Patent Application
20190212633
This application is a Continuation of International Patent Application No. PCT/JP2017/033744, filed on Sep. 19, 2017, which claims the benefit of Japanese Patent Application No. 2016-188090, filed on Sep. 27, 2016, both of which are hereby incorporated by reference herein in their entirety.
The present invention relates to an imaging apparatus having a plurality of mechanical shutters with different traveling (moving) directions in exposing an image sensor.
Some imaging apparatuses include a shutter with a mechanical front curtain configured to control an exposure start and a mechanical rear curtain configured to control an exposure end. Other imaging apparatuses have an electronic front curtain configured to electronically realize a function similar to that of the mechanical front curtain by rest scanning that resets electric charges in an image sensor configured to photoelectrically convert an object image and to output an electric signal. These imaging apparatuses can accurately image a changing object by improving the number of imageable number (frame rate).
For example, Japanese Patent Laid-Open No. (“JP”) 2-134625 discloses a shutter that alternately performs an opening control and a light shielding control in both a forward (or onward) travel and a backward (or return) travel through two mechanical curtains forming a slit for a forward travel exposure and a backward travel exposure, and improves a frame rate. JP 2011-146925 also discloses an imaging apparatus that includes an electronic front curtain that controls exposure starts from the upper and lower sides of an image sensor toward the center at the same time, a first mechanical rear curtain that travels from the top to the bottom and controls the light shielding, and a second mechanical rear curtain that travels from the bottom to the top and controls the light shielding. The imaging apparatus in JP 2011-146925 can improve the frame rate by moving the electronic front curtain from the top and the bottom of the image sensor to the center, and then by moving the first and second mechanical rear curtains so that they intersect each other at the center to shield the entire image sensor from the light.
However, the shutter disclosed in JP 2-134625 used for the imaging apparatus having the image sensor causes the following problem. In general, in the slit exposure that moves the two mechanical curtains, an object moving in a direction orthogonal to the traveling directions of the mechanical curtains causes a rolling shutter distortion that distorts an image due to the charge accumulation timing shifts in the image sensor from the exposure start to the exposure end. Then, the forward travel exposure and the backward travel exposure as disclosed in JP 2-134625 cause different rolling shutter distortions between the forward travel exposure and the backward travel exposure due to the different traveling direction of the mechanical curtains. In other words, the different rolling shutter distortions alternate between the odd-numbered images acquired by the forward travel exposure and the even-numbered images acquired by the backward travel exposure, and impairs the image continuity.
The imaging apparatus disclosed in JP 2011-146925 simultaneously drives the first and second mechanical rear curtains from the top and the bottom, unlike the conventional configuration, and thus generates a rolling shutter distortions different from that of the conventional one. As a result, the user who is accustomed to the conventional rolling shutter distortion gets confused.
The present invention provides an imaging apparatus that can improve a frame rate with a mechanical shutter while suppressing a rolling shutter distortion.
An imaging apparatus according to one aspect of the present invention includes an image sensor configured to photoelectrically convert light from an object, a mechanical shutter configured to travel in a first direction and a second direction different from the first direction relative to an imaging plane of the image sensor, and a control unit configured to control imaging about an operation of the mechanical shutter. The control unit provides a control so as to provide first imaging that causes the mechanical shutter to travel in the first direction in synchronization with an exposure of the image sensor and second imaging that causes the mechanical shutter to travel in the second direction in synchronization with the exposure of the image sensor. The control unit determines whether to perform one of the first imaging and the second imaging or to perform both the first imaging and the second imaging continuously based on an imaging mode and predetermined information on an imaging scene, and controls the imaging in accordance with a determination result.
An imaging apparatus according to another aspect of the present invention includes an image sensor, a mechanical shutter configured to travel in a first direction and a second direction different from the first direction relative to an imaging plane of the image sensor, a control unit configured to control an exposure about an exposure operation using the image sensor, and an acquisition unit configured to acquire predetermined information on at least one of the number of travels and a traveling characteristic of the mechanical shutter. The control unit provides a control so as to provide first imaging that causes the mechanical shutter to travel in the first direction in synchronization with an exposure of the image sensor and second imaging that causes the mechanical shutter to travel in the second direction in synchronization with the exposure of the image sensor. When one of the first imaging and the second imaging is to be performed, the control unit determines based on the predetermined information which of the first imaging or the second imaging is to be performed, and controls the imaging in accordance with a determination result.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Referring now to the accompanying drawings, a description will be given of embodiments according to the present invention.
An imaging lens 114 as an imaging optical system forms an object image by forming light from an object. In the drawing, the imaging lens 114 is expressed by a single lens, but actually includes a plurality of lenses such as a focus lens and a magnification-varying lens.
A lens CPU 115 controls focus driving and zoom driving of the imaging lens 114 via a lens driving circuit 116, and controls driving of a diaphragm (aperture stop) 117a via a diaphragm driving circuit 117. The lens CPU 115 communicates with the camera CPU 113 in the camera body 100 to be described later via a communication contact 118 in the lens unit 101 and a communication contact 119 in the camera body 100. For example, the lens CPU 115 transmits lens information to the camera CPU 113 via the communication contacts 118 and 119 in accordance with a request from the camera CPU 113.
Next follows a description of the configuration of the camera body 100. In a viewfinder observation state where a mirror 102 is disposed on an imaging optical path as illustrated in the figure, the light from the object that has passed through the imaging lens 114 and the diaphragm 117 is reflected by the mirror 102, and guided to a finder optical system 103 and a focusing image sensor 120. Thereby, the user (photographer) can observe the object image through the finder optical system 103. The camera CPU 113 recognizes the object through the focusing image sensor 120, and detects (calculates) a defocus amount for the object. A driving amount of the focus lens for obtaining an in-focus state on the object is transmitted to the lens CPU 115 through the communication contact 119, and the lens CPU 115 drives the focusing lens 115 for autofocusing (AF).
When an unillustrated release button is pressed by the user, the camera CPU 113 retreats the mirror 102 from the imaging optical path to transfer from the viewfinder observation state to an imaging state. Thereby, the light from the imaging lens 114 passes through a shutter opening in a mechanical shutter unit 105 and enters an image capturing image sensor (simply referred to as an image sensor hereinafter) 104 such as a CMOS sensor and a CCD sensor. Thereby, the image sensor 104 is exposed.
The image sensor 104 has a plurality of pixels, and each pixel photoelectrically converts the object image during exposure and accumulates electric charges corresponding to a luminance of the object image. A scanning clock (horizontal driving pulse) and a predetermined control pulse are supplied from a pulse generating circuit 107 to the image sensor 104, and the exposure is controlled using an electronic shutter (electronic front curtain) that sequentially resets a plurality of pixels. The vertical scanning clock out of the scanning clock generated by the pulse generating circuit 107 is modulated into a predetermined clock frequency by a vertical driving modulation circuit 108 and input to the image sensor 104. The vertical driving modulation circuit 108 determines a scanning pattern of the electronic shutter. The pulse generating circuit 107 also outputs a clock signal to a signal processing circuit 109 to be described later.
The mechanical shutter unit 105 has a first mechanical shutter 105a and a second mechanical shutter 105b each including a plurality of shutter blades (light shielding blades) although concrete configurations thereof will be described later. Each of the first and second mechanical shutters 105a and 105b can travel in a forward (or outward) travel (or movement) direction (first direction) and a backward (or return) travel direction (second direction) described below. Both of the first and second mechanical shutters 105a and 105b travel in the forward travel direction for a forward travel exposure of the image sensor 104, and both of them travel in the backward travel direction for a backward travel exposure of the image sensor 104. The camera CPU 113 controls driving of the first and second mechanical shutters 105a and 105b via a shutter driving circuit 106.
The signal processing circuit 109 performs correlated double sampling processing (CDS), autogain (AG) processing and other processing (color processing, gamma correction, etc.) for the electric signal generated by the electric charges read out of the image sensor 104, and generates image data. The generated image data is used by the camera CPU 113 to calculate a moving speed of the object. The image data is displayed as a captured image on a display device 151 via an image display circuit 110, or recorded on a recording medium, such as an unillustrated semiconductor memory, by an image recording circuit 111.
A switch unit 112 includes a plurality of switches and the like to be operated by the user. More specifically, it includes a main switch that turns on and off the main power supply of the camera body 100. The switch unit 112 also includes a release switch. When the release button is half-pressed, the camera is turned on (SW1 ON) to start an imaging preparation operation such as photometry and AF, and when it is fully pressed, it is turned on (SW 2 ON) to start an imaging operation, from the exposure of the image sensor 104 to display and record the image data. The switch unit 112 also includes an imaging mode setting dial operated by the user to set an arbitrary imaging mode. The release switch and the imaging mode setting dial are designated by reference numerals 112a and 112b in
An information storage unit 150 stores information such as a traveling characteristic of the mechanical shutter unit 105 and the number of travels of each mechanical shutter detected by SH detection sensors 105c and 105d.
Referring now to
The plurality of shutter blades 200a are rotatably connected to a first blade driving plate 210 (210a, 210b). These shutter blades 200a can move in accordance with the rotation of the first blade driving plate 210 between a light shielding position where the shutter blades 200a are unfolded so as to cover the opening 206a and shield the image sensor 104 from the light and a light introducing position where the shutter blades 200a is folded to retreat from the opening 206a and allow the light to pass.
A first cam disc 207 has a protrusion 207a and a central shaft hole portion 207c, and a disc weight 207b is attached to the first cam disc 207. The protrusion 207a is engaged with an arm of a first biasing spring 208. One of the two shaft portions 205c provided to the cam base 205 is engaged with the central shaft hole portion 207c. The inertial mass of the disk weight 207b is set larger than the total inertial mass of the plurality of shutter blades 200a, the first blade driving plate 210, and a first driving lever 209 described later.
A cylindrical portion 204a of the first cover 204 is inserted into a coil portion of the first biasing spring 208. The first driving lever 209 is rotatably attached to an unillustrated shaft portion provided on the cam base 205. A boss portion 209a of the first drive lever 209 is slidably engaged with an unillustrated cam groove portion formed in a back surface of the first cam disc 207. As the first cam disc 207 rotates, the cam groove portion thereof slides relative to the boss portion 209a of the first drive lever 209 and presses it, whereby the first drive lever 209 rotates.
The first blade driving plate 210 includes a first main driving plate 210a and a first auxiliary driving plate 210b. Both the first main driving plate 210a and the first auxiliary driving plate 210b are rotatably connected to the plurality of shutter blades 200a and are rotatably held by the shutter base plate 206. A shaft portion 209b provided on the arm of the first driving lever 209 is engaged with a driving hole portion provided in the first main driving plate 210a. Therefore, as the first driving lever 209 rotates, the first blade driving plate 210 also rotates, and the shutter blade 200a is driven between the light shielding position and the light introducing position. The first auxiliary driving plate 210b has a detection hole portion (not illustrated in
Next follows the configuration of the second mechanical shutter 105b. The second mechanical shutter 105b has a plurality of shutter blades 200b, a second motor 211, and a second pinion gear 212 integrally rotatably attached to the output shaft of the motor 211. The second motor 211 is held by a second motor attachment plate 213. The second motor attachment plate 213 is fixed onto a second cover 214. The second cover 214 is fixed onto the cam base 205.
The plurality of shutter blades 200b are rotatably connected to a second blade driving plate 220 (220a, 220b). The shutter blades 200b can move in accordance with the rotation of the second blade driving plate 220 between a light shielding position where the shutter blades 200b is unfolded so as to cover the opening 206a and to shield the light toward the image sensor 104 and a light introducing position where the shutter blades 200b is folded so as to retreat from the opening 206a and allow the light to pass.
A second cam disc 217 has a protrusion 217a and a central shaft hole portion 217c, and a disc weight 217b is attached to the second cam disc 217. The protrusion 217a is engaged with an arm of a second biasing spring 218. The other of the two shaft portions 205c provided on the cam base 205 is engaged with the central shaft hole portion 217c. The inertial mass of the disc weight 217b is set larger than the total inertial mass of the plurality of shutter blades 200b, the second blade driving plate 220, and a second driving lever 219 described later.
A cylindrical portion 214a of the second cover 214 is inserted into the coil portion of the second biasing spring 218. The second driving lever 219 is rotatably attached to a shaft portion 205d provided to the cam base 205. A boss portion 219a of the second driving lever 219 is slidably engaged with an unillustrated cam groove portion formed in a back surface of the second cam disc 217. As the second cam disc 217 rotates, the cam groove portion in the second cam disc 217 slides relative to the boss portion 219a of the second drive lever 219 and presses it, whereby the second drive lever 219 rotates.
The second blade driving plate 220 includes a second main driving plate 220a and a second auxiliary driving plate 220b. Both the second main driving plate 220a and the second auxiliary driving plate 220b are rotatably connected to the plurality of shutter blades 200b and are rotatably held by the shutter base plate 206. A shaft portion 219b provided on the arm of the second driving lever 219 is engaged with a driving hole portion provided in the second main driving plate 220a. Therefore, as the second driving lever 219 rotates, the second blade driving plate 220 also rotates, and the shutter blade 200b is driven between the light shielding position and the light introducing position. The second auxiliary driving plate 220b is provided with a detection hole portion (not illustrated in
Referring now to
As illustrated in
Since the object image formed by the imaging lens 114 is inverted upside down on the image sensor 104, the charge accumulation scanning is performed in a direction from the bottom to the top as illustrated in
During the backward travel exposure illustrated in
Where the forward travel and the backward travel alternate as described above, the reading timing of the charge accumulated in the image sensor 104 and the next shutter traveling timing are controlled so as not to overlap. More specifically, for example, after reading of the accumulated charges out of all the lines of the image sensor 104 is completed in accordance with the forward travel of the shutter blade A, the next charge accumulation of the image sensor 104 starts in synchronization with the backward travel of the shutter blade B.
As described above, since the object image formed by the imaging lens 114 is inverted upside down on the image sensor 104, the charge accumulation scanning is performed in a direction from the top to the bottom as illustrated in
The shutter blade A and the shutter blade B serve as the front curtain and the rear curtain alternately in the forward travel exposure and the backward travel exposure for the round-travel exposure or so as to continue the forward travel imaging (first imaging) and the backward travel imaging (second imaging). Alternatively, only one of the forward travel imaging and the backward travel imaging may be performed.
Referring now to
Referring now to
The camera CPU 113 includes an information acquisition unit 113a, a scene determination unit 113b, and an operation SH determination unit 113d. The information acquisition unit 113a acquires information on the imaging mode (referred to as imaging mode information hereinafter) set by the user through the imaging mode setting dial 112b. The information acquisition unit 113a acquires the image data into which the signal processing circuit 109 converts the image obtained by the focusing image sensor 120.
The information acquisition unit 113a sends the acquired imaging mode information and image data to the scene determination unit 113b. Based on the imaging mode information from the information acquisition unit 113a, the scene determination unit 113b selects a one-way imaging control (first imaging control) that performs only one of the forward travel imaging or the backward travel imaging is to be performed, or a round-travel imaging control (the second imaging control) that performs both of them continuously. The scene determination unit 113b detects (acquires) the height AY and the lateral moving speed AX of the object on the imaging screen as the information of the object from the image data acquired from the information acquisition unit 113a. Then, it is determined based on the height AY and the lateral moving speed AX of the object whether the rolling shutter distortion occurs, or whether the imaging scene includes an object that causes the rolling shutter distortion. A method of this determination will be described later in detail.
The operation SH determination unit 113d determines one of the one-way imaging control and the round-travel imaging control based on the imaging mode information and the determination result of the object in the scene determination unit 113b (about whether the height AY and/or the lateral moving speed AX cause the rolling shutter distortion). This determination will also be described in detail later. The imaging control determined by the operation SH determination unit 113d is transmitted to the shutter driving circuit 106. The shutter driving circuit 106 performs the transmitted imaging control.
Referring now to a flowchart in
In the step S102, the camera CPU 113 detects the imaging mode set by the imaging mode setting dial 112b (obtains the imaging mode information), and determines which of an A1 mode, a B1 mode, and a C1 mode the detected imaging mode is. Now, in an example, assume that that a low-speed continuous capturing mode is the B1 mode and a high-speed continuous capturing mode is the A1 mode, in which the continuous capturing speed is faster than that of the low-speed continuous capturing mode. A mode for determining the imaging control based on the detection result of the object (imaging scene) is the C1 mode. When the imaging mode is the A1 mode, the camera CPU 113 proceeds to the step S104, and when it is the B1 mode, it proceeds to the step S107. If the mode is the C1 mode, the flow proceeds to the step S103.
In the step S103, the camera CPU 113 detects the information on the object (imaging scene) from the image data obtained by the focusing image sensor 120. More specifically, it detects the height AY and the lateral moving speed AX of the object on the imaging screen. Then, it is determined whether the rolling shutter distortion occurs based on a determination method to be described later using the height AY and lateral moving speed AX. If it is determined that no rolling shutter distortion occurs, then the flow proceeds to the step S104, and if it is determined that the rolling shutter distortion occurs, then the flow proceeds to the step S107.
In the step S104, the camera CPU 113 determines that the imaging control to be executed this time is the round-travel imaging control as the SW2 in the release switch 112a turns on, and the flow proceeds to the step S105.
In the step S105, the camera CPU 113 determines whether or not the current state of the shutter unit 105 is in the pre-forward travel state in which the shutter blade A is located at the light introducing position and the shutter blade B is located at the light shielding position. If it is in the pre-forward travel state, the camera CPU 113 proceeds to the step S106. If the current state of the shutter unit 105 is in the pre-backward travel state in which the shutter blade A is located at the light shielding position and the shutter blade B is located at the light introducing position, the flow proceeds to the step S108.
On the other hand, in the step S107, the camera CPU 113 determines that the imaging control to be executed this time is the one-way imaging control and proceeds to the step S108.
In the step S108, the camera CPU 113 determines that the imaging control to be executed this time is the backward travel imaging, and proceeds to the step S109.
In the step S109, when the camera CPU 113 detects that the SW2 in the release switch 112a turns on, the flow proceeds to the step S110, and otherwise the camera CPU 113 returns to the step S101.
In the step S110, the camera CPU 113 executes the imaging control determined prior to the step S108 and proceeds to the step S111.
In the step S111, the camera CPU 113 determines whether the imaging control executed in the step S110 was the one-way imaging control or round-travel imaging control. If it is the one-way imaging control, the flow proceeds to the step S112 and if it is the round-travel imaging control, the flow proceeds to the step S113.
In the step S112, the camera CPU 113 sets the shutter unit 105 to the above pre-backward travel state and proceeds to the step S115.
In the step S113, the camera CPU 113 determines whether the imaging control determined in the step S110 was the backward travel imaging control. If it was the forward travel imaging control, the camera CPU 113 proceeds to the step S112 to set the shutter unit 105 to the pre-backward travel state and proceeds to the step S115. If it is the backward travel imaging control, the flow proceeds to the step S114.
In the step S114, the camera CPU 113 sets the shutter unit 105 to the above pre-forward travel state and proceeds to the step S115.
In the step S115, the camera CPU 113 determines whether or not the camera body 100 has been powered off by the main switch in the switch unit 112.
If it is not powered off, the camera CPU 113 returns to the step S101, and if it is powered off, the flow proceeds to the step S116.
In the step S116, the camera CPU 113 sets the shutter unit 105 to the pre-backward travel state and ends this processing.
Referring now to
The method of determining the rolling shutter distortion is merely illustrative, and another determination method may be used.
While this embodiment describes that the camera CPU 113 determines which of the forward travel imaging control and the backward travel imaging control is to be used for the one-way imaging control, but the user may arbitrarily set it. The user may arbitrarily set which of the one-way imaging control and the round-travel imaging control is to be performed based on the information on the imaging.
Next follows a description of a second embodiment according to the present invention. The camera body 100 according to this embodiment has the same configuration as that of the first embodiment, but the shutter blade A serves as the rear curtain in the forward travel imaging and the shutter blade B serves as the rear curtain in the backward travel imaging. This embodiment operates or moves the front curtain by the electronic shutter (referred to as an electronic front curtain hereinafter) prior to moving the rear curtain in each of the forward travel imaging and the backward travel imaging.
Referring now to
In the forward travel exposure illustrated in
As also described in the first embodiment, the object image formed by the imaging lens 114 is inverted upside down on the image sensor 104, and the charge accumulation scanning illustrated in
In the backward travel exposure illustrated in
Even in the imaging using the electronic front curtain, similar to the first embodiment, where the forward travel and the backward travel alternate, the reading timing of the charge accumulated in the image sensor 104 and the next shutter traveling timing are controlled so as not to overlap.
As described above, since the object image formed by the imaging lens 114 is inverted upside down on the image sensor 104, the charge accumulation scanning is performed in a direction from the top to the bottom as illustrated in
The shutter blades A and the shutter blades B serve as the front curtain and the rear curtain alternately in the forward travel exposure and the backward travel exposure for the round-travel exposure or so as to continue the forward travel imaging and the backward travel imaging. Alternatively, only one of the forward travel imaging and the backward travel imaging may be performed.
Referring now to
Each of the SH detection sensors 105c and 105d includes a photo interrupter (PI) or a photo reflector (PR) having a light emitting portion and a light receiving portion configured to receive detection light from the light emitting portion. The SH detection sensor 105c detects the traveling timing of the shutter blade A by detecting the switching of the presence and absence of the received detection light as the first blade driving plate 210b rotates. Similarly, the SH detection sensor 105d detects the traveling timing of the shutter blade B by detecting the switching of the presence and absence of the received detection light as the second blade driving plate 220b rotates. Each SH detection sensor outputs a low signal as the SH detection signal when the detection light is received and outputs a high signal as the SH detection signal when the detection light is not received.
As illustrated in
In
In
Then, when the top end of the shutter blade A reaches the center of the imaging plane 14 as described in
In
Then, as described with reference to
On the other hand, in the forward travel exposure illustrated in
ΔH=H−H0
The forward traveling characteristic change amount ΔH is stored in the information storage unit 150.
In the backward travel exposure illustrated in
ΔI=I−I0
The backward traveling characteristic change amount ΔI is also stored in the information storage unit 150.
Referring now to
The information acquisition unit 113a of the camera CPU 113 acquires the imaging mode information obtained from the imaging mode setting dial 112b in the switch unit 112 and image data into which the signal processing circuit 109 converts the image obtained by the imaging device 104. The information acquisition unit 113a acquires information (referred to as actual traveling characteristic information hereinafter) on the traveling characteristic of each of the current shutter blades A and B using the SH detection signals from the SH detection sensors 105c and 105d. The information acquisition unit 113a acquires information (referred to as SH traveling number information hereinafter) on a count value that counts the number of travels of each of the initial shutter blades A and B. The information acquisition unit 113a acquires the reference SH traveling characteristic information initially stored in the information storage unit 150.
The information acquisition unit 113a sends the acquired imaging mode information and image data to the scene determination unit 113b, and the actual SH traveling characteristic information and the reference SH traveling characteristic information to the SH traveling characteristic change amount calculation unit 113c. The information acquisition unit 113a sends the obtained SH traveling number information to the operation SH determining unit 113d.
Based on the imaging mode information received from the information acquisition unit 113a, the scene determination unit 113b determines whether the imaging control is to be the one-way imaging control or the round-travel imaging control, or is to be determined based on the information on the object (imaging scene) detected from the image data. The scene determination unit 113b obtains the height AY and the lateral moving speed AX of the object on the imaging screen as the information on the object and determines whether or not the rolling shutter distortion occurs using them or whether the imaging scene contains an object that causes the rolling shutter distortion. This determination is made by the method described in the first embodiment with reference to
Based on the actual SH traveling characteristic information and the reference SH traveling characteristic information received from the information acquisition unit 113a, the SH traveling characteristic change amount calculation unit 113c calculates the traveling characteristic change amounts ΔH and ΔI of the shutter blades A and B, respectively. Then, it sends the comparison result of ΔH and ΔI to the operation SH determination unit 113d. Based on the imaging mode information and the determination result of the scene determination unit 113b, the motion SH determination unit 113d selects one of the one-way imaging control or the round-travel imaging control to be performed. When one-way imaging control is to be performed, the operation SH determination unit 113d selects one of the forward travel imaging control and the backward travel control to be executed based on the comparison result of ΔH and ΔI and the SH traveling number information acquired from the SH traveling characteristic change amount calculation unit 113c. The operation SH determination unit 113d determines the traveling direction (reset scanning direction) of the electronic front curtain based on the shutter blades to be operated.
The information on the imaging control determined by the operation SH determination unit 113d is transmitted to the shutter driving circuit 106 and the reset scanning direction of the electronic front curtain is transmitted to the vertical driving modulation circuit 108. Thereby, the imaging control using the electronic front curtain and the shutter blade (A or B) is performed.
Referring now to flowcharts in
In the step S202, the camera CPU 113 detects the imaging mode set by the imaging mode setting dial 112b (obtains the imaging mode information), determines whether the detected imaging mode is one of an A2 mode, a B2 mode, and a C2 mode. As in the step S102 in the first embodiment, assume that a low-speed continuous capturing mode is the B2 mode, and a high-speed continuous capturing mode having a higher continuous capturing speed than that of the low-speed continuous capturing mode is the A2 mode. The mode for determining the imaging control based on the detection result of the object (imaging scene) is the C2 mode. When the imaging mode is the A2 mode, the camera CPU 113 proceeds to the step S204, and when it is the B2 mode, it proceeds to the step S208. When it is the C2 mode, the flow proceeds to the step S203.
In the step S203, the camera CPU 113 detects the information of the object (imaging scene) in the image data obtained by the image sensor 104. More specifically, similar to the step S103 in the first embodiment, the height AY of the object and the lateral moving speed AX on the imaging screen are detected. Then, it is determined whether the rolling shutter distortion occurs by the determination method described in the first embodiment using the height AY and the lateral travel speed AX. If it is determined that no rolling shutter distortion occurs, the flow proceeds to the step S204, and if it is determined that the rolling shutter distortion occurs, the flow proceeds to the step S208.
In the step S204, the camera CPU 113 determines the imaging control to be executed this time as the round-travel imaging control when the SW2 in the release switch 112a turns on, and proceeds to the step S205.
In the step S205, the camera CPU 113 determines whether the imaging control executed last time was the forward travel imaging control. If it was the forward travel imaging control, the flow proceeds to the step S206, and if it was the backward travel imaging control, the flow proceeds to the step S207.
In the step S206, the camera CPU 113 determines that the imaging control to be executed this time is the backward travel imaging control, and proceeds to the step S217.
In the step S207, the camera CPU 113 determines the imaging control to be executed this time as the forward travel imaging control, and proceeds to the step S217.
In the step S208, the camera CPU 113 determines that the imaging control to be executed this time is the one-way imaging control, and proceeds to the step S209.
In the step S209, the camera CPU 113 determines whether a difference between the number of travels AN of the shutter blades A and the number of travels BN of the shutter blades B indicated by the SH traveling number information is equal to or less than a predetermined number N of times. When |AN−BN|<N, the camera CPU 113 proceeds to the step S213, and if |AN−BN|<N, the flow proceeds to the step S210.
In the step S210, the camera CPU 113 compares the number of travels AN of the shutter blade A with the number of travels BN of the shutter blade B. If AN>BN, the flow proceeds to the step S211, and if AN<BN, the flow proceeds to the step S212.
In the step S211, the camera CPU 113 determines that the imaging control to be executed this time is the backward travel imaging control, and proceeds to the step S217.
In the step S212, the camera CPU 113 determines the imaging control to be executed this time as the forward travel imaging control, and proceeds to the step S217.
In the step S213, the camera CPU 113 calculates the traveling characteristic change amounts ΔH and ΔI of the shutter blades A and B respectively using the actual SH traveling characteristic information and the reference SH traveling characteristic information, and determines whether the difference between ΔH and ΔI is equal to or less than a predetermined value J. If |ΔH−ΔI|>J, the camera CPU 113 proceeds to the step S214, and if |ΔH−ΔI|>J, the flow proceeds to the step S215.
In the step S214, the camera CPU 113 determines a smaller one of the traveling characteristic change amounts ΔH and ΔI of the shutter blade A and the shutter blade B. If ΔH>ΔI, the flow proceeds to the step S215, and if ΔH>ΔI, the flow proceeds to the step S216.
In the step S215, the camera CPU 113 determines that the imaging control to be executed this time is the backward travel imaging control, and proceeds to the step S217.
In the step S216, the camera CPU 113 determines the imaging control to be executed this time as the forward travel imaging control, and proceeds to the step S217.
In the step S217, when the camera CPU 113 detects that the SW2 in the release switch 112a turns on, the flow proceeds to the step S218. Otherwise, the camera CPU 113 returns to the step S201.
In the step S218, the camera CPU 113 executes the imaging control determined in the step S216, and proceeds to the step S219.
In the step S219, the camera CPU 113 determines whether the imaging control executed this time is the forward travel imaging control or the backward travel imaging control. If it is the forward travel imaging control, the flow proceeds to the step S220, if it is the backward travel imaging control, the flow proceeds to the step S222.
In the step S220, the camera CPU 113 adds 1 to the number of travels AN of the shutter blades A and proceeds to the step S221.
In the step S221, the camera CPU 113 updates the traveling characteristic change amount ΔH of the shutter blade A and proceeds to the step S224.
In the step S222, the camera CPU 113 adds 1 to the number of travels BN of the shutter blades B and proceeds to the step S223.
In the step S223, the camera CPU 113 updates the traveling characteristic change amount ΔI of the shutter blade B, and proceeds to the step S224.
In the step S224, the camera CPU 113 determines whether the camera body 100 has been powered off by the main switch in the switch unit 112.
If the power is not turned off, the camera CPU 113 returns to the step S201, and when it is turned off, the camera CPU 113 ends this processing.
This embodiment describes acquiring the image data used by the scene determination unit 113b from the image sensor 104, but it may be acquired from the focusing image sensor 120 or a photometry image sensor. This embodiment describes that the camera CPU 113 determines one of the forward travel imaging control and the backward travel imaging control to be performed as the one-way imaging control, but the user may arbitrarily set it. The user may arbitrarily set which of the one-way imaging control and the round-travel imaging control is to be performed based on the information on the imaging.
Each of the above embodiments select the one-way imaging control or the round-travel imaging control based on the information on the imaging, and can improve the frame rate using the first and second mechanical shutters, suppressing the rolling shutter distortion.
Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.
The present invention can provide an imaging apparatus that can improve a frame rate with a mechanical shutter while suppressing a rolling shutter distortion.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-188090 | Sep 2016 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2017/033744 | Sep 2017 | US |
| Child | 16354250 | US |
