Imaging apparatus, imaging method, and imaging program

An imaging apparatus includes an imaging element, a moving mechanism that corrects a shake, a curtain that blocks an incidence ray on the imaging element by traveling in a column direction, and a processor configured to, in a state where the moving mechanism moves the imaging element, in a case where an instruction to start imaging with an exposure time period less than or equal to a predetermined time period is received, perform a moving amount reduction control for reducing a moving amount for moving the imaging element from an elapse of a timing of reception of the instruction until a start of exposure of the imaging element, compared to a moving amount of the imaging element at the timing of reception of the instruction, in a state where the moving amount reduction control is performed, start a reset control for sequentially resetting a plurality of pixels included in the imaging element along the column direction for each line in a row direction, and after an elapse of a time period corresponding to the exposure time period from the start of the reset control, cause the curtain to travel in the column direction.

BACKGROUND

1. Technical Field

The disclosed technology relates to an imaging apparatus, an imaging method, and an imaging program.

2. Related Art

JP2012-129588A discloses an imaging apparatus comprising an imaging element consisting of a plurality of pixels, a mechanical rear curtain that travels in order to block incidence of light on the imaging element, a reset unit that sequentially performs reset scanning on the imaging element for each line before traveling of the mechanical rear curtain, and a correction control unit that corrects a timing of the reset scanning performed by the reset unit for each line based on a moving amount of the imaging element which is moved based on a detection result of vibration.

SUMMARY

An embodiment according to the disclosed technology provides an imaging apparatus, an imaging method, and an imaging program capable of reducing an uneven exposure value in an image obtained by imaging, compared to a case where a moving amount for moving the imaging element from an elapse of a timing of reception of an instruction to start imaging until a start of exposure of the imaging element is not reduced compared to a moving amount of the imaging element at the timing of reception of the instruction to start imaging.

A first aspect according to the disclosed technology is an imaging apparatus comprising an imaging element in which a plurality of pixels are arranged in a row direction and a column direction, a correction unit that corrects a shake by moving the imaging element, a curtain that blocks an incidence ray on the imaging element by traveling in the column direction, and a control unit that, in a state where the correction unit moves the imaging element, in a case where an instruction to start imaging with an exposure time period less than or equal to a predetermined time period is received, performs a moving amount reduction control for reducing a moving amount for moving the imaging element from an elapse of a timing of reception of the instruction until a start of exposure of the imaging element, compared to a moving amount of the imaging element at the timing of reception of the instruction, in a state where the moving amount reduction control is performed, starts a reset control for sequentially resetting the plurality of pixels included in the imaging element along the column direction for each line in the row direction, and after an elapse of a time period corresponding to the exposure time period from the start of the reset control, causes the curtain to travel in the column direction.

A second aspect according to the disclosed technology is the imaging apparatus according to the first aspect, in which the moving amount reduction control is a stop control for stopping the imaging element within a target range including a target position using a moving target position of the imaging element at a predetermined first timing as the target position.

A third aspect according to the disclosed technology is the imaging apparatus according to the second aspect, in which the control unit derives a timing of the resetting along the column direction based on the target position of the imaging element and performs the resetting along the column direction at the derived timing.

A fourth aspect according to the disclosed technology is the imaging apparatus according to the third aspect, in which the control unit derives the timing of the resetting in accordance with traveling speed characteristics of the curtain.

A fifth aspect according to the disclosed technology is the imaging apparatus according to any one of the second to fourth aspects, in which the stop control is a control for stopping the imaging element within the target range while imaging for still images of a plurality of frames is performed in accordance with the instruction issued once.

A sixth aspect according to the disclosed technology is the imaging apparatus according to any one of the second to fifth aspects, in which the control unit, in a case of performing the stop control on the imaging element, performs processing of smoothing information indicating the target position of the imaging element in the stop control.

A seventh aspect according to the disclosed technology is the imaging apparatus according to the sixth aspect, in which the control unit, in a case of performing the stop control on the imaging element, performs a control for fixing an output value obtained by smoothing the information indicating the target position of the imaging element in the stop control, at a timing of a start of the stop control.

An eighth aspect according to the disclosed technology is the imaging apparatus according to any one of the first to seventh aspects, in which the control unit starts the reset control in a case where the moving amount of the imaging element is decreased to or below a predetermined value.

A ninth aspect according to the disclosed technology is the imaging apparatus according to any one of the first to eighth aspects, in which the control unit performs a control for restoring a roll rotation amount of the imaging element to an initial position, on the correction unit at a predetermined second timing.

A tenth aspect according to the disclosed technology is the imaging apparatus according to any one of the first to ninth aspects, in which the control unit, after the timing of reception of the instruction, performs a control for correcting the shake in the row direction by moving the imaging element, on the correction unit in only the row direction at an initial position of the imaging element.

An eleventh aspect according to the disclosed technology is the imaging apparatus according to any one of the first to tenth aspects, in which the control unit further performs shading correction in the column direction on an image obtained by imaging.

A twelfth aspect according to the disclosed technology is an imaging method comprising a step of, in a case where an instruction to start imaging with an exposure time period less than or equal to a predetermined time period is received during shake correction of correcting a shake by moving an imaging element in which a plurality of pixels are arranged in a row direction and a column direction, reducing a moving amount for moving the imaging element from an elapse of a timing of reception of the instruction until a start of exposure of the imaging element, compared to a moving amount of the imaging element at the timing of reception of the instruction, a step of, in a state where the step of reducing the moving amount is performed, starting a reset control for sequentially resetting the plurality of pixels included in the imaging element along the column direction for each line in the row direction, and a step of causing a curtain blocking an incidence ray on the imaging element to travel after an elapse of a time period corresponding to the exposure time period from the start of the reset control.

A thirteenth aspect according to the disclosed technology is an imaging program causing a computer to execute a procedure of, in a case where an instruction to start imaging with an exposure time period less than or equal to a predetermined time period is received during shake correction of correcting a shake by moving an imaging element in which a plurality of pixels are arranged in a row direction and a column direction, reducing a moving amount for moving the imaging element from an elapse of a timing of reception of the instruction until a start of exposure of the imaging element, compared to a moving amount of the imaging element at the timing of reception of the instruction, a procedure of, in a state where the procedure of reducing the moving amount is performed, starting a reset control for sequentially resetting the plurality of pixels included in the imaging element along the column direction for each line in the row direction, and a procedure of causing a curtain blocking an incidence ray on the imaging element to travel after an elapse of a time period corresponding to the exposure time period from the start of the reset control.

A fourteenth aspect according to the disclosed technology is an imaging apparatus comprising an imaging element in which a plurality of pixels are arranged in a row direction and a column direction, a correction unit that corrects a shake by moving the imaging element, a curtain that blocks an incidence ray on the imaging element by traveling in the column direction, and a processor configured to, in a state where the correction unit moves the imaging element, in a case where an instruction to start imaging with an exposure time period less than or equal to a predetermined time period is received, perform a moving amount reduction control for reducing a moving amount for moving the imaging element from an elapse of a timing of reception of the instruction until a start of exposure of the imaging element, compared to a moving amount of the imaging element at the timing of reception of the instruction, in a state where the moving amount reduction control is performed, start a reset control for sequentially resetting the plurality of pixels included in the imaging element along the column direction for each line in the row direction, and after an elapse of a time period corresponding to the exposure time period from the start of the reset control, cause the curtain to travel in the column direction.

DETAILED DESCRIPTION

First, abbreviations used in the present specification will be described. The abbreviation “AE” stands for “Auto Exposure”. The abbreviation “AF” stands for “Auto Focus”. The abbreviation “MF” stands for “Manual Focus”. The abbreviation “VCM” stands for “Voice Coil Motor”. The abbreviation “CMOS” stands for “Complementary Metal Oxide Semiconductor”. The abbreviation “CPU” stands for “Central Processing Unit”. The abbreviation “I/F” stands for “InterFace”. The abbreviation “TTL” stands for “Through The Lens”. The abbreviation “ROM” stands for “Read Only Memory”. The abbreviation “RAM” stands for “Random Access Memory”. The abbreviation “LAN” stands for “Local Area Network”. The abbreviation “EEPROM” stands for “Electrically Erasable Programmable Read Only Memory”. The abbreviation “SSD” stands for “Solid State Drive”. The abbreviation “USB” stands for “Universal Serial Bus”. The abbreviation “DVD-ROM” stands for “Digital Versatile Disc Read Only Memory”. The abbreviation “FPGA” stands for “Field Programmable Gate Array”. The abbreviation “PLD” stands for “Programmable Logic Device”. The abbreviation “ASIC” stands for “Application Specific Integrated Circuit”. The abbreviation “SoC” stands for “System on Chip”. The abbreviation “PID” stands for “Proportional-Integral-Differential”. The abbreviation “fps” stands for “frame per second”.

In the following description, a “shake” refers to a phenomenon in which in an imaging apparatus in which an image of subject light showing a subject is formed on a light-receiving surface through an optical system, a subject image obtained by forming the image of the subject light on the light-receiving surface changes because of a change in positional relationship between an optical axis of the optical system and the light-receiving surface due to a vibration exerted on the imaging apparatus.

Example of the vibration exerted on the imaging apparatus includes, in a case of an outdoor space, a vibration caused by traffic of an automobile, a vibration caused by wind, a vibration caused by construction work, and the like and, in a case of an indoor space, a vibration caused by an operation of an air conditioner, a vibration caused by entrance and exit of a person, and the like.

First Embodiment

Hereinafter, a first embodiment according to the disclosed technology will be described with reference to the drawings. In a case where concepts of upward, downward, leftward, and rightward directions are used in describing members or configurations in the drawings, the concepts simply mean, unless otherwise specified, upward, downward, leftward, and rightward directions in the drawings and do not mean absolute directions. In addition, in the following description, a meaning of “being parallel” includes a meaning of being completely parallel and also a meaning of being approximately parallel including an error allowed in design and manufacturing. Furthermore, in the following description, a meaning of “being perpendicular” includes a meaning of being completely perpendicular and also a meaning of being approximately perpendicular including an error allowed in design and manufacturing.

FIG.1is a perspective view illustrating an example of an exterior of an imaging apparatus100according to the first embodiment. The imaging apparatus100is a digital camera that acquires and records a still image, and includes a camera body200and an interchangeable lens300interchangeably mounted on the camera body200.

The camera body200and the interchangeable lens300are interchangeably mounted by joining a mount256comprised in the camera body200to a mount346(refer toFIG.2) corresponding to the mount256on the interchangeable lens300side.

The camera body200comprises an imaging element20. The interchangeable lens300includes an imaging lens16. In a case where the interchangeable lens300is mounted on the camera body200, the subject light showing the subject is incident on the imaging lens16, and the image of the subject light incident on the imaging lens16is formed on the imaging element20by the imaging lens16.

A finder window241is disposed on a front surface of the camera body200. In addition, a release button211and a dial212are disposed on an upper surface of the camera body200. A display34(refer toFIG.2) is disposed on a rear surface of the camera body200.

In the imaging apparatus100, an imaging mode and a playback mode are selectively set as an operation mode. The dial212is operated in a case of setting various modes such as the imaging mode and the playback mode. In the imaging mode, an MF mode in which the MF can be executed, and an AF mode in which the AF can be executed are selectively set in accordance with an instruction of a user. For example, switching between the MF mode and the AF mode is implemented by receiving the instruction from the user by a reception device14(refer toFIG.2) including the dial212.

The release button211is configured to be capable of detecting a push operation in two stages of an imaging preparation instruction state and an imaging instruction state. For example, the imaging preparation instruction state refers to a state where a push is performed to an intermediate position (half push position) from a standby position, and the imaging instruction state refers to a state where a push is performed to a final push position (full push position) exceeding the intermediate position. Hereinafter, the “state where a push is performed to the half push position from the standby position” will be referred to as a “half push state”, and the “state where a push is performed to the full push position from the standby position” will be referred to as a “full push state”.

In a state where the AF mode is set in the imaging apparatus100, for example, an imaging condition is adjusted by setting the release button211to the half push state. Then, in a case where the full push state is subsequently set, main exposure is performed. That is, by setting the release button211to the half push state, an exposure value state is set by performing an AE function, and then, a focusing control is performed by performing an AF function. In a case where the release button211is set to the full push state, imaging is performed.

The imaging lens16comprises a focus lens302(refer toFIG.2as well). The image of the subject light is formed on a light-receiving surface21of the imaging element20by the focus lens302, and the subject light is photoelectrically converted by the imaging element20. Here, a CMOS image sensor is applied as an example of the imaging element20. A signal charge obtained by photoelectric conversion is accumulated in the imaging element20. The accumulated signal charge is read out at a predetermined frame rate (for example, 60 fps) as a digital signal corresponding to the signal charge (voltage) by a CPU12, described later. Here, while the CMOS image sensor is illustrated as an example of the imaging element20, the disclosed technology is not limited thereto. An image sensor of another type such as a charge coupled device (CCD) image sensor may be used as the imaging element20.

As illustrated inFIG.2as an example, the imaging apparatus100includes the CPU12, the reception device14, the imaging element20, a primary storage unit26, a secondary storage unit27, an image processing unit28, a light measurement sensor29, a shake sensor30, a position sensor31, the display34, a display control unit36, and an external I/F39. The CPU12, the reception device14, the imaging element20, the primary storage unit26, the secondary storage unit27, the image processing unit28, the display control unit36, and the external I/F39are connected to each other through a bus40. The CPU12controls the entire imaging apparatus100.

The CPU12performs a shake correction control for correcting the shake (hereinafter, simply referred to as the “shake correction control”), a moving amount reduction control for reducing a moving amount for moving the imaging element20from an elapse of a timing of reception of an instruction to start imaging until a start of exposure of the imaging element20, compared to a moving amount of the imaging element20at the timing of reception of the instruction to start imaging (hereinafter, simply referred to as the “moving amount reduction control”), an exposure control for adjusting an exposure time period (hereinafter, simply referred to as the “exposure control”), various correction on an acquired image, and the like. The CPU12is an example of a “control unit (processor)” according to the embodiments of the disclosed technology.

The reception device14includes the release button211and the dial212and receives the instruction for the imaging apparatus100from the user. The display34is connected to the display control unit36. The display34displays an image obtained by imaging by the imaging element20(hereinafter, simply referred to as the “image”).

The primary storage unit26is a volatile memory used as a work area or the like in a case of executing various programs. Example of the primary storage unit26includes a RAM.

The secondary storage unit27stores the various programs. The secondary storage unit27is a non-volatile memory. Example of the secondary storage unit27includes an EEPROM or a flash memory.

The image processing unit28performs shading correction on the image. In addition, the image processing unit28performs various image processing such as white balance adjustment and gamma correction on the image. By performing the image processing by the image processing unit28, a live view image, a still image for recording, a motion picture image for recording, and the like are selectively generated. The image on which the image processing is performed by the image processing unit28is acquired by the CPU12.

The CPU12outputs the image such as the live view image to the display control unit36. The display control unit36displays the image input from the CPU12on the display34.

The external I/F39is connected to a communication network such as a LAN and/or the Internet and transmits and receives various information between the CPU12and an external apparatus such as a server, a personal computer, and/or a printer through the communication network.

The light measurement sensor29is a sensor of a TTL type. The disclosed technology is not limited thereto, and the imaging element20may be used as the light measurement sensor29. The shake sensor30detects the shake of the imaging apparatus100. Example of the shake sensor30includes a gyro sensor. The shake sensor30is not limited to the gyro sensor and may be an acceleration sensor or the like. Example of the position sensor31includes a device formed with a hall element.

The imaging element20has an electronic shutter function, and exposure is started by starting resetting of the imaging element20using an electronic shutter. In the first embodiment, a CMOS sensor in which a plurality of pixels, that is, photoelectric conversion elements, are two-dimensionally arranged in a row direction and a column direction is employed as an example of the imaging element20.

As illustrated inFIG.3as an example, the camera body200comprises a moving frame50, a support unit60, and a plurality of voice coil motors52. Hereinafter, the “voice coil motor” will be referred to as the “VCM”. The imaging element20is fixed to the moving frame50. The moving frame50is movably supported by the support unit60. The support unit60is fixed to the camera body200. As an example, the VCMs52are configured to include a permanent magnet fixed to the moving frame50and a coil fixed to the support unit60.

The imaging apparatus100has a function (hereinafter, referred to as a “shake correction function”) of correcting the shake. As illustrated inFIG.2, the imaging apparatus100comprises a motor driver51. The shake correction function is a function implemented by the CPU12, the motor driver51, the VCMs52, and the like. The motor driver51is connected to the CPU12and the VCMs52. The motor driver51drives the VCMs52under control of the CPU12. The CPU12moves the imaging element20fixed to the moving frame50by providing motive power generated by driving the VCMs52to the moving frame50. The imaging apparatus100has a movable range22. The movable range22is a range in which the imaging element20can move. For example, the movable range22is a rectangular range that is wider than an outer frame of the imaging element20in a plan view in a plane parallel to the light-receiving surface21. The VCMs52are an example of a “correction unit (moving mechanism) according to the embodiments of the disclosed technology. The correction unit that moves the imaging element20is not limited to the voice coil motors. For example, a stepping motor or a piezo actuator may be used.

The imaging element20corrects the shake by moving in a plane parallel to the light-receiving surface21, in other words, a plane perpendicular to an optical axis of the imaging lens16. In a case where the shake correction function is not performed, the imaging element20is arranged at an initial position as illustrated inFIG.3. The initial position refers to a position of the imaging element20in a case where the shake correction function is not performed. For example, the position of the imaging element20in a case where the shake correction function is not performed refers to a position at which an optical axis L1of the interchangeable lens300passes through a center CT of the imaging element20.

The imaging element20is moved by the plurality of VCMs52in a direction H, a direction V, and a rotation direction R illustrated inFIG.3. The direction H refers to a direction corresponding to the row direction of the pixels of the imaging element20at the initial position. The direction V refers to a direction corresponding to the column direction of the pixels of the imaging element20at the initial position. The rotation direction R refers to a rotation direction about the optical axis L1as a rotation axis. In the present specification, directions of the direction H, the direction V, and the rotation direction R include both directions.

In the present specification, moving the imaging element20in the direction H in order to correct the shake in the direction H will be referred to as a “horizontal shift”. In addition, moving the imaging element20in the direction V in order to correct the shake in the direction V will be referred to as a “vertical shift”. In addition, moving the imaging element20in the rotation direction R in order to correct the shake in the rotation direction R will be referred to as “roll rotation”. In addition, the position of the imaging element20in the direction H will be referred to as a “horizontal position”. In addition, the position in the direction V will be referred to as a “vertical position”. Furthermore, a rotation amount in the rotation direction R will be referred to as a “roll rotation amount”.

As illustrated inFIG.4as an example, at the initial position, the imaging element20is arranged at a center of the movable range22. The imaging element20includes the plurality of pixels, and the plurality of pixels are arranged in the row direction and the column direction at the initial position. Here, the “pixels” refer to photoelectric conversion elements. In the imaging element20, all of the pixels in one row direction will be referred to as a pixel line24. In the imaging element20, a plurality of the pixel lines24are arranged in the column direction.

The imaging apparatus100performs the exposure using a focal-plane shutter system that uses an electronic shutter functioning as a front curtain and uses a mechanical curtain as a rear curtain. As illustrated inFIG.4as an example, in a case of imaging the subject, the pixel lines24of the imaging element20are sequentially reset from a first row to a last row along the column direction. In the example illustrated inFIG.4, the pixel line24of a target in which the resetting is currently started among the plurality of pixel lines24is illustrated as a reset line23. The resetting of the pixels means discharging charges that are accumulated in the pixels by light. By starting the resetting, the exposure is started. In the imaging apparatus100, a reset control is performed by the CPU12in a state where the moving amount reduction control described later is performed. The reset control refers to a control for sequentially resetting the plurality of pixels included in the imaging element20from the first row along the column direction, that is, a direction Q, for each line in the row direction. InFIG.4, only a part of the pixel lines24is illustrated.

In addition, the imaging apparatus100includes a rear curtain65. The rear curtain65is an example of a “curtain” according to the embodiments of the disclosed technology. The rear curtain65is a mechanical curtain and is arranged closer to the subject side than the light-receiving surface21. The rear curtain65blocks an incidence ray on the light-receiving surface21by traveling in a direction of arrow S, that is, the column direction, from an upper part of the drawing by receiving biasing force by a spring or the like. The rear curtain65is fixed to the camera body200independently of the moving frame50to which the imaging element20is fixed. Thus, the rear curtain65does not move in connection with movement of the imaging element20. Thus, the rear curtain65travels within a range that covers the movable range22of the imaging element20. The rear curtain65is controlled to travel in the direction V after an elapse of a time period corresponding to the exposure time period from a start of the reset control. That is, a difference between a timing of the resetting and a timing of traveling of the rear curtain65is the exposure time period. The timing of the resetting is a timing at which each pixel line24is reset. The timing of traveling of the rear curtain65is a timing at which the rear curtain65passes through a position of the reset pixel line24.

As illustrated inFIG.5Aas an example, the light-receiving surface21and the rear curtain65are separated by a distance D. In a case where an imaging instruction is received from the user, the imaging apparatus100starts the resetting from the pixel line24of a first column Next, the rear curtain65starts traveling after an elapse of the exposure time period. InFIG.5AtoFIG.5C, the pixel line24that is reset is illustrated by thick solid line, and the pixel line24that is not reset is illustrated by dotted line. As illustrated inFIG.5Aas an example, an interval Z between the reset line23and a lower end of the rear curtain65is a distance in which the rear curtain65travels during the exposure time period. The interval Z corresponds to a slit width that is a gap occurring between the front curtain and the rear curtain in a case where both of the front curtain and the rear curtain are mechanical curtains.

As illustrated inFIG.5Bas an example, in a case where the reset line23and the lower end of the rear curtain65reach near a center of the imaging element20, the subject light within a range of an angle β out of the subject light within a range of an angle α passing through a point P reaches the reset pixel line24, and the reset pixel line24is exposed. However, as illustrated inFIG.5Cas an example, in a case where the reset line23and the lower end of the rear curtain65further proceed in the column direction, the subject light of a part of the subject light within the angle α passing through the point P is shaded by the rear curtain65. A range of an angle γ (<angle β) reaches the reset pixel line24, and the reset pixel line24is exposed. In such a manner, in a case where the light-receiving surface21and the rear curtain65are spaced, an exposure amount at a point in time illustrated inFIG.5Bas an example is greater than the exposure amount at a point in time illustrated inFIG.5Cas an example, even in a case where the resetting of the pixel lines24and traveling of the rear curtain65are controlled such that the interval between the reset line23and the lower end of the rear curtain65correspond to a constant exposure time period. Thus, an uneven exposure value occurs in one image obtained by imaging the subject. Here, the “exposure value” is brightness in the image depending on the exposure time period. In addition, for example, the “uneven exposure value” means that the exposure value varies for each section in the image.

As a method of resolving a problem that the exposure amount changes in accordance with a position of the rear curtain65, a method of changing a position of the reset line23depending on the position of the rear curtain65is considered. Specifically, in a case where the rear curtain65is in an upper portion of the imaging element20, a reset speed of the reset line23is decreased. By decreasing the reset speed, the interval Z is decreased. In addition, in a case where the rear curtain65is in a lower portion of the imaging element20, the reset speed of the reset line23is increased. By increasing the reset speed, the interval Z is increased. By controlling in such a manner, a change in received light amount is reduced regardless of the position of the rear curtain65, and the uneven exposure value can be reduced. This will be referred to as correction of the uneven exposure value.

Meanwhile, performing the shake correction function changes the position of the imaging element20. In a case where the imaging element20moves in the direction H, a vertical position of the reset line23with respect to the rear curtain65does not change. Thus, correction of the uneven exposure value is not affected. However, in a case where the imaging element20moves in the direction V, the vertical position of the reset line23with respect to the rear curtain65changes, and the exposure amount changes. Thus, correction of the uneven exposure value is not performed as designed, and the uneven exposure value occurs. Correction of the uneven exposure value is performed on an assumption that the imaging element20is at a predetermined position, for example, the initial position.

Therefore, as illustrated inFIG.6as an example, in the imaging apparatus100, the secondary storage unit27stores an imaging control program130. The CPU12reads out the imaging control program130from the secondary storage unit27, loads the read imaging control program130into the primary storage unit26, executes imaging control processing (refer toFIG.8) in accordance with the loaded imaging control program130. The imaging control processing (refer toFIG.8) is implemented by causing the CPU12to operate as a shake correction control unit112, a moving amount reduction control unit116, an exposure time period determination unit118, and an exposure control unit120in accordance with the imaging control program130.

The shake correction control unit112controls the VCMs52based on a signal received from the shake sensor30. The VCMs52correct the shake by moving the imaging element20in accordance with an instruction of the shake correction control unit112. In a case where an instruction to pause the shake correction control is received from the exposure time period determination unit118, the shake correction control unit112pauses the shake correction control.

In a state where the VCMs52move the imaging element20, in a case where the instruction to start imaging with the exposure time period less than or equal to a predetermined time period is received from the user, the moving amount reduction control unit116performs a control for reducing the moving amount for moving the imaging element20from the elapse of the timing of reception of the instruction until the start of the exposure of the imaging element20, compared to the moving amount of the imaging element20at the timing of reception of the instruction. This control will be referred to as the “moving amount reduction control”.

For example, the “predetermined time period” of the exposure time period is predetermined by performing a sensory test as to whether or not the shake remaining in the image acquired after changing the exposure time period can be allowed in a case where the shake correction control is not performed. The predetermined exposure time period is stored in the secondary storage unit27. Alternatively, the imaging apparatus100may be configured to enable the user to set the exposure time period as a reference for starting the moving amount reduction control.

In a case where an instruction to start the moving amount reduction control is received from the exposure time period determination unit118, the moving amount reduction control unit116starts the moving amount reduction control.

In the present specification, the “moving amount reduction control” includes a stop control. The “stop control” is a control for stopping the imaging element20within a target range including a target position using a moving target position of the imaging element20at a predetermined timing as the target position. The “target range” refers to a range that can suppress the uneven exposure value and includes a positioning error in a control for moving the imaging element20to the target position. For example, the “predetermined timing” refers to a timing at which the moving amount reduction control unit116receives the instruction to start the moving amount reduction control from the exposure time period determination unit118. The “predetermined timing” is not limited thereto and may be a timing at which the moving amount reduction control unit116starts the moving amount reduction control, a timing at which the reception device14receives the instruction to start imaging from the user, or the like. Here, the “predetermined timing” is an example of a “predetermined first timing” according to the embodiments of the disclosed technology. Hereinafter, the “moving target position at the predetermined timing” of the imaging element20will be referred to as a “specific timing position”. That is, the specific timing position is the target position for stopping the imaging element20. In the first embodiment, the moving amount reduction control unit116performs a control for stopping the imaging element20within the target range including the target position using the position of the imaging element20in at least the column direction as the target position.

In a case where the instruction to start imaging is received from the user, the exposure time period determination unit118derives the exposure time period required for imaging at the timing of reception of the instruction based on a signal received from the light measurement sensor29. The exposure time period determination unit118notifies the exposure control unit120of the derived exposure time period. In addition, the exposure time period determination unit118determines whether or not the derived exposure time period is less than or equal to the predetermined time period. In a case where it is determined that the derived exposure time period is less than or equal to the predetermined time period, the exposure time period determination unit118instructs the shake correction control unit112to pause the shake correction control. In addition, in a case where it is determined that the derived exposure time period is greater than the predetermined time period, the exposure time period determination unit118instructs the moving amount reduction control unit116to start the moving amount reduction control.

The exposure control unit120derives the timing of the resetting of the imaging element20and the timing of the start of traveling of the rear curtain65based on information about the specific timing position and the exposure time period notified from the exposure time period determination unit118. In a case where a condition under which the exposure is started is satisfied, the exposure control is performed at the derived timing of the resetting and the timing of the start of traveling of the rear curtain65. For example, the condition under which the exposure is started is a case where the moving amount of the imaging element20is decreased to or below a predetermined value.

Next, a flow of the series of imaging control processing performed by the shake correction control unit112, the moving amount reduction control unit116, the exposure time period determination unit118, and the exposure control unit120will be described in time series. Here, it will be assumed that the shake correction control is started by the shake correction control unit112in a stage in which the imaging apparatus100is powered ON. As illustrated inFIG.7as an example, the exposure time period determination unit118derives the exposure time period. Specifically, in a case where the instruction to start imaging is received from the user, the exposure time period determination unit118derives the exposure time period at the timing of reception of the instruction to start imaging. For example, the instruction to start imaging refers to a full push on the release button by the user.

Next, the exposure time period determination unit118performs a shake correction control pause determination. Specifically, the exposure time period determination unit118determines whether or not to pause the shake correction control based on the derived exposure time period. In a case where it is determined that the exposure time period is less than or equal to the predetermined time period, the exposure time period determination unit118outputs a shake correction control pause instruction to the shake correction control unit112and outputs a moving amount reduction control start instruction to the moving amount reduction control unit116.

Next, the moving amount reduction control unit116acquires target position information about the imaging element20. Specifically, based on information from the shake sensor30, the moving amount reduction control unit116acquires target position information for stopping the imaging element20and starts the moving amount reduction control.

Next, the exposure control unit120sets a front curtain register for the reset control. Specifically, the exposure control unit120acquires the target position information about the imaging element20. The exposure control unit120derives the timing of the resetting along the column direction of each pixel line based on the target position information in the direction V in the acquired target position information. The exposure control unit120stores the derived timing of the resetting in the front curtain register of the primary storage unit26as timing data.

A method of deriving the timing of the resetting along the column direction of each pixel line will be specifically described. A degree of change in received light amount on the light-receiving surface21(hereinafter, simply referred to as the “received light amount”) depending on the position of the rear curtain65is predetermined by calculation corresponding to an incidence angle of a luminous flux and the position of the imaging element20in the direction V. As described usingFIG.5AtoFIG.5C, as a height of the position of the imaging element20in the direction V is increased, the degree of change in received light amount is increased. Therefore, based on the position of the imaging element20in the direction V, the exposure control unit120derives the timing of the resetting for changing a size of the slit such that the degree of change in received light amount is reduced.

Alternatively, the timing of the resetting along the column direction of each pixel line may be stored in the secondary storage unit27as a timing table including the position of the imaging element20in the direction V as a parameter. In this case, the exposure control unit120reads out the timing of the resetting corresponding to the acquired position of the imaging element20in the direction V from the timing table and performs the reset control.

Next, the exposure control unit120starts resetting the imaging element20by generating a front curtain control pulse. Each pixel line is reset along the column direction in accordance with the timing data stored in the front curtain register. The start of the resetting of the imaging element20is the start of the exposure.

Next, after the time period corresponding to the exposure time period elapses, the exposure control unit120causes the rear curtain65to travel by generating a rear curtain control pulse. InFIG.7, a reset direction of the front curtain and a traveling direction of the rear curtain65are illustrated as a direction of dotted line illustrated in the drawing. In the example illustrated inFIG.7, the reset speed of the front curtain and a traveling speed of the rear curtain65are gradually increased. For the rear curtain65that receives the biasing force by the spring or the like, characteristics of a change in traveling speed depending on the position, that is, traveling speed characteristics, are decided. Thus, the exposure control unit120derives the timing of the resetting in accordance with the traveling speed characteristics of the rear curtain65and performs the resetting at the derived timing of the resetting.

Next, after the start of the resetting of the front curtain, that is, after the predetermined time period elapses from the start of the exposure, the CPU12reads out digital signals of the exposed pixels and stores the read digital signals in the primary storage unit26. Reading does not need to wait until the exposure of all pixels is finished, and the pixels of which the exposure is finished may be sequentially read out.

InFIG.7, while a waiting time period is present from acquisition of information related to the target position for stopping the imaging element20until setting of the front curtain register, this waiting time period is a time period until the condition under which the exposure is started is satisfied. During the waiting time period until the start of the exposure, a live preview image is continuously displayed on the display34.

Next, an action of the imaging apparatus100will be described with reference toFIG.8toFIG.15.

FIG.8is a flowchart illustrating an example of a flow of imaging control processing that is executed by the CPU12in accordance with the imaging control program130in a case where the imaging apparatus100is powered ON.

In the imaging control processing illustrated inFIG.8as an example, first, in step S32, the shake correction control unit112starts the shake correction control illustrated inFIG.9as an example. Then, the imaging control processing transitions to step S34.

In shake correction control processing illustrated inFIG.9, first, in step S320, the shake correction control unit112acquires shake information from the shake sensor30. Then, the shake correction control processing transitions to step S321. The shake sensor30is, for example, a gyro sensor, and the shake information is, for example, angular velocity information. Hereinafter, the shake information will be described as an angular velocity indicating the angular velocity information.

In step S321, the shake correction control unit112performs zero-point correction or the like on the acquired angular velocity and then, performs high-pass filter processing for removing a low-frequency component of the angular velocity on which the zero-point correction cannot be performed. Then, the shake correction control processing transitions to step S322.

In step S322, the shake correction control unit112performs gain adjustment on the angular velocity. Then, the shake correction control processing transitions to step S323.

In step S323, the shake correction control unit112converts the angular velocity into a position to which the imaging element20is to be moved in order to cancel the shake, by calculating an integral of the angular velocity. Then, the shake correction control processing transitions to step S324. An integral value of the angular velocity per calculation time period corresponds to a changed amount of the position.

In step S324, the shake correction control unit112performs shift amount restriction on the moving amount. Then, the shake correction control processing transitions to step S325. The shift amount restriction is processing of restricting movement of the imaging element20exceeding the movable range22.

In step S325, based on the moving amount on which the shift amount restriction is performed, the shake correction control unit112derives the target position to which the imaging element20is moved, and sets the moving target position as the moving target position.

The moving target position set in step S325is calculated and set each time the angular velocity from the shake sensor30is sampled. In addition, current position information acquired in step S326is acquired each time information from the position sensor31is sampled, and is used in calculation for a feedback control. In this case, a period of moving target position calculation may be different from a period of feedback control calculation. In a case where the periods of the moving target position calculation and the feedback control are different, aliasing accompanied by resampling, that is, folding noise, may occur.

In the first embodiment, in a case of performing the shake correction control on the imaging element20, the moving amount reduction control unit116performs processing of smoothing information indicating the target position of the imaging element20in order to suppress occurrence of the aliasing. Specifically, in a case of setting the target position in step S325, the moving amount reduction control unit116uses a low-pass filter70. In a case where the period of the moving target position calculation is shorter than the period of the feedback control calculation, that is, in a case of downsampling, the low-pass filter70performs in the period of the moving target position calculation. In a case where the period of the moving target position calculation is greater than or equal to the period of the feedback control calculation, that is, in a case of upsampling, the low-pass filter70performs in the period of the feedback control calculation.

The CPU12includes the low-pass filter70. As illustrated inFIG.10as an example, the low-pass filter70has functions as a delay circuit71, a first filter circuit72, a second filter circuit73, and an adder74. The low-pass filter70has a function of outputting an output Y(t) represented by an expression below with respect to an input X(t).
Y(t)=B×Y(t−1)+A×(X(t)+X(t−1))

Here, X(t) is the target position before smoothing at sampling time point t, and Y(t) is the target position after smoothing. A time point represented by (t−1) is a sampling time point immediately before t. In addition, A is a filter coefficient of the first filter circuit72, and B is a filter coefficient of the second filter circuit73. These may be variable values changeable in accordance with the instruction of the user, or may be fixed values.

For example, in a case where the period of the moving target position calculation is the same as the period of the feedback control calculation, the low-pass filter70does not need to be disposed.

In subsequent step S326, the shake correction control unit112acquires the current position information about the imaging element20from the position sensor31. Then, the shake correction control processing transitions to step S327. The current position information is derived based on the information received from the position sensor31.

In step S327, the shake correction control unit112performs the feedback control for moving the imaging element20to the moving target position based on the moving target position set in step S325and the current position information acquired in step S326. For example, the feedback control is a PID control.

In subsequent step S328, the shake correction control unit112determines whether or not a shake correction control processing finish condition is satisfied. Here, for example, the “shake correction control processing finish condition” refers to a condition that power is OFF, or a condition that an instruction to finish the shake correction control processing is received from the exposure time period determination unit118. In step S328, in a case where the shake correction control processing finish condition is satisfied, a positive determination is made, and the shake correction control unit112finishes the shake correction control processing. In step S328, in a case where the shake correction control processing finish condition is not satisfied, a negative determination is made, and the shake correction control processing transitions to step S320.

Returning to the imaging control processing inFIG.8, in step S34, the exposure time period determination unit118determines whether or not the release button211is in the full push state. In step S34, in a case where the release button211is in the full push state, a positive determination is made, and the imaging control processing transitions to step S36. In step S34, in a case where the release button211is not in the full push state, a negative determination is made, and the determination in step S34is performed again.

In step S36, the exposure time period determination unit118derives the exposure time period based on information from the light measurement sensor29. Then, the imaging control processing transitions to step S38.

In step S38, the exposure time period determination unit118determines whether or not the derived exposure time period is less than or equal to the predetermined time period. In step S38, in a case where the exposure time period derived in step S36is not less than or equal to the predetermined time period, a negative determination is made, and the imaging control processing transitions to step S48. In step S38, in a case where the exposure time period derived in step S36is less than or equal to the predetermined time period, a positive determination is made, and the imaging control processing transitions to step S39.

In step S39, the exposure time period determination unit118outputs the instruction to start the moving amount reduction control to the moving amount reduction control unit116. In addition, in step S39, the exposure time period determination unit118outputs the instruction to pause the shake correction control to the shake correction control unit112. Then, the imaging control processing transitions to step S40.

In step S40, the moving amount reduction control unit116starts executing the moving amount reduction control processing illustrated inFIG.11as an example. Then, the imaging control processing transitions to step S42.

In the moving amount reduction control processing illustrated inFIG.11, processing of step S320to step S324is the same as processing of step S320to step S324of the shake correction control processing illustrated inFIG.9. Specifically, in step S320, the moving amount reduction control unit116acquires the angular velocity from the shake sensor30. In step S321, the moving amount reduction control unit116performs the high-pass filter processing on the acquired angular velocity. In step S322, the moving amount reduction control unit116performs the gain adjustment on the angular velocity. In step S323, the moving amount reduction control unit116converts the angular velocity into the moving amount by calculating the integral of the angular velocity. In step S324, the moving amount reduction control unit116performs the shift amount restriction on the moving amount.

Next, in step S401, the moving amount reduction control unit116sets the target position to which the imaging element20is stopped. Specifically, the moving amount reduction control unit116acquires the specific timing position of the imaging element20based on the information from the shake sensor30. The moving amount reduction control unit116sets the specific timing position as the target position for stopping the imaging element20. Specifically, in step S322illustrated inFIG.11, a gain for processing the angular velocity from the shake sensor30is adjusted to zero. Accordingly, an input value for calculating the integral of the angular velocity becomes zero, and an output value (position) of calculation of the integral of the angular velocity becomes constant. Accordingly, the specific timing position is fixed as the target position for stopping the imaging element20. Then, the moving amount reduction control processing transitions to step S403.

In step S403, the moving amount reduction control unit116acquires the current position information about the imaging element20based on the information from the position sensor31. Then, the moving amount reduction control processing transitions to step S405.

In step S405, from the target position set in step S401and the current position information acquired in step S403, the moving amount reduction control unit116performs the feedback control for stopping the imaging element20within the target range including the target position and then, transitions to step S406.

In step S406, the moving amount reduction control unit116determines whether or not a moving amount reduction control processing finish condition is satisfied. In step S406, in a case where the moving amount reduction control processing finish condition is satisfied, a positive determination is made, and the moving amount reduction control unit116finishes the moving amount reduction control processing. In step S406, in a case where the moving amount reduction control processing finish condition is not satisfied, a negative determination is made, and the moving amount reduction control processing transitions to step S320. Here, for example, the “moving amount reduction control processing finish condition” refers to a condition that exposure processing is started.

Returning to the imaging control processing illustrated inFIG.8, in step S42, the exposure control unit120acquires the target position information about the imaging element20from the moving amount reduction control unit116. Then, the imaging control processing transitions to step S44.

In step S44, the exposure control unit120sets the front curtain register based on the target position information in the direction V in the acquired target position information. Then, the imaging control processing transitions to step S46.

In step S46, the exposure control unit120determines whether or not an exposure start condition is satisfied. In step S46, in a case where the exposure start condition is satisfied, a positive determination is made, and the imaging control processing transitions to step S48. In a case where the exposure start condition is not satisfied, a negative determination is made, and the determination in step S46is performed again in the imaging control processing.

Here, for example, the “exposure start condition” refers to a condition that the moving amount of the imaging element20is decreased to or below the predetermined value. In this case, in step S46, the exposure control unit120derives the moving amount from the target position of the imaging element20based on the information from the position sensor31, and determines whether or not the moving amount of the imaging element20is decreased to or below the predetermined value. In step S46, in a case where the moving amount of the imaging element20is decreased to or below the predetermined value, a positive determination is made, and the imaging control processing transitions to step S48. In step S46, in a case where the moving amount of the imaging element20is not decreased to or below the predetermined value, a negative determination is made, and the determination in step S46is performed again.

The “exposure start condition” is not limited to the above example. For example, the “exposure start condition” may be a condition that a predetermined time period elapses from the start of the moving amount reduction control.

In step S48, the exposure control unit120performs the exposure. Specifically, the exposure control unit120performs the reset control on the imaging element20at the timing of the resetting of the imaging element20set in step S44, and after the exposure time period elapses, starts traveling of the rear curtain65. Then, the imaging control processing transitions to step S50.

In step S50, the moving amount reduction control unit116determines whether or not an imaging control processing finish condition is satisfied. In step S50, in a case where the imaging control processing finish condition is satisfied, a positive determination is made, and the moving amount reduction control unit116finishes the imaging control processing. In a case where the imaging control processing finish condition is not satisfied, a negative determination is made, and the imaging control processing returns to step S32. Here, for example, the “imaging control processing finish condition” refers to a condition that power is OFF.

The imaging apparatus100having the above configuration can reduce the moving amount for moving the imaging element from the elapse of the timing of reception of the instruction to start imaging until the start of the exposure of the imaging element, compared to the moving amount of the imaging element at the timing of reception of the instruction to start imaging. Thus, the uneven exposure value in the image obtained by imaging can be reduced, compared to a case of not reducing the moving amount of the imaging element.

In addition, by performing the stop control for stopping the imaging element20within the target range including the target position using the moving target position of the imaging element20at the predetermined first timing as the target position, the moving amount reduction control unit116can stop the imaging element20more quickly than in a case of performing the stop control using the initial position of the imaging element20as a target.

In addition, by deriving the timing of the resetting along the column direction of the imaging element20based on the target position of the imaging element20and performing the resetting along the column direction at the derived timing, the exposure control unit120can further reduce the uneven exposure value in the obtained image, compared to a case of not deriving the timing of the resetting along the column direction of the imaging element20based on the target position of the imaging element20.

In addition, the exposure control unit120derives the timing of the resetting in accordance with the traveling speed characteristics of the rear curtain65and performs the resetting at the derived timing of the resetting. Accordingly, the uneven exposure value in the obtained image can be further reduced, compared to a case of not resetting the pixel lines24in accordance with the characteristics of the change in traveling speed of the rear curtain65.

The moving amount reduction control unit116uses the low-pass filter70. By using the low-pass filter70, occurrence of the aliasing accompanied by resampling, that is, the folding noise, in a case where the calculation periods of the moving target position calculation for the imaging element20and the feedback control are different can be suppressed.

In addition, the exposure control unit120derives the moving amount from the target position of the imaging element20and starts the reset control in a case where the moving amount of the imaging element20is decreased to or below the predetermined value. Accordingly, the exposure can be started earlier than in a case of starting the reset control after the elapse of the predetermined time period from the moving amount reduction control.

Second Embodiment

Next, a second embodiment will be described with reference to the drawings. In the first embodiment, the gain for processing the angular velocity from the shake sensor30is set to zero in order to fix the specific timing position as the target position for stopping the imaging element20. Accordingly, the input value for calculating the integral of the angular velocity becomes zero, and the output value of calculation of the integral of the angular velocity becomes constant. The target position is fixed. In addition, the moving amount reduction control unit116uses the low-pass filter70for suppressing the folding noise. Consequently, information indicating the moving target position is smoothed. In such a case, in a case where the output value of calculation of the integral of the angular velocity is constant, as illustrated inFIG.12Aas an example, an output of the low-pass filter70changes due to a transient response as illustrated by dotted line in the drawing at a timing at which an input into the low-pass filter70becomes a constant value as illustrated by solid line in the drawing. In a case where the output of the low-pass filter70changes, it takes time for the moving amount of the imaging element20to decrease.

Therefore, in the second embodiment, in a case of performing the stop control on the imaging element20, for example, at a timing of the start of the stop control, the moving amount reduction control unit116performs a control for fixing an output value obtained by smoothing the information indicating the target position of the imaging element20in the stop control. For example, as illustrated inFIG.12Bas an example, the moving amount reduction control unit116fixes an output value of the low-pass filter70. Specifically, the moving amount reduction control unit116holds the output value from the low-pass filter70at the timing of the start of the moving amount reduction control and uses the held value as an input value of the feedback control as the target position of the imaging element20. Accordingly, the output value obtained by smoothing the information indicating the target position of the imaging element20can be fixed. By using this method, the moving amount reduction control on the imaging element20can be prevented from being affected by a change in output of the low-pass filter70.

Third Embodiment

Next, a third embodiment will be described with reference to the drawings. The imaging element20is driven in the direction H, the direction V, and the rotation direction R for shake correction. Thus, in a case where the shake correction control is paused, and the moving amount reduction control is started, as illustrated inFIG.13Aas an example, the roll rotation amount about an optical axis of the imaging element20illustrated by dotted line may be different from the roll rotation amount at the initial position illustrated by solid line.

In a case where the exposure is performed in a state where the roll rotation amount about the optical axis of the imaging element20is different from the roll rotation amount at the initial position, a direction of the resetting of the imaging element20does not match the traveling direction of the rear curtain65. Thus, a light amount incident on the light-receiving surface21of the imaging element20is different from a designed light amount, and the exposure value is not adjusted as designed. Therefore, in the third embodiment, the moving amount reduction control unit116performs a control for restoring the roll rotation amount of the imaging element20to the roll rotation amount at the initial position in the moving amount reduction control.

The moving amount reduction control processing according to the third embodiment will be described usingFIG.13Bas an example. Step S320to step S403are the same steps asFIG.11and thus, will not be described. Next, in step S404, the moving amount reduction control unit116performs the control for restoring the roll rotation amount of the imaging element20to the initial position on the VCMs52at a predetermined timing. Then, the moving amount reduction control processing transitions to step S405.

Here, for example, the “predetermined timing” refers to a timing at which the moving amount reduction control unit116acquires the current position information about the imaging element20. However, the predetermined timing is not limited thereto and may be the timing at which the moving amount reduction control unit116starts the moving amount reduction control, the timing at which the reception device14receives the instruction to start imaging from the user, or the like. Here, the “predetermined timing” is an example of a “predetermined second timing” according to the embodiments of the disclosed technology.

In step S405, the moving amount reduction control unit116performs the feedback control for stopping the imaging element20within the target range and then, transitions to step S406. Step S406is the same as the step described usingFIG.11.

As illustrated inFIG.13A, arrangement of the imaging element20before restoring the roll rotation amount to the initial position is arrangement illustrated by dotted line. In this case, the reset direction in a case of exposing the imaging element20is a direction illustrated by arrow P1. However, since the traveling direction of the rear curtain65is the direction of arrow S, the reset direction does not match the traveling direction of the rear curtain65. However, the reset direction in a case where the roll rotation amount is restored to the same roll rotation amount as the initial position as illustrated by solid line by rotating the imaging element20in a direction of arrow R1in the drawing is a direction of arrow P2illustrated by solid line. That is, the reset direction and the traveling direction of the rear curtain65can be matched, and the uneven exposure value can be corrected as designed.

Fourth Embodiment

Next, a fourth embodiment will be described with reference to the drawings. The uneven exposure value in the acquired image occurs due to a change in position of the imaging element20in the column direction from the initial position. Movement of the imaging element20in the row direction is not a cause of the uneven exposure value. Therefore, in the fourth embodiment, after the timing of reception of the instruction to start imaging with less than or equal to the predetermined exposure time period, the shake correction control unit112performs, on the VCMs52, a control for correcting the shake in the row direction by stopping movement of the imaging element20in the column direction at the initial position and moving the imaging element20in only the row direction.

The moving amount reduction control according to the fourth embodiment will be described usingFIG.14as an example. Step S320to step S403are the same steps asFIG.11and thus, will not be described. Next, in step S405, the moving amount reduction control unit116performs the feedback control for moving the imaging element20to the target position. Next, the moving amount reduction control transitions to step S407.

In step S407, the moving amount reduction control unit116determines whether or not horizontal shift driving is necessary. That is, a determination as to whether or not the shake in the direction H is detected is performed. More specifically, a determination as to whether or not a component in the direction H is detected from the output signal of the shake sensor30is performed.

In step S407, in a case where the horizontal shift driving is not necessary, a negative determination is made, and the moving amount reduction control processing transitions to step S411. In step S407, in a case where the horizontal shift driving is necessary, a positive determination is made, and the moving amount reduction control processing transitions to step S409.

In step S409, the moving amount reduction control unit116performs the horizontal shift driving on the imaging element20. Then, the moving amount reduction control processing transitions to step S411.

In step S411, the moving amount reduction control unit116determines whether or not the moving amount reduction control processing finish condition is satisfied. In step S411, in a case where the moving amount reduction control processing finish condition is satisfied, a positive determination is made, and the moving amount reduction control unit116finishes the moving amount reduction control processing. In step S411, in a case where the moving amount reduction control processing finish condition is not satisfied, a negative determination is made, and the moving amount reduction control processing transitions to step S320. Here, for example, the “moving amount reduction control processing finish condition” refers to a condition that exposure processing is started.

As described above, by moving the imaging element20in the row direction for the shake correction, the shake in the row direction can be corrected, compared to a case of not moving the imaging element20in the row direction.

Fifth Embodiment

Next, a fifth embodiment will be described with reference to the drawings. The user can set a special imaging mode such as a continuous shooting mode and a bracket imaging mode as the imaging mode for a still picture. For example, the continuous shooting mode is a mode in which images of a plurality of frames are automatically and continuously captured during a full push on a shutter button. The bracket imaging mode is a mode in which images of a plurality of frames are captured with a plurality of predetermined different exposure values. In the fifth embodiment, the moving amount reduction control unit116performs a control for stopping the imaging element20within the target range during such a special imaging mode, that is, while imaging for still images of a plurality of frames is performed in accordance with the instruction to start imaging issued once.

The moving amount reduction control processing according to the fifth embodiment will be described usingFIG.15as an example. Step S320to step S405are the same steps asFIG.11and thus, will not be described.

In step S420, the moving amount reduction control unit116determines whether or not the current imaging mode is the special imaging mode. In step S420, in a case where the current imaging mode is not the special imaging mode, a negative determination is made, and the moving amount reduction control processing transitions to step S320. In step S420, in a case where the current imaging mode is the special imaging mode, a positive determination is made, and the moving amount reduction control processing transitions to step S422.

In step S422, the moving amount reduction control unit116determines whether or not the exposure is started. In step S422, in a case where the exposure is not started, a negative determination is made, and the determination in step S422is performed again. In step S422, in a case where the exposure is started, a positive determination is made, and the moving amount reduction control processing transitions to step S424.

In step S424, the exposure control unit120determines whether or not the entire exposure is finished. In step S424, in a case where the entire exposure is not finished, a negative determination is made, and the determination in step S424is performed again. In step S424, in a case where the entire exposure is finished, a positive determination is made, and the moving amount reduction control processing transitions to step S426.

In step S426, the moving amount reduction control unit116determines whether or not the special imaging mode is finished. In step S426, in a case where the special imaging mode is finished, a positive determination is made. The moving amount reduction control unit116finishes the moving amount reduction control processing and transitions to step S32illustrated inFIG.8. In step S426, in a case where the special imaging mode is not finished, a negative determination is made, and the moving amount reduction control processing returns to step S320. Here, for example, the “finish of the special imaging mode” refers to a case where the user unsets the special imaging mode.

In the imaging for the still images of the plurality of frames, in a case where the shake is corrected for each frame, and the imaging element is stopped at each correction and resumed, it takes time for the moving amount of the imaging element20to decrease to or below a predetermined moving amount. Meanwhile, by stopping the imaging element within the target range until the imaging of the plurality of frames is finished, a time interval of the imaging of the plurality of frames can be decreased.

Sixth Embodiment

As described in each embodiment, in a case where the exposure time period is less than or equal to the predetermined time period, the uneven exposure value in the obtained image can be suppressed by stopping the imaging element20. However, even in a case where such a control is performed, the uneven exposure value may remain in the image. In order to deal with such a case, the image processing unit28may further perform the shading correction in the column direction on the image obtained by imaging.

Specifically, as illustrated inFIG.16, the image processing unit28extracts a still image close to the time of imaging from the live preview image and acquires profile (1) of brightness in the column direction. Similarly, the image processing unit28acquires profile (2) of the brightness, in the column direction, of the image obtained using the above imaging method. Next, the image processing unit28acquires a correction parameter obtained by dividing profile (1) by profile (2). Next, the image processing unit28acquires an image in which the brightness is corrected by multiplying the image obtained using the above imaging method by the correction parameter.

By performing the shading correction as described above, even in a case where the uneven exposure value occurs in the image obtained using a method of adjusting the timing of the resetting of the front curtain, the uneven exposure value can be suppressed, compared to a case where the shading correction is not performed.

While the imaging apparatus according to each embodiment is the digital camera, the disclosed technology is not limited thereto and can be applied to, for example, an imaging apparatus such as a digital video camera, or an imaging module mounted in an electronic endoscope, a mobile phone with a camera, and the like.

Each processing of the imaging control processing, the shake correction control processing, the moving amount reduction control processing, and the exposure control processing according to the embodiments of the disclosed technology is merely an example. Accordingly, unnecessary steps may be deleted, new steps may be added, or a processing order may be rearranged without departing from a gist of the disclosed technology.

In the above description, while an example of a form of executing various types of processing according to the embodiments of the disclosed technology by the CPU12is illustrated, the disclosed technology is not limited thereto. Various programs according to the embodiments of the disclosed technology may be executed by a CPU other than the CPU12.

Here, the “various programs according to the embodiments of the disclosed technology” refer to the imaging control program and the like. These programs will be referred to as a “program PG”. For example, as illustrated inFIG.17, the program PG may be stored in any portable storage medium700such as an SSD, a USB memory, or a DVD-ROM. The storage medium700is a non-temporary storage medium. In this case, the program PG of the storage medium700is installed on the imaging apparatus100, and the installed program PG is executed by the CPU12.

Alternatively, the program PG may be stored in a storage unit of another computer, a server apparatus, or the like connected to the imaging apparatus100through a communication network (not illustrated), and the program PG may be downloaded in accordance with a request from the imaging apparatus100. In this case, the downloaded program PG is executed by the CPU12of the imaging apparatus100.

In the above embodiments, for example, various processors illustrated below can be used as a hardware resource for executing various types of processing according to the embodiments of the disclosed technology. Example of the processors includes a CPU that is a general-purpose processor functioning as the hardware resource for executing the various types of processing according to the embodiments of the disclosed technology by executing software, that is, the program, as described above. In addition, example of the processors includes a dedicated electric circuit such as an FPGA, a PLD, or an ASIC that is a processor having a circuit configuration dedicatedly designed to execute a specific type of processing.

The hardware resource for executing the various types of processing according to the embodiments of the disclosed technology may be configured with one of those various processors or may be configured with a combination of two or more processors of the same type or different types (for example, a combination of a plurality of FPGAs or a combination of a CPU and an FPGA). In addition, the hardware resource for executing various types of processing according to the embodiments of the disclosed technology may be one processor.

Example of the configuration with one processor includes, first, as represented by a computer such as a client and a server, a form in which one processor is configured with a combination of one or more CPUs and software, and in which this processor functions as the hardware resource for executing the various types of processing according to the embodiments of the disclosed technology. Second, as represented by an SoC or the like, a form of using a processor that implements, by one IC chip, a function of the entire system including a plurality of hardware resources for executing the various types of processing according to the embodiments of the disclosed technology is included. In such a manner, the various types of processing according to the embodiments of the disclosed technology are implemented using one or more of the various processors as the hardware resource.

Furthermore, as a hardware structure of those various processors, more specifically, an electric circuit in which circuit elements such as semiconductor elements are combined can be used.

In the present specification, “A and/or B” has the same meaning as “at least one of A or B”. This means that “A and/or B” may be only A, only B, or a combination of A and B. In addition, in the present specification, the same approach as “A and/or B” is applied to a case where three or more matters are represented by connecting the matters with “and/or”.

All documents, patent applications, and technical standards disclosed in the present specification are incorporated in the present specification by reference to the same extent as in a case where each of the documents, patent applications, technical standards are specifically and individually indicated to be incorporated by reference.