JP3186219B2 - Image stabilization device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration detecting means such as an angular velocity sensor for detecting vibration applied to an optical device, and to correct the vibration of the optical axis of the optical device due to the vibration, that is, to remove the influence of the vibration. The present invention relates to an improvement in an image blur prevention device including a correction optical unit such as a variable apex angle prism.

[0002]

2. Description of the Related Art A conventional example to which the present invention is applied will be described below by taking a video movie as an example.

In recent years, in video movies, focus,
Since all important operations for photographing an iris and the like are automated, even a person unskilled in the operation is less likely to cause a photographing failure.

[0004] In addition, the size and weight of video movies have been reduced, and it has become easier to carry them and to easily shoot them with one hand.

[0005] However, conversely, the image fluctuation of the photographed image has become conspicuous. Therefore, a technique for preventing a photographing failure due to camera shake has recently been studied.

[0006] The above-mentioned camera shake is usually 1 Hz in frequency.
Although it is a vibration of about 12 Hz, in order to be able to capture an image in which no shake occurs even if such a shake occurs, the vibration of the video movie due to the shake is detected,
In accordance with the detected value, the correction optical means must be displaced in accordance with the direction of the vibration displacement. Therefore, in order to achieve the above object, it is important to accurately detect camera vibration.

In principle, the detection of the shake of a video movie is, for example, an angular acceleration sensor that outputs an angular acceleration signal and an angular velocity signal, an angular velocity sensor, and a first-order integration of the angular acceleration signal and the angular velocity signal. This can be performed by mounting a shake detection system including integration means for outputting an angular velocity signal and an angular displacement signal by performing second-order integration on a video movie.

Here, an outline of a shake detection system using an angular velocity sensor will be described with reference to FIG.

In the example shown in FIG. 12, a vertical motion of a video movie in a pitch (PITCH) direction indicated by an arrow 54a and a yaw (YA) indicated by an arrow 54b are perpendicular to the optical axis.
FIG. 2 is a diagram of a system for detecting a horizontal shake of a video movie in a W) direction. Reference numeral 52 denotes a lens barrel having a correction optical system. Angular velocity sensors 53a and 53b (not shown) for detecting minute vertical velocities of the vertical, horizontal, and shake of the video movie are provided near the lower part of the front of the lens barrel. It is attached at an arbitrary position so as to coincide with the correction axis of the means.

Here, the angular velocity signal θ detected by the angular velocity sensor 53a is integrated by an integrator 55a, converted into an angular displacement signal d, and this is used as a detected shake signal to correct image blur. Consider the case.

FIG. 13A shows the operation of the first-order integrator 55a. The angular velocity signal θ input to the integrator 55a is converted here as an angular displacement signal d. However, the angular velocity sensor 53a actually includes a slight DC component as a bias, as indicated by the angular velocity signal in FIG. If an output including such a bias component is integrated by the integrator 55a as it is, the bias component is also integrated, and the resulting angular displacement signal includes an error as shown in FIG. 13B. .

In order to solve this problem, a method of connecting high frequency band pass means (high pass filter, hereinafter referred to as HPF) before inputting to the integrator 55a has been considered.
That is, a configuration in which the HPF 56a is added to the portion surrounded by the broken line in FIG. Thereby, the angular velocity sensor 5
The angular velocity signal θ detected by the HPF 56a
According to (56b), an output having a DC component or an extremely low frequency component is blocked, so that the integration of the bias component in the integrator 55a is reduced. Therefore, if the correction optical system is driven by a shake signal corresponding to the integrated output (angular displacement signal d) in this configuration, image shake can be removed.

The HPF 56a (56b) comprises a resistor 57 and a capacitor 58, for example, as shown in FIG. 14, and the integrator 55a (55b) comprises an operational amplifier 59, a capacitor 60 and a resistor 61.

Here, as described above, the cutoff frequency of the HPF 56a which has a function of blocking an output having a DC component or an extremely low frequency component is a resistance 57 and a capacitor 5
8 is determined by the time constant. Normally, the camera shake that can occur when shooting with a camera is 1 to 12 Hz as described above.
Therefore, the cutoff frequency may be set low so as not to affect this range. As a specific example, a resistor 5
If 7 is set to “3 MΩ”, the capacitor 58 is set to “1 μF”, and the time constant is set to “3 seconds”, the bias component can be removed while reducing the influence on the camera shake detection.

[0015]

However, in this type of apparatus, when the photographer suddenly changes the angle of view, such as panning and tilting, the moving angular velocity and the moving angular displacement of the photographing apparatus vary. In some cases, there are limitations in the image correction system and the like, and there is a difficulty in adapting.

In general, when photographing a moving image, the following two photographing modes can be roughly classified.

One is a mode for continuously taking a picture with the same composition, and the other is a mode for taking a picture while changing the composition.
That is, the shooting mode is performed while performing camera work such as panning and tilting. In the former shooting mode, since the same composition is used for shooting, image blurring during high-magnification zooming is particularly problematic, and a shooting device having a conventional image stabilizing function reduces image blurring in this shooting mode. is there. On the other hand, in the latter photographing mode, it is important that the screen can be determined according to the photographer's will.

Here, if a photographing apparatus in which the image stabilization characteristics are set so as to suppress the image blur in the former photographing mode is used in the latter photographing mode, it is possible to quickly respond in a direction desired by the photographer. Operability is significantly impaired. This is because, when an abrupt angle-of-view change operation such as panning or tilting is performed, this is determined to be a camera shake, and a function for suppressing this, that is, an image stabilizing function is activated.

As described above, the function of suppressing image blur and the function of quick response to a sudden change in the angle of view of the photographer are contradictory. In a photographing apparatus having this kind of image stabilizing function, the latter is used. In order to correspond to the shooting mode,
The configuration is such that the image stabilizing function can be suppressed or invalidated. However, a configuration in which the photographer inputs a distinction between the former and latter photographing modes by a switch and changes the characteristics of the image stabilizing function in accordance with the switch needs to be avoided from the viewpoint of operability. That is, it is desirable to automatically change the image stabilizing characteristics according to the camera operation of the photographer. In addition, the change in the image stabilizing characteristics must be performed accurately so as not to cause deterioration of the quality of the photographed image or to give the photographer uncomfortable feeling.

In other words, in order to realize the above, it is necessary to automatically determine whether a camera shake or an abrupt angle-of-view change operation (panning or tilting operation) has been performed. Appropriate control of the corresponding correction optical means was required.

Next, another problem to be solved by the invention will be described.

When considering the anti-vibration function, the operation state of anti-vibration,
If there is a case where the non-operating state is switched, there is a possibility that the correction amount of the correction optical unit is set to “0” as one of the means. However, there are some controls that are inconvenient to do so. For example, when a system that performs control using a difference component between the above-described angular displacement signal and a signal indicating the correction amount of the correction optical unit is considered, another control system must be added in order to stop the image stabilization operation. In addition, when shifting from the stop state of the image stabilization to the operation state, a discontinuous state corresponding to a difference component between the angular displacement signal and the signal indicating the correction amount of the correction optical unit occurs.

An object of the present invention is to provide an image stabilizing apparatus capable of improving the image stabilizing effect in a normal still state and improving the followability and the operability in an angle-of-view changing operation state.

[0024]

[0025]

Means for Solving the Problems In order to achieve the above object, according to the present invention, a shake detecting means for detecting vibration applied to an optical device, and a shake of an optical axis of the optical device due to the vibration. A correcting optical unit for correcting, a calculating unit including a high frequency band passing unit and an integrating unit for calculating a driving amount of the correcting optical unit according to an output signal of the shake detecting unit, and an angle of view changing operation being performed. Angle change operation detecting means for detecting the time constant, and the time constant of the high frequency band passing means and the product
An image stabilization apparatus comprising : a time constant changing unit that changes a time constant of the minute unit;
When it is detected that the angle-of-view changing operation is
The time constant of the high frequency band passing means and the
By changing the time constant of the integrating means together,
It is not detected that the cutoff frequency is being changed.
Change to a higher frequency side and
This is an image blur prevention device that increases the centripetal force to the movable center of the step .

[0026] In order to achieve the above object,
The present invention described in Item 2 detects vibration applied to an optical device.
Shake detection means, and shake of the optical axis of the optical device due to the vibration
Correction optical means for correcting the vibration, and an output signal of the shake detecting means.
Calculating the driving amount of the correction optical means according to the
A calculating means including a wavenumber range passing means and an integrating means;
Angle-of-view changing operation detecting means and second angle-of-view changing operation detecting means
Wherein the first angle of view change is provided.
Detection operation means for detecting the further operation and the second angle-of-view changing operation detecting means.
Of the high-frequency band-passing means and the integrating means based on the
To selectively change one or both time constants
An image blur prevention device having constant variable means.
You.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIGS. 1A and 1B are views showing the schematic arrangement of an image blur prevention apparatus according to a first embodiment of the present invention.

In FIG. 1 (a), reference numeral 1 denotes an angular velocity detecting means composed of a vibrating gyroscope or the like for detecting camera shake, 2 an HPF for passing a high frequency component of the angular velocity signal from the angular velocity detecting means 1, and 3 an HPF 2 Integrating means 4 for integrating the angular velocity signal input through the converter and converting it into an angular displacement signal, based on the angular displacement signal from the integrating means 3, determines whether or not an angle of view changing operation such as panning or tilting is performed. This is an angle-of-view changing operation detecting means for detecting (details will be described in detail with reference to FIGS. 2 and 3). 5 is a characteristic switching means for switching the characteristics of the HPF 2 in response to a signal from the angle-of-view change operation detecting means 4, that is, a characteristic switching means for changing a high-pass band of frequency. This is a characteristic switching unit that switches the characteristic of the integrating unit 3, that is, changes the high-pass band of the frequency. Numeral 7 denotes a calculating means for calculating a driving amount of a correcting optical means to be described later based on the input angular displacement signal and a correcting signal to be described later.
A correction optical unit 9 such as a variable apex prism driven by a driving unit (not shown) in response to a signal from the controller 9 detects a current position (a displacement amount from a movable center) of the correction optical unit 8 and drives the correction signal. The correction amount detecting means outputs to the means 7.

FIG. 1 (b) shows the HPF 2, the integrating means 3,
FIG. 9 is a circuit diagram showing a specific configuration example of each of the characteristic switching means 5 and 6.

The HPF 2 includes a capacitor C 1 and a resistor R
1, R4. The integrating means 3 is a capacitor
C2 , a resistor R2 and an operational amplifier OP1. The characteristic switching means 5 is controlled by switches SW1 and SW3.
The characteristic switching means 6 includes switches SW2 and SW4, respectively. BUF1 is a buffer, and R3 is a resistor.

Here, assuming that the range of changing the high-pass band of the frequency in the characteristic switching means 5 and 6 (change range of the time constant), that is, the cutoff frequency is around 1 Hz, for example, a relatively high cutoff frequency (1Hz or more)
If the normal shooting is performed, an impression that the effect of the image stabilization is weakened is obtained. However, the ability to follow the angle-of-view changing operation such as panning (the DC component of the correction amount of the correction optical unit 8 is small, that is, Ideally, a state in which the movable center is at the center during vibration isolation is ideal). That is, as described above, by using the time constant of each of the HPF 2 and the integrating means 3, that is, the variable cutoff frequency, together with the panning detection and the like, the cutoff frequency is set to a low frequency in a normal stationary state. Strengthen the anti-vibration effect, enhance the anti-vibration effect,
In an angle-of-view changing operation state such as panning, the cutoff frequency is set to a high frequency to reduce the effect of image stabilization, thereby improving the followability and the operability. Also, by preparing a large number of these cut-off frequencies and switching them appropriately, it is possible to cope with any photographing state without feeling uncomfortable.

In the above HPF 2, only the pass band of the frequency is limited. However, feedback is applied to the integrating means 3, and when viewed as a system, the centripetal force of the correcting optical means 8 to the movable center increases. Is equivalent to

FIG. 2 is a diagram for explaining a method of detecting an angle-of-view changing operation (panning operation in the embodiment) in the angle-of-view changing operation detecting means 4.

The angle-of-view changing operation detecting means 4 determines the range of the output signal of the angular velocity detecting means 1 at each position within the entire range (movable range) in which the correcting optical means 8 can be displaced, by using the center point (angular displacement signal). Is divided into two ranges at the time of “0”), and the output signal continues to stay in one range (or the number of samplings within a certain time).
It is determined whether or not panning is performed.

That is, if the camera shake is considered to be an alternating current, the output signal of the angular velocity detecting means 1 should cross the center point within one second even if the frequency of the camera shake is 0.5 to several tens Hz. . Therefore, when the vehicle does not cross the center point within a predetermined time, it is determined that the panning operation is being performed. In addition,
The predetermined time during which the output signal of the angular velocity detecting means 1 will pass through the center point is determined by the frequency characteristic of the camera shake detecting system when the integrating means 3 is used as in this embodiment. become.

Next, the operation when the angle-of-view changing operation detecting means 4 is constituted by a microcomputer will be described with reference to the flowchart of FIG. [Step 101] An angular displacement signal from the angular velocity detecting means 1 via the integrating means 3 is fetched by A / D conversion or the like. [Step 102] The captured angular displacement signal is represented in FIG.
It is checked whether or not it is within the first range shown in FIG. As a result, if it is within the first range, the process proceeds to step 103; otherwise, the process proceeds to step 107 if it is within the second range. [Step 103] “1” is added to the counter 1 that counts that the angular displacement signal remains within the first range. [Step 104] The counter 2 used when a signal stays in another second range is reset. [Step 105] It is determined whether or not the count value of the counter 1 has reached a count number representing a predetermined time t for determining a panning operation. If not, the process returns to step 101, and if it has, the process proceeds to step 106. [Step 106] Here, a panning mode flag is set.

If it is determined in step 102 that the value is not within the first range, that is, the value is within the second range, the process proceeds to step 107 as described above. [Step 107] “1” is added to the counter 2 that counts that the angular displacement signal stays within the second range. [Step 108] The counter 1 used when a signal stays in another first range is reset. [Step 109] It is determined whether or not the count value of the counter 2 has reached a count number representing a predetermined time t for determining a panning operation. If not, the process returns to step 101; move on.

If the panning flag mode is reset simultaneously with the counter reset in steps 104 and 108, the mode can be easily switched.

Next, the operation of the apparatus including the above-described panning operation detection will be described with reference to the flowchart of FIG. [Step 201] When the power is turned on, all of the switches SW1 to SW4 are turned on so that there is no passing signal in the camera shake frequency band, and the system is stabilized by accelerating the charging time for the capacitor. . [Step 202] The correction optical unit 8 is held at the movable center. [Step 203] The state of the anti-vibration switch input from the outside is determined. If the anti-vibration switch is on, the process proceeds to step 205;
Go to 04. [Step 204] Set the switches SW1 to SW4 to O
N, and the correction optical means 8 is held at the movable center. Then, the process returns to step 203. [Step 205] Since the image stabilization switch is ON, all of the switches SW1 to SW4 are turned OFF.
A signal in a camera shake frequency range is allowed to pass, and an image stabilization operation is started. [Step 206] The state of the image stabilization switch is determined again. If the image stabilization switch is ON, the process proceeds to Step 207, and if it is OFF, the process returns to Step 204. [Step 207] It is checked whether or not it is determined that the panning operation is being performed by the angle-of-view change operation detecting means 4. If the panning operation is being performed, the process proceeds to Step 208.
Otherwise, go to step 209. [Step 208] The switch SW3 is turned on to cut off the low frequency range of the image stabilizing frequency band at a relatively high frequency compared to camera shake, and narrow the low frequency component of the pass signal band. At the same time, the switch SW4 is also turned on to increase the centripetal force of the correction optical unit 8 toward the movable center. Then, the process returns to step 206. [Step 209] Here, since the panning operation is not being performed or the panning operation has been completed, the switch S
If W3 and W4 are ON, they are turned OFF and the mode is returned to the normal mode.

If the image stabilization switch is turned off in the middle of the loop from step 206 to step 209, the process returns from step 206 to step 204, where all of the switches SW1 to SW4 are turned on and the correction optical means is turned on. Leave it held at the movable center.

(Second Embodiment) In the second embodiment, the panning mode of the first embodiment is divided into two types, that is, an angular displacement signal obtained by integrating the signal from the angular velocity detecting means 1 or a correction. A mode for detecting a panning operation in accordance with a vertical angle displacement signal from an optical unit is added.

For example, the movable center and the movable end (correction limit end)
A threshold level is provided at the midpoint between the two and the panning operation is performed when the threshold is reached from the movable end. This is referred to as a panning mode 2, and the panning mode 1 based on the panning detection shown in the first embodiment.

When the panning mode 1 is detected, the switch SW3 is turned on to limit the pass band of the angular displacement signal. In addition, the switch SW4 is turned ON by detecting the panning mode 2, and the return to the movable center is strengthened, and the centripetal force is strengthened. When the camera shake is large, it is easy to hit the movable end. In addition, when a relatively high-frequency vibration, such as in a running automobile, is applied with a large amplitude, it is better to increase the centripetal force.

FIG. 5 is a flowchart showing the operation of the image blur prevention apparatus when the above-described panning detection is performed. The circuit configuration is the same as in FIG. [Step 301] When the power is turned on, all of the switches SW1 to SW4 are turned on so that there is no passing signal in the camera shake frequency band, and the system is stabilized by accelerating the charging time to the capacitor. . [Step 302] The correction optical unit 8 is held at the movable center. [Step 303] The state of the anti-vibration switch input from the outside is determined, and if this anti-vibration switch is ON, the process proceeds to step 305;
Go to 04. [Step 304] Set the switches SW1 to SW4 to O
N and the correction optical means is held at the movable center. Then, the process returns to step 303. [Step 305] Since the image stabilization switch is ON, all of the switches SW1 to SW4 are turned OFF.
A signal in a camera shake frequency range is allowed to pass, and an image stabilization operation is started. [Step 306] The state of the image stabilization switch is determined again. If the image stabilization switch is ON, the process proceeds to Step 307, and if it is OFF, the process returns to Step 304. [Step 307] It is checked whether a flag indicating the panning mode 1 is set. If the flag is the panning mode 1, the process proceeds to step 308. If not, the process proceeds to step 309. [Step 308] The switch SW3 is turned on to cut off the low frequency range of the image stabilization frequency band at a relatively high frequency compared to camera shake, thereby suppressing the low frequency component of the pass signal band. [Step 309] When the panning mode 1 is released, the switch SW3 is turned off to return to the normal mode. [Step 310] It is checked whether or not the flag indicating the panning mode 2 is set. If the flag is the panning mode 2, the process proceeds to the step 311; otherwise, the process proceeds to the step 31.
Proceed to 2. [Step 311] The switch SW4 is turned on, the return of the correction optical unit 8 to the movable center is increased, and the centripetal force is increased. [Step 312] When the panning mode 2 is released, the switch SW4 is turned off to return to the normal mode.

If the image stabilization switch is turned off during the loop from step 306 to step 312, the process returns from step 306 to step 304, where all of the switches SW1 to SW4 are turned on, and the correction optical unit 8 is turned on. Is held at the movable center.

FIG. 6 shows the second embodiment of the present invention.
F2 is a diagram showing a change in frequency characteristics when the cutoff frequency of the integrating means 3 is changed.

(Third Embodiment) Referring to FIG.
In the second characteristic switching, the time constant is switched by changing the resistance value. In this embodiment, however, this is performed by switching the capacitance of the capacitor as shown in FIG.

In FIG. 7, C1a and C1b are capacitors corresponding to the capacitor C1 of FIG.
The time constant of the HPF 2 is switched by connecting or short-circuiting the capacitor C1b by turning ON / OFF the W3.

In the HPF 2 having this configuration, the cut-off frequency fc is changed to fc = 1 / 2π · C1a · R1 by turning on the switch SW3 and fc = 1 / 2π · (C1a // C1b) · R1 by turning off the switch SW3. be able to.

According to the first to third embodiments,
By detecting an angle-of-view change operation such as panning, H
Since the cutoff frequency of the angular velocity signal from the angular velocity detecting means 1 is changed by switching the time constants of the PF 2 and the integrating means 3, that is, in a normal still photographing state, the cutoff frequency is set to a low frequency to improve the vibration reduction. Because it is strengthened, the anti-vibration effect can be enhanced, and in the state of changing the angle of view such as panning, the cut-off frequency is set to a high frequency to reduce the effectiveness of anti-vibration, thereby improving follow-up and operability It becomes possible.

(Fourth Embodiment) FIGS. 8A and 8B are views showing the schematic arrangement of an image blur prevention apparatus according to a fourth embodiment of the present invention.

In FIG. 8A, reference numeral 11 denotes an angular velocity detecting means such as a vibrating gyroscope for detecting camera shake, 12 denotes an HPF for passing a high frequency component of the angular velocity signal from the angular velocity detecting means 11, and 13 denotes the HPF 12. Integration means for integrating an angular velocity signal input through the camera into an angular displacement signal. When the input of the angular velocity signal is interrupted by an angular velocity input interrupting means described later (when the image stabilization is not activated), the correcting optical means is used. Is output as a reference signal to maintain at the movable center. 1
Reference numeral 4 denotes an angle-of-view change operation detection for detecting whether or not an angle-of-view change operation such as panning or tilting is performed based on the angular displacement signal from the integration means 13 (details will be described in detail with reference to FIGS. 2 and 3). Means. Reference numeral 15 denotes a characteristic switching unit that switches the characteristics of the HPF 12 according to a signal from the angle-of-view changing operation detecting unit 14, that is, a characteristic switching unit that changes a high-pass band of frequency. This is a characteristic switching unit that switches the characteristics of the integrating unit 13, that is, changes the high-pass band of the frequency.
Reference numeral 17 denotes a calculating means for calculating a driving amount of a correction optical means described later based on the input angular displacement signal and a correction signal described later, and 18 is driven by a driving means (not shown) by a signal from the calculating means 17. A correction optical unit 19 such as a variable apex angle prism, and a correction amount detection unit 19 that detects the current position (displacement amount from the movable center) of the correction optical unit 18 and outputs a correction signal to the driving unit 17. Reference numeral 20 denotes the angular velocity detecting means 1 based on a signal from the angle-of-view changing operation detecting means 14.
This is an angular velocity input interrupting means for interrupting the input to the subsequent stage of the angular velocity signal which is the output of 1.

FIG. 8B shows the angular velocity input cutoff means 2.
0 , HPF 12, integrating means 13, characteristic switching means 15, 1
FIG. 6 is a circuit diagram showing a specific configuration of each of them.

The HPF 12 includes a capacitor C1 and resistors R1 and R4. The integration means 13 includes a capacitor C2 , a resistor R2, and an operational amplifier OP1. The characteristic switching means 15 is controlled by switches SW1 and SW3.
The characteristic switching means 16 is constituted by switches SW2 and SW4, and the angular velocity input cutoff means 20 is constituted by switch SW5.

Here, assuming that the range of changing the high-pass band of the frequency in the characteristic switching units 15 and 16 (change range of the time constant), that is, the cutoff frequency is around 1 Hz, for example, a relatively high cutoff Frequency (1Hz
If the normal shooting is performed in the above manner, an impression that the effect of image stabilization is weakened is obtained. However, the ability to follow the angle-of-view changing operation such as panning (the DC component of the correction amount of the correction optical unit 18 is small) In other words, ideally, the state where the movable center is at the center during image stabilization during panning is ideal). That is, as described above, the time constant of each of the HPF 12 and the integrating means 13, that is, the variable cutoff frequency is used in combination with panning detection and the like, so that the cutoff frequency is set to a low frequency in a normal stationary state. strengthen handed anti-vibration, enhanced vibration damping effect, shielding the angle changing operation conditions such as panning
By setting the cutoff frequency to a high frequency, it is possible to weaken the effectiveness of vibration reduction, and to improve the followability and the operability. Also, by preparing a large number of these cut-off frequencies and switching them appropriately, it is possible to cope with any photographing state without feeling uncomfortable.

In the HPF 12, only the pass band of the frequency is limited. However, feedback is applied to the integration means 13 , and when viewed as a system, the centripetal force of the correction optical means 18 to the movable center increases. Is equivalent to

FIG. 2 is a diagram for explaining a method of detecting the angle-of-view changing operation (panning operation in the embodiment) in the angle-of-view changing operation detecting means 14.

The angle-of-view change operation detecting means 14 determines the range of the output signal of the angular velocity detecting means 11 at each position within the entire movable range (movable range) of the correcting optical means 18 by the center point (angular displacement signal). When the output signal is "0"), it is divided into two ranges, and it is determined whether or not the panning is performed based on the time during which the output signal remains in one range (or the number of samplings within a certain time).

That is, when the camera shake is considered to be an alternating current, the output signal of the angular velocity detecting means 11 should cross the center point within one second even if the frequency of the camera shake is set to 0.5 to several tens Hz. . Therefore, when the vehicle does not cross the center point within a predetermined time, it is determined that the panning operation is being performed. The predetermined time during which the output signal of the angular velocity detecting means 11 will pass through the center point depends on the frequency characteristic of the system when the integrating means 13 is used in the camera shake detecting system as in this embodiment. Will be determined.

Next, the operation when the angle-of-view changing operation detecting means 4 is constituted by a microcomputer will be described with reference to the flowchart of FIG. [Step 101] An angular displacement signal from the angular velocity detecting means 11 via the integrating means 13 is fetched by A / D conversion or the like. [Step 102] The captured angular displacement signal is represented in FIG.
It is checked whether or not it is within the first range shown in FIG. As a result, if it is within the first range, the process proceeds to step 103; otherwise, the process proceeds to step 107 if it is within the second range. [Step 103] “1” is added to the counter 1 that counts that the angular displacement signal remains within the first range. [Step 104] The counter 2 used when a signal stays in another second range is reset. [Step 105] It is determined whether or not the count value of the counter 1 has reached a count number representing a predetermined time t for determining a panning operation. If not, the process returns to step 101, and if it has, the process proceeds to step 106. [Step 106] Here, a panning mode flag is set.

If it is determined in step 102 that the value is not within the first range, that is, if it is within the second range, the process proceeds to step 107 as described above. [Step 107] “1” is added to the counter 2 that counts that the angular displacement signal stays within the second range. [Step 108] The counter 1 used when a signal stays in another first range is reset. [Step 109] It is determined whether or not the count value of the counter 2 has reached a count number representing a predetermined time t for determining a panning operation. If not, the process returns to step 101; move on.

If the panning flag mode is reset simultaneously with the counter reset in steps 104 and 108, the mode can be switched easily.

Next, the angle-of-view changing operation detecting means 14
The operation of the apparatus, including the detection of the panning operation, will be described with reference to the flowchart of FIG. [Step 401] When the power is turned on, the switch SW5 is turned on, and an angular velocity signal is input to the HPF 12. [Step 402] Here, the switches SW1 to SW4
Are turned on to prevent passing signals in the camera shake frequency band, and to stabilize the system by accelerating the charging time to the capacitor. [Step 403] The correction optical unit 18 is held at the movable center. [Step 404] The state of the anti-vibration switch input from outside is determined. If the anti-vibration switch is on, the process proceeds to step 406;
Go to 05. [Step 405] The switch SW5 is turned off to cut off the input of the angular velocity signal to the HPF 12 (therefore, the reference signal is output from the integration means 13), and the switches SW1 to SW4 are kept on. Thus, the correction optical unit 18 is held at the movable center. Then, the process returns to step 404 . [Step 406] Here, since the image stabilization switch is ON, the switch SW5 is turned ON, and the angular velocity signal is set to HP.
In addition to inputting the signal to F12, all of the switches SW1 to SW4 are turned off so that signals in the camera shake frequency range can be passed, and the image stabilization operation is started. [Step 407] The state of the image stabilization switch is determined again. If the image stabilization switch is ON, the process proceeds to Step 408, and if it is OFF, the process returns to Step 405. [Step 408] It is checked whether or not it is determined that the panning operation is being performed by the angle-of-view changing operation detecting unit 14. If the panning operation is being performed, the process proceeds to step 409.
Otherwise, go to step 410. [Step 409] The switch SW3 is turned on to cut the low frequency region of the vibration-proof frequency band at a relatively high frequency as compared with camera shake, thereby narrowing the low frequency component of the pass signal band. At the same time, the switch SW4 is also turned on to increase the centripetal force of the correction optical unit 18 toward the movable center. Then, the process returns to step 407. [Step 410 ] Here, since the panning operation is not being performed or the panning operation has been completed, the switch S
If W3 and W4 are ON, they are turned OFF and the mode is returned to the normal mode, and the process returns to step 407.

If the anti-vibration switch is turned off during the loop from step 407 to step 410, the process returns from step 407 to step 405, where the switch SW5 is turned off and the HPF of the angular velocity signal is set.
12 and the switches SW1 to SW
4 is turned on, and the correction optical unit 18 is kept at the movable center.

(Fifth Embodiment) FIG. 10 shows an angular velocity input cutoff means 20 and HPF 1 according to a fifth embodiment of the present invention.
2 is a circuit diagram showing a specific configuration of each of an integrating means 13 and characteristic switching means 15 and 16;

The HPF 12 to the characteristic switching means 16
Are arranged and arranged in the same manner as in the embodiment of FIG. On the other hand, the angular velocity input cutoff means 20 composed of the switch SW5 is arranged as shown in FIG. 10, and is turned on when the anti-vibration switch is turned on to cut off the input of the angular velocity signal to the HPF 12.

Next, a series of operations including the detection of the panning operation of the image blur prevention apparatus provided with the angular velocity input blocking means 20 having the above configuration will be described with reference to the flowchart of FIG. [Step 501] When the power is turned on, the switch SW5 is turned off, and an angular velocity signal is input to the HPF 12. [Step 502] Here, the switches SW1 to SW4
Are further turned on so that there is no passing signal in the camera shake frequency band, and the charging time to the capacitor is accelerated to stabilize the system. [Step 503] The correction optical unit 18 is held at the movable center. [Step 504] The state of the anti-vibration switch input from the outside is determined. If the anti-vibration switch is on, the process proceeds to step 506;
Go to 05. [Step 505] The switch SW5 is turned on to cut off the input of the angular velocity signal to the HPF 12 (therefore, the reference signal is output from the integration means 13), and the switches SW1 to SW4 are also kept on. Thus, the correction optical unit 18 is held at the movable center. Then, the process returns to step 503. [Step 506] Since the image stabilization switch is ON, the switch SW5 is turned OFF, and the angular velocity signal is set to H.
Input to PF12 and switches SW1 to SW4
Are turned off to allow signals in the camera shake frequency range to pass, and the image stabilization operation is started. [Step 507] The state of the image stabilization switch is determined again. If the image stabilization switch is ON, the process proceeds to Step 508, and if it is OFF, the process returns to Step 505. [Step 508] It is checked whether or not it is determined that the panning operation is being performed by the angle-of-view changing operation detecting means 14. If the panning operation is being performed, the process proceeds to step 509.
Otherwise, proceed to step 510 . [Step 509] The switch SW3 is turned on to cut off the low frequency range of the image stabilization frequency band at a relatively high frequency as compared with camera shake, thereby narrowing the low frequency component of the pass signal band. At the same time, the switch SW4 is also turned on to increase the centripetal force of the correction optical unit 18 toward the movable center. Then, the process returns to step 507. [Step 510 ] Here, since the panning operation is not being performed or the panning operation has been completed, the switch S
If W3 and W4 are ON, they are turned OFF, the mode is returned to the normal mode, and the process returns to step 507.

If the anti-vibration switch is turned off during the loop from step 507 to step 510, the process returns from step 507 to step 505, and the switch SW5 is turned on to turn on the HPF1 of the angular velocity signal.
2 and the switches SW1 to SW4
Are also turned on, and the correction optical unit 18 is kept at the movable center.

According to the fourth and fifth embodiments, the input of the angular velocity signal to the integrating means 13 is cut off when the vibration-proof operation is stopped. Since the correction optical unit 18 is held at the movable center by the reference signal, the discontinuity of the signal can be eliminated, and the switching between the anti-vibration operation and the non-operation can be performed smoothly without giving the photographer an uncomfortable feeling. Become.

[0071]

As described above, according to the present invention, the vibration damping effect in a normal stationary state is enhanced,
Improves followability and operability in the angle-of-view changing operation state
Can be .

[0072]

[0073]

[0074]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a block and a circuit configuration of an image blur prevention apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating detection of a panning operation in each embodiment of the present invention.

FIG. 3 is a flowchart illustrating an example of an operation of detecting a panning operation in each embodiment of the present invention.

FIG. 4 is a diagram illustrating a series of operations including panning operation detection according to the first embodiment of the present invention.

FIG. 5 is a flowchart illustrating a series of operations including panning operation detection according to a second embodiment of the present invention.

FIG. 6 is a diagram showing characteristics in each mode in the device of the second embodiment.

FIG. 7 is a circuit diagram showing a configuration of a main part of an image blur prevention device according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a block and a circuit configuration of an image blur prevention device according to a fourth embodiment of the present invention.

FIG. 9 is a diagram illustrating a series of operations including panning operation detection according to a fourth embodiment of the present invention.

FIG. 10 is a circuit diagram showing a main configuration of an image blur prevention apparatus according to a fifth embodiment of the present invention.

FIG. 11 is a diagram illustrating a series of operations including panning operation detection according to a fifth embodiment of the present invention.

FIG. 12 is a diagram for describing a configuration of a conventional image blur prevention device.

13 is a diagram showing signal waveforms of the image blur prevention device of FIG.

14 is a circuit diagram showing a configuration of the integrator and the HPF of FIG.

[Description of sign]

 1,11 angular velocity detecting means 2,12 HPF 3,13 integrating means 4,14 angle-of-view change operation detecting means 5,6,15,16 characteristic switching means 17 angular velocity input cutoff means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-193721 (JP, A) JP-A-1-130144 (JP, A) JP-A-3-248132 (JP, A) JP-A-3-193 161726 (JP, A) JP-A-3-161722 (JP, A) JP-A-4-68323 (JP, A) JP-A-61-201226 (JP, A) JP-A-63-285408 (JP, A) JP-A-63-285424 (JP, A) JP-A-63-275917 (JP, A) JP-A-63-158518 (JP, A) JP-A-63-8627 (JP, A) JP-A-63-8629 (JP, A) JP-A-2-173625 (JP, A) JP-A-5-328201 (JP, A) JP-A-5-14801 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) G03B 5/00

Claims (6)

(57) [Claims] A shake detection unit configured to detect a vibration applied to the optical device; a correction optical unit configured to correct a shake of an optical axis of the optical device due to the vibration; and the correction optical unit according to an output signal of the shake detection unit. Computing means including high frequency band passing means and integrating means for calculating the driving amount of, an angle-of-view changing operation detecting means for detecting that an angle-of-view changing operation is being performed , and
The time constant of the high frequency band passing means and the time constant of the integrating means are
An image stabilizing apparatus comprising : a time constant changing unit that changes an angle of view;
Is detected by the time constant varying means,
The time constant of the high frequency band passing means and the time constant of the integrating means
By changing both the numbers, the cutoff frequency can be changed
Higher frequency than when it is not detected that
To the movable side of the correction optical means.
An image blur prevention device characterized by increasing centripetal force . 2. A shake detector for detecting vibration applied to an optical device.
Output means, and corrects the shake of the optical axis of the optical device due to the vibration.
Correction optical means, and an output signal from the shake detecting means.
Calculating the driving amount of the correction optical means,
Calculating means including passing means and integrating means;
And a second angle-of-view changing operation detecting means.
An image shake preventing apparatus, wherein the first angle-of-view changing operation is performed.
Detecting means based on the detection results of the detecting means and the second angle-of-view changing operation detecting means.
Either the high-frequency band-passing means or the integrating means
Time constant for selectively changing one or both time constants
An image blur prevention device comprising a changing means. 3. The method according to claim 1, wherein the first angle-of-view changing operation detecting means detects an image.
By detecting that the angle changing operation is being performed,
It is characterized by changing the time constant of the high frequency band pass means
The image blur prevention device according to claim 2. 4. An image forming apparatus according to claim 2, wherein said second angle-of-view changing operation detecting means detects an image.
By detecting that the angle changing operation is being performed,
The time constant of the integrating means is changed.
2. The image blur prevention device according to 2. 5. The apparatus according to claim 1, wherein the first angle-of-view change detecting means is configured to:
It is detected that the angle of view is being changed based on the output of the
The angle-of-view change detection means for outputting the angle of view.
4. The image blur prevention device according to 2 or 3. 6. The second angle-of-view change detecting means,
The angle-of-view changing operation is being performed according to the displacement position of the positive optical means.
The angle-of-view change detecting means for detecting
The image blur prevention device according to claim 2 or 4.