JP2019152888A - Imaging device - Google Patents

Abstract

To provide a desirable interchangeable lens using a motion vector.SOLUTION: The interchangeable lens includes: a blurring correction lens for correcting blurring of an image; an angular velocity sensor for detecting an angular velocity; an operation unit for operating the reference value of an output signal of the angular velocity sensor; a reception unit for receiving motion vector information and version information from a camera; a correction unit for correcting the reference value, using the motion vector information, and performing control to drive the blurring correction lens, using the output signal of the angular velocity sensor and the reference value corrected by the correction unit.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an interchangeable lens.

  There has been proposed a technique for acquiring an image motion signal obtained by analyzing a captured image of a camera and correcting a reference value of an angular velocity sensor (gyro) based on the image motion signal (see Patent Document 1).

Japanese Patent No. 4419466

  The present invention receives a blur correction lens that corrects image blur, an angular velocity sensor that detects angular velocity, a calculation unit that calculates a reference value of an output signal of the angular velocity sensor, motion vector information, and version information from a camera. The shake correction lens using the receiving unit, the correction unit that corrects the reference value using the motion vector information, the output signal of the angular velocity sensor, and the reference value corrected by the correction unit. The present invention relates to an interchangeable lens including a control unit that controls driving.

It is sectional drawing which shows typically a camera provided with the blurring correction apparatus of 1st Embodiment. It is a block diagram of the blurring correction apparatus of 1st Embodiment. It is a figure explaining the calculation timing of the motion vector in cases other than the wide side. (A)-(c) is a figure explaining the information of the motion vector calculation method sent to a camera side transmission / reception part from a lens side transmission / reception part, when the focal distance of a lens barrel is wide. It is the flowchart which showed the flow of operation | movement of the blurring correction apparatus of 1st Embodiment. It is a figure explaining a reference value calculating part, (a) is a reference value calculating part, (b) is a figure showing LPF of a reference value calculating part. It is a flowchart which shows a reference value correction calculation. It is a relationship diagram of a reference value error and a motion vector, (a) is a reference value calculation result, (b) is a motion vector. It is the graph which showed the reference value after amendment when a reference value error ingredient has been correctly detected with a motion vector. It is the graph which showed the motion vector detected erroneously. This is a reference value calculation result when the reference value correction is performed using the motion vector information of the subject blur component. It is the graph which compared this embodiment and the comparison form. It is a block diagram of the blurring correction apparatus of 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings and the like.
FIG. 1 is a cross-sectional view schematically showing a camera system 1 including the shake correction apparatus of the first embodiment.
The camera system 1 includes a digital single-lens reflex camera 1A and a lens barrel 1B that is detachably attached to the camera 1A.

(camera)
The camera 1A includes a camera CPU (camera control unit) 2A, an imaging device 3, a recording medium 13, a camera storage unit 14, a signal processing circuit 15, an AF sensor 16, a release switch 17, a rear liquid crystal 18, a mirror 19, a shutter 20, and A camera side transmission / reception unit 21 for communication with the lens barrel 1B is provided.

The camera CPU 2A is a central processing unit that performs overall control of the camera system 1.
The imaging element 3 is an element that captures a subject image formed by the photographing lenses (4, 5, 6), exposes the subject light to convert it into an electrical image signal, and outputs it to the signal processing circuit 15. The image pickup device 3 is configured by an element such as a CCD or a CMOS.

The recording medium 13 is a medium for recording captured image data, and an SD card, a CF card, or the like is used.
The camera storage unit 14 is, for example, an EEPROM, stores adjustment value information such as a gain value of the angular velocity sensor 12, information unique to the lens barrel, and the like, and outputs the information to the camera CPU 2A or the lens CPU 2B.
The signal processing circuit 15 is a circuit that receives an output from the image sensor 3 and performs processing such as noise processing and A / D conversion.

The AF sensor 16 is a sensor for performing AF (automatic focus adjustment), and a CCD or the like can be used.
The release switch 17 is a member that performs a photographing operation of the camera system 1 and is a switch that operates a shutter driving timing and the like.

  The rear liquid crystal (display unit) 18 is a color liquid crystal display that is provided on the rear surface of the camera 1A and displays a subject image (reproduced image, live view image) photographed by the image sensor 3 and information (menu) related to operation. is there.

  The shutter 20 is disposed behind the mirror 19. Subject light is incident on the shutter 20 when the mirror 19 rotates upward and becomes ready for photographing. The shutter 20 travels through a shutter curtain in response to a shooting instruction from the release switch 17 or the like, and controls subject light incident on the image sensor 3.

  The camera-side transmitting / receiving unit 21 contacts a lens-side transmitting / receiving unit 22 described later when the lens barrel 1B is attached to the camera 1A. Thereby, transmission / reception between the camera 1A and the lens barrel 1B becomes possible. Information transmitted and received between the camera 1A and the lens barrel 1B will be described later.

(Lens barrel)
The lens barrel 1B includes a zoom lens group 4, a focus lens group 5, a shake correction lens group (optical element) 6, a zoom lens group drive mechanism 7, a focus lens group drive mechanism 8, and a shake correction lens group drive mechanism (optical element drive). Unit) 9, a diaphragm 10, a diaphragm driving mechanism 11, an angular velocity sensor 12, a lens CPU (control unit) 2B, and a lens side transmission / reception unit 22.

  The lens CPU 2B calculates the movement amount of the lens groups such as the zoom lens group 4, the focus lens group 5, and the blur correction lens group 6. The zoom lens group drive mechanism 7, the focus lens group drive mechanism 8, the blur correction lens group drive mechanism 9 and the aperture drive mechanism 11 are instructed to move the zoom lens group 4, the focus lens group 5, and the blur correction lens group 6. Move.

The zoom lens group 4 is a lens group that is driven by the zoom lens group drive mechanism 7 and moves along the optical axis direction to continuously change the magnification of the image.
The focus lens group 5 is a lens group that is driven by the focus lens group drive mechanism 8 and moves in the optical axis direction to focus.
The shake correction lens group 6 (optical element) is a lens group that is optically shake-corrected and driven on a plane perpendicular to the optical axis by a shake correction lens group drive mechanism 9 such as a VCM.

The diaphragm 10 is a mechanism that is driven by the diaphragm drive mechanism 11 and controls the amount of subject light passing through the photographing lenses (4, 5, 6).
The angular velocity sensor 12 is a sensor that detects an angular velocity of shake that occurs in the lens barrel 1B.
As described above, when the lens barrel 1B is attached to the camera 1A, the lens side transmission / reception unit 22 comes into contact with the camera side transmission / reception unit 21, and transmission / reception between the camera 1A and the lens barrel 1B becomes possible.

(Blur correction device)
FIG. 2 is a block diagram illustrating the shake correction apparatus 100 of the present embodiment.
The shake correction apparatus 100 includes a camera CPU 2A, a lens CPU 2B, an angular velocity sensor 12, a shake correction lens group drive mechanism (lens drive unit) 9, a lens position detection unit 23, a shake correction lens group 6, a camera side transmission / reception unit 21, and a lens side transmission / reception. The unit 22 is provided.

The camera CPU 2A includes a signal processing unit 40 and a motion vector calculation unit 41.
The lens CPU 2B includes an amplification unit 31, a first A / D conversion unit 32, a second A / D conversion unit 33, a reference value calculation unit 34, a reference value correction amount calculation unit 35, and a target position calculation unit 36 including an integration unit therein. A center bias calculator 37, a center bias remover 38, a drive amount calculator 39, a reference value determination unit 44, and a lens storage unit 45.
The angular velocity sensor 12 is a sensor such as a vibrating gyroscope that detects angular velocities around the X axis (Pitch), Y axis (Yaw), and Z axis (Roll) of the lens barrel 1B.

The amplifying unit 31 amplifies the output of the angular velocity sensor 12.
The first A / D converter 32 performs A / D conversion on the output of the amplifier 31.
The reference value calculation unit 34 calculates the reference value of the vibration detection signal (output of the first A / D conversion unit 32) obtained from the angular velocity sensor 12. The angular velocity reference value is, for example, a vibration detection signal output from the angular velocity sensor 12 when the camera system 1 (camera 1A, lens barrel 1B) is stationary. The reference value calculation unit 34 can obtain the reference value based on, for example, the output of a low-pass filter that reduces a predetermined high-frequency component from the output of the angular velocity sensor 12.
Then, the reference value calculated by the reference value calculation unit 34 is subtracted from the output of the first A / D conversion unit 32 by the subtraction unit 43.
The target position calculation unit 36 calculates the target position of the blur correction lens group 6 based on the output of the angular velocity sensor 12 after the reference value is subtracted by the subtraction unit 43.

The center bias calculator 37 biases the centripetal force for moving the blur correction lens group 6 toward the center of the movable range based on the target position of the blur correction lens group 6 calculated by the target position calculator 36. Calculate as a quantity.
Then, the control position of the blur correction lens group 6 is calculated by subtracting the calculated bias amount from the target position of the blur correction lens group 6.
By performing the centering bias processing in this manner, it is possible to effectively prevent the blur correction lens group 6 from colliding with the hard limit, and further, it is possible to improve the appearance of the captured image.

  The drive amount calculation unit 39 is a blur correction lens group obtained from the target position from the target position calculation unit 36 and the value detected by the lens position detection unit 23 and A / D converted by the second A / D conversion unit 33. 6 is used to calculate the driving amount of the blur correction lens group driving mechanism 9.

The image sensor 3 is provided on the planned focal plane of the photographing optical system. The image pickup device 3 is composed of a device such as a CCD or a CMOS, and generates an analog image signal by photoelectrically converting an input subject image.
The signal processing unit 40 performs predetermined processing on the image signal generated by the image sensor 3.

The motion vector calculation unit 41 calculates a motion vector (first motion vector, MV1) indicating the motion of the image (motion direction, amount of motion) from the captured image processed by the signal processing unit 40.
Specifically, the motion vector calculation unit 41 detects the motion direction and the motion amount of the image by comparing the luminance information included in two consecutive frame image data captured by the image sensor 3. Calculate the motion vector. The first motion vector can be calculated by, for example, comparing frame image data captured at a certain first time with frame image data captured at a second time after the first time. The present invention is not limited to the one that is calculated by comparing the luminance information included in two consecutive frame image data that have been captured.

  The center bias removing unit 38 is a bias amount calculated by the center bias calculating unit 37 (subtracted from the target position of the blur correction lens group 6) from the first motion vector (MV1) that is the output of the motion vector calculating unit 41. Is subtracted.

  The reference value correction amount calculation unit 35 calculates a reference value correction amount based on the second motion vector (MV2) from which the center bias amount has been removed by the center bias removal unit 38.

The reference value determination unit 44 determines whether or not the corrected reference value (reference value voltage, null voltage) exceeds the limit range (limit voltage range) when the reference value is corrected using the reference value correction amount. To do.
The reference value limit range is set by the manufacturer of the angular velocity sensor 12, for example, and the reference value limit range is stored in the lens storage unit 45 such as an EEPROM. The limit range of the reference value is, for example, the maximum shake width guaranteed for each angular velocity sensor (the maximum value and the maximum value or the absolute value of the shake width range). For example, the angular velocity sensor 12 is designed so that the reference value of the angular velocity sensor does not exceed the reference value limit range. The limit range is, for example, ± 1 dps at the time of shipment.

When the output of the reference value calculation unit 34 is within the limit range of the reference value based on the determination result of the reference value determination unit 44, the subtraction unit (reference value correction unit) 42 Then, the reference value correction amount obtained by the reference value correction amount calculator 35 is subtracted.
The subtraction unit (reference value correction unit) 42 obtains the reference value correction amount calculation unit 35 from the output of the reference value calculation unit 34 when the output of the reference value calculation unit 34 is outside the limit range of the reference value. The reference value correction amount is not subtracted.

(Transmission / reception information between the camera-side transceiver unit and the lens-side transceiver unit)
Next, information transmitted / received between the camera side transmission / reception unit 21 and the lens side transmission / reception unit 22 will be described.
Information sent from the camera-side transceiver 21 to the lens-side transceiver 22 is, for example, motion vector information or camera information.

  The motion vector information includes a first motion vector MV1, which is represented by the magnitude in the X-axis direction, the Y-axis direction, the Roll direction, and the like. Further, the motion vector information includes a detection delay time, a motion vector valid / invalid flag (X-axis direction, Y-axis direction, Roll direction), engine version information for calculating the motion vector, and the like.

  The version information represents, for example, the number of revisions of software for calculating a motion vector. For example, when the motion vector is calculated by the first software of the first engine built in the first camera, the motion vector information includes the first motion vector MV1, the detection delay time, the motion vector valid / invalid flag, Information (version information) indicating that the version is one is included. Similarly, when the motion vector is calculated by the second software of the second engine built in the second camera (software obtained by revising the first software), the motion vector information is the first motion vector MV1, detection. Delay time, motion vector valid / invalid flag, information indicating the second version, and the like are included. The version information may be a value that increases as the version increases, such as 1, 2, 3,..., Or may change in alphabetical order, such as a, b, c. , 8d5, feh, 2lu,...

  For example, the definition of the motion vector MV1, the calculation method of the motion vector MV1 (formulas for calculating the motion vector MV1, etc.), the update period of the motion vector MV1, the accuracy of the motion vector MV1, etc. May vary depending on version.

  Since the contents of the motion vector MV1 may change depending on the version of the software of the engine, it is assumed that the lens CPU 2B uses the motion vector MV1 (the motion vector MV1 to which version information is not associated) whose version is unknown. When blur correction control is performed, the blur correction performance may be deteriorated as compared with the case where the motion vector MV1 is not used.

  According to the present embodiment, since the lens barrel 1B receives version information in association with the first motion vector MV1, the lens CPU 2B can perform a blur correction calculation suitable for the version information, and perform a suitable blur correction. It can be carried out.

  In the present embodiment, it is preferable that the lens CPU 2B performs the blur correction control using the first motion vector MV1 and the version information. For example, the lens CPU 2B includes a determination unit (not shown) that determines whether there is version information related to the first motion vector MV1, and the version information related to the first motion vector MV1 is If there is not, the image blur correction is performed without using the first motion vector MV1, and if there is version information related to the first motion vector MV1, the image blur correction may be performed using the first motion vector MV1. preferable. This is because if the first motion vector MV1 inappropriate for the lens CPU 2B is used, the blur correction performance may be deteriorated as compared with the case where the motion vector MV1 is not used.

  In the present embodiment, the lens CPU 2B includes a determination unit that determines whether the version information related to the first motion vector MV1 is appropriate for the lens CPU 2B, and relates to the first motion vector MV1. If the obtained version information is not appropriate for the lens CPU 2B (for example, if the version is too old or the version is too new to be processed by the lens CPU 2B), image blur correction is performed without using the first motion vector MV1. When the version information related to the first motion vector MV1 is appropriate for the lens CPU 2B, it is preferable to perform image blur correction using the first motion vector MV1. This is because if the first motion vector MV1 inappropriate for the lens CPU 2B is used, the blur correction performance may be deteriorated as compared with the case where the motion vector MV1 is not used.

  In the present embodiment, the lens CPU 2B includes a determination unit that determines whether the version information related to the first motion vector MV1 is appropriate for the lens CPU 2B, and the version related to the first motion vector MV1. The lower the degree of appropriateness of the information to the lens CPU2B, the closer to the image blur correction without using the first motion vector MV1, and the higher the degree of appropriateness of the version information related to the first motion vector MV1 to the lens CPU2B, the first. It is preferable to perform image blur correction so as to have characteristics close to the above-described image blur correction using one motion vector MV1. For example, it can be determined that the version that can be processed by the lens CPU 2 </ b> B is higher as the version is newer.

  The camera information includes panning determination degree, tilting determination degree, frame rate, exposure time information, information indicating that a movie is being shot, information indicating that a menu is being displayed on the rear liquid crystal, and the camera power Information indicating that the camera is turned on, information indicating that the camera is turned off, information indicating that the camera is in a sleep state, and the like.

For example, the camera side transmission / reception unit 21 does not transmit motion vector information to the lens side transmission / reception unit 22 when the camera 1A is shooting a moving image. Also, the motion vector information is not transmitted to the lens-side transmitting / receiving unit 22 even during the display of images and characters on the rear liquid crystal 18. These are for reducing the load on the CPU or reducing the power consumption.
Further, when the camera 1A is shooting a moving image, the lens-side transceiver unit 22 may not receive the motion vector information from the camera-side transceiver unit 21 even if the camera-side transceiver unit 21 transmits the motion vector information. . In addition, during the display of images and characters on the rear liquid crystal 18, even if the camera side transmission / reception unit 21 transmits motion vector information, the lens side transmission / reception unit 22 does not receive the motion vector information from the camera side transmission / reception unit 21. There may be.
For example, the camera-side transmitting / receiving unit 21 receives camera information (information indicating that a video is being captured, a back surface, etc. when the camera 1A is shooting a video or when an image or character is being displayed on the rear liquid crystal 18. Information indicating that the menu is being displayed on the liquid crystal) can be transmitted to the lens-side transmitting / receiving unit 22. The lens side transmitting / receiving unit 22 may determine the state of the camera 1A based on the camera information and may not receive motion vector information.

  On the other hand, focal length information and instruction information on a motion vector calculation method based on the focal length information are sent from the lens side transmitting / receiving unit 22 to the camera side transmitting / receiving unit 21.

  The instruction information of the motion vector calculation method is, for example, a frame interval at the time of motion vector calculation. FIG. 3 is a diagram for explaining the calculation timing of the motion vector in a normal case (a case other than the wide side described later). As shown in the figure, a motion vector is calculated from the image of the (n−1) th frame and the image of the next nth frame, and is transmitted from the camera side transmitting / receiving unit 21 to the lens side transmitting / receiving unit 22 at time t6 shown in the drawing. Is done.

  Time t1 is the time when exposure of the image of the (n-1) th frame is started. Time t2 is an average time of detection times of images in the (n-1) th frame. Time t4 is the time when the exposure of the image of the nth frame is started. Time t5 is an average time of detection times of images in the nth frame. Time t6 is a timing at which the motion vector calculated from the n-1 image and the n image is transmitted from the camera side transmitting / receiving unit 21 to the lens side transmitting / receiving unit 22, and the generation time of this motion vector is t5 It is reasonable to consider t3 between t2 and t6-t3, a detection delay time occurs.

  FIGS. 4A to 4C are diagrams for explaining instruction information of a motion vector calculation method sent from the lens-side transmitting / receiving unit 22 to the camera-side transmitting / receiving unit 21 when the focal length of the lens barrel 1B is wide. It is.

On the wide (wide angle) side, the amount of image plane blurring is small. For this reason, if the motion vector is calculated between consecutive frames as in the tele (telephoto) side, the reliability of the motion vector may be reduced. For this reason, in the present embodiment, in the case of the wide side, the motion vector detection accuracy is improved by performing a calculation to increase the frame interval during the motion vector calculation.
This calculation method is determined by the lens CPU 2B and is instructed to the motion vector calculation unit 41 of the camera CPU 2A via the lens-side transmission / reception unit 22 and the camera-side transmission / reception unit 21.

FIG. 4A is a diagram for explaining a first example of this motion vector calculation method.
In the first example, in order to increase the frame interval, for example, a motion vector is calculated from an image of the (n−3) th frame and an image of the (n−1) th frame that is the next two frames. Then, the next motion vector is calculated from the image of the (n−2) th frame and the image of the nth frame that is the next two frames.

FIG. 4B is a diagram for explaining a second example of the motion vector calculation method.
In the second example, in order to further increase the frame interval, a motion vector is calculated from, for example, the image of the n-6th frame and the image of the n-2th frame that is four points ahead.
Then, the next motion vector is calculated from the image of the (n−5) th frame and the image of the (n−1) th frame that is four points ahead. Further, the next motion vector is calculated from the image of the (n−4) th frame and the image of the nth frame that is the fourth frame ahead.

FIG. 4C illustrates a third example of the motion vector calculation method.
In the third example, a motion vector is calculated from, for example, an image of the n−4th frame and an image of the n−2th frame that is the next two frames. Then, the next motion vector is calculated from the image of the (n-3) th frame, the next image of the (n-2) th frame, and the image of the nth frame that is the next two frames.
Thus, in this embodiment, in the case of the wide side, the motion vector detection accuracy can be improved by increasing the frame interval at the time of motion vector calculation.

  The instruction information of the motion vector calculation method may be, for example, a communication version set in a lens barrel 1B described later. The camera CPU 2A determines the blur correction performance of the lens barrel 1B based on the communication version set in the lens barrel 1B, and motion vector information (motion vector MV1, version information suitable for the blur correction performance of the lens barrel 1B). Etc.) can be transmitted.

  For example, when the communication version of the camera 1A is 7, and the communication version of the lens barrel 1B is 6, the communication version 6 is used for communication between the camera 1A and the lens barrel 1B. For example, after the power of the camera 1A is turned on, after the lens barrel 1B is attached to the camera 1A, etc., instruction information on the calculation method of the motion vector from the lens CPU 2B to the camera CPU 2A (set in the lens barrel 1B) Communication version 6) is transmitted. The camera CPU 2A determines the blur correction performance of the lens barrel 1B based on the information of the communication version 6, and transmits motion vector information (motion vector MV1, version information, etc.) suitable for the blur correction performance of the lens barrel 1B. be able to.

(Operation of the image stabilizer)
Next, an operation flow of the shake correction apparatus 100 according to the present embodiment will be described.
FIG. 5 is a flowchart showing an operation flow of the shake correction apparatus 100 of the present embodiment.

  After the camera system 1 is turned on, the shake correction apparatus 100 starts an operation for optical image stabilization. Depending on the camera, when the half-push switch is pressed, the shake correction apparatus 100 starts computation for optical image stabilization (step S001).

After the output of the angular velocity sensor 12 is amplified by the amplification unit 31, it is A / D converted by the first A / D conversion unit 32 (step S002).
The reference value calculation unit 34 calculates a reference value (a value corresponding to zero deg / s) of the calculated angular velocity based on the signal after A / D conversion of the output of the angular velocity sensor 12. Since the reference value of the angular velocity changes depending on the temperature characteristic, the drift characteristic immediately after startup, etc., for example, the stationary output of the angular velocity sensor 12 at the time of factory shipment cannot be used as the reference value.

  As a method for calculating the reference value, a method of calculating a moving average for a predetermined time and a method of calculating by LPF processing are known. In the present embodiment, reference value calculation by LPF processing is used.

  6A and 6B are diagrams illustrating the reference value calculation unit 34. FIG. 6A illustrates the reference value calculation unit 34 (HPF), and FIG. 6B illustrates the LPF 34a of the reference value calculation unit 34. .

  The cut-off frequency fc of the LPF 34 is generally set to a low frequency of about 0.1 [Hz]. This is because camera shake has a dominant frequency of about 1 to 10 [Hz]. If the fc is 0.1 [Hz], there is little influence on the camera shake component, and good blur correction can be performed.

  However, during actual shooting, low-frequency motion such as fine adjustment of the composition (a level at which panning cannot be detected) is added, which may cause an error in the ω0 calculation result. In addition, since fc is low (time constant is large), there is a problem that it takes time to converge to a true value when the error is once increased. In the present embodiment, this ω0 error is corrected.

Returning to FIG. 5, when the information of the first motion vector MV1 is updated (S004, YES), the process proceeds to S005, and when not updated (S004, NO), the process proceeds to S006. The description of S004 to S005 will be described later in detail.
In addition, since information on the first motion vector MV1 cannot be obtained during exposure, this step is performed until immediately before the exposure.
The outputs of the angular velocity sensor 12 after subtracting the reference value are integrated, and the target position of the shake correction lens group 6 is calculated based on the focal length, subject distance, shooting magnification, and shake correction lens characteristic information (S006).
Center bias processing is performed to prevent the blur correction lens group 6 from reaching the movable end (S007).

  There are various center bias processing methods such as a method of setting a bias amount according to target position information, HPF processing, incomplete integration processing (in S006), and the method is not limited here.

The lens driving amount is calculated from the difference between the target position information including the center bias component and the blur correction lens position information (S008).
The blur correction lens group 6 is driven to the target position (S009), and the process returns to S002.

Next, reference value correction (S004 to S005, S011 to S016) will be described. FIG. 7 is a flowchart showing the reference value correction calculation.
As described above, when the information of the first motion vector MV1 is updated (S004), the process proceeds to S005. If it has not been updated, the process proceeds to S006.
Since the optical blur correction control cycle is sufficiently early with respect to the MV1 update cycle, the same arithmetic processing as normal image stabilization is performed until the MV1 is updated. Here, it is assumed that the control period of optical blur correction is 1 [ms] and the update period of the first motion vector MV1 is 33 [ms] (= 30 [fps]). A well-known technique is used for the calculation method of the first motion vector MV1.

All the received first motion vectors MV1 are summed (S011).
The center bias component calculated in S007 is converted to the same scale as the first motion vector MV1 (S012).
The conversion method is calculated based on the focal length, the subject distance, the shooting magnification, and the resolution information of the first motion vector MV1.

Bias_MV = Bias_θ * f1 + β / MV_pitch
Bias_MV: Center bias component (same motion vector scale)
Bias_θ: Center bias component (angle)
f: Focal length β: Image magnification MV_pitch: MV1 pitch size

  In addition, since a delay time occurs until the first motion vector MV1 is detected, it is preferable that the center bias component also has a delay time equivalent to that of the first motion vector MV1. For example, if there is a delay time of 3 frames at 30 [fps], the delay is about 100 [ms]. Therefore, the center bias component included in the first motion vector MV1 can be calculated more accurately by using the bias information before 100 [ms].

The center bias component calculated in S012 is subtracted from the first motion vector MV1 (S013). Thereby, the information of the second motion vector MV2 due to the reference value error can be acquired.
A difference: MV_diff between the latest second motion vector MV2 (n) and the second motion vector MV2 (n-1) one frame before is acquired (S014).
An amount for correcting the reference value is set based on MV_diff. As the reference value, a correction amount is set based on the following idea (S015).

MV_diff> 0: ω0_comp = −ω0_comp_def
MV_diff <0: ω0_comp = + ω0_comp_def
MV_diff = 0: ω0_comp = 0

ω0_comp: reference value correction amount ω0_comp_def: reference value correction constant

In S016, the corrected ω0 value is calculated from the current ω0 and ω0_comp. This result is compared with the reference value voltage adjustment value, and it is determined whether or not ω0 (reference value) <reference value limit range (reference value limit voltage range).
If this relationship is satisfied, it is determined that the calculated motion vector information is correct, and the process proceeds to S017.

  Here, ω0_comp calculated in S015 is subtracted from the reference value calculated in S003 (S017). Specifically, when the value of V4 ′ in FIG. 6B is corrected, the reference value is corrected using the motion vector only during the exposure preparation period (during half-push vibration isolation and during moving image shooting). And normal reference value calculation is performed during exposure.

  According to the present embodiment, the reference value correction is performed only during the exposure preparation period. However, since it is possible to start exposure with the reference value immediately before exposure being closer to the true value, it is favorable even during exposure. Blur correction is possible.

FIG. 8 is a relationship diagram between the reference value error and the motion vector. (A) is a reference value calculation result, and (b) is a motion vector.
FIG. 8 shows the reference value error and the detected motion vector amount (after removing the bias component). Since the motion vector has a detection delay time, it is detected with a delay. Here, the detection delay time: T1 = 1 frame.

  Here, first, comparative embodiments will be described for easy understanding of the present embodiment. In the comparison mode, the reference value is corrected based on the motion vector information in FIG. The corrected reference value is shown below.

The comparison form does not include step S016 in the flowchart of FIG. 7. When the reference value correction amount is calculated in step S016, the reference value is calculated using the reference value correction amount regardless of the size of the corrected reference value. To do.
As shown in FIG. 9, when the reference value error component can be accurately detected from the motion vector, the reference value error can be reduced, leading to an improvement in the image stabilization performance.

However, the detected motion vector information cannot be separated into the subject blur component and the reference value error component depending on the shooting scene, and erroneous information may be detected. FIG. 10 is a graph showing an erroneously detected motion vector (subject blur component).
FIG. 11 shows a reference value calculation result when the reference value correction is performed using the motion vector information of the subject blur component. As shown in FIG. 11, when incorrect motion vector information such as a subject blur component is sent, the reference value error is increased.

  In order to prevent this, the motion vector detection unit needs to classify whether the detected motion vector is a camera shake component or a subject blur component, but depending on the shooting scene, it cannot be determined and is erroneously detected. There is also a case where it ends up.

In recent years, the performance of an angular velocity sensor has been improved, and a sensor having a very small reference value voltage range (below the camera shake component) has been proposed. Therefore, by using this information, it is possible to suppress a reference value error when a motion vector is erroneously detected.
In the present embodiment, in step S016 of FIG. 7, the reference value information corrected by the motion vector is compared with the reference value limit range of the angular velocity sensor, and when the corrected reference value exceeds the reference value limit range. Therefore, it is determined that there is an error in the obtained motion vector information, and the reference value is not corrected.

That is, as described above, in S016, the corrected ω0 value is calculated from the current ω0 and ω0_comp. This result is compared with the reference voltage adjustment value to determine whether or not ω0 (reference value) <reference value limit range.
If this relationship is satisfied, it is determined that the calculated motion vector information is correct, and the process proceeds to S017. If this relationship is not satisfied, it is determined that the motion vector is erroneously detected (subject blur component or the like), and the process proceeds to S006 without performing the reference value correction process.

FIG. 12 is a graph comparing the present embodiment with the comparative embodiment.
According to this embodiment, when the reference value is corrected using the motion vector information, the reference value limit range of the angular velocity sensor is stored, and whether or not the corrected reference value is within the reference value voltage adjustment range. A determination unit is provided.
As a result, as shown in FIG. 12, when the motion vector information is correct (when a camera shake component is detected), the reference value error is reduced, and even when a motion vector is erroneously detected (object blur component detection), the reference value error is reduced. A blur correction system that can suppress the increase can be realized.

  As described above, according to the present embodiment, since the reference value correction processing based on the motion vector is changed based on the determination result of the reference value determination unit 44, it is possible to prevent an adverse effect on optical image stabilization due to erroneous detection of the motion vector. It becomes.

In the determination result of the reference value determination unit 44, the reference value correction unit 42 corrects the reference value when the corrected reference value falls within the limit range, and the corrected reference value is outside the limit range. In such a case, the reference value is not corrected.
When the reference value is outside the limit range, it is considered that the motion vector is erroneously detected (subject blur component detection). In this case, since the reference value is not corrected, it is possible to realize a shake correction system that can suppress an increase in the reference value error.
On the other hand, when the reference value is within the limit range, it is considered that the motion vector information is correct (when a camera shake component is detected). In this case, since the reference value is corrected, the reference value error can be reduced.

  According to the present embodiment, the motion vector information is transmitted from the camera side transmission / reception unit 21 to the lens side transmission / reception unit 22. Therefore, even in the case of the present embodiment in which the camera 1A and the lens barrel 1B are separate, the lens barrel 1B can receive motion vector information.

  When the camera 1A is shooting a moving image by the image sensor 3 or displaying a menu on the rear liquid crystal 18, no motion vector information is transmitted / received between the camera side transmitting / receiving unit 21 and the lens side transmitting / receiving unit 22. Consumption can be suppressed.

  When the version information of the motion vector calculation unit 41 is included in the motion vector information, the accuracy of the motion vector can be grasped by the lens CPU 2B, and appropriate calculation can be performed in each unit.

  Since the lens side transmission / reception unit 22 transmits the calculation method performed by the motion vector calculation unit 41 to the camera 1A, accurate motion vector information can be obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 13 is a block diagram of the shake correction apparatus 200 of the first embodiment. The blur correction apparatus 200 of the second embodiment is different from the blur correction apparatus 100 of the first embodiment in that an electronic blur correction process is performed by the signal processing unit 40 in the camera CPU 2A according to the determination result of the reference value determination unit 44. The method is changed. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In the second embodiment, the determination result information on whether or not the corrected reference value is within the reference value limit range in the reference value determination unit 44 is transmitted to the lens side transmission / reception unit 22.
Then, the determination result is sent from the lens side transmission / reception unit 22 to the signal processing unit 40 via the camera side transmission / reception unit 21.
The signal processing unit 40 has a function of an electronic shake correction processing unit, and determines whether to perform electronic shake correction according to the determination result.
The electronic blur correction is an electronic cutout stabilization process in which the cutout position of the image captured by the image sensor 3 is changed and displayed on the rear liquid crystal 18 according to the amount of motion vector calculated by the motion vector calculation unit 41. .

In the present embodiment, when the corrected reference value is within the reference value limit range, the signal processing unit 40 determines that the motion vector is a camera shake component, and performs an electronic shake correction process.
If the corrected reference value exceeds the reference value limit range, it is determined that the detected motion vector is erroneously detected, such as a subject blur component, and in this case, electronic blur correction is not performed.

  According to the second embodiment, in addition to the same effects as in the first embodiment, when the corrected reference value exceeds the reference value limit range, it is determined that the detected motion vector is erroneously detected, such as a subject blur component. In this case, since the electronic shake correction is not performed, the display image can be prevented from being deteriorated.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In 3rd Embodiment, the same code | symbol is attached | subjected to the part similar to 1st Embodiment or 2nd Embodiment, and the description is abbreviate | omitted.

  In the third embodiment, a communication version is defined for communication between the camera 1A and the lens barrel 1B. In this embodiment, advanced communication can be performed as the number of communication versions increases. The camera 1A and the lens barrel 1B have a predetermined communication version set at the time of factory shipment. When the user updates the communication version supplied from the camera manufacturer, the communication version can be upgraded.

For communication between the camera 1A and the lens barrel 1B, the highest version in common between the communication version of the camera 1A and the communication version of the lens barrel 1B is selected.
For example, when the communication version of the camera 1A is 5 and the communication version of the lens barrel 1B is 8, the communication version 5 is used for communication between the camera 1A and the lens barrel 1B. Similarly, when the communication version of the camera 1A is 7 and the communication version of the lens barrel 1B is 2, the communication version 2 is used for communication between the camera 1A and the lens barrel 1B.

  In the present embodiment, the camera CPU 2A determines that the communication version that can be supported by the lens barrel 1B is a predetermined version (for example, version 5 or higher) and a request signal is received from the lens barrel 1B. The motion vector information (including the first motion vector MV1, version information, etc.) is transmitted. This is because the lens CPU 2B satisfies the predetermined version requirements and receives a request signal from the lens barrel 1B, so that it is considered that the blur correction control using the motion vector information can be performed by the lens barrel 1B.

  On the other hand, when the communication version that the lens barrel 1B can handle is a predetermined version (for example, when it is less than version 5), or when there is no request signal from the lens barrel 1B, the camera CPU 2A described above. The motion vector information (including the first motion vector MV1, version information, etc.) is not transmitted. Since it is at least one of the case where the predetermined version requirement is not satisfied or the case where there is no request signal from the lens barrel 1B, it seems that the blur correction control using the motion vector information is impossible by the lens barrel 1B. Because. In this case, communication efficiency (reduction of communication data capacity) can be achieved as much as no motion vector information is transmitted. Further, when the lens barrel 1B does not satisfy the predetermined version requirement, the blur correction performance is deteriorated as compared with an unfavorable control using the motion vector information (for example, the case where the motion vector MV1 is not used). This is to prevent the image stabilization control) from being performed.

  The request signal from the lens barrel 1B is, for example, when the lens barrel 1B starts blurring correction after the camera 1A is turned on (for example, a shooting preparation operation (for example, half-pressing the release button) ) After the camera has issued an instruction to start image blur correction (for example, a switch for operating whether to disable blur correction or an operation that disables blur correction). It is transmitted from the tube 1B to the camera 1A.

(Deformation)
The present invention is not limited to the above-described embodiment, and various modifications and changes as described below are possible, and these are also within the scope of the present invention.
(1) In the above-described embodiment, the form in which the lens barrel is detachable from the camera has been described. However, the present invention is not limited to this. For example, a so-called compact camera in which a lens barrel and a camera are integrated may be used. Moreover, although the form which has a mirror in a camera was demonstrated, it is not limited to this, The camera of a mirrorless structure may be sufficient. Furthermore, not only a camera but a mobile phone, another portable information terminal, etc. may be sufficient.

(2) In the above-described embodiment, the example in which the motion vector is used from the image for each of the plurality of frames when the focal length of the lens barrel is wide has been described. When information indicating that the focal length is on the wide-angle side is received, transmission of motion vector information or the like from the camera-side transmitting / receiving unit 21 to the lens-side transmitting / receiving unit 22 may be stopped.
In addition, although embodiment and a deformation | transformation form can also be used in combination as appropriate, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiment described above.

(3) In the above-described second embodiment, the electronic blur correction processing method performed by the signal processing unit 40 in the camera CPU 2A is changed according to the determination result of the reference value determination unit 44. The camera 1 </ b> A may include the image sensor 3 that can be driven to correct image blur, and may perform drive control of the image sensor 3 according to the determination result of the reference value determination unit 44. Further, at least two of the image blur correction using the blur correction lens, the electronic blur correction performed by the signal processing unit 40 in the camera CPU 2A, and the image blur correction using the driveable image sensor 3 are corrected. It may be what performs.

(4) In the above-described embodiment, the reference value correction unit 42 calculates the reference value correction amount calculation unit from the output of the reference value calculation unit 34 when the output of the reference value calculation unit 34 is within the limit range of the reference value. If the reference value correction amount obtained by 35 is subtracted, and the output of the reference value calculation unit 34 is outside the limit range of the reference value, the reference value correction amount calculation unit 35 obtained from the output of the reference value calculation unit 34 Although the embodiment in which the value correction amount is not subtracted has been described, the present invention is not limited to this.

  For example, the reference value correction unit 42 first subtracts the reference value correction amount obtained by the reference value correction amount calculation unit 35 from the output of the reference value calculation unit 34, and the reference value calculation unit 34. The reference value correction amount obtained by the reference value correction amount calculation unit 35 may be averaged from the output obtained by subtracting the second weight. In this case, when the output of the reference value calculation unit 34 is within the limit range of the reference value, the first weight is set larger than the second weight, and the output of the reference value calculation unit 34 is the limit range of the reference value. When it is out of the range, it is preferable to make the second weight larger than the first weight.

  1: camera system 1A: camera, 1B: lens barrel 1B: camera CPU, 2B: lens CPU, 3: image sensor, 4: zoom lens group, 5: focus lens group, 6: blur correction lens group, 7: zoom Lens group drive mechanism, 8: Focus lens group drive mechanism, 9: Blur correction lens group drive mechanism, 12: Angular velocity sensor, 21: Lens position detection unit, 31: Amplification unit, 32: First A / D conversion unit, 33: Second A / D converter, 34: reference value calculator, 35: center bias remover 38: reference value correction amount calculator, 36: target position calculator, 37: center bias calculator, 38: center bias remover, 39: Drive amount calculation unit, 40: Signal processing unit, 41: Vector calculation unit, 42: Reference value correction unit, 43: Subtraction unit, 44: Reference value determination unit, 45: Lens storage unit, 100, 200: B Correction device

The present invention relates to an imaging apparatus .

The present invention captures an image of a subject formed by an optical system and outputs a signal;
An image generation unit that generates an image based on the signal, and a change in the position of the image of the subject on the image sensor based on the two images captured with a time difference corresponding to the focal length of the optical system And a motion vector calculation unit that calculates a motion vector indicating

Claims (6)

An image stabilization lens that corrects image blur,
An angular velocity sensor for detecting angular velocity;
A calculation unit for calculating a reference value of an output signal of the angular velocity sensor;
A receiver for receiving motion vector information and version information from the camera;
A correction unit that corrects the reference value using the motion vector information;
An interchangeable lens comprising: a control unit that performs control to drive the blur correction lens using the output signal of the angular velocity sensor and the reference value corrected by the correction unit. In the interchangeable lens according to claim 1,
The interchangeable lens in which the control unit makes control different when the version information received by the receiving unit is older than a predetermined version and when the version information is newer than the predetermined version. In the interchangeable lens according to claim 2,
When the version information received by the receiving unit is older than the predetermined version, the control unit uses the output signal of the angular velocity sensor and the reference value corrected by the correcting unit. When the version information received by the receiving unit is newer than the predetermined version, control is performed using the output signal of the angular velocity sensor and the reference value calculated by the calculating unit. Do the interchangeable lens. In the interchangeable lens according to any one of claims 1 to 3,
The receiving unit receives camera information including information on the state of the camera;
The said control part is an interchangeable lens which controls whether the said receiving part receives the said motion vector information based on the said camera information which the said receiving part received. In the interchangeable lens according to claim 4,
The reception unit is at least one of the case where the control unit determines that the camera is shooting a movie based on the camera information and the case where the camera determines that the menu is being displayed. Is an interchangeable lens that does not receive the motion vector information. In the interchangeable lens according to any one of claims 1 to 5,
The interchangeable lens which has a transmission part which transmits the information used in order that the said camera calculates a motion vector.

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