, specifically, the effective aperture value (actual F-number).

[0029] The lens control unit 205 controls each unit of the lens unit 200. For example, the lens control unit 205 acquires the effective aperture value of the aperture 202 detected by the aperture position acquisition unit 207, and transmits the acquired effective aperture value to the camera control unit 104. The lens control unit 205 also switches the drive mode of the aperture 202 between a manual aperture mode and an automatic aperture mode. The manual aperture mode and the automatic aperture mode will be described with reference to FIG. 2.

[0030] 2 is an external perspective view of the lens unit 200. The lens unit 200 has a fixed barrel 210 and an aperture drive ring 208 attached to the fixed barrel 210 so as to be rotatable in two directions indicated by double-headed arrows around the imaging optical axis indicated by the dashed line. The aperture drive ring 208 is provided with a scale 209. The fixed barrel 210 is printed or engraved with a number of settable aperture values ​​(F-numbers) and the word "Auto" indicating that the aperture value is set by the camera 100.

[0031] When the user rotates the aperture drive ring 208 to align the scale 209 with one of the aperture values ​​printed on the fixed barrel 210 (when the aperture drive ring 208 is in the first position), the mode that controls the drive of the aperture 202 becomes manual aperture mode. On the other hand, when the user rotates the aperture drive ring 208 to align the scale 209 with Auto printed on the fixed barrel 210 (when the aperture drive ring 208 is in the second position), the mode that controls the drive of the aperture 202 becomes automatic aperture mode.

[0032] In manual aperture mode, the user can set the aperture value to be instructed to the lens control unit 205 by rotating the aperture drive ring 208 to align the scale 209 with a desired one of the aperture values ​​printed on the fixed barrel 210. The lens control unit 205, which is the main controller of the aperture 202, controls the aperture drive unit 204 to drive and control the aperture 202, i.e., adjust the aperture diameter, so that the aperture value becomes the aperture value set by the user by rotating the aperture drive ring 208 (hereinafter referred to as the "set aperture value"). At this time, as will be described later with reference to FIG. 5, the lens control unit 205 determines the speed at which the aperture 202 is controlled based on the difference between the current effective aperture value of the aperture 202 and the set aperture value, and the greater the difference, the faster the speed at which the aperture 202 is driven and controlled.

[0033] When the user rotates the aperture drive ring 208 to align the scale 209 from one of the aperture values ​​to "Auto" printed on the fixed barrel 210, the drive mode of the aperture 202 switches from manual aperture mode to automatic aperture mode. In automatic aperture mode, the camera control unit 104 mainly controls the aperture 202 and controls the drive of the aperture 202 via the lens control unit 205. As will be described in detail later, in automatic aperture mode, the lens control unit 205 controls the aperture drive unit 204 to adjust the opening diameter of the aperture 202 so that the aperture 202 becomes the target aperture value transmitted from the camera control unit 104.

[0034] Next, a description will be given of the live view operation of the camera 100. FIG.

[0035] It is assumed that frame images 305-309, each consisting of a digital signal, are generated in this order from charges read out from the image sensor 102. First, the photometry processing unit 107 performs photometry calculations 310 and 311 to calculate the luminance value (photometric value = Bv) of the subject image from the frame images 305 and 306. Then, the exposure control unit 108 performs exposure calculations 312 and 313 to calculate exposure control values ​​based on the photometric values ​​calculated by the photometry calculations 310 and 311 and a program diagram previously stored in ROM. As described above, the exposure control values ​​are composed of an aperture value Av, a shutter speed Tv, and a gain amount Sv. The exposure control unit 108 further performs exposure settings 314 and 315 to transmit the exposure control values ​​(Av, Tv, Sv) calculated by the exposure calculations 312 and 313 to the image sensor 102, the analog signal processing unit 103, and the digital gain unit 105. As a result, the exposure control values ​​(Av, Tv, Sv) calculated by the exposure calculations 312 and 313 are reflected in the frame images 308 and 309, respectively.

[0036] Photometry calculation 310 and exposure calculation 312 for frame image 305 are performed in the interval between vertical synchronization signals VD301 and VD302 output from the timing generation unit 112, and exposure setting 314 is performed in the interval between VD302 and VD303. The exposure control value set in exposure setting 314 is reflected in frame image 308, which is image data accumulated in the interval between VD303 and VD304.

[0037] Similarly, photometry calculation 311 and exposure calculation 313 for frame image 306 are performed in the section between VD302 and VD303, exposure setting 315 is performed in the section between VD303 and VD304, and the exposure control value set in exposure setting 315 is reflected in frame image 309.

[0038] In this way, by controlling the exposure of the subsequently generated frame images 308 and 309 based on the photometric value and exposure control value calculated from the frame images 305 and 306, it is possible to obtain frame images with an appropriate exposure amount in response to changes in the brightness of the subject image.

[0039] Next, we will explain the aperture control that is executed during live view operation of the camera 100. Figure 4 is a flowchart of the aperture control that is executed during live view operation of the camera 100. Each process (step) indicated by an S number in this flowchart is realized by the camera control unit 104 executing a predetermined program stored in ROM and comprehensively controlling the operation of each unit of the imaging system 1.

[0040] When the camera control unit 104 detects that the power switch, which is one element of the operation unit 117, has been turned on, it starts up the imaging system 1 to start the live view operation, and also starts this processing, which is part of the exposure calculation and exposure setting described with reference to Fig. 3. The processing according to this flowchart is repeatedly executed after the start of the live view operation.

[0041] In S400, the camera control unit 104 reads out the electric charges accumulated in the image sensor 102 and acquires one frame image.

[0042] In S401, the camera control unit 104 acquires the effective aperture value from the lens control unit 205.

[0043] In S402, the camera control unit 104 acquires the setting of the aperture drive ring 208 (one of a plurality of aperture values ​​or Auto) from the lens control unit 205.

[0044] In S403, the camera control unit 104 causes the photometry processing unit 107 to perform photometry calculations and obtains photometry values ​​as the calculation results.

[0045] In S404, the camera control unit 104 executes aperture control subject determination processing. Details of the processing in S404 will be described later, but in the aperture control subject determination processing, it is determined whether the aperture control subject should be set to the camera control unit 104 or the lens control unit 205 (in other words, whether it is necessary to set it).

[0046] In S405, the camera control unit 104 branches the process depending on the aperture control subject determined in S404. Specifically, if the camera control unit 104 determines in S404 that the aperture control subject needs to be set to the camera control unit 104, the camera control unit 104 executes the process of S406. Note that in FIG. 4, the camera control unit 104 and the lens control unit 205 are abbreviated as "camera" and "lens," respectively.

[0047] In S406, the camera control unit 104 determines whether the subject of aperture control will change. Specifically, if the subject of aperture control is set to the lens control unit 205 and it is determined in S404 that the subject of aperture control needs to be set to the camera control unit 104, it is determined in S406 that the subject of aperture control will change. On the other hand, if the subject of aperture control is set to the camera control unit 104 and it is determined in S404 that the subject of aperture control needs to be set to the camera control unit 104, it is determined in S406 that the subject of aperture control will not change.

[0048] If the camera control unit 104 determines that the aperture control entity will change (YES in S406), it executes the processing of S407, and if it determines that the aperture control entity will not change (NO in S406), it executes the processing of S408.

[0049] In S407, the camera control unit 104 switches the subject of aperture control from the lens control unit 205 to the camera control unit 104. Specifically, the camera control unit 104 transmits to the lens control unit 205 an instruction to switch the subject of aperture control from the lens control unit 205 to the camera control unit 104 (hereinafter referred to as a "switching instruction"). When the lens control unit 205 receives the switching instruction from the camera control unit 104, it transitions to a mode in which it drives the aperture 202 in accordance with the command from the camera control unit 104. In other words, a transition from manual aperture mode to automatic aperture mode is performed. In the automatic aperture mode, the camera control unit 104 forcibly controls the lens control unit 205 so that the effective aperture value of the aperture 202 becomes the target aperture value instructed by the camera control unit 104. When the processing of S407 ends, the camera control unit 104 executes the processing of S408.

[0050] In S408, the camera control unit 104 calculates an exposure control value for acquiring a live view (frame image). Specifically, the exposure control unit 108 calculates a target aperture value Av, a shutter speed Tv, and a gain amount Sv based on the photometric value acquired in the most recent S403 and a program diagram pre-stored in ROM, and notifies the camera control unit 104 of the target aperture value Av. Note that with regard to S408 in FIG. 4, only the setting of the "target aperture value," which is information related to S409, is described.

[0051] In S409, the camera control unit 104 controls the driving of the aperture 202 via the lens control unit 205 so that the target aperture value Av notified by the exposure control unit 108 in S408 is reached, and this completes the processing for one routine.

[0052] If the camera control unit 104 determines in S404 that the lens control unit 205 needs to be set as the aperture control subject, the camera control unit 104 executes the process of S410.

[0053] In S410, the camera control unit 104 determines whether the subject of aperture control will change. If the camera control unit 104 determines that the subject of aperture control will change (YES in S410), it executes the process of S411, and if it determines that the subject of aperture control has not changed (NO in S410), it executes the process of S417.

[0054] The determination method in S410 is the same as the determination method in S406. When the subject aperture control is set to the lens control unit 205 and it is determined in S404 that the subject aperture control needs to be set to the lens control unit 205, it is determined in S410 that the subject aperture control will not change. On the other hand, when the subject aperture control is set to the camera control unit 104 and it is determined in S404 that the subject aperture control needs to be set to the lens control unit 205, it is determined in S410 that the subject aperture control will change.

[0055] In S411, the camera control unit 104 determines whether the difference between the effective aperture value and the set aperture value acquired in the most recent S401 and S402 is equal to or greater than a predetermined number of stops. If the camera control unit 104 determines that the difference between the aperture values ​​is equal to or greater than the predetermined number of stops (YES in S411), it executes the process of S412, and if it determines that the difference between the aperture values ​​is less than the predetermined number of stops (NO in S411), it executes the process of S415. The predetermined number of stops can be, for example, one stop.

[0056] In S412, the camera control unit 104 calculates an exposure control value for acquiring a live view frame image. Specifically, the exposure control unit 108 sets the aperture setting acquired in the most recent S402 to the target aperture setting Av. Then, the exposure control unit 108 calculates the shutter speed Tv and the gain amount Sv based on the set target aperture setting Av, based on the photometric value acquired in the most recent S403 and a program diagram pre-stored in ROM. The camera control unit 104 notifies the lens control unit 205 of the target aperture setting Av calculated by the exposure control unit 108 in this way. Note that with respect to S412 in FIG. 4, only the setting of the "target aperture setting," which is information related to S413, is described.

[0057] In S413, the camera control unit 104 causes the lens control unit 205 to execute high-speed drive control of the aperture 202. Specifically, the camera control unit 104 controls the drive of the aperture 202 via the lens control unit 205 so that the aperture 202 reaches the target aperture value Av notified to the lens control unit 205 in S412. At this time, it is desirable that the drive speed of the aperture 202 be the maximum controllable speed, and at least a speed faster than when the lens control unit 205 drives the aperture 202 as the aperture control main body in the manual aperture mode.

[0058] Here, the aperture drive speed table 500 in the manual aperture mode is shown in Fig. 5. In S413, the aperture 202 is driven and controlled at a speed faster than 20 / 8 (stops / second) defined in the aperture drive speed table 500.

[0059] In S414, the camera control unit 104 transmits a switching instruction to the lens control unit 205 to switch the subject of aperture control from the camera control unit 104 to the lens control unit 205. Upon receiving the switching instruction from the camera control unit 104, the lens control unit 205 transitions the lens unit 200 to a manual aperture mode in which aperture driving is achieved by operating the aperture drive ring 208. This completes the processing for one routine.

[0060] In manual aperture mode, when the aperture value set on the aperture drive ring 208 is changed by user operation, the lens control unit 205 first calculates the amount of deviation ΔAv between the effective aperture value acquired from the aperture position acquisition unit 207 and the aperture value set on the aperture drive ring 208. The lens control unit 205 then determines the drive speed of the aperture 202 based on the aperture drive speed table 500, and drives the aperture drive unit 204 so that the effective aperture value of the aperture 202 becomes the aperture value set by the aperture drive ring 208. At this time, the drive speed (stops / second) of the aperture 202 is set faster as the amount of deviation ΔAv between the effective aperture value and the set aperture value increases, and slower as the amount of deviation ΔAv decreases, as shown in FIG. For example, if the effective aperture value of the aperture 202 is F2 and the set aperture value set on the aperture drive ring 208 is F4, the deviation amount ΔAv is two stops, which corresponds to the case of "ΔAv≧12 / 8" in Figure 5, and a drive speed of 20 / 8 (stops / second) is required.

[0061] If the determination in S411 is 'NO', in S415 the camera control unit 104 calculates an exposure control value for acquiring a live view frame image. The processing in S415 is the same as the processing in S412, so a description thereof will be omitted. Note that for S415 in FIG. 4, only the setting of the "target aperture value," which is information related to S416, is described.

[0062] In S416, the camera control unit 104 controls the driving of the diaphragm 202 via the lens control unit 205 so that the target aperture value Av is reached, and then executes the processing of S414. The diaphragm 202 is driven in S416 at a driving speed corresponding to the deviation amount ΔAv found in S411 in the diaphragm driving speed table 500. If the predetermined number of stops used as the criterion in S411 is one stop, the driving speed of the diaphragm 202 in S416 will be 10 / 8 (stops / second) or less.

[0063] If the determination in S410 is 'NO', in S417 the camera control unit 104 calculates exposure control values ​​for acquiring a live view (frame image). Specifically, the exposure control unit 108 calculates the shutter speed Tv and gain amount Sv based on the effective aperture value acquired in the most recent S401, the photometric value acquired in the most recent S403, and a program diagram pre-stored in ROM. Here, the lens control unit 205 is the subject of aperture control, and since the manual aperture mode remains in effect, the camera control unit 104 does not issue a drive instruction to the lens control unit 205, and the processing for one routine ends.

[0064] As described above, the process according to this flowchart is repeatedly executed after the start of the live view operation. That is, when one routine of processing is completed by either S409, S414, or S417, the process is executed again from S400.

[0065] Next, the process of determining the subject of aperture control in S404 will be described with reference to Fig. 6, which is a flowchart of the process of determining the subject of aperture control in S404.

[0066] In S601, the camera control unit 104 determines whether the aperture setting acquired in S402 is 'Auto'. If the camera control unit 104 determines that the aperture setting is 'Auto' (YES in S601), it executes the process of S605, and if it determines that the aperture setting is not 'Auto' (NO in S601), it executes the process of S602.

[0067] In S602, the camera control unit 104 determines whether the shooting mode is a still image shooting mode. If the camera control unit 104 determines that the shooting mode is a still image shooting mode (YES in S602), it executes the process of S603, and if it determines that the shooting mode is not a still image shooting mode (NO in S602), it executes the process of S606. Note that if the determination in S602 is NO, the shooting mode is expected to be a moving image shooting mode in which consecutively captured frame images are continuously recorded to record the process of scene transitions.

[0068] In S603, the camera control unit 104 determines whether or not focus detection processing is being executed. For example, the camera control unit 104 determines that focus detection processing is being executed when an instruction for an AF operation is received by operating an AF instruction button, which is one element of the operation unit 117. If the camera control unit 104 determines that focus detection processing is being executed (YES in S603), it executes the processing of S605, and if it determines that focus detection processing is not being executed (NO in S603), it executes the processing of S604.

[0069] In S604, the camera control unit 104 determines whether or not flickering light source detection processing is being executed. For example, the camera control unit 104 determines that flickering light source detection processing is being executed when an instruction for flickering light source detection has been received by operating a flickering light source detection instruction button, which is one element of the operation unit 117. If the camera control unit 104 determines that flickering light source detection processing is being executed (YES in S604), it executes the processing of S605, and if it determines that flickering light source detection processing is not being executed (NO in S604), it executes the processing of S606.

[0070] In S605, the camera control unit 104 determines that it is necessary to set the aperture control subject to the camera control unit 104, and ends this processing.

[0071] In S606, the camera control unit 104 determines that the lens control unit 205 must be set as the subject of aperture control, and ends this processing.

[0072] Note that if the determination in S602 is "NO," it is assumed that the shooting mode is video shooting mode, as described above. In video shooting mode, it is desirable to have a high response to the user's operation to change the aperture value setting via the aperture drive ring 208. Therefore, it is desirable that the lens control unit 205 be the main controller of the aperture 202 in video shooting mode. Furthermore, since focus detection processing using image plane phase difference AF generally has reduced detection accuracy when the aperture is set to a small aperture, it is desirable that the camera control unit 104 control the aperture 202 to an aperture suitable for focus detection processing. Therefore, if the determination in S603 is "YES," it is desirable that the camera control unit 104 be the main controller of the aperture. In flicker light source detection processing, depending on the brightness of the subject image, an image with appropriate brightness may not be obtained, resulting in reduced detection accuracy. Therefore, it is desirable that the camera control unit 104 be the main controller of the aperture 202 to an aperture suitable for flicker light source detection processing. Therefore, if the determination in S604 is "YES," it is desirable that the camera control unit 104 be the main controller of the aperture. On the other hand, even in the still image shooting mode, if the determinations in S603 and S604 are both 'NO', it is assumed that the camera 100 is in a steady shooting standby state in which no special processing is being performed. In this case, from the viewpoint of improving response to the user's operation to change the aperture value setting via the aperture drive ring 208, in this embodiment, it is desirable for the lens control unit 205 to be the main controller of the aperture 202.

[0073] As described above, in the imaging system 1, during live view operation, the control entity of the aperture 202 is appropriately switched depending on the position of the aperture drive ring 208 and the operation of the imaging system 1. The usefulness of performing the processing according to the flowchart of Fig. 4 at that time will be described below in comparison with a reference example (comparative example).

[0074] First, a reference example of the present invention will be described. For example, in a video shooting mode in which the process of scene transitions is recorded by continuously recording consecutively captured frame images, it is desirable that the aperture drive control be performed immediately in conjunction with a change in aperture value setting by the user. On the other hand, in a still image shooting mode in which images are recorded one-off, it is desirable that the drive control of the aperture 202 be performed based on an aperture drive instruction from the camera 100. In this way, it is desirable that the aperture control entity be the camera control unit 104 in the still image shooting mode and the lens control unit 205 in the video shooting mode.

[0075] Here, when the aperture control subject is set to the camera control unit 104, the user may start video recording by pressing the video button. In this case, the aperture control subject is switched from the camera control unit 104 to the lens control unit 205 to start video recording, but at this time, a problem occurs in that there is a long shooting time lag between pressing the video button and the start of video recording. This problem will be described with reference to FIG. 8 as a reference example.

[0076] FIG. 8 is a timing chart relating to a reference example of processing for switching the subject of aperture control from the camera control unit 104 to the lens control unit 205.

[0077] When a user operates the operation unit 117 to issue a moving image recording start request 801, the camera control unit 104 notifies the exposure control unit 108 of preparation for switching the shooting mode 802. As described above, when switching the shooting mode from the still image shooting mode to the moving image shooting mode, it is necessary to switch the subject of aperture control from the camera control unit 104 to the lens control unit 205. Therefore, the exposure control unit 108 notifies the lens control unit 205 of an instruction 803 to switch the subject of aperture control.

[0078] In response to the switching instruction 803, the lens control unit 205 notifies the exposure control unit 108 of aperture control subject switching completion 803a, indicating that the aperture control subject will be switched from the camera control unit 104 to the lens control unit 205. In response to the aperture control subject switching completion 803a, the exposure control unit 108 notifies the camera control unit 104 of shooting mode switching preparation completion 802a, and the camera control unit 104 switches the shooting mode to the video shooting mode.

[0079] When the lens control unit 205 is notified that the aperture control subject has been switched to itself, it sends an aperture drive instruction 804 to the aperture drive unit 204 so as to set the aperture value (F22 in FIG. 8) set by the aperture drive ring 208. In response to the aperture drive instruction 804, the aperture drive unit 204 drives the aperture 202 using aperture drive control 805.

[0080] For example, when the shooting mode is a still image shooting mode, it is assumed that the aperture 202 is controlled to an aperture value (F2 in FIG. 8) determined by the camera control unit 104 in order to suppress performance degradation of a specific camera function. In this case, the aperture drive control 805 executes drive control so that the aperture value changes from F2 to F22. At this time, it is desirable to drive the aperture 202 smoothly in consideration of image quality in live view, so in video shooting mode, where the aperture control is mainly performed by the lens control unit 205, it is necessary to drive the aperture 202 at a slow speed.

[0081] Next, the camera control unit 104 notifies the exposure control unit 108 of a moving image recording preparation 806. Moving images need to be recorded at the aperture value desired by the user (set by the user). Therefore, the exposure control unit 108 completes the processing of the moving image recording preparation 806 upon completion of driving the aperture 202 to the aperture value set by the aperture drive ring 208 (F22 in FIG. 8), and notifies the camera control unit 104 of this completion. Upon receiving the completion notification of the moving image recording preparation 806, the camera control unit 104 starts moving image recording.

[0082] In this type of control, it takes time to complete the drive control of the diaphragm 202 being driven by the diaphragm drive control 805. As a result, it also takes time to complete the processing of the video recording preparation 806, resulting in a long shooting time lag from the instruction to start video recording to the actual start of video recording.

[0083] A sequence according to an embodiment that solves this problem will be described with reference to Fig. 7. Fig. 7 is a timing chart according to an embodiment of the process of switching the subject of aperture control from the camera control unit 104 to the lens control unit 205. At this time, in the flowchart of Fig. 4, the process proceeds through a route that passes through S404, S405, S410, and S411.

[0084] When a video recording start request 701 is issued by a user operation, the camera control unit 104 notifies the exposure control unit 108 of a shooting mode switching preparation 702. Here, in order to quickly switch to the aperture value set by the aperture drive ring 208 (F22 in FIG. 7), the exposure control unit 108 notifies the lens control unit 205 of a high-speed aperture drive instruction 703 before switching the aperture control subject. Upon receiving the high-speed aperture drive instruction 703, the lens control unit 205 notifies the aperture drive unit 204 of an aperture drive instruction 704. Upon receiving the aperture drive instruction 704, the aperture drive unit 204 drives the aperture 202 at high speed using aperture drive control 705. At this time, it is desirable to drive the aperture 202 at the maximum controllable speed, which allows the aperture 202 to be quickly switched to the target value (F22 in FIG. 7).

[0085] When the exposure control unit 108 completes drive control of the aperture 202 to the aperture setting value (F22 in FIG. 7) set by the aperture drive ring 208, it sends an aperture control subject switching instruction 706 to the lens control unit 205 to switch the aperture control subject to the lens control unit 205. Then, the exposure control unit 108 notifies the camera control unit 104 that the processing of the shooting mode switching preparation 702 has been completed, with the aperture control subject now being switched to the lens control unit 205. Upon receiving this completion notification, the camera control unit 104 switches the shooting mode from the still image shooting mode to the video shooting mode.

[0086] Next, the camera control unit 104 notifies the exposure control unit 108 of the moving image recording preparation 707. At this time, the aperture control main body has already been switched to the lens control unit 205. Also, the aperture 202 has completed driving to the aperture value set by the aperture drive ring 208 (F22 in FIG. 7). In other words, preparation for moving image recording has already been completed. Therefore, the exposure control unit 108 immediately notifies the camera control unit 104 of the completion of the moving image recording preparation 707, and the camera control unit 104 starts moving image recording upon receiving this completion notification.

[0087] As described above, in this embodiment, when switching from still image capture mode to video capture mode, the aperture 202 is driven at high speed so that the aperture value set by the aperture drive ring 208 is reached, and then the aperture control entity is switched from the camera control unit 104 to the lens control unit 205. This makes it possible to reduce the time required for preparations to start video recording, compared to the reference example of Fig. 8. In other words, when a user issues an instruction to start video recording in still image capture mode, the shooting time lag until video recording actually starts can be reduced.

[0088] While the present invention has been described in detail above based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the gist of the present invention are also included in the present invention. Furthermore, each of the above-described embodiments merely represents one embodiment of the present invention, and each embodiment can be combined as appropriate.

[0089] For example, in the above embodiment, when focus detection or flicker detection is not performed in still image capture mode, it is determined that the lens control unit 205 should be set as the main control unit for the aperture. In contrast, for users who do not frequently capture moving images or who often set exposure conditions automatically when capturing still images, it is desirable that the camera control unit 104 be the main control unit for the aperture 202 in still image capture mode. Therefore, for example, a configuration may be adopted in which the user can set the camera control unit 104 to be the main control unit for the aperture 202 in still image capture mode through a menu setting on the camera 100, regardless of the operating status of the imaging system 1.

[0090] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0091] The disclosure of this embodiment includes the following configuration, method, and program. (Configuration 1) An imaging system having a lens device and an imaging device, wherein the lens device comprises an aperture, a first setting means for setting the aperture to a first aperture value in response to a user operation, and a first control means for controlling the driving of the aperture; the imaging device comprises a second setting means for setting the aperture to a second aperture value based on a photometric value, a second control means for controlling the driving of the aperture via the first control means, and a switching means for switching between a first mode in which the first control means controls the driving of the aperture to the first aperture value and a second mode in which the second control means controls the driving of the aperture to the second aperture value; and the imaging system is characterized in that, when switching from the second mode to the first mode, the second control means controls the driving of the aperture to the first aperture value via the first control means, and then the switching means switches the control entity of the aperture from the second control means to the first control means. (Configuration 2) The imaging system described in Configuration 1 is characterized in that the lens device has a detection means for detecting the effective aperture value of the aperture, and the second control means, when switching from the second mode to the first mode, drives the aperture at the maximum controllable drive speed if the deviation between the effective aperture value and the first aperture value is equal to or greater than a predetermined number of steps. (Configuration 3) The imaging system described in Configuration 2 is characterized in that the lens device has a memory means that stores a table that specifies the drive speed of the aperture for the amount of deviation, and the second control means, when switching from the second mode to the first mode, controls the drive of the aperture at the drive speed specified for the amount of deviation in the table if the amount of deviation is less than the predetermined number of steps. (Configuration 4) The imaging system described in Configuration 3, characterized in that in the first mode, the first control means controls the drive of the aperture at a drive speed of the aperture specified in the table for the deviation amount. (Configuration 5) The imaging system described in any one of configurations 1 to 4, characterized in that the imaging device is provided with a determination means for determining that the second control means will be the control entity of the aperture in video shooting mode, and for determining that the second control means will be the control entity of the aperture in still image shooting mode. (Configuration 6) The imaging system described in any one of configurations 1 to 4 is characterized in that the imaging device is equipped with a determination means that determines the second control means to be the control entity of the aperture in video shooting mode, and in still image shooting mode, when neither focus detection nor flicker detection is performed, determines the first control means to be the control entity of the aperture, and when focus detection or flicker detection is performed, determines the second control means to be the control entity of the aperture. (Configuration 7) An imaging system described in any one of configurations 1 to 6, characterized in that the first setting means is switchable between a first position in which the aperture control entity is set to the first aperture value by the first control means, and a second position in which the aperture control entity is set to the second control means. (Configuration 8) An imaging system comprising: a first control means for controlling the driving of an aperture so that the aperture becomes a first aperture value set in response to user operation; a second control means for controlling the driving of the aperture via the first control means so that the aperture becomes a second aperture value set based on the photometric value of a subject; a setting means for setting the imaging system to a first mode in which the driving of the aperture is controlled by the first control means, or a second mode in which the driving of the aperture is controlled by the second control means; and a determination means for determining whether to set the imaging system to the first mode or the second mode depending on the state of the imaging system, wherein when switching from the second mode to the first mode based on the determination, the second control means drives the aperture to the first aperture value via the first control means, and then the setting means switches the control entity of the aperture from the second control means to the first control means. (Method 1) A control method for an imaging system having a lens device equipped with a first control means and an imaging device equipped with a second control means, comprising the steps of: detecting the state of the imaging system during live view operation; determining, based on the detected state, whether to set the aperture of the lens device to a first mode in which the first control means drives and controls the aperture to a first aperture value set in response to user operation; or a second mode in which the second control means drives and controls the aperture via the first control means to a second aperture value set based on a photometric value; and, when switching from the second mode to the first mode based on the determination, the second control means drives the aperture to the first aperture value via the first control means, and then switching the control entity of the aperture from the second control means to the first control means. (Program 1) A program that causes a computer to execute each step of the imaging system control method described in Method 1. [Explanation of symbols]

[0092] 1. Imaging system 100 Camera (imaging device) 104 Camera control unit 200 Lens unit (lens device) 204 Aperture drive unit 205 Lens control unit 208 Aperture drive ring

Claims

1. An imaging system having a lens device and an imaging device, The lens device Aperture and a first setting means for setting the aperture to a first aperture value in response to a user operation; a first control means for controlling the driving of the diaphragm; The imaging device is a second setting means for setting the aperture to a second aperture value based on a photometric value; a second control means for controlling the driving of the diaphragm via the first control means; a switching means for switching between a first mode in which the first control means controls the diaphragm to be driven to the first aperture value and a second mode in which the second control means controls the diaphragm to be driven to the second aperture value, an imaging system characterized in that, when switching from the second mode to the first mode, the second control means controls the aperture to the first aperture value via the first control means, and then the switching means switches the control entity of the aperture from the second control means to the first control means.

2. the lens device has a detection means for detecting an effective aperture value of the diaphragm, 2. The imaging system according to claim 1, wherein, when switching from the second mode to the first mode, if a difference between an effective aperture value and the first aperture value is equal to or greater than a predetermined number of steps, the second control means drives the aperture at a maximum controllable drive speed.

3. the lens device has a storage means for storing a table that defines the driving speed of the aperture relative to the amount of deviation, 3. The imaging system according to claim 2, wherein, when switching from the second mode to the first mode, if the amount of deviation is less than the predetermined number of steps, the second control means controls driving of the diaphragm at a driving speed specified for the amount of deviation in the table.

4. 4. The imaging system according to claim 3, wherein in the first mode, the first control means controls the driving of the diaphragm at a driving speed of the diaphragm specified for the deviation amount in the table.

5. The imaging system according to any one of claims 1 to 4, characterized in that the imaging device is provided with a determination unit that determines the second control unit to be the main controller of the aperture in a video shooting mode, and that determines the second control unit to be the main controller of the aperture in a still image shooting mode.

6. The imaging system according to any one of claims 1 to 4, characterized in that the imaging device comprises a determination unit that determines the second control unit to be the main controller of the aperture in a video shooting mode, that determines the first control unit to be the main controller of the aperture in a still image shooting mode when neither focus detection nor flicker detection is being performed, and that determines the second control unit to be the main controller of the aperture when focus detection or flicker detection is being performed.

7. 5. The imaging system according to claim 1, wherein the first setting means is switchable between a first position in which the first control means sets the first aperture value to the aperture, and a second position in which the second control means sets the second control means to control the aperture.

8. a lens device including a first control means; an imaging device including a second control unit; and a control method for an imaging system including the imaging device, Detecting a state of the imaging system during a live view operation; determining whether to set the aperture of the lens device to a first mode in which the first control means drives and controls the aperture of the lens device to a first aperture value set in response to a user operation, or a second mode in which the second control means drives and controls the aperture via the first control means to a second aperture value set based on a photometric value, according to the detected state; and when switching from the second mode to the first mode based on the determination, the second control means drives the aperture to the first aperture value via the first control means, and then switches control of the aperture from the second control means to the first control means.

9. A program that causes a computer to execute each step of the method for controlling an imaging system according to claim 8.

10. 1. An imaging system, comprising: a first control means for controlling the driving of the aperture so as to achieve a first aperture value set in response to a user operation; a second control means for controlling the driving of the aperture via the first control means so that the aperture value becomes a second aperture value that is set based on a photometric value of the subject; a setting means for setting a first mode in which the first control means controls the driving of the diaphragm, or a second mode in which the second control means controls the driving of the diaphragm; a determination unit that determines whether to set the first mode or the second mode according to a state of the imaging system, an imaging system characterized in that, when switching from the second mode to the first mode based on the determination, the second control means drives the aperture to the first aperture value via the first control means, and then the setting means switches the control entity of the aperture from the second control means to the first control means.

Images