JP2012088596A - Optical device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform tap detection with high accuracy in an optical device having a vibration control function based on angular speed detection, by using an estimation result of an acceleration disturbance applied to the device.SOLUTION: The optical device executes a function corresponding to a tapping operation of softly tapping a device body and drives a correction member (shift lens) in a direction orthogonal to an optical axis to correct image blur. An angular speed detection unit 218 detects an angular speed of deflection applied to the device. A position detection unit 105 detects a position of the correction member. A disturbance estimation unit 106 estimates an acceleration disturbance applied to the device, and a tap detection unit 107 determines that the tapping operation has been performed if the estimated acceleration disturbance is equal to or larger than a threshold. A characteristic change unit 108 changes vibration control characteristics when the tap detection unit 107 is detecting the tapping operation, and controls a cut-off frequency of a digital filter unit 101 or a gain of a target position calculation unit 102 so as to retain the correction member in a position in which the correction member was located when the tapping operation was detected.

Description

  The present invention relates to an optical apparatus having an image stabilization control function and a control method therefor.

Recent optical devices such as digital cameras are equipped with a camera shake correction function, and several methods are known. A general system includes an angular velocity sensor for detecting a camera shake, an arithmetic unit that integrates the detected angular velocity, and a drive unit that moves a shift lens or an image sensor in a direction in which camera shake is corrected.
Further, when the user operates the imaging device, it is common to use an input device such as a button, switch, or wheel installed in the imaging device. However, as the image pickup apparatus is further reduced in size, a space for installing the input device as described above is limited. Therefore, in addition to an operation with a normal input device, so-called tapping detection (hereinafter referred to as tap detection) has been proposed in which an input is given by tapping a touch panel or an imaging device. In the apparatus disclosed in Patent Document 1, a sensor for detecting acceleration is arranged, and when a predetermined signal pattern is input, a corresponding function is executed.

JP 2008-176661 A

In an apparatus as shown in Patent Document 1, it is necessary to arrange an acceleration sensor for tap detection. Although a method of performing tap detection only by the output of the angular velocity sensor for detecting camera shake is conceivable, the angular velocity sensor only detects rotation in the pitch direction or yaw direction applied to the imaging device. In tap detection, it is necessary to accurately detect not only the rotational direction applied to the imaging apparatus but also the translational movement. In addition, it is necessary to take measures to prevent a drop in the anti-vibration performance immediately after the tapping operation and prevent troubles in tap detection.
Accordingly, an object of the present invention is to perform tap detection with high accuracy using an estimation result of acceleration disturbance applied to the device in an optical device having an image stabilization control function based on angular velocity detection.

In order to solve the above problems, an apparatus according to the present invention performs a function corresponding to a tapping operation of hitting an apparatus main body and drives an correcting member in a direction orthogonal to the optical axis to correct an image blur. An angular velocity detection means for detecting an angular velocity of a shake applied to the optical device, a position detection means for detecting the position of the correction member, an angular velocity detection signal by the angular velocity detection means, and a position detection signal by the position detection means And a control means for calculating the drive control amount of the correction member and controlling the drive of the correction member.
The control means applies to the optical device by performing reverse characteristic conversion on the position detection signal using data of reverse characteristics related to gain characteristics of position control in a state in which no disturbance is applied to the optical device. A disturbance estimation means for estimating the acceleration disturbance, a tap detection means for determining that a tapping operation has been performed when the magnitude of the acceleration disturbance estimated by the disturbance estimation means is equal to or greater than a threshold, and the tap detection means A characteristic changing means is provided for changing the image stabilization control characteristic so that the correction member is kept at the position when the tapping action is detected when the movement is being detected.

  According to the present invention, tap detection can be performed with high accuracy using an estimation result of acceleration disturbance applied to an optical device without mounting an acceleration sensor.

It is a block diagram showing an example of composition of an imaging device as an optical apparatus concerning one embodiment of the present invention. FIG. 6 is a block diagram illustrating a configuration example for performing camera shake correction and tap detection in order to describe the first embodiment of the present invention in conjunction with FIGS. 3 to 5; It is the graph which illustrated the frequency characteristic (A) and reverse frequency characteristic (B) of a shift lens unit. It is a flowchart explaining camera shake correction and tap detection. It is a graph explaining an example of an attenuation gain table. FIG. 8 is a block diagram illustrating a configuration example for performing camera shake correction and tap detection in order to describe the second embodiment of the present invention in conjunction with FIG. 7. It is a flowchart explaining camera shake correction and tap detection.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. As an optical apparatus according to an embodiment of the present invention, an application example to an image pickup apparatus having a tapping function and a camera shake correction function for executing a desired function by tapping the apparatus main body will be described. Control for moving a correction lens (shift lens) or an image sensor as a correction member is known as a camera shake correction method. However, since the present invention can be applied to any method, a shift lens is used as a correction member in the following. Will be described.

FIG. 1 is an overall block diagram illustrating a configuration example of a digital camera as an imaging apparatus according to an embodiment of the present invention.
The zoom unit 201 constituting the imaging optical system includes a zoom lens for zooming. The zoom drive control unit 202 controls the drive of the zoom unit 201. The shift lens unit 203 as a shake correction optical system includes a shift lens whose position can be changed in a plane substantially perpendicular to the optical axis. The image stabilization control unit 204 controls driving of the shift lens unit 203.
The aperture / shutter unit 205 is used for exposure control, and the aperture / shutter drive control unit 206 controls driving of the aperture / shutter unit 205. The focus unit 207 includes a focus adjustment lens that performs focus adjustment. A focus drive control unit 208 controls driving of the focus unit 207. Each drive control unit receives a control signal from a control unit 212 described later, and performs drive control of each unit.
An imaging unit 209 including an imaging element converts a light image that has passed through each lens group into an electrical signal. The imaging signal processing unit 210 converts the electrical signal output from the imaging unit 209 into a video signal. The video signal processing unit 211 processes the video signal output from the imaging signal processing unit 210 according to the application.
The control unit 212 controls the entire system, and performs various processes by interpreting and executing a program (not shown) by a CPU (Central Processing Unit). The display control unit 213 performs display control of the image obtained by the video signal processing unit 211. The display unit 214 displays an image according to the video signal output from the display control unit 213. The power supply unit 215 supplies power to each part of the system as needed. The operation unit 216 is a user interface for operating the imaging apparatus, and transmits a user operation instruction to the control unit 212. The storage unit 217 stores various data such as video information and control parameters. The angular velocity detection unit 218 includes an angular velocity sensor that detects shake such as camera shake, and sends an angular velocity detection signal to the image stabilization control unit 204.

Next, the operation of the imaging apparatus having the above configuration will be described.
The operation unit 216 includes a shutter release button and includes a two-stage switch that is turned on or off according to the operation. When the user presses the shutter release button about halfway, the first switch SW1 is turned on. The focus drive control unit 208 drives the focus unit 207 to perform focus adjustment, and the aperture / shutter drive control unit 206 drives the aperture / shutter unit 205 to set an appropriate exposure amount. Further, when the user presses the shutter release button all the way down and the second switch SW2 is turned on, the image data obtained from the light image exposed to the imaging unit 209 is stored in the storage unit 217. At this time, if there is an instruction to turn on the shake correction function from the operation unit 216, the control unit 212 instructs the image stabilization control unit 204 to perform a shake correction operation. In response to this, the image stabilization control unit 204 performs shake correction control until the control unit 212 gives an instruction to turn off the shake correction function. When the operation unit 216 has not been operated for a predetermined time or more, the control unit 212 issues an instruction to cut off the power supply to the display unit 214 and the like in order to save power.
The operation unit 216 is provided with mode designation means (not shown), and the user can select a still image shooting mode and a moving image shooting mode. In each mode, the operating conditions of the actuator and the like are changed. When the user operates the operation unit 216 and receives a zooming instruction from the zoom unit 201, the control unit 212 receives this and issues an instruction to the zoom drive control unit 202. The zoom drive control unit 202 drives the zoom unit 201 to move the zoom lens to the instructed zoom position. At the same time, the focus drive control unit 208 drives the focus unit 207 to perform focus adjustment. At that time, the control unit 212 detects the focus state based on the image information processed by the video signal processing unit 211 and sends a focus adjustment control signal to the focus drive control unit 208.

[First Embodiment]
FIG. 2 is a block diagram showing a configuration example for performing tap detection together with camera shake correction in the first embodiment of the present invention. The angular velocity detection unit 218 includes a sensor that detects an angular velocity in the vertical direction (also referred to as the PITCH direction) of the imaging device and a sensor that detects an angular velocity in the lateral direction (also referred to as the YAW direction) of the imaging device. Since the configuration of the image stabilization control unit is the same except for the difference in detection direction, only the configuration of the image stabilization control unit in the vertical direction will be described below.
The image stabilization control unit 204 determines a target position from the amount of shake correction in the vertical direction, and sends a drive signal to an actuator (not shown) to control the position of the shift lens unit 203. The position detection unit 105 detects the position of the shift lens unit 203. The shift lens unit 203 is provided with a magnet, and the position detection unit 105 detects the magnetic field. Control that selectively combines PID control, that is, P (proportional) control, I (integral) control, and D (differential) control, as described later, using a signal indicating the actual position of the shift lens unit 203 and a target position. Is done. In this way, even when camera shake or the like occurs in the image pickup apparatus, image blur at the time of shooting can be prevented by driving control of the shift lens unit 203.

Next, components of the image stabilization control unit 204 will be described.
The AD converter 100 receives the angular velocity detection signal from the angular velocity detector 218 and converts the analog data into digital data. The converted signal is sent to the digital filter unit 101. The digital filter unit 101 includes a high-pass filter (hereinafter referred to as HPF) 101a capable of changing a cutoff frequency and a low-pass filter (hereinafter referred to as LPF) 101b. The HPF 101a cuts a DC (direct current) component included in the angular velocity detection signal, and the LPF 101b converts the angular velocity detection signal into an angle signal. The shake is detected from the angle obtained by integrating the angular velocity. The digital filter unit 101 outputs the processed signal to the target position calculation unit 102.
The target position calculation unit 102 multiplies the angle data processed by the digital filter unit 101 by a distance conversion constant for converting the angle into a distance, and calculates a shake correction amount as the target position. Further, the target position calculation unit 102 attenuates the target position according to the position of the shift lens unit 203 to prevent the position of the shift lens unit 203 from staying at the control end (the limit position of the drive control range). The target position information output from the target position calculation unit 102 is sent to the first subtraction unit DEC1, where the deviation between the target position and the lens position indicated by the position detection signal obtained from the position detection unit 105 is calculated. The PID control unit 103 calculates a feedback control amount so that this deviation becomes zero. The PID control unit 103 obtains a control amount from the deviation between the target position and the lens position, and outputs a position command to the drive signal output unit 104 via the second subtraction unit DEC2. As a result, the shift lens is driven to the target position along the direction orthogonal to the optical axis, and camera shake correction is performed.
The second subtraction unit DEC2 subtracts the output of the disturbance estimation unit 106 from the output of the PID control unit 103 and outputs the result to the drive signal output unit 104. FIG. 2 schematically shows that a disturbance is added to the drive control amount. The disturbance estimation unit 106 estimates acceleration disturbance using the drive control amount and the position information of the shift lens unit 203. By feeding back the estimated disturbance amount to the control amount, the responsiveness to the disturbance is improved, and the follow-up accuracy of the shift lens unit 203 to the target position is increased.
The disturbance estimation unit 106 includes an inverse characteristic conversion unit 106 a that models the inverse frequency characteristic of the shift lens unit 203, and a position detection signal from the position detection unit 105 is input thereto.

FIG. 3 is a graph for explaining an example of the frequency characteristic and the inverse frequency characteristic of the shift lens unit 203, where the horizontal axis represents frequency (Hz) and the vertical axis represents gain (dB).
FIG. 3A illustrates frequency characteristics in a state where no disturbance is applied to the imaging apparatus. In general, vibration of camera shake is a composite waveform of a sine wave. Therefore, a change in response gain with respect to a sine wave for each frequency becomes a frequency characteristic of the shift lens with respect to camera shake. In this example, the gain is constant in the low band, and once the frequency increases, the first peak is shown and then the gain decreases as the frequency increases. Further, in the high range, the gain decreases as the frequency increases through the second peak.
FIG. 3B illustrates the inverse frequency characteristic. In this example, the gain is constant in the low frequency range, and when the frequency increases, the bottom once appears and then increases as the frequency increases. This is a characteristic that cancels the gain characteristic in the low frequency range of FIG. Furthermore, at higher frequencies, the gain increases with increasing frequency.
In the case of an angular velocity, since it can be detected by the angular velocity detector 218, shake correction can be performed by position control. This means that when inverse conversion of the frequency characteristics of the shift lens unit 203 is performed, the gain of the angular velocity component (camera shake) is canceled for a frequency lower than that in the high frequency range. On the other hand, in the case of acceleration, since the angular velocity detection unit 218 cannot detect it, shake correction cannot be performed. As a result, even if the frequency characteristic is inversely converted, the gain of the acceleration component remains, which becomes a disturbance.

The signal converted by the inverse characteristic conversion unit 106a, that is, the signal passed through the inverse model of the dynamic characteristic model of the shift lens unit 203 is sent to the subtraction unit DEC3. The subtraction unit DEC3 subtracts the drive control amount signal related to PID control from the output signal of the inverse characteristic conversion unit 106a, obtains a disturbance estimated value that is the difference between the two, and sends it to the second subtraction unit DEC2. As a result, a so-called disturbance observer system that extracts the input end disturbance applied to the shift lens unit 203 is realized. The reason for detecting tapping by the disturbance observer system is as follows.
The disturbance estimated by the disturbance observer system is the acceleration applied to the shift lens unit 203 itself. Since the disturbance observer system estimates all the accelerations received by the shift lens unit 203 regardless of the applied direction, it can detect not only the rotation direction of the imaging apparatus but also the translational direction (shift direction). Therefore, compared to the tap detection method that uses only the output of the angular velocity sensor for detecting camera shake, in this embodiment, the shift in the shift direction that cannot be detected by the angular velocity sensor can be accurately detected. Will improve.

On the other hand, the estimated disturbance value calculated by the disturbance estimation unit 106 is also sent to a band-pass filter (hereinafter referred to as BPF) 109. The BPF 109 extracts only a specific frequency component from the input signal and sends it to the tap detection unit 107. The tap detection unit 107 compares the output value of the BPF 109 with a preset threshold value, and determines that a tapping operation has been performed when an acceleration disturbance equal to or greater than the threshold value is detected.
The determination result of the tap detection unit 107 is sent to the characteristic change unit 108. The characteristic changing unit 108 receives the signal digitized by the AD converting unit 100 and changes the cutoff frequency of the HPF 101a or LPF 101b in the digital filter unit 101 based on the relationship with the tap detection result. Alternatively, the characteristic change unit 108 changes the attenuation rate for the target position signal set by the target position calculation unit 102.

Next, the shake correction operation in the present embodiment will be specifically described with reference to the flowchart shown in FIG.
First, when the image pickup apparatus is turned on, the image stabilization control operation starts (S501). The image stabilization control operation is executed in the vertical direction and the horizontal direction of the imaging apparatus by a control interrupt process that occurs at a constant period (for example, 125 μsec). When a control interruption occurs, an angular velocity detection signal is acquired by the angular velocity detector 218 (S502). In the angular velocity detection signal, the DC component is cut by the HPF 101a in the digital filter unit 101, and the angular velocity is converted into an angle by integration processing by the LPF 101b (S503). Then, the target position calculation unit 102 calculates a target position related to the position control of the shift lens unit 203.
The position detection unit 105 detects the position of the shift lens unit 203 (S504), and the first subtraction unit DEC1 calculates a deviation between the target position and the current position (S505). The PID control unit 103 performs calculation so that the deviation becomes zero (S506). The disturbance estimation unit 106 estimates the disturbance from the drive control amount output from the second subtraction unit DEC2 and the current position of the shift lens unit 203 (S507). The second subtraction unit DEC2 subtracts the estimated disturbance amount from the control amount output from the PID control unit 103, and calculates the drive control amount (S508). The disturbance shown in FIG. 2 is canceled by the estimated disturbance amount, the drive control amount is sent to the drive signal output unit 104, and a drive signal for the shift lens unit 203 is output (S509). The shift lens unit 203 is driven according to a drive signal by an actuator (not shown). This improves the accuracy of position control that follows the target position.

On the other hand, the estimated disturbance value used for position control of the shift lens unit 203 represents the influence of gravity and the magnitude of disturbance such as panning and tapping. If this estimated disturbance value is observed, it can be used for tapping operation detection processing. However, since the estimated disturbance value is an estimated value of all disturbances applied to the shift lens unit 203, it is difficult to accurately perform tap detection if it is used as it is. Due to the nature of disturbance components generally assumed, the gravity term appears as a constant DC component depending on the attitude of the imaging apparatus, and the panning operation and camera shake generally appear at a low frequency vibration of 10 Hz or less. On the other hand, the tapping operation is a disturbance with a relatively high frequency applied in a pulse shape. Therefore, by extracting only a relatively high frequency component from the estimated disturbance value using the BPF 109, only the influence of the disturbance due to the tapping operation can be detected. The BPF 109 performs bandpass filter processing on the estimated disturbance value (S510). In S511, the tap detection unit 107 compares the estimated disturbance value extracted only in a specific frequency band with a preset threshold value. If the estimated disturbance value is equal to or greater than the threshold value and the level of the angular velocity detection signal from the AD conversion unit 100 is equal to or greater than the threshold value, the tap detection unit 107 determines that a tapping operation has been performed, and proceeds to S513 to detect tap detection. Turn on the flag. The value of the tap detection flag indicates whether a tap ping operation is being detected. When a tapping operation is detected, the detection signal is notified to the control unit 212, and processing for executing a function corresponding to the tapping operation is performed.
If the determination condition is not satisfied in S511 (in the case of NO), the tap detection unit 107 determines that the tapping operation is not performed, proceeds to S512, turns off the tap detection flag, and ends the process. In some cases, disturbance due to camera shake and disturbance due to tapping cannot be distinguished only by frequency. Regarding the discrimination between the two, the estimated disturbance value by the tapping operation is larger than the estimated disturbance value due to the influence of camera shake, and can be dealt with by adjusting the threshold used for tap detection. Further, the reason for not only determining the level of the estimated disturbance value but also determining the level of the angular velocity detection signal for tap detection is as follows. For example, the estimated disturbance value may be large when frictional changes (such as a rubbed surface) applied to the shift lens unit 203 or when the shift lens is in the vicinity of the control end and the image stabilization control is performed. In this case, if the tap detection is performed only by determining the level of the estimated disturbance value, there is a possibility that erroneous detection is caused. Therefore, erroneous detection can be avoided by determining the level of the angular velocity detection signal and using the determination result. In simultaneous observation of the angular velocity detection signal and the estimated disturbance value, a disturbance applied only to the movable part of the shift lens unit 203 and a disturbance applied to the entire imaging apparatus can be distinguished and detected.

By the way, when the estimated disturbance value applied to the shift lens unit 203 is used in tap detection in parallel with the image stabilization control operation, the tap detection is hindered due to a decrease in image stabilization performance immediately after the tapping operation, saturation of the estimated disturbance value, or the like. It is necessary to take measures to avoid it. For example, when the lens position at the time of image stabilization is near the control end, the tapping operation causes the lens target position to remain in the vicinity of the control end position, and the estimated disturbance value remains saturated. Can be mentioned. As a countermeasure, a process of returning the shift lens position to the center of the drive control range as much as possible during the detection of the tapping operation or a process of preventing the shift lens position from staying near the control end position is necessary. The vicinity of the control end position means a range that includes a position within a certain range from the control end position and in which the shift lens may stay.
During the detection of the tapping operation, the characteristic changing unit 108 changes the image stabilization control characteristic in S514 and keeps the shift lens at the position when the tapping operation is detected to suppress the stay near the control end position. Specific examples of the characteristic change include the following forms.
(A) The control form which changes the cut-off frequency of the digital filter part 101 which filters an angular velocity detection signal.
(B) A control mode by changing attenuation processing for the angular velocity detection signal.

In the control mode (A), the digital filter unit 101 changes the cutoff frequency of the LPF 101b in S514 when it is determined that the tap is being detected by looking at the value of the tap detection flag. For example, the characteristic changing unit 108 changes the cutoff frequency of the LPF 101b that converts the angular velocity detection signal into an angle signal when it is determined that tap detection is being performed, and changes the cutoff frequency when it is determined that tap detection has ended. Change to the low frequency side. By ignoring the influence of the low frequency component included in the angular velocity detection signal, it is possible to prevent the lens target position from staying in the vicinity of the control end position. Here, an example of changing the cutoff frequency of the LPF 101b has been described, but the same effect can be obtained by changing the cutoff frequency of the HPF 101a for removing DC components.
In the case of the control mode (B), the characteristic changing unit 108 changes the attenuation gain table of the angular velocity detection signal in S514. The attenuation process is a process of multiplying the angular velocity detection signal by a gain (attenuation gain K) so that the magnitude of the signal becomes smaller as the shift lens position is closer to the control end position. When the angular velocity of shake is ω, the lens position (angle) is θ, the angular velocity ω before attenuation processing is ω1, and the angular velocity ω after attenuation processing is ω2, the relationship between them is as follows. However, the attenuation gain K is the ratio of the output magnitude (ω2) after the attenuation process to the output magnitude (ω1) before the attenuation process.

上式中のω１，ω２，θは時間ｔの関数であり、Ｋはθの関数である。
図５は減衰ゲインテーブルの一例をグラフで示す。縦軸は減衰ゲインＫを百分率で表し、横軸はシフトレンズユニット２０３の位置を表す。「メカ中心」はシフトレンズの駆動制御範囲の中心位置を表し、「メカ制御端」は駆動制御範囲における、いずれか一方の制御端位置を表す。減衰ゲインテーブルに示す値は、シフトレンズユニット２０３の位置に応じて変化する。グラフ線５０１は通常時の減衰ゲインテーブルを表しており、レンズ駆動のメカ中心位置で減衰ゲインＫの値が１００％、つまり減衰処理前の角速度検出信号の大きさ（ω１）に対して減衰処理後の角速度検出信号の大きさ（ω２）が同じである。このとき、係数値として１倍がかかるため角速度信号は減衰しない（ω２＝ω１）。そして、レンズ位置が中心位置からある程度離れると、Ｋ値が次第に小さくなっていき、メカ制御端で０％となる。つまり、レンズ位置がメカ制御端に近づくほど、角速度ω２が小さくなり、これによりレンズ目標位置が大きくならないように抑制できる。
タップ検出時には、減衰ゲインテーブルがグラフ線５０２に示すように変更される。本例ではＫ値がメカ中心位置で１００％であり、メカ制御端に近づくにつれてＫ値が次第に小さくなり、メカ制御端にて０％となる。タップ検出の終了時には通常の減衰ゲインテーブル（グラフ線５０１参照）に戻す処理が行われる。タップ検出中、減衰ゲインＫの乗算によって角速度信号がより早く小さくなるので、シフトレンズ位置が制御端位置に留まらないように防止できる。

In the above equation, ω1, ω2, and θ are functions of time t, and K is a function of θ.
FIG. 5 is a graph showing an example of the attenuation gain table. The vertical axis represents the attenuation gain K as a percentage, and the horizontal axis represents the position of the shift lens unit 203. “Mechanical center” represents the center position of the drive control range of the shift lens, and “Mechanical control end” represents one of the control end positions in the drive control range. The value shown in the attenuation gain table changes according to the position of the shift lens unit 203. A graph line 501 represents an attenuation gain table in a normal state. The attenuation gain K is 100% at the mechanical center position of the lens drive, that is, the attenuation process is performed with respect to the magnitude (ω1) of the angular velocity detection signal before the attenuation process. The magnitude (ω2) of the subsequent angular velocity detection signal is the same. At this time, since the coefficient value is multiplied by 1, the angular velocity signal is not attenuated (ω2 = ω1). When the lens position moves away from the center position to some extent, the K value gradually decreases and becomes 0% at the mechanical control end. That is, the closer the lens position is to the mechanical control end, the smaller the angular velocity ω2, thereby suppressing the lens target position from becoming large.
When a tap is detected, the attenuation gain table is changed as indicated by the graph line 502. In this example, the K value is 100% at the mechanical center position, and as the mechanical control end is approached, the K value gradually decreases and becomes 0% at the mechanical control end. At the end of tap detection, processing for returning to the normal attenuation gain table (see graph line 501) is performed. During tap detection, the angular velocity signal is reduced earlier by multiplication of the attenuation gain K, so that the shift lens position can be prevented from remaining at the control end position.

  According to the first embodiment, it is not necessary to provide a special sensor such as an acceleration sensor in an imaging apparatus having a camera shake correction function based on angular velocity detection, and tap detection is performed by obtaining an estimation result of acceleration disturbance applied to the apparatus. Can do. Further, it is possible to achieve both the improvement of the vibration isolation performance immediately after the tapping operation and the improvement of the tap detection accuracy.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 6 shows a configuration example of an apparatus according to the second embodiment. Since the configuration of the imaging apparatus is basically the same as that of the first embodiment, differences will be described below. In this embodiment, an adjustment presence / absence notification unit 300, a zoom drive control unit 202, and a lens position determination unit 301 are added.
The adjustment presence / absence notification unit 300 notifies the tap detection unit 107 whether or not the camera shake correction function has been adjusted. The adjustment of the camera shake correction function is an adjustment performed to adjust the detection sensitivity of the angular velocity detection sensor, the variation in detection sensitivity of the position detection sensor, etc., and to correct the relationship of the shift lens movement amount with respect to the angular velocity detection signal. . The zoom drive control unit 202 notifies the tap detection unit 107 whether or not the zoom unit 201 that changes the focal length of the optical system is being driven. The lens position determination unit 301 acquires position information from the position detection unit 105, determines the position of the shift lens unit 203, and notifies the determination result to the tap detection unit 107. The determination condition is whether or not the lens position is within a predetermined range from the center of the drive control range.

Next, the shake correction operation of this embodiment will be specifically described with reference to the flowchart shown in FIG. The difference from FIG. 4 is S701 to S703 between S511 and S513, and these processes will be described below.
If it is determined in S511 that the estimated disturbance value is equal to or greater than the threshold and the level of the angular velocity detection signal is equal to or greater than the threshold (YES in S511), the process proceeds to S701. In response to the notification from the adjustment presence / absence notification unit 300, the tap detection unit 107 determines whether the camera shake correction function has been adjusted. When the adjustment of the camera shake correction function is not adjusted, the process proceeds to S512, the tap detection flag is turned off, and the process is ended (S515). If the camera shake correction function is not adjusted correctly, the position of the shift lens tends to remain near the control end, and disturbance estimation may not be performed correctly. Therefore, in order to prevent erroneous detection, the tap detection is set not to be performed.

  On the other hand, if it is determined in S701 that the camera shake correction function has been adjusted, the process proceeds to S702. The tap detection unit 107 receives a notification from the zoom drive control unit 202 as to whether zoom driving is in progress. If the zoom is being driven, the process proceeds to S512, where the tap detection flag is turned off and the process is terminated (S515). During zoom driving, the shift lens may be disturbed by mechanical vibrations of the zoom mechanism and the like, which may cause erroneous tap detection. In order to prevent this, it is set not to perform tap detection.

  On the other hand, if it is determined in S702 that the zoom drive is not being performed, the tap detection unit 107 receives the determination result from the lens position determination unit 301, and the position of the shift lens unit 203 is within a predetermined range from the center of the drive control range. It is determined whether or not (S703). The predetermined range is determined in advance by actual measurement or the like, and a comparison reference value is set. When the position of the shift lens unit 203 exceeds a predetermined range from the center of the drive control range, the lens position remains at the control end position, and erroneous detection may occur during tap detection. Accordingly, the process proceeds to S512, where the tap detection flag is turned off and the process is terminated (S515). If the position of the shift lens unit 203 is within a predetermined range from the center of the drive control range, the process proceeds to S513.

  According to the second embodiment, by adding the determination condition as to whether or not to perform tap detection, the accuracy of tap detection can be improved, and erroneous detection can be avoided.

  In the above embodiment, a digital camera has been described as an example of an optical device, but the present invention is not limited to a digital camera. The present invention is widely applicable to, for example, video cameras, optical devices such as interchangeable lenses used in video cameras and single-lens reflex cameras, and electronic devices including an imaging optical system such as a mobile phone.

DESCRIPTION OF SYMBOLS 101 Digital filter part 102 Target position calculation part 105 Position detection part 106 Disturbance estimation part 107 Tap detection part 108 Characteristic change part 202 Zoom drive control part 218 Angular velocity detection part 300 Adjustment presence notification part 301 Lens position determination part

Claims (10)

An optical device that performs a function corresponding to a tapping operation of hitting the device main body and corrects image blur by driving a correction member in a direction orthogonal to the optical axis,
Angular velocity detection means for detecting angular velocity of vibration applied to the optical device;
Position detecting means for detecting the position of the correction member;
Control means for calculating the drive control amount of the correction member by using the angular velocity detection signal by the angular velocity detection means and the position detection signal by the position detection means and performing drive control of the correction member;
The control means includes
Acceleration disturbance applied to the optical device is estimated by performing inverse characteristic conversion on the position detection signal using inverse characteristic data related to gain characteristics of position control in a state in which no disturbance is applied to the optical device. Disturbance estimation means for
Tap detecting means for determining that the tapping operation has been performed when the magnitude of the acceleration disturbance estimated by the disturbance estimating means is equal to or greater than a threshold;
When the tap detection means is detecting a tapping operation, the apparatus has a characteristic changing means for changing the image stabilization control characteristic so as to keep the correction member at the position when the tapping operation is detected. Optical equipment.   The tap detection means determines that a tapping operation has been performed when the magnitude of the acceleration disturbance is equal to or greater than a threshold and the magnitude of the angular velocity detection signal is equal to or greater than the threshold. The optical apparatus according to 1. The disturbance estimation means includes:
Reverse characteristic conversion means for performing the reverse characteristic conversion;
The optical apparatus according to claim 1, further comprising a subtracting unit that subtracts a drive control amount of the correction member from an output of the inverse characteristic converting unit to calculate the acceleration disturbance. The control means further includes a filter means capable of changing a cutoff frequency for performing a filtering process on the angular velocity detection signal,
The characteristic changing unit is configured to cut off the filter unit so as to suppress the retention of the correction member in the vicinity of the control end position of the drive control range of the correction member when the tap detection unit is detecting a tapping operation. 4. The optical apparatus according to claim 1, wherein the frequency is changed. The control means performs an attenuation process for attenuating the angular velocity detection signal,
The characteristic changing unit is configured to reduce the magnitude of the angular velocity detection signal when the tap detection unit is detecting a tapping operation, so that the magnitude of the angular velocity detection signal is smaller than when the tap detection unit is not detecting the tapping operation. The optical apparatus according to claim 1, wherein the optical device is changed.   The characteristic changing means reduces the gain in the attenuation process as the correction member approaches the control end position from the center position of the drive control range when the tap detection means is detecting a tapping operation. The optical apparatus according to claim 5. An adjustment presence / absence notification means for notifying the tap detection means whether or not the movement amount of the correction member with respect to the angular velocity detection signal has been adjusted;
The tap detection means does not detect the tapping operation when notified that the adjustment is not performed from the adjustment presence / absence notification means. Optical equipment. Zoom drive control means for controlling the focal length of the optical system of the optical apparatus,
8. The tapping operation is not detected when the tap detection unit is notified from the zoom drive control unit that the focal length is changed. 8. The optical instrument described. A position determination means for determining whether or not the position of the correction member detected by the position detection means exceeds a preset range;
9. The tap detection unit does not detect the tapping operation when notified from the position determination unit that the position of the correction member exceeds a preset range. The optical apparatus according to any one of the above. A control method executed by an optical device that performs a function corresponding to a tapping operation of hitting the device body and corrects image blur by driving a correction member in a direction orthogonal to the optical axis,
A detection step of detecting an angular velocity of shake applied to the optical device and a position of the correction member;
A control step of performing drive control of the correction member by calculating a drive control amount of the correction member using the angular velocity detection signal and the position detection signal detected in the detection step;
The control step includes
Acceleration disturbance applied to the optical device is estimated by performing inverse characteristic conversion on the position detection signal using inverse characteristic data related to gain characteristics of position control in a state in which no disturbance is applied to the optical device. A disturbance estimation step,
A tap detection step of determining that the tapping operation has been performed when the magnitude of the acceleration disturbance estimated in the disturbance estimation step is equal to or greater than a threshold;
An optical apparatus comprising: a characteristic changing step of changing an image stabilization control characteristic so that the correction member is held at a position when the tapping action is detected during the detection of the tapping action in the tap detecting step. Control method.

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