Patent Description:
An electronic image-stabilization method (EIS) that electronically corrects image blur and an optical image-stabilization method that optically corrects image blur are conventionally known. An optical image-stabilization method includes a lens shift type image stabilization method (OIS) that moves a correction lens constituting part of an imaging optical system in a direction that intersects an optical axis, and an image-sensor shift type image stabilization system (IIS) that moves an image sensor in a direction that intersects the optical axis.

<CIT> discloses a method of starting the IIS using the image sensor in a case where a correction amount of the correction lens in the OIS reaches a limit of the movable range. <CIT> discloses an image pickup apparatus that performs image stabilization (IS) control by reducing a proportion of the OIS in a correction ratio and increasing a proportion of the IIS in the correction ratio, as the correction amount of the correction lens in the OIS increases.

The method disclosed in <CIT> discontinuously changes the correction ratio between the OIS and the IIS, causes overshoot in which the correction lens or the image sensor is moved beyond the command value, or an IS member to delay following the command value, and deteriorates the IS performance. At that time, shake and noise are generated, the IS quality is deteriorated, and the noise is recorded in a captured moving image. The image pickup apparatus disclosed in <CIT> cannot make high-performance IS because when the correction lens contacts the movable end in the OIS, a proportion of the IIS using the image sensor in the correction ratio is not <NUM>%. <CIT> discloses a camera and lens apparatus that performs cooperative OIS and IIS image shake correction wherein a ratio of OIS and IIS correction amounts is determined based on information about mechanical movable amount of the image sensor performing the IIS as well as information about the size of readout area in said image sensor. <CIT> discloses an interchangeable lens apparatus, a camera and a control method to set a correction ratio between OIS and IIS stabilization based on information a correctable angle range and focal length of the interchangeable lens that performs the OIS when attached to the camera, the correctable angle is converted to a value to determine the IIS correctable amount. Further examples of prior art disclosing calculating a ratio between a first image stabilization correction means and a second image stabilization correction means may be found in <CIT> and in <CIT>.

The disclosure provides a control apparatus, an image pickup apparatus, a lens apparatus, a control method, and a program, each of which performs high-quality and high-performance image stabilization using a plurality of image stabilization units.

The present invention in its first aspect provides a control apparatus as specified in claims <NUM> to <NUM>.

The present invention in its second aspect provides a image pickup apparatus as specified in claim <NUM>.

The present invention in its third aspect provides a lens apparatus as specified in claim <NUM>.

The present invention in its fourth aspect provides a control method as specified in claim <NUM>.

The present invention in its fifth aspect provides a program as specified in claim <NUM>.

Further features of the disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Referring now to the accompanying drawings, a detailed description will be given of embodiments according to the disclosure.

Referring now to <FIG>, a description will be given of an imaging system <NUM> according to a first embodiment of the disclosure. <FIG> is a block diagram of an imaging system <NUM>. As illustrated in <FIG>, the imaging system <NUM> includes a camera body (image pickup apparatus) <NUM> and an interchangeable lens (lens apparatus) <NUM>. The camera body <NUM> and the interchangeable lens <NUM> are attachable to and detachable from each other and connected to communicate with each other. However, this embodiment is not limited to this example, and is applicable to an image pickup apparatus in which a camera body and a lens apparatus are integrated with each other.

The camera body <NUM> includes a camera MPU <NUM>, an operation unit <NUM>, an image sensor <NUM>, a camera-side contact terminal <NUM>, a gyro sensor <NUM>, an image sensor actuator <NUM>, a position sensor <NUM>, and a rear display (unit) <NUM>. The camera MPU (control apparatus) <NUM> includes a computer that controls overall control of the camera body <NUM> and the interchangeable lens <NUM>, and controls various operations such as auto-exposure (AE), autofocus (AF), and imaging according to an input from an operation unit <NUM>, which will be described below. The MPU <NUM> includes at least one processor, and a memory coupled to the at least one processor. The memory has instructions that, when executed by the processor, perform various operations. The camera MPU <NUM> communicates various commands and information with a lens MPU (control apparatus) <NUM> as a computer through the camera-side contact terminal <NUM> and a lens-side contact terminal <NUM> provided on the interchangeable lens <NUM>. The camera-side contact terminal <NUM> and the lens-side contact terminal <NUM> also include power terminals for supplying power from the camera body <NUM> to the interchangeable lens <NUM>.

The operation unit <NUM> includes a mode dial for setting various imaging modes, a release button for instructing a start of an imaging preparation operation and an imaging operation, and the like. A half-press operation of the release button turns on a first switch SW1, and a full-press operation turns on a second switch SW2. When the first switch SW1 is turned on, AE and AF are performed as imaging preparation operations, and when the second switch SW2 is turned on, a start of an imaging (exposure) operation is instructed, and the imaging operation is started a predetermined time after this instruction. Turning off and on of the first switch SW1 and the second switch SW2 are notified from the camera MPU <NUM> to the lens MPU <NUM> through communication.

The image sensor <NUM> includes a photoelectric conversion element such as a CCD sensor or a CMOS sensor, and photoelectrically converts an object image (optical image) formed by the imaging optical system of the interchangeable lens <NUM> to generate an imaging signal (image data). The camera MPU <NUM> generates a still image and a moving image (video signal) using the imaging signal from the image sensor <NUM>.

A gyro sensor (camera-side gyro sensor) <NUM> is a shake sensor that detects angular shake (camera shake) of the camera body <NUM> due to manual shake or the like and outputs a camera shake detection signal as an angular velocity signal. The camera MPU <NUM> drives the image sensor actuator <NUM> based on the camera shake detection signal and a proportion of IIS in a correction ratio received from the interchangeable lens <NUM>, which will be described below, to move the image sensor <NUM> in a direction orthogonal to the optical axis of the imaging optical system. This configuration reduces (corrects) image blur caused by the camera shake. At this time, the camera MPU <NUM> feedback-controls the image sensor actuator <NUM> so that a position of the image sensor <NUM> detected by the position sensor (image sensor position sensor) <NUM> (a moving amount from the position on the optical axis as a moving center) approaches a target position. Thereby, IIS is performed by moving the image sensor <NUM>. In this embodiment, the image sensor <NUM> corresponds to a second image stabilization unit (second IS unit). The IIS is performed for camera shake in the vertical direction (pitch direction) and camera shake in the horizontal direction (yaw direction).

The rear display (display unit) <NUM> displays a moving image corresponding to the video signal generated by the camera MPU <NUM> based on the imaging signal from the image sensor <NUM>. Before imaging, the user can observe the displayed image as a viewfinder image (live-view image). After imaging, a still image or moving image for recording generated by imaging can be displayed on the rear display <NUM>. In this embodiment, "imaging" means imaging for recording.

The interchangeable lens <NUM> includes the lens MPU <NUM>, a gyro sensor <NUM>, the lens-side contact terminal <NUM>, a correction lens <NUM> that constitutes part of the imaging optical system, and a position sensor <NUM>. The gyro sensor (lens-side gyro sensor) <NUM> is a shake sensor that detects angular shake (lens shake) of the interchangeable lens <NUM> and outputs a lens-shake detection signal as an angular velocity signal.

The lens MPU <NUM> drives the lens actuator <NUM> based on the lens-shake detection signal and a proportion of OIS in the correction ratio, which will be described below, to move the correction lens (optical element) <NUM>, which constitutes the part of the imaging optical system, in a direction orthogonal to the optical axis of the imaging optical system. This configuration reduces (corrects) image blur caused by lens shake. At this time, the lens MPU <NUM> performs feedback control over the lens actuator <NUM> so that a position of the correction lens <NUM> detected by the position sensor (lens position sensor) <NUM> (a moving amount from the position on the optical axis as the moving center) approaches a target position. Thereby, OIS is performed by moving the correction lens <NUM>. In this embodiment, the correction lens <NUM> corresponds to a first image stabilization unit (first IS unit).

OIS is also performed for lens shake in the pitch direction and lens shake in the yaw direction, similar to the IIS. The correction lens <NUM> may be moved in a direction orthogonal to the optical axis (a direction intersecting the optical axis), may be translated in a plane perpendicular to the optical axis, or may be moved about a point on the optical axis as a center.

In this embodiment, the camera MPU <NUM> includes a calculating unit 102a and a determining unit 102b, and performs image stabilization using the correction lens (first IS unit) <NUM> and an image sensor (second IS unit) <NUM>. The calculating unit 102a calculates the shortest distance from the current position of the correction lens <NUM> to the position of the movable end. The determining unit 102b determines the correction ratio (proportion of OIS in the correction ratio and proportion of IIS in the correction ratio) between the correction lens <NUM> and the image sensor <NUM> so that a proportion of the image sensor <NUM> in the correction ratio increases as the shortest distance becomes shorter.

Referring now to <FIG>, a description will be given of temporal changes in correction command values for OIS and IIS. <FIG> explains temporal changes in correction command values for OIS and IIS according to a comparative example, and <FIG> explains the temporal changes in correction command values for OIS and IIS according to this embodiment.

<FIG> illustrates correction command values of OIS and IIS in a case where OIS using the correction lens <NUM> is preferentially performed and IIS is used to correct only blur (correction residue) that cannot be corrected when the correction lens <NUM> reaches the movable end. This control method provides control such that the correction command values of the OIS and the IIS are suddenly stopped and driven at the timing of starting and stopping driving the IIS. In the case where the correction command value is suddenly stopped, the position of an image stabilization member such as the correction lens <NUM> cannot actually stop, and an overshoot beyond the correction command value occurs. In this case, the correction member will perform an operation that is irrelevant to shake, and the image stabilization performance will be deteriorated. In a case where the image stabilization control is suddenly started, the image stabilization member cannot follow the correction command value at first and the image stabilization member is moved according to the correction command value after a predetermined time elapses. This case also leads to deterioration of the image stabilization performance. If OIS and IIS are to be suddenly stopped or driven, shake and noise are generated and impair the usability of the user and the noise is recorded in the captured video. In order to solve this problem, the following countermeasure is taken in this embodiment.

<FIG> illustrates correction command values for OIS and IIS according to this embodiment. Until the shortest distance to the movable end of the correction lens <NUM> in the OIS becomes equal to or less than a threshold, image stabilization (image stabilization control) is performed only by the OIS. On the other hand, when the shortest distance to the movable end of the correction lens <NUM> is equal to or less than the threshold, the IIS by the image sensor <NUM> is started. As the shortest distance to the movable end of the correction lens <NUM> becomes smaller, the proportion of the OIS in the correction ratio is decreased and the proportion of the IIS in the correction ratio is increased. Therefore, the proportion of the OIS in the correction ratio is made low before the correction lens <NUM> contacts the movable end, and a changing amount in the correction command value when the correction lens <NUM> actually contacts the movable end becomes small. As a result, overshoot is less likely to occur. In a case where the IIS is started, the correction command value of the IIS gradually increases from a small value, so a follow-up delay in the IIS is unlikely to occur. Since the correction lens <NUM> in the OIS and the image sensor <NUM> in the IIS are not suddenly stopped or driven, noise or shake can be prevented.

Referring now to <FIG>, a description will be given of the shortest distance to the movable end of the correction lens <NUM> in OIS. <FIG> explains the shortest distance to the movable end of the correction lens <NUM>. Reference numeral <NUM> denotes the movable range of the correction lens <NUM> in the OIS. Since the movable range <NUM> may change depending on a zoom state and a focus state of the imaging optical system in the interchangeable lens <NUM>, it is necessary to take this fact into account. Depending on the mechanical configuration, the movable range <NUM> may not be circular. Reference numeral <NUM> denotes the position of the correction lens <NUM> in the OIS. During the OIS, the correction lens <NUM> can be driven (moved) only within the movable range <NUM>. In a case where the correction lens <NUM> exists at the position <NUM>, a length <NUM> is the shortest distance to the movable end of the correction lens <NUM> (the shortest distance between the end of the movable range <NUM> of the correction lens <NUM> and the end of the position <NUM> of the correction lens <NUM>).

Referring now to <FIG>, a description will be given of a relationship between the shortest distance to the movable end of the correction lens <NUM> in the OIS (the shortest distance to the movable end of the OIS) and the correction ratio between the OIS and the IIS. <FIG> illustrates a relationship between the shortest distance to the movable end of the OIS and the correction ratio. In <FIG>, an abscissa axis indicates the shortest distance to the movable end of the OIS, and an ordinate axis indicates the correction ratio.

In a case where the shortest distance to the movable end of the correction lens <NUM> in the OIS is larger than a threshold Dt1, the proportion of the OIS in the correction ratio is set to <NUM>%, and image stabilization control is performed only with the OIS. On the other hand, in a case where the shortest distance to the movable end of the correction lens <NUM> in the OIS becomes smaller than the threshold Dt1, driving of the image sensor <NUM> in the IIS is started. As the shortest distance to the movable end of the correction lens <NUM> in the OIS becomes smaller, the proportion of the IIS in the correction ratio is increased and the proportion of the OIS in the correction ratio is decreased. In a case where the shortest distance to the movable end of the correction lens <NUM> in the OIS becomes <NUM>, that is, in a case where the correction lens <NUM> contacts the movable end (the correction lens <NUM> reaches the movable end), the proportion of the IIS in the correction ratio is set to <NUM>%, and image stabilization control is performed only with the IIS.

The threshold Dt1 for starting the IIS (starting driving the image sensor <NUM>) may be changed according to the control characteristics of the OIS and the IIS (such as an overshoot characteristic and a follow-up characteristic). For example, in a case where the control characteristics of the OIS and the IIS are such that overflow is less likely to occur and the follow-up characteristic is good, the threshold Dt1 may be made smaller and only the OIS may be used for image stabilization (image stabilization control) until the OIS becomes closer to the movable end. Although the proportion of the OIS in correction ratio and the proportion of the IIS in the correction ratio are linearly changed in <FIG>, the disclosure is not limited to this example and they may be changed according to a nonlinear function, or stepwise, or the like. This is similarly applied to other embodiments.

Referring now to <FIG>, a description will be given of image stabilization processing (control method) in the imaging system <NUM> according to this embodiment. <FIG> is a flowchart of the image stabilization processing. The left side of <FIG> illustrates processing to be performed by the camera body <NUM> (camera MPU <NUM>), and the right side illustrates processing to be performed by the interchangeable lens <NUM> (lens MPU <NUM>). The camera MPU <NUM> and lens MPU <NUM> execute the image stabilization processing according to a computer program. In a case where the camera body <NUM> is powered on, power is supplied to the interchangeable lens <NUM>, and communication between the camera MPU <NUM> and the lens MPU <NUM> is started, this processing is started in step S501.

First, in step S501, the lens MPU <NUM> notifies the camera body <NUM> of movable range information on the correction lens <NUM> in OIS. The movable range information includes information on a maximum correctable amount of the movable range of the correction lens <NUM> that varies according to the focus state and the zoom state of the interchangeable lens <NUM> and the like.

Next, in step S502, the camera MPU <NUM> calculates the shortest distance to the movable end of the correction lens <NUM> as described with reference to <FIG>, based on the movable range information on the correction lens <NUM> in the OIS and the current position of the correction lens <NUM>. The current position of the correction lens <NUM> can be received as position information actually detected by the position sensor <NUM> from the interchangeable lens <NUM>. Alternatively, the current position may be set to a correction command value for the correction lens <NUM> transmitted to the interchangeable lens <NUM> immediately before in step S505.

Next, in step S503, the camera MPU <NUM> determines the correction ratio between the OIS and the IIS based on the shortest distance to the movable end of the correction lens <NUM>, as described with reference to <FIG>. Next, in step S504, the camera MPU <NUM> calculates a command value (correction command value) for each of the OIS and the IIS based on the correction ratio between the OIS and the IIS determined in step S503. By multiplying all the correction command values by each proportion in the correction ratio, the correction command values of the OIS and the IIS can be acquired. Next, in step S505, the camera MPU <NUM> notifies the interchangeable lens <NUM> of the correction command value (OIS command value) for the OIS calculated in step S504.

Next, in step S506, the camera MPU <NUM> performs IIS (image stabilization control (IIS control) using the image sensor <NUM>) in accordance with the correction command value (IIS command value) for the IIS calculated in step S504. In step S507, the lens MPU <NUM> performs OIS (image stabilization control (OIS control) using the correction lens <NUM>) in accordance with the correction command value (OIS command value) of the OIS notified from the camera MPU <NUM> in step S505.

Cooperative image stabilization can be performed with the OIS and IIS by repeating the above steps at a high-speed period. This embodiment preferentially uses the OIS for image stabilization control, and uses the IIS to correct blur (correction residue) that cannot be completely corrected by the OIS alone. This configuration can provide image stabilization control that does not cause deterioration of image stabilization performance, noise, or shake.

In this embodiment, the second image stabilization unit includes the image sensor <NUM>, but is not limited to this example, and may include an electronic image stabilization unit of an electronic image stabilization method (EIS).

A description will now be given of a second embodiment according to the disclosure. In the first embodiment, in a case where image stabilization performance and the power consumption performance of OIS are higher than those of IIS, the OIS is preferentially used for image stabilization control, and the IIS is used to correct blur that cannot be corrected by the OIS. On the other hand, in the disclosure, IIS has image stabilization performance and power consumption performance higher than those of OIS, the IIS is preferentially used for image stabilization, and the OIS is used to correct blur that cannot be corrected by the IIS. That is, in this embodiment, the image sensor <NUM> corresponds to the first image stabilization unit, and the correction lens <NUM> corresponds to the second image stabilization unit. A basic configuration of the imaging system <NUM> (camera body <NUM> and interchangeable lens <NUM>) according to this embodiment is similar to that of the first embodiment described with reference to <FIG>, corresponding elements will be designated by the same reference numerals, and a description thereof will be omitted.

Referring now to <FIG>, a description will be given of temporal changes in correction command values for OIS and IIS according to this embodiment. <FIG> explains temporal changes in correction command values for OIS and IIS according to this embodiment.

Until the shortest distance to the movable end of the image sensor <NUM> in the IIS becomes equal to or less than a threshold, image stabilization (image stabilization control) is performed only by the IIS. On the other hand, in a case where the shortest distance to the movable end of the image sensor <NUM> is equal to or less than the threshold, the OIS using the correction lens <NUM> is started. As the shortest distance to the movable end of the image sensor <NUM> becomes smaller, the proportion of the IIS in the correction ratio is decreased and the proportion of the OIS in the correction ratio is increased. Therefore, the proportion of the IIS in the correction ratio is made smaller before the image sensor <NUM> contacts the movable end, and a changing amount in the correction command value becomes small when the image sensor <NUM> actually contacts the movable end. As a result, overshoot is less likely to occur. In addition, since the correction command value of the OIS gradually increases from a small value when the OIS is started, a follow-up delay in the OIS is less likely to occur. Since the image sensor <NUM> in the IIS and the correction lens <NUM> in the OIS are not suddenly stopped or driven, noise and shake can be prevented.

Referring now to <FIG>, a description will be given of the shortest distance to the movable end of the image sensor <NUM> in IIS. <FIG> explains the shortest distance to the movable end of the image sensor <NUM>. Reference numeral <NUM> denotes an image circle. The image circle <NUM> changes according to the focus state and the zoom state of the imaging optical system in the interchangeable lens <NUM>, the center position shifts depending on the interchangeable lens <NUM>, and thus it is necessary to receive information on these changes from the interchangeable lens <NUM> by communication. Reference numeral <NUM> denotes an effective diameter to be actually recorded as a captured image in the image sensor <NUM>. The size of the effective area <NUM> changes depending on a moving image capturing mode or the like.

In the camera body <NUM>, if the effective area <NUM> of the image sensor <NUM> protrudes outside the image circle <NUM>, light shielding will occur in a captured image. Therefore, in IIS, it is necessary to drive the image sensor <NUM> so that the effective area <NUM> of the image sensor <NUM> falls within the range of the image circle <NUM>. Reference numeral <NUM> denotes a range in which an effective area <NUM> of the image sensor <NUM> can exist in a case where the image sensor <NUM> is moved within a range in which the image sensor <NUM> can be driven mechanically and electrically in the IIS. As described above, the movable range of the image sensor <NUM> in the IIS is a range in which the effective area <NUM> of the image sensor <NUM> is within the range of the image circle <NUM> and inside the range <NUM>. In a case where the current position of the image sensor <NUM> is a position of the effective area <NUM> illustrated in <FIG>, a length <NUM> becomes the shortest distance to the movable end of the image sensor <NUM> in the IIS (the shortest distance between the edge of the image circle <NUM> and the edge of the effective area <NUM> as the current position).

Referring now to <FIG>, a description will be given of a relationship between the shortest distance to the movable end of the image sensor <NUM> in the IIS (the shortest distance to the movable end of IIS) and the correction ratio between the OIS and the IIS. <FIG> illustrates a relationship between the shortest distance to the movable end of the IIS and the correction ratio. In <FIG>, an abscissa axis indicates the shortest distance to the movable end of the IIS, and an ordinate axis indicates the correction ratio.

In a case where the shortest distance to the movable end of the image sensor <NUM> in the IIS is larger than a threshold Dt2, the proportion of the IIS in the correction ratio is set to <NUM>%, and image stabilization control is performed only by the IIS. On the other hand, in a case where the shortest distance to the movable end of the image sensor <NUM> in the IIS is smaller than the threshold Dt2, driving of the correction lens <NUM> in the OIS is started. As the shortest distance to the movable end of the image sensor <NUM> in the IIS is smaller, the proportion of the OIS in the correction ratio is increased and the proportion of the IIS in the correction ratio is decreased. In a case where the shortest distance to the movable end of the image sensor <NUM> in the IIS becomes <NUM>, that is, in a case where the image sensor <NUM> reaches the movable end, the proportion of the OIS in the correction ratio is set to <NUM>%, and only the OIS is used for image stabilization control. Threshold Dt2 for starting the OIS (starting driving the correction lens <NUM>) may be changed according to the control characteristics (such as an overshoot characteristic and a follow-up characteristic) of the OIS and the IIS.

Referring now to <FIG>, a description will be given of image stabilization processing (control method) in the imaging system <NUM> according to this embodiment. <FIG> is a flowchart of the image stabilization processing. The left side of <FIG> illustrates processing to be performed by the camera body <NUM> (camera MPU <NUM>), and the right side illustrates processing to be performed by the interchangeable lens <NUM> (lens MPU <NUM>). The camera MPU <NUM> and lens MPU <NUM> execute the image stabilization processing according to a computer program. In a case where the camera body <NUM> is powered on, power is supplied to the interchangeable lens <NUM>, and communication between the camera MPU <NUM> and the lens MPU <NUM> is started, this processing is started in step S901.

First, in step S901, the lens MPU <NUM> notifies the camera body <NUM> of image circle information on the interchangeable lens <NUM>. The image circle information includes information on the radius of the image circle and the center position of the image circle.

Next, in step S902, the camera MPU <NUM> calculates the shortest distance to the movable end of the image sensor <NUM> in the IIS. The shortest distance is calculated based on the image circle information received from the lens MPU <NUM>, the information on the effective area of the image sensor <NUM>, and a stroke amount that can be mechanically and electrically driven in the IIS, as explained with reference to <FIG>.

Next, in step S903, the camera MPU <NUM> determines the correction ratio between the OIS and the IIS, as described with reference to <FIG>, based on the shortest distance to the movable end of the image sensor <NUM> calculated in the step S902. Next, in step S904, the camera MPU <NUM> calculates a command value (correction command value) for each of the OIS and the IIS based on the correction ratio between the OIS and the IIS determined in step S903. Next, in step S905, the camera MPU <NUM> notifies the interchangeable lens <NUM> of the correction command value (OIS command value) for the OIS calculated in step S904.

Next, in step S906, the camera MPU <NUM> performs the IIS (image stabilization control (IIS control) using the image sensor <NUM>) in accordance with the correction command value (IIS command value) for the IIS calculated in step S904. In step S907, the lens MPU <NUM> performs the OIS (image stabilization control (OIS control) using the correction lens <NUM>) in accordance with the correction command value (OIS command value) for the OIS notified from the camera MPU <NUM> in step S905.

Cooperative image stabilization can be performed with the OIS and IIS by repeating the above steps at a high-speed period. This embodiment preferentially uses the IIS for image stabilization control and uses the OIS to correct blur (correction residue) that cannot be completely corrected by the IIS alone. This configuration can provide image stabilization control that does not cause deterioration of image stabilization performance, noise, or shake.

In this embodiment, the second image stabilization unit includes the correction lens <NUM>, but it is not limited to this example, and may include the electronic image stabilization unit of the electronic image stabilization method (EIS).

A description will now be given of a third embodiment according to the disclosure. The first and second embodiments discuss the configuration for performing image stabilization control using OIS and IIS. On the other hand, this embodiment will discuss a configuration for performing image stabilization control using, an electronic image stabilization method (EIS) in addition to the OIS and the IIS. That is, in this embodiment, the correction lens (first image stabilization unit) <NUM>, the image sensor (second image stabilization unit) <NUM>, and the electronic image stabilization unit (third image stabilization unit) are used for image stabilization. This embodiment assumes that image stabilization performance is higher in order of OIS, IIS, and EIS. That is, a configuration will be described in which image stabilization control is performed using the OIS as the first priority, the IIS as the second priority, and the EIS for the blur residue. A basic configuration of the imaging system <NUM> (camera body <NUM> and interchangeable lens <NUM>) according to this embodiment is similar to that of the first embodiment described with reference to <FIG>, corresponding elements will be designated by the same reference numerals, and a description thereof will be omitted.

Referring now to <FIG>, a description will be given of temporal changes in correction command values for OIS, IIS, and EIS in this embodiment. <FIG> explains temporal changes in the correction command values for the OIS, IIS, and the EIS in this embodiment. Until the shortest distance to the movable end of the correction lens <NUM> in the OIS becomes equal to or less than a threshold, image stabilization control is made only with the OIS. In a case where the shortest distance to the movable end of the correction lens <NUM> in the OIS becomes equal to or less than the threshold, the IIS (driving of the image sensor <NUM>) is started. As the shortest distance (second shortest distance) to the movable end of the correction lens <NUM> in the OIS becomes smaller, the proportion of the OIS in the correction ratio is decreased and the proportion of the IIS in the correction ratio is increased.

The EIS is not performed until the shortest distance to the movable end of the image sensor <NUM> in the IIS becomes equal to or less than a threshold. In a case where the shortest distance to the movable end of the image sensor <NUM> in IIS is equal to or less than the threshold, the EIS is started. As the shortest distance to the movable end of the image sensor <NUM> in the IIS becomes smaller, the proportion of the IIS in the correction ratio is decreased and the proportion of the EIS in the correction ratio is increased.

Referring now to <FIG>, a description will be given of a relationship among the shortest distance from the correction lens <NUM> to the movable end in the OIS (shortest distance to movable end of OIS), the shortest distance from the image sensor <NUM> to the movable end in the IIS (to movable end of IIS), and the correction ratio.

<FIG> illustrates a relationship between the shortest distance to the movable end of the OIS and the correction ratio. In <FIG>, an abscissa axis indicates the shortest distance to the movable end of the OIS, and an ordinate axis indicates the correction ratio. In a case where the shortest distance to the movable end of the OIS is larger than a threshold Dt3, the proportion of the OIS in the correction ratio is set to <NUM>%, and image stabilization control is performed only with the OIS. In a case where the shortest distance to the movable end of the OIS becomes smaller than the threshold Dt3, the IIS and EIS are started. As the shortest distance to the movable end of the OIS becomes smaller, the proportion of the combination of the IIS and EIS in the correction ratio are increased, and the proportion of the OIS in the correction ratio is decreased. In a case where the OIS reaches the movable end, the proportion of the combination of the IIS and EIS in the correction ratio is set to <NUM>%, and image stabilization control is performed only with the IIS and EIS.

<FIG> illustrates a relationship between the shortest distance (second shortest distance) to the movable end of the IIS and the correction ratio. In <FIG>, an abscissa axis indicates the shortest distance to the movable end of IIS, and an ordinate axis indicates the correction ratio. In a case where the shortest distance to the movable end of the IIS is larger than a threshold Dt4, the proportion of the IIS in the correction ratio is set to <NUM>%, and image stabilization control is performed only with the IIS. On the other hand, in a case where the shortest distance to the movable end of the IIS becomes smaller than the threshold Dt4, the EIS is started. As the shortest distance to the movable end of the IIS becomes smaller, the proportion of the EIS in the correction ratio is increased and the proportion of the IIS in the correction ratio is decreased. In a case where the IIS reaches the movable end, the proportion of the EIS in the correction ratio is set to <NUM>%, and image stabilization control is performed only with the EIS.

Referring now to <FIG>, a description will be given of image stabilization processing (control method) in the imaging system <NUM> according to this embodiment. <FIG> is a flowchart of the image stabilization processing. The left side of <FIG> illustrates processing to be performed by the camera body <NUM> (camera MPU <NUM>), and the right side illustrates processing to be performed by the interchangeable lens <NUM> (lens MPU <NUM>). The camera MPU <NUM> and lens MPU <NUM> execute the image stabilization processing according to a computer program. In a case where the camera body <NUM> is powered on, power is supplied to the interchangeable lens <NUM>, and communication between the camera MPU <NUM> and the lens MPU <NUM> is started, this processing is started in step S1201.

First, in step S1201, the lens MPU <NUM> calculates the shortest distance from the current position of the correction lens to the movable end. At this time, since the movable end of the OIS changes according to the zoom state and focus state of the interchangeable lens <NUM>, it is necessary to take this fact into account. Next, in step S1202, the lens MPU <NUM> notifies the camera body <NUM> of the shortest distance to the movable end of the OIS calculated in step S1201 and image circle information.

Next, in step S1203, the camera MPU <NUM> calculates the shortest distance to the movable end of the IIS based on the image circle information received from the lens MPU <NUM>, the effective area of the image sensor <NUM>, and information on a movable range that can be mechanically and electrically driven. Next, in step S1204, the camera MPU <NUM> determines the correction ratio among the OIS, IIS, and EIS. The correction ratio is determined, as described with reference to <FIG>, based on the shortest distance to the movable end of the OIS received from the lens MPU <NUM> in step S1202 and the shortest distance to the movable end of the IIS calculated in step S1203.

Next, in step S1205, the camera MPU <NUM> calculates a correction command value for each of the OIS, IIS, and EIS based on their proportions in the correction ratio determined in step S1204. Next, in step S1206, the camera MPU <NUM> notifies the interchangeable lens <NUM> of the correction command value of the OIS.

Next, in step S1207, the camera MPU <NUM> performs image stabilization control using the EIS based on the correction command value (EIS command value) for the EIS calculated in step S1206. In step S1208, the camera MPU <NUM> performs image stabilization control using the IIS based on the correction command value (IIS command value) for the IIS calculated in step S1206. In step S1209, the lens MPU <NUM> performs image stabilization control using the OIS based on the correction command value (OIS command value) for the OIS calculated in step S1206.

Cooperative image stabilization can be performed with the OIS, IIS, and EIS by repeating the above steps at a high-speed period. This embodiment performs image stabilization control in the priority order the OIS and IIS, and image stabilization control is performed with the EIS for blur (correction residue) that cannot be completely corrected by the OIS and IIS. This configuration can provide image stabilization control that does not cause deterioration of image stabilization performance, noise, or shake.

In this embodiment, the calculating unit 102a calculates the second shortest distance from the current position of the image sensor (second image stabilization unit) to the position of the movable end. The determining unit 102b determines the correction ratio among the correcting lens (first image stabilization unit) <NUM>, the image sensor (second image stabilization unit), and the electronic image stabilization unit (third image stabilization unit). At this time, the determining unit 102b increases the proportion of the third image stabilization unit in the correction ratio as the second shortest distance becomes shorter. In this embodiment, the correction lens <NUM> corresponds to the first image stabilization unit, and the image sensor <NUM> corresponds to the second image stabilization unit, but the lens <NUM> may correspond to the second image stabilization unit.

Embodiment(s) of the disclosure 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 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.

As described above, in each embodiment, the determining unit 102b increases the proportion of the second image stabilization unit in the correction ratio as the shortest distance from the current position of the first image stabilization unit to the position of the movable end becomes shorter. In a case where the shortest distance is greater than a predetermined threshold (Dt1, Dt2, Dt3), the determining unit may perform image stabilization with the first image stabilization unit, and in a case where the shortest distance is less than the predetermined threshold, image stabilization may be performed by cooperatively controlling the first image stabilization unit and the second image stabilization unit. The determining unit may change the predetermined threshold based on at least one control characteristic (such as the overshoot characteristic and the follow-up characteristic) of the first image stabilization unit or the second image stabilization unit. The first image stabilization unit may have image stabilization performance (movable range, optical performance, image sensor performance, etc.) higher than that of the second image stabilization unit. The first image stabilization unit may consume power less than the second image stabilization unit.

Each embodiment can provide a control apparatus, an image pickup apparatus, a lens apparatus, a control method, and a storage medium (or program), each of which can perform (high-quality and high-performance) image stabilization while maintaining image stabilization performance without generating noise or shake using a plurality of image stabilization units.

For example, in each embodiment, the camera MPU <NUM> includes the calculating unit 102a and the determining unit 102b, but the lens MPU <NUM> or the like may perform at least part of at least one function of the calculating unit and the determining unit.

Claim 1:
A control apparatus configured to perform image stabilization using a first image stabilization unit (<NUM>) and a second image stabilization unit (<NUM>), the control apparatus comprising a determining unit (102b) configured to determine a correction ratio between the first image stabilization unit and the second image stabilization unit,
characterized in that the determining unit determines the correction ratio between the first image stabilization unit and the second image stabilization unit such that a proportion of the second image stabilization unit in the correction ratio increases as a shortest distance to a movable end of the first image stabilization unit decreases,
wherein the determining unit determines the correction ratio between the first image stabilization unit and the second image stabilization unit such that the proportion of the second image stabilization unit at a first timing in which a shortest distance to a movable end of the first image stabilization unit is a first distance is larger than the proportion of the second image stabilization unit at a second timing different from the first timing in which the shortest distance to the movable end of the first image stabilization unit is a second distance longer than the first distance.