JP7374650B2 - Imaging device and its control method - Google Patents

Description

The present invention relates to an imaging device such as a digital camera or a digital video camera, and more particularly to an imaging device capable of anti-vibration operation that reduces (corrects) image blur.

Patent Document 1 discloses that a motion vector is detected from a video signal generated using an image sensor, and the motion vector is used to detect an output signal from a vibration detection unit (angular velocity meter) that detects shake of the imaging device. A method of correcting is disclosed.

Japanese Patent Application Publication No. 2012-256077

However, the method disclosed in Patent Document 1 increases noise contained in the output from the vibration detection section, and there is a risk that image blur may not be reduced satisfactorily due to the influence thereof.

The present invention provides an imaging device that can reduce image blur without being significantly affected by noise included in the output signal of a vibration detection section.

An imaging device according to one aspect of the present invention is capable of attaching and detaching an interchangeable lens. The imaging device includes an imaging device that captures an image of a subject, a motion vector detection unit that detects a motion vector using an output from the imaging device, and a motion vector detection device that reduces image blur in response to a first signal indicating the motion vector. The camera includes a camera shake-proofing means that performs a vibration-proofing operation to move an image sensor, and a communication means that communicates with the interchangeable lens. The interchangeable lens generates a correction signal using a second signal based on the output from the vibration detection means for detecting shake, and performs a vibration-proofing operation by moving the vibration-proof lens based on the correction signal. The imaging device includes a gain control unit that acquires information for changing the gain for the second signal in generating the correction signal in response to the first signal detected when the interchangeable lens is in anti-vibration operation. have The communication means is characterized in that it transmits information for changing the gain acquired by the gain control means to the interchangeable lens.

Another aspect of the present invention is an interchangeable lens that is attachable to and detachable from an imaging device, and includes a vibration detection means for detecting shake, and a correction signal using a second signal based on the output from the vibration detection means. and a lens vibration-proofing means for performing a vibration-proofing operation for moving the vibration-proofing lens based on the correction signal. The imaging device acquires information for changing the gain for the second signal in generating the correction signal in response to the first signal detected when the interchangeable lens is in the anti-vibration operation, and changes the gain to the second signal. Send information for changes to the interchangeable lens. The interchangeable lens is characterized in that it has a gain changing means that changes the gain for the second signal in accordance with the information for changing the gain received from the imaging device.
An imaging device according to another aspect of the present invention includes an imaging device that captures a subject image, a motion vector detection unit that detects a motion vector using an output from the imaging device, and a first signal that indicates the motion vector. A camera vibration isolating means that performs a vibration-proofing operation to move an image sensor to reduce image shake based on the vibration, a vibration detection means that detects vibration, and a second signal based on the output from the vibration detection means. A lens anti-vibration means performs an anti-vibration operation to move an anti-vibration lens in accordance with the generated correction signal, and a first signal detected while the lens anti-vibration means is in an anti-vibration operation performs correction. The present invention includes a gain acquisition means for acquiring information for changing the gain for the second signal in signal generation, and a gain changing means for changing the gain for the second signal according to the information for changing the gain. It is characterized by

Another aspect of the present invention provides a control method that provides an imaging device with a detachable interchangeable lens, which includes an imaging device that captures an image of a subject, and a motion vector that detects a motion vector using an output from the imaging device. The present invention is applied to an imaging apparatus having a detection means and a camera vibration isolation means that performs vibration isolation operation to move an image sensor so as to reduce image blur in response to a first signal indicating a motion vector. The interchangeable lens generates a correction signal using a second signal based on the output from the vibration detection means for detecting shake, and performs a vibration-proofing operation by moving the vibration-proof lens based on the correction signal. The control method includes the steps of receiving, from the interchangeable lens, information indicating whether or not the interchangeable lens is in anti-vibration operation, and a first signal detected when the interchangeable lens is in anti-vibration operation. Accordingly, the method includes the steps of: acquiring information for changing the gain for the second signal in generating the correction signal; and transmitting the acquired information for changing the gain to the interchangeable lens. do.

Note that a computer program that causes the computer of the imaging device to execute processing according to the control method described above also constitutes another aspect of the present invention.

According to the present invention, image blur can be favorably reduced without being significantly influenced by noise included in the output of the vibration detection means.

FIG. 1 is a block diagram showing the configuration of a camera system in Example 1 of the present invention. 3 is a diagram showing signal processing waveforms in Example 1. FIG. FIG. 3 is a diagram illustrating polarity determination in Example 1. FIG. 3 is a diagram showing polarity determination waveforms in Example 1. 5 is a flowchart showing processing in Example 1. 5 is a diagram showing the relationship between exposure time and extraction frequency in Example 1. FIG. FIG. 2 is a block diagram showing the configuration of a camera system in Example 2 of the present invention. FIG. 7 is a diagram showing the relationship between focal length and extraction frequency in Example 2. FIG. 7 is a diagram illustrating a shake correction position and a shake correction width in Example 3. 10 is a flowchart showing processing in Example 2.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a camera system 11 according to a first embodiment of the present invention, which includes a camera body 11a and an interchangeable lens 11b detachably attached to the camera body 11a. A camera CPU 115a provided in the camera body 11a controls the operation of each part of the camera body 11a shown within a broken line frame 116a in the figure. In addition, the camera CPU 115a communicates with the lens CPU 115b provided in the interchangeable lens 11b as a communication means to exchange various commands, data, etc. control the operation of each part.

The interchangeable lens 11b has an imaging optical system 19. The imaging optical system 19 forms an image of light from an object (not shown), and forms an image of the object on an image sensor 12a included in an imaging section 12 provided within the camera body 11a. The imaging optical system 19 includes an anti-vibration lens 19a.

The vibration detection unit (vibration detection means) 18 provided in the interchangeable lens 11b includes an angular velocity sensor such as a vibrating gyroscope that outputs a signal (hereinafter referred to as angular velocity signal) indicating the angular velocity of camera shake due to hand shake, etc., and the angular velocity sensor. and a processing circuit that integrates the angular velocity signal from and generates an angular shake signal (second signal) indicating the displacement of the angular shake. The angular shake signal from the vibration detection section 18 is input to the signal processing section 111, and is also input to the polarity determination section 113 in the camera body 11a via the lens CPU 115b and camera CPU 115a.

The signal processing unit 111 uses the angular shake signal from the vibration detection unit 18 to calculate a target shift position, which is a target movement position of the anti-shake lens 19a for reducing (correcting) image shake due to camera shake, and converts the angular shake signal from the vibration detection unit 18 into a target shift position. Outputs a shake correction signal indicating the position. Furthermore, the signal processing section (gain changing means) 111 performs gain processing (this will be described later) on the shake correction signal, and outputs the shake correction signal subjected to the gain processing to the lens image stabilization section 110.

The lens anti-vibration unit (lens anti-vibration means) 110 holds the anti-vibration lens 19a movably in a direction perpendicular to the optical axis 10 of the imaging optical system 19, for example in the direction of an arrow 19b (shift direction), and also provides anti-vibration. It has a shift actuator such as a VCM that drives the lens 19a in the shift direction. The lens image stabilization unit 110 drives the shift actuator to move (shift) the image stabilization lens 19a to the target shift position indicated by the image stabilization signal received from the signal processing unit 111. Thereby, in the interchangeable lens 11b, an anti-vibration operation is performed to correct image blur that occurs on the image sensor 12a due to camera shake. The lens CPU 115b transmits the operating state of the lens vibration isolator 110 (such as whether vibration isolating is in progress) to the camera CPU 115a through communication.

The image sensor 12a photoelectrically converts (images) a subject image and outputs an image signal as an electrical signal. An image processing unit 13 provided within the camera body 11a performs various image processing on the imaging signal to generate a video signal. The video signal is displayed on a display unit (not shown) or recorded on a recording medium in the storage unit 14. Further, the video signal is output to a vector processing section (motion vector detection means) 15.

The vector processing unit 15 detects a motion vector indicating the movement of a feature point between two temporally consecutive frame images included in the video signal, and detects a signal indicating the motion vector (first signal: hereinafter referred to as a motion vector). A signal (referred to as a signal) is output to a camera image stabilization section (camera image stabilization means) 114, a narrowband filter (first filter) 16, and a polarity determination section (determination means) 113 provided in the camera body 11a.

The camera image stabilization unit 114 holds the image sensor 12a movably in a direction perpendicular to the optical axis 10, for example, in the direction of an arrow 12b (shift direction), and uses a shift actuator such as a VCM that drives the image sensor 12a in the shift direction. has. The camera image stabilization unit 114 moves (shifts) the image sensor 12a to a target shift position that is a target movement position corresponding to a signal indicating a motion vector detected by the vector processing unit 15 (hereinafter referred to as a motion vector signal). drive the shift actuator. In this way, in the camera body 11a, the camera vibration isolation unit 114 performs a vibration isolation operation using the detected motion vector.

As described above, in the interchangeable lens 11b, the lens anti-vibration unit 110 performs an anti-vibration operation, but this anti-vibration operation alone may not be able to completely correct image blur and image blur may remain. In this case, the remaining image shake (hereinafter referred to as shake correction residual) is detected by the vector processing unit 15 as a motion vector. The vector processing unit 15 inputs a motion vector signal corresponding to the remaining shake correction to the camera image stabilization unit 114. The camera image stabilization unit 114 performs an anti-vibration operation to shift the image sensor 14 to a target shift position according to this motion vector signal. As a result, the residual amount of shake correction is reduced, and good image stabilization performance is obtained.

FIG. 2A illustrates a waveform 20 of a motion vector detected by the vector processing unit 15. Here, a motion vector whose direction and magnitude, shown on the vertical axis, change with time, shown on the horizontal axis, is shown.

The motion vector signal from the vector processing section 15 is also output to the narrowband filter 16. FIG. 2(b) shows the motion vector waveform extracted by the narrowband filter (first filter) 16 as waveform 21 in FIG. 2(b). The narrowband filter 16 extracts a motion vector component in a predetermined frequency band from the motion vector signal from the vector processing section 15 and outputs it to a rectification processing section (rectification means) 17 . The predetermined frequency band referred to here is variably set, for example, between 1 Hz and 7 Hz, depending on the imaging conditions of the camera system 11.

The frequency band of parallel shake, which will be described later, which is one type of camera shake, is approximately distributed from 1 Hz to 7 Hz, and the narrow band filter 16 is designed to attenuate motion vector components in frequency bands other than that frequency band (predetermined frequency band). In this way, noise superimposed on the vibration detection section 18 is cut. Comparing the waveform 20 in FIG. 2(a) and the waveform 21 in FIG. 2(b), in the waveform 21 extracted by the narrow band filter 16, motion vector components with frequencies lower than the predetermined frequency band are removed. The waveform is close to a sine wave within a predetermined frequency band.

Camera shake includes angular shake and parallel shake. Angular shake can be detected by calculation using an angular velocity signal from the vibration detection unit 18 provided in the interchangeable lens 11b, but parallel shake cannot be detected. . As a result, under imaging conditions where parallel shake is large (for example, close-up imaging such as macro imaging), the lens image stabilization unit 110, to which the image stabilization signal generated from the angular velocity signal by the signal processing unit 111 is input, uses a camera that includes parallel shake. Image blur due to shake cannot be sufficiently corrected.

Therefore, in this embodiment, image shake due to parallel shake is detected as a motion vector by the vector processing section 15, and the motion vector signal is input to the rectification processing section 17 via the narrow band filter 16. The rectification processing unit 17 rectifies (smoothes) the motion vector signal in a predetermined frequency band extracted by the narrowband filter 16 as shown by a waveform 22 in FIG. 2(c), and converts the smoothed signal value into a bias value. (third signal) is input to the comparison processing section (processing means) 112. The bias value is a value that corresponds to the amplitude of the motion vector signal in a predetermined frequency band.

The comparison processing section 112 outputs to the signal processing section 111 a multiplication coefficient as an output according to the bias value from the rectification processing section 17 and the determination result of the polarity determination section 113, which will be described later. The multiplication coefficient is used to change the gain for the angular shake signal from the vibration detection section 18 during the vibration-proofing operation of the lens vibration-proofing section 110. The comparison processing unit 112 outputs the multiplication coefficient to the signal processing unit 111 at predetermined intervals (for example, 0.2 seconds) to update the gain.

The signal processing unit 111 calculates the gain for the angular shake signal from the vibration detection unit 18 in the vibration-proofing operation of the lens vibration-proofing unit 110 (i.e., the gain of the vibration-proofing lens 19a from the angular shake signal) according to the multiplication coefficient from the comparison processing unit 112. gain when calculating the target shift position). As described above, the vibration detection unit 18 cannot detect parallel shake, but the lens vibration isolation unit 110 corrects parallel shake by changing the gain for the angular shake signal from the vibration detection unit 18 based on the motion vector signal. be able to. This is because the parallel runout is synchronized with the angular runout, so changing the gain for the angular runout is equivalent to detecting the parallel runout as well.

In this way, by smoothing the output of the narrowband filter 16 by the rectification processing unit 17, the amplitude of the motion vector signal that changes with the period of camera shake is averaged. Then, the signal processing unit 111 changes the gain of the shake correction signal based on the average value. A specific example of the multiplication coefficient used to change the gain will be described later. The polarity determining unit 113 determines whether the motion vector signal from the vector processing unit 15 is insufficient or excessive for the remaining corrections after shake correction. The polarity determination unit 113 is provided to prevent image blur correction from becoming overcorrected by excessively increasing the gain of the vibration detection unit 18.

FIG. 3 shows the configuration of the polarity determining section 113. As described above, the motion vector signal from the vector processing section 15 and the angular vibration signal from the vibration detection section 18 are input to the polarity determination section 113, and these are respectively filtered by narrowband filters 113a and 113a having the same characteristics as the narrowband filter 16. 113b. As a result, a motion vector signal and an angular shake signal in a predetermined frequency band are obtained.

4A and 4B show a waveform 41 of the angular shake signal output from the vibration detection section 18 and waveforms 42 and 43 of the motion vector signal output from the vector processing section 15. FIG. 4(a) shows a case where the phases of the waveform 41 of the angular shake signal and the waveform 42 of the motion vector signal match, and FIG. 4(b) shows the case where the phases are reversed (inverse phase). Indicate the case. The fact that the waveform 41 of the angular shake signal and the waveform 42 of the motion vector signal match in phase indicates that the motion vector signal is insufficient for the remaining shake correction. Conversely, the fact that the waveform 41 of the angular shake signal and the waveform 43 of the motion vector signal are in opposite phases indicates that the motion vector signal is excessive (overcorrected) with respect to the remaining shake correction. .

The multiplier 113c multiplies the waveform 41 of the angular shake signal and the waveforms 42 and 43 of the motion vector signal. FIG. 4C shows the result of multiplication of the waveform 41 of the angular shake signal and the waveforms 42 and 43 of the motion vector signal. Waveform 44 is the result of multiplying waveform 41 and waveform 42 in FIG. 4(a), and waveform 45 is the result of multiplying waveform 41 and waveform 43 in FIG. 4(b).

The integration unit 113d calculates the time integral value of the waveforms 44 and 45. This shows whether the image blur correction is insufficient or excessive. That is, if the time integral values of the waveforms 44 and 45 are positive, image blur correction within the integral time is insufficient, and if negative, it is excessive. Further, if the time integral value is 0, there is no excess or deficiency in image blur correction. In this way, the polarity determining unit 113 outputs a determination result indicating whether the image blur correction (that is, the vibration-proofing operation of the lens vibration-proofing unit 110) is insufficient, excessive, or insufficient, to the comparison processing unit 112.

The comparison processing section 112 outputs the following to the signal processing section 111 provided in the interchangeable lens 11b according to the determination result from the polarity determination section 113. If the image blur correction is insufficient, a multiplication coefficient greater than 1 is output, if there is an excess or deficiency, a multiplication coefficient 1 is output, and in the case of overcorrection, a multiplication coefficient smaller than 1 is output. At this time, the comparison processing section 112 outputs a larger multiplication coefficient as the amount of deficiency in image blur correction indicated by the bias value from the rectification processing section 17 is larger, and outputs a smaller multiplication coefficient as the amount of overcorrection becomes larger. Note that the camera CPU 115a may transmit the multiplication coefficient from the comparison processing section 112 to the signal processing section 111 via the lens CPU 115b.

The signal processing section 111 changes the gain for the angular shake signal from the vibration detection section 18 according to the multiplication coefficient from the comparison processing section 112, as described above. Specifically, the changed gain is calculated by multiplying the gain reference value by a multiplication coefficient.

In this embodiment, the camera CPU 115a, the narrowband filter 16, the rectification processing section 17, the comparison processing section 112, and the polarity determination section 113 constitute a gain control means.

The image stabilization control process including the above gain process will be explained using the flowchart shown in FIG. The camera CPU 115a as a computer executes this process according to a computer program.

When the user half-presses the release button (not shown) provided on the camera body 11a, in step S501, the camera CPU 115a performs imaging preparation operations such as AF and AE, and also activates the vibration detection unit 18 via the lens CPU 115b. This causes the lens vibration isolation section 110 to start vibration isolation operation. The camera CPU 115a also causes the vector processing unit 15 to detect a motion vector from the video signal generated by the image processing unit 13 using the image signal output from the image sensor 12a, and generate a motion vector signal. Furthermore, the camera CPU 115a causes the narrowband filter 16 to extract a motion vector signal in a predetermined frequency band, causes the rectification processing section 17 to smooth the extracted motion vector signal, and sends the obtained bias value to the comparison processing section 112. Let them input.

Next, in step S502, the camera CPU 115a sends the polarity determining unit 113 an angular shake signal and a motion vector signal in a predetermined frequency band extracted from the angular shake signal from the vibration detection unit 18 and the motion vector signal from the vector processing unit 15. By comparison, it is determined whether the motion vector signal is insufficient (insufficient shake correction), excessive (overcorrection), or not excessive or insufficient (appropriate shake correction) with respect to the remaining shake correction.

Next, in step S503, the camera CPU 115a determines whether or not the determination result by the polarity determination unit 113 in step S502 indicates that the shake correction is insufficient, and if the shake correction is insufficient, the process proceeds to step S504; otherwise, the process proceeds to step S505. Proceed to.

In step S504, the camera CPU 115a causes the comparison processing section 112 to output the multiplication coefficient to the signal processing section 111 of the interchangeable lens 11b. The comparison processing unit 112 outputs a multiplication coefficient greater than 1 in response to the determination result by the polarity determination unit 113 that the shake correction is insufficient. At this time, as described above, the larger the amount of shake correction deficiency, the larger the multiplication coefficient is output. For example, if the insufficient amount of shake correction is the standard amount, 1.2 is output as the multiplication coefficient, and if the amount of insufficient shake correction is twice the reference amount, 1.4 is output as the multiplication coefficient, and the insufficient amount of shake correction is output. If the amount is half of the reference amount, 1.1 is output as the multiplication coefficient. Then, the process advances to step S508.

In step S505, the camera CPU 115a determines whether or not the determination result by the polarity determining unit 113 in step S502 is over-shake correction, and if it is over-shake correction, the process proceeds to step S506; otherwise, the process proceeds to step S507. .

In step S506, the camera CPU 115a causes the comparison processing section 112 to output the multiplication coefficient to the signal processing section 111. The comparison processing unit 112 outputs a multiplication coefficient smaller than 1 for the determination result of excessive shake correction by the polarity determination unit 113. At this time, as described above, the larger the over-shake correction amount, the smaller the multiplication coefficient is output. For example, if the over-shake correction amount is the reference amount, 0.8 is output as the multiplication coefficient, and if the over-shake correction amount is twice the reference amount, 0.6 is output as the multiplication coefficient, and the over-shake correction is If the amount is half of the reference amount, 0.9 is output as the multiplication coefficient. Then, the process advances to step S508.

In step S507, the camera CPU 115a causes the comparison processing section 112 to output the multiplication coefficient to the signal processing section 111. The comparison processing unit 112 outputs 1 as a multiplication coefficient for the determination result of the appropriate shake correction by the polarity determination unit 113.

In step S508, the camera CPU 115a causes the signal processing unit 111 to change the gain for the angular shake signal from the vibration detection unit 18 according to the multiplication coefficient input from the comparison processing unit 112 via the lens CPU 115b.

Next, in step S509, the camera CPU 115a determines whether a predetermined time (for example, 0.2 seconds) has elapsed since the gain change in step S508, and when the predetermined time has elapsed, the process proceeds to step S510.

In step S510, the camera CPU 115a determines whether the release button has been fully pressed (S2-ON), and if S2-ON is selected, the camera CPU 115a performs an imaging operation to obtain a still image. End the anti-vibration control process. On the other hand, if S2-ON is not on, the process returns to step S501. The reason for waiting for a predetermined time in step S509 is to make the waiting time longer than the processing time required by the rectification processing unit 17, thereby oscillating the loop of detecting a motion vector after changing the gain and changing the gain again. This is to prevent

As explained above, by correcting the angular shake signal from the vibration detection unit 18 using the motion vector signal obtained by the vector processing unit 15, the lens vibration isolation unit 110 can perform an appropriate vibration isolation operation. , it is possible to satisfactorily correct not only angular shake but also parallel shake that occurs during close-up imaging such as macro imaging.

The noise component included in the angular shake signal from the vibration detection section 18 increases as the gain is changed by the signal processing section 111. In particular, since the low frequency fluctuation signal generated when the vibration detection unit 18 starts up has a large amplitude, the operation of the lens vibration isolation unit 110 that is driven in response to the angular vibration signal from the vibration detection unit 18 is the cause of the deterioration of the vibration isolation performance. It also becomes. Therefore, in this embodiment, the following measures against fluctuation signals are taken.

Due to the vibration-proofing operation of the lens vibration-proofing unit 110, which is driven in accordance with the angular shake signal whose gain has been changed by the signal processing unit 111, the image-shaking in the predetermined frequency band extracted by the narrow-band filter 16 is transmitted to the image sensor 12a. It is gradually attenuated. Then, the proportion of the noise component generated in the vibration detection unit 18 in the motion vector signal (remaining shake correction) obtained by the vector processing unit 15 increases.

The output of the vector processing unit 15 is input to the camera image stabilization unit 114 that shifts the image sensor 12a in the shift direction, so the image sensor 12a is shifted and driven according to the motion vector signal that has a large amount of noise components, and the image sensor 12a Reduces the residual image stabilization at the top. In this way, the camera image stabilization unit 114 corrects the remaining image stabilization that could not be completely corrected by the lens image stabilization unit 110.

By changing the anti-vibration operation of the camera anti-vibration unit 114 and the gain for the angular shake signal from the vibration detection unit 18 as described above, image shake can be effectively corrected without being significantly influenced by noise included in the angular shake signal. can do.

Note that even if the subject exhibits low-frequency movement (for example, movement in a certain direction), the movement is corrected by the camera shake prevention unit 114 using the motion vector detected by the vector processing unit 15, and Parallel shake is corrected by the lens vibration isolation section 110.

As described above, the predetermined frequency (hereinafter referred to as extraction frequency) extracted by the narrow band filter 17 is variable, and in this embodiment, the extraction frequency is changed according to the exposure time during image capturing. Specifically, when the exposure time is short, the extraction frequency is set higher than when the exposure time is long. This is because when the exposure time is short, image blur due to high-frequency camera shake becomes dominant, so the extraction frequency is set to a high frequency to improve the accuracy of correcting high-frequency image blur.

FIG. 6 shows the relationship between exposure time and extraction frequency. The horizontal axis shows the exposure time, and for example, the left end is 1 second, the right end is 1/60 second, and so on, the shorter the exposure time is on the right side. Further, the vertical axis indicates the extraction frequency, and the lower end is 1 Hz, the upper end is 7 Hz, and so on, the higher the extraction frequency is. A graph line 61 indicates that the exposure time and the extraction frequency are inversely proportional (when the exposure time is halved, the extraction frequency is doubled). In this way, by changing the extraction frequency according to the exposure time (imaging conditions), stable image blur correction can be performed at all times.

Further, various types of interchangeable lenses 11b having different configurations of imaging optical systems, focal lengths, etc. can be attached to the camera body 11a. If the interchangeable lens 11b has a vibration detection unit 18 and a signal processing unit 111 having a gain change function, information for changing the gain based on the motion vector signal obtained by the camera body 11a (multiplication from the comparison processing unit 112) coefficient) is transmitted to the signal processing unit 111, and the gain for the angular shake signal from the vibration detection unit 18 is changed. As a result, even if various interchangeable lenses 11b that can be attached to the camera body 11a have lens vibration isolating sections 110 with different drive characteristics and vibration detection sections 18 with different detection characteristics, the vector processing section 15 can Since the motion vector indicating the amount of shake correction remaining under the characteristics is detected, stable image stabilization performance can be obtained.

In this embodiment, a case has been described in which the image stabilization control process is performed during the imaging preparation operation and the image stabilization control process is not performed during the imaging operation. If nondestructive readout or divided readout of the imaging signal is possible, motion vectors may be detected and image stabilization control processing may be performed.

FIG. 7 shows the configuration of a camera system 11, which is a second embodiment of the present invention, and includes a camera body 11a and an interchangeable lens 11b detachably attached to the camera body 11a. The camera CPU 115a controls the operation of each part of the camera body 11a' shown within a broken line frame 116a' in the figure. In addition, the camera CPU 115a communicates with the lens CPU 115b provided in the interchangeable lens 11b to exchange various commands and data, and operates each part in the interchangeable lens 11b shown in the broken line frame 116b via the lens CPU 115b. control. In this embodiment, the same reference numerals as in the first embodiment are given to the same components as in the first embodiment. This example differs from Example 1 in the following points.

(1) It does not have the rectification processing section 17, the polarity determination section 113, and the comparison processing section 112 shown in Example 1, and the rectification processing section (first rectification means) 73 and the rectification processing section (second rectification processing section) are not provided. ) 74 and a comparison processing section (processing means) 75.
(2) A narrowband filter (second filter) 71 having the same characteristics as the narrowband filter (first filter) 16 is added to the camera body 11a.
(3) It has an addition section (addition means) 72 that adds the signal from the narrowband filter 16 and the signal from the narrowband filter 71.
(4) Compare the signals from the rectification processing units 73 and 74 and the rectification processing units 73 and 74 that rectify the signal from the addition unit 72 and the signal from the narrowband filter 71, respectively, and output a multiplication coefficient to the signal processing unit 111. The point is that a comparison processing section 75 is newly provided.

An angular shake signal from a vibration detection unit 18 provided in the interchangeable lens 11b is input to a narrow band filter 71 provided in the camera body 11a'. Narrowband filter 71 has the same characteristics as narrowband filter 16. The angular shake signal from the vibration detection unit 18 is input to the narrow band filter 71 having the same characteristics as the narrow band filter 16, thereby extracting the angular shake signal in the same frequency band as the motion vector signal.

The adder 72 adds the motion vector signal and the angular shake signal extracted by each of the narrowband filters 16 and 71. The amplitude of this addition result will be larger than the amplitude of the angular shake signal extracted by the narrow band filter 71 if the shake correction is insufficient with respect to the remaining shake correction, and will be extracted by the narrow band filter 71 if the shake is over corrected. is smaller than the amplitude of the angular shake signal. This can be seen from the fact that in FIG. 4, waveform 41 and waveform 42 have the same phase, so when they are added together, the amplitude increases, and waveform 41 and waveform 43 have opposite phases, so when they are added together, the amplitude decreases.

The output from the adding section 72 is a motion vector signal indicating the remaining amount of shake correction, whether the shake is insufficiently corrected or overcorrected, and a shake correction signal indicating the target shift position of the anti-shake lens 19a by the lens anti-shake section 110. Since it is the result of addition with the signal, it is equal to the angular shake signal output from the vibration detection unit 18 in the case of proper shake correction.

The rectification processing unit 73 converts the amplitude of this addition result into a bias value. On the other hand, the rectification processing section 74 converts the amplitude of the angular vibration signal from the vibration detection section 18 extracted by the narrow band filter 71 into a bias value.

The comparison processing section 75 compares the bias value from the rectification processing section 73 and the bias value from the rectification processing section 74 to obtain a multiplication coefficient for the signal processing section 111. Specifically, the bias value from the rectification processing section 73 is divided by the bias value from the rectification processing section 74 to obtain a multiplication coefficient. If the shake correction is insufficient, the bias value from the rectification processing section 73 is larger than the bias value from the rectification processing section 74, so a multiplication coefficient greater than 1 is calculated, and the larger the bias value from the rectification processing section 73, the larger the multiplication. The coefficients are calculated. In addition, in the case of over-shake correction, the bias value from the rectification processing section 73 is smaller than the bias value from the rectification processing section 74, so the multiplication coefficient is smaller than 1, and the smaller the bias value from the rectification processing section 73, the smaller the multiplication coefficient. is required. The comparison processing section 75 transmits the obtained multiplication coefficient to the signal processing section 111 of the interchangeable lens 11b. Note that the camera CPU 115a may transmit the multiplication coefficient from the comparison processing section 112 to the signal processing section 111 via the lens CPU 115b.

The signal processing unit 111 changes the gain for the angular shake signal from the vibration detection unit 18 at predetermined time intervals (for example, 0.2 seconds) according to the multiplication coefficient from the comparison processing unit 75.

In this way, in this embodiment, the comparison processing section 75 calculates the excess or deficiency of image blur correction by dividing the bias value from the rectification processing section 73 by the bias value from the rectification processing section 74, and performs multiplication according to the result. This embodiment differs from the first embodiment in that coefficients are input to the signal processing unit 111 to change the gain for the angular shake signal. In this embodiment, the camera CPU 115a, narrowband filters 16 and 71, addition section 72, rectification processing sections 73 and 74, and comparison processing section 75 constitute a gain control means.

FIG. 8 shows the image stabilization control process mainly executed by the camera CPU 115a in this embodiment. Steps that are the same as those shown in FIG. 5 in the first embodiment are given the same reference numerals as in FIG.

When the user half-presses the release button (not shown) provided on the camera body 11a, in step S1001, the camera CPU 115a performs imaging preparation operations such as AF and AE, and also activates the vibration detection unit 18 via the lens CPU 115b. This causes the lens vibration isolation section 110 to start vibration isolation operation. The camera CPU 115a also causes the vector processing unit 15 to generate a motion vector signal from the video signal generated by the image processing unit 13 using the image signal output from the image sensor 12a, and causes the narrowband filter 16 to generate a motion vector signal in a predetermined frequency band. A motion vector signal is extracted and output to the adder 72. Furthermore, the camera CPU 115a causes the narrow band filter 71 to extract an angular shake signal in a predetermined frequency band from the angular shake signal of the vibration detection section 18 inputted through the lens CPU 115b, and outputs this to the addition section 72. In addition, the camera CPU 115a causes the addition unit 72 to add the motion vector signal and the angular shake signal from the narrowband filters 16 and 71, and causes the rectification processing unit 73 to compare the bias value obtained from the added signal by the addition unit 72 to the comparison processing unit 75. Output to . Further, the camera CPU 115a causes the rectification processing section 73 to output the bias value obtained from the angular shake signal from the narrowband filter 71 to the comparison processing section 75. The camera CPU 115a then causes the comparison processing unit 75 to divide the bias value input from the rectification processing unit 73 by the bias value input from the rectification processing unit 74, and transmits a multiplication coefficient according to the result to the signal processing unit 111. let

Next, in step S1002, the camera CPU 115a determines whether or not the image sensor 12a is being exposed, and repeats this determination during the exposure. This is to avoid sudden fluctuations in shake correction due to changes in the gain for the vibration detection section 18 during exposure. That is, when exposure is started, the gain for the vibration detection section 18 is fixed to the gain that was changed just before. When the exposure is completed, the process advances to step S508. The processing from step S508 to step S510 is the same as the processing from step S508 to step S510 described in the first embodiment, and the camera CPU 115a returns to step S1001 if S2-ON is not determined in step S510.

As explained above, by changing the gain for the angular shake signal from the vibration detection unit 18 using the motion vector signal obtained by the vector processing unit 15, it is possible to reduce the influence of noise included in the angular shake signal. Therefore, the lens vibration isolating section 110 can perform an appropriate vibration-proofing operation, and it is possible to satisfactorily correct not only angular shake but also parallel shake that occurs during close-up imaging such as macro imaging.

Furthermore, in the first embodiment, the extraction frequency of the narrowband filter 16 is changed according to the exposure time, but the extraction frequency of the narrowband filters 16 and 71 is changed according to the focal length of the imaging optical system 19 in addition to the exposure time. Good too. Specifically, when the focal length is long, the extraction frequency may be changed to a lower frequency side than when the focal length is short. Since the amount of image blur increases when the focal length is long, the lens image stabilization unit 110, which has a large amount of image blur that can correct large amplitude and low frequency image shake, takes charge of this. This is because the camera image stabilization unit 114, which allows for a small amount of image blur, eliminates the need to correct low-frequency image blur.

FIG. 9 shows the relationship between the focal length of the imaging optical system 19 and the extraction frequency. The horizontal axis indicates the focal length; for example, the left end is 24 mm, the right end is 168 mm, and the focal length is longer toward the right. The vertical axis indicates the extraction frequency; for example, the lower end is 1 Hz, the upper end is 7 Hz, and the higher the extraction frequency is. A graph line 81 indicates that the focal length and the extraction frequency are inversely proportional (when the focal length is doubled, the extraction frequency is halved). By changing the extraction frequency according to the focal length (imaging condition) of the imaging optical system 19 in this manner, stable image blur correction can be performed at all times.

Note that when the target shift position of one of the anti-shake lens 19a driven by the lens anti-vibration unit 110 or the image sensor 12a driven by the camera anti-shake unit 114 approaches the end of its movable range, the shift position of the other one approaches the end of its movable range. The extraction frequencies of the narrowband filters 16 and 71 may be changed so as to change the shift position to a position further away from the optical axis 10 (that is, increase the shift amount). For example, when the target shift position of the anti-vibration lens 19a reaches a position 92 near the end of its movable range as shown by a broken line waveform 91 in FIG. As shown by the solid line waveform 91', the shift amount of the image pickup element 12a is increased so as to suppress the shift amount of the anti-shake lens 19a from increasing any further, and compensate for the image blur correction for the remaining shift amount. . Similarly, when the target shift position of the image sensor 12a approaches the end of its movable range, the extraction frequency of the narrow band filters 16 and 71 is changed to a lower frequency to prevent the shift amount of the image sensor 12a from increasing any further. The amount of shift of the anti-vibration lens 19a is increased.
(Other examples)
The present invention provides a system or device with a program that implements one or more of the functions of the embodiments described above via a network or a storage medium, and one or more processors in the computer of the system or device reads and executes the program. This can also be achieved by processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention.

11a Camera body 11b Interchangeable lens 12a Image sensor 15 Vector processing section 16 Narrow band filter 17 Rectification processing section 18 Vibration detection section 19a Anti-vibration lens 110 Lens anti-vibration section 111 Signal processing section 112 Comparison processing section 113 Polarity determination section 114 Camera anti-shake Department

Claims (13)

An imaging device capable of attaching and detaching an interchangeable lens,
an image sensor that captures a subject image;
motion vector detection means for detecting a motion vector using the output from the image sensor;
camera shake-proofing means for performing a vibration-proofing operation of moving the image sensor so as to reduce image shake in accordance with a first signal indicating the motion vector;
and a communication means for communicating with the interchangeable lens,
The interchangeable lens generates a correction signal using a second signal based on an output from a vibration detection means for detecting shake, and performs a vibration-proofing operation of moving the vibration-proof lens based on the correction signal,
The imaging device acquires information for changing a gain for the second signal in generating the correction signal in response to the first signal detected when the interchangeable lens is in anti-vibration operation. has a gain control means to
The imaging device is characterized in that the communication means transmits information for changing the gain acquired by the gain control means to the interchangeable lens. The communication means receives the second signal from the interchangeable lens, and the gain control means includes:
a first filter that extracts a signal in a predetermined frequency band from the first signal;
rectifying means for generating a third signal obtained by smoothing the signal extracted by the first filter;
determining means for determining whether the vibration-proofing operation of the interchangeable lens is excessive or insufficient using the first signal and the second signal;
2. The imaging apparatus according to claim 1, further comprising processing means for outputting an output for changing the gain according to the surplus/deficiency determination result and the third signal. The communication means receives the second signal from the interchangeable lens, and the gain control means includes:
a first filter that extracts a signal in a predetermined frequency band from the first signal;
a second filter that extracts a signal in the predetermined frequency band from the second signal;
Adding means for adding signals extracted by each of the first and second filters;
a first rectifying means for smoothing the added signal from the adding means to generate a third signal;
a second rectifier for smoothing the signal extracted by the second filter to generate a fourth signal;
2. The imaging apparatus according to claim 1, further comprising processing means for outputting an output for changing the gain according to the third signal and the fourth signal. 4. The imaging apparatus according to claim 2, wherein the camera image stabilization means performs the image stabilization operation in response to the first signal that is not input to the first filter. 5. The imaging apparatus according to claim 2, wherein the gain control means changes the predetermined frequency band according to an exposure time of the imaging device. The imaging device according to any one of claims 2 to 5, wherein the gain control means changes the predetermined frequency band according to a focal length of the interchangeable lens. 7. The gain control means changes the predetermined frequency band according to the position of one of the vibration-proof lens and the image sensor in the vibration-proof operation. The imaging device described. 8. The gain control means according to claim 1, wherein the gain control means transmits to the interchangeable lens a coefficient by which a reference value of the gain in the interchangeable lens is multiplied as information for changing the gain. The imaging device according to any one of the items. 9. The imaging device according to claim 1, wherein the gain control means causes the interchangeable lens to update the gain at predetermined time intervals. Imaging that detects a motion vector using an output from an image sensor that captures an image of a subject, and performs a vibration-proofing operation in which the image sensor is moved so as to reduce image blur according to a first signal indicating the motion vector. An interchangeable lens that can be attached to and detached from the device,
vibration detection means for detecting vibration;
and a lens vibration isolating means that generates a correction signal using a second signal based on the output from the vibration detection means and performs a vibration-proofing operation of moving the vibration-proof lens based on the correction signal ,
The imaging device acquires information for changing a gain for the second signal in generating the correction signal in response to the first signal detected when the interchangeable lens is in anti-vibration operation. and transmitting information for changing the gain to the interchangeable lens,
The interchangeable lens is characterized in that the interchangeable lens has a gain changing unit that changes the gain for the second signal in accordance with information for changing the gain received from the imaging device. an image sensor that captures a subject image;
motion vector detection means for detecting a motion vector using the output from the image sensor;
camera shake-proofing means that performs a vibration-proofing operation to move the image sensor so as to reduce image shake based on a first signal indicating the motion vector;
vibration detection means for detecting vibration;
lens vibration isolation means for performing a vibration isolation operation of moving the vibration isolation lens in accordance with a correction signal generated using a second signal based on the output from the vibration detection means;
Gain acquisition for acquiring information for changing the gain for the second signal in generating the correction signal in response to the first signal detected when the lens vibration isolation means is in vibration isolation operation. means and
An imaging device comprising: gain changing means for changing the gain for the second signal according to information for changing the gain . The imaging device is capable of attaching and detaching an interchangeable lens, and includes an imaging device that captures an image of a subject, a motion vector detection unit that detects a motion vector using an output from the imaging device, and a first signal indicating the motion vector. A method for controlling an imaging device, comprising: a camera vibration isolating means that performs a vibration damping operation to move the image sensor so as to reduce image blur according to the image stabilization;
The interchangeable lens generates a correction signal using a second signal based on an output from a vibration detection means for detecting shake, and performs a vibration-proofing operation of moving the vibration-proof lens based on the correction signal,
The control method includes:
receiving information from the interchangeable lens indicating whether or not the interchangeable lens is in anti-vibration operation;
Acquiring information for changing the gain for the second signal in generating the correction signal according to the first signal detected when the interchangeable lens is in anti-vibration operation;
A method for controlling an imaging device, comprising the step of transmitting information for changing the acquired gain to the interchangeable lens. The imaging device is capable of attaching and detaching an interchangeable lens, and includes an imaging device that captures an image of a subject, a motion vector detection unit that detects a motion vector using an output from the imaging device, and a first signal indicating the motion vector. A computer of an imaging apparatus having a camera vibration isolating unit that performs a vibration damping operation that moves the image sensor so as to reduce image blur according to the image blur is caused to execute processing according to the control method according to claim 12. A computer program that does.