JP3192491B2 - Anti-vibration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a vibration isolator incorporated in a still camera, a video camera, and the like.

[0002]

2. Description of the Related Art In recent years, automation of photographing apparatuses such as still cameras and video cameras has been advanced, and apparatuses equipped with automatic exposure and automatic focusing mechanisms have been widely put into practical use. Some techniques for realizing a shake correction (vibration-proof) function for automatically correcting image shake have also been put to practical use.

[0003] In general, the apparatus having the image stabilizing function includes a shake detecting means for detecting a shake of the whole apparatus, a shake correcting means for correcting an image shake caused by the shake, and a drive for driving the shake correcting means. And a control means for calculating a camera shake correction amount according to the output of the shake detecting means and controlling the driving of the driving means.

As the shake detecting means, there is an angular velocity meter or the like. As the shake correcting means, two glass plates are connected by a deformable bellows-like film (bellows), and a high refractive index high refractive index is provided therein. There is a variable apex angle prism filled with liquid.

[0005]

However, when the above-mentioned variable apex angle prism is used as the shake correcting means, the variable apex angle prism always faces upward (a C-shape) with respect to the pitch side glass plate due to the weight of the internal fluid. ) Is applied with a rotational moment. For this reason, the operation of rotating the glass plate on the pitch side downward (an inverted C-shape) requires a larger torque than the torque required for the operation of rotating the glass plate upward, and in some cases, cannot be rotated to a predetermined angle. It is possible. That is, as the camera shake correction operation, the camera shake above the center can be removed with sufficient margin by turning the glass plate on the pitch side upward, while the camera glass on the pitch side is used for the camera shake below the center. There has been a problem that the image cannot be rotated downward to a predetermined angle, and image blur remains on the screen.

Next, another problem will be described.

As described above, as a shake correcting means, for example, a variable apex angle prism in which two glass plates are combined with a deformable bellows-like film (bellows) and a liquid having a high refractive index is sealed therein. However, since the control characteristics of the variable apex angle prism change because of changes in the ambient temperature or an increase in axial play or material deterioration due to long-term use,
A problem such as an oscillation phenomenon may occur, and vibration may occur on the screen, and the screen may not stop, and it may not be possible to continue shooting.

To cope with this problem, Japanese Patent Application No. 3-254242 proposes a method of adding an analog circuit for oscillation detection to detect oscillation and avoiding the above-mentioned problem by lowering the loop gain. However, according to this method, there are problems such as an increase in the number of parts and an increase in cost, which is not preferable.

Next, another problem will be described.

As described above, as a shake correcting means, a variable apex prism in which two glass plates are connected by a deformable bellows-like film (bellows) and a liquid having a high refractive index is sealed therein is provided. However, in general, the refractive index of the above liquid changes with a change in temperature. For example, silicon oil has a refractive index nd at room temperature of about “1.40”, but when the temperature rises or falls by 25 ° C., the refractive index decreases or increases by about “0.01”. In this case, the image blur correction rate also increases or decreases in accordance with the correction. Therefore, when the ambient temperature is high, the camera shake cannot be completely corrected, and the image blur remains.

[0011]

[0012]

An object of the present invention is to provide an image stabilizing apparatus capable of always performing optimal image shake correction irrespective of an ambient temperature during image stabilization.

[0014]

In order to achieve the above object, the present invention provides at least two optical members, a deformable connecting member for connecting the two optical members, and the two optical members and the connecting member. A variable apex prism made of a liquid sealed in a space formed by the member, a shake detection means for detecting a shake of the apparatus, a driving means for driving the variable apex prism, and a signal from the shake detection means Control means for controlling the driving means in accordance with the image blur correction,
Temperature detecting means for detecting the ambient temperature, the variable angle pre
In which refractive index information for each temperature of the liquid is stored
Means, the temperature detection means according to the temperature information from the temperature detection means
Reading the refractive index information from the storage means, and based on the refractive index information,
And a driving amount changing means for changing a driving amount of the variable apex angle prism by changing a signal from the shake detecting means .

[0015]

[0016]

[0017]

[0018]

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

FIGS. 1 to 3 relate to a first embodiment of the present invention, and FIG. 1 is a diagram showing a schematic configuration of a vibration isolator.

In FIG. 1, reference numerals 2a and 2b denote two glass plates opposed to each other, and a liquid having a high refractive index (not shown) is filled in a space sealed by the two glass plates and a bellows-shaped film 3 for sealing the outer periphery thereof. ) Are satisfied, and these constitute a variable apex angle prism.

The films 3 are joined by welding by heat, and have a two- or three-stage bellows shape (bellows).
Are formed, and the variable apex angle prism can be inclined in an arbitrary direction to have an apex angle.

The variable apex angle prism is sandwiched between frames 4a and 4b, and each glass plate is held so as to be rotatable about a pitch axis 5a and a yaw axis 5b. A flat coil 6a is fixed to one end of the front frame 4a, and a permanent magnet 7a and yokes 8a, 9a are arranged opposite to both surfaces thereof to form a closed magnetic circuit. The frame body 4a further has an arm 11a having a slit 10a, and a light-emitting element 12a and a light-receiving element 13a are arranged on both sides of the arm 11a so that the light beam emitted from the light-emitting element 12a passes through the slit 10a. The light is irradiated to the light receiving element 13a.

Here, the light emitting element 12a is, for example, an IRED.
The light receiving element 13a is, for example, a PS whose output changes depending on the position of the spot of the received light beam.
D or the like.

Although not shown in FIG. 1, the flat coil 6b, the permanent magnet 7b, the yoke 8b, 9
b, the slit 10b, the arm 11b, the light emitting element 12b, and the light receiving element 13b are arranged and function in the same manner as the operation on the pitch side.

14a and 14b are pitch directions of the entire apparatus,
This is a shake detector attached to a support portion of the device so as to detect a shake amount in the yaw direction. Reference numeral 15 denotes a control circuit which includes an A / D converter, a D / A converter, a CPU, a memory, and the like, and controls the system. Reference numeral 16 denotes a coil drive circuit that supplies a current to the coils 6a and 6b in accordance with a command from the control circuit 15.

FIG. 2 shows a flat coil 6a, a permanent magnet 7a,
FIGS. 2A and 2B are diagrams showing an arrangement of a pitch side actuator composed of a yoke 8a (a yoke 9a is not shown). FIG. 2A shows a conventional arrangement, and FIG. 2B shows an arrangement in the first embodiment. , Respectively.

FIG. 3 is a graph showing the torque generated by the actuator on the pitch side, and FIG.
FIG. 3 shows the torque generated in the conventional arrangement shown in FIG.
2B shows the generated torque in the arrangement of the first embodiment shown in FIG. 2B, respectively.

Next, the operation of the above configuration will be described step by step.

When the entire apparatus is shaken due to shaking of the hand holding the photographing apparatus, the shake detectors 14a and 14b
Outputs a signal proportional to the magnitude of camera shake. This signal is input to the control circuit 15, where it is multiplied by an appropriate multiplier to calculate the magnitude of the apex angle required to remove the shake by the variable apex prism.

On the other hand, the shaft 5 of the facing glass plates 2a, 2b
The rotation angles around a and 5b, that is, the variation of the pitch of the variable apex angle prism and the apex angle in the yaw direction are changed by the light emitting elements 12a and 12b.
b, the luminous flux emitted from the glass plates 2a, 2
arm 11a, 11b of frame 4a, 4b rotating integrally with b
This appears in the movement of the spot position on the light receiving surface when the light passes through the slits 10a and 10b attached to the light receiving element 13a and 13b and irradiates the light receiving elements 13a and 13b. The light receiving elements 13a and 13b transmit to the control circuit 15 an output according to the movement amount of the spot, that is, the magnitude of the apex angle of the variable apex angle prism.

The control circuit 15 calculates the difference between the magnitude of the calculated apex angle described above and the magnitude of the apex angle at the present time, and multiplies this by a predetermined amplification factor to obtain the coils 6a, 6a.
It is transmitted to the coil drive circuit 16 as the drive command signal b. The coil drive circuit 16 supplies a drive current according to the coil drive command signal to the coils 6a and 6b to generate a coil drive force.

The variable apex angle prism rotates by the coil driving force around the axes 5a and 5b, and is deformed to match the calculated apex angle. In other words, the variable apex angle prism is configured to perform shake correction control according to a feedback control law using the value of the apex angle calculated to correct the shake as a reference signal and the current apex angle value as a feedback signal. Have been.

However, in the variable apex angle prism, a rotating moment for rotating the glass plate 2a on the pitch side upward (C-shape) is always applied to the glass plate 2a on the pitch side by the weight of the internal fluid. Therefore, as described above, the operation of rotating the glass plate 2a on the pitch side downward (an inverted C shape) requires a larger torque than the operation required for the operation of rotating the glass plate 2a upward. It may not be possible to rotate to a predetermined angle. That is, in the camera shake correction operation, the camera shake upward from the center can be removed with sufficient margin by turning the glass plate 2a on the pitch side upward, while the camera shake 2a on the pitch side can be removed from the camera shake below the center. May not be able to be rotated downward to a predetermined angle, and image blur will remain on the screen.

The torque generated by the actuator is not the same at all positions, but always decreases as the absolute value of the apex angle increases, due to the influence of magnetic flux leakage in the central neutral zone and the peripheral portion.

FIG. 3 (a) is a view showing this, in which the abscissa represents the magnitude of the apex angle in which the direction in which the pitch side glass plate 2a is rotated upward is negative, and the ordinate represents a predetermined current. The generated torque at the time is plotted.

From FIG. 3A, it can be seen that, for example, when the apex angle is 5 degrees, the generated torque is 20% lower than when it is 0 degrees.

Then, as shown in FIG. 2B, when the permanent magnet 7a and the yoke 8a, 9a are mounted at a predetermined angle with respect to the vertical line, the generated torque at that time becomes as shown in FIG. 3B. become. Then, the torque generated when the pitch side glass plate 2a is rotated downward is larger than the torque generated when the pitch side glass plate 2a is rotated upward. On the other hand, the torque required when rotating the variable apex angle prism is large when rotating downward and small when rotating upward because the rotating moment is applied by the weight of the internal liquid.

Accordingly, the driving force against the load is constant in either direction, so that the camera shake in any direction is corrected, and a good screen without camera shake is obtained.

(Second Embodiment) FIG. 4 is a side view showing a pitch-side actuator of a vibration isolator according to a second embodiment of the present invention.

In the second embodiment, the permanent magnet 7a and the yoke 8a, 9a are not inclined at a predetermined angle with respect to the vertical line, but the coil 6a is inclined at a predetermined angle with respect to the vertical line as shown in FIG. Things.

With this configuration, the generated torque at that time is in the state shown in FIG. 5, and the driving force against the load is constant in either direction as in the first embodiment. Therefore, the camera shake is corrected regardless of the camera shake in any direction, and a good screen without camera shake is obtained.

According to the first and second embodiments, the permanent magnet 7a and the yoke 8a, 9a are mounted at a predetermined angle with respect to the vertical line, or the coil 6a is tilted at a predetermined angle with respect to the vertical line. As a result, it is possible to avoid the adverse effect caused by the asymmetry of the load torque due to the own weight of the variable apex angle prism, which is the shake correcting means, and to completely correct the shake even in any direction of the camera shake, and to reduce the image shake. Thus, a good image having no image is obtained.

In the first and second embodiments, an example is described in which a variable apex prism is used as the shake correcting means. However, the present invention is not limited to this. A type in which the correction lens is shifted in a direction orthogonal to the optical axis may be used.

(Third Embodiment) FIG. 6 is a view showing a variable apex angle prism which is a shake correcting means disposed in a vibration isolator according to a third embodiment of the present invention. The same portions as 2 are denoted by the same reference numerals.

In FIG. 6, reference numeral 1 denotes a liquid having a high refractive index sealed in a space sealed by glass plates 2a and 2b and a bellows-like film 3 for sealing the outer periphery thereof, and 201 denotes a center position of the glass plate 2a. , 202 is the center position of the bellows, 2
03 is a margin for welding bellows.

The torque required to rotate the above variable apex angle prism depends on the shape of the bellows. The longer the length of the bellows in the diameter direction, the smaller the torque, the smaller the torque. Is needed.

Using this property, as shown in FIG. 6, the center 201 of the circumference of the glass plate 2a and the center 2 of the circumference of the bellows are used.
02 and the pitch side glass plate 2
When a is rotated upward (C-shape), a larger torque is required because the bellows in that direction are shorter than the others, but a rotational moment due to the own weight of the internal liquid 1 is applied in the same upward rotational direction. When the pitch side glass plate 2a is rotated downward (inverted C-shape), the rotation moment due to the weight of the internal liquid 1 is applied in the opposite direction, but the bellows in the rotation direction is longer than the other. , Can be rotated with a small torque, so that this is also offset.

Therefore, the torque required during rotation is constant irrespective of the direction, so that it is possible to avoid the adverse effect caused by the asymmetry of the load torque due to the weight of the variable apex angle prism, which is the shake correction means, and However, a good image without image blur can be obtained even after the correction.

(Fourth Embodiment) FIG. 7 is a view showing a variable apex angle prism which is a shake correcting means arranged in a vibration isolator according to a fourth embodiment of the present invention. The same portions as 2 are denoted by the same reference numerals.

In FIG. 7, reference numeral 301 denotes an enlarged welding margin for the bellows.

In the fourth embodiment, the center of the circumference is not shifted in order to have a difference in the length of the bellows as in the third embodiment. The third embodiment has the same effect as the third embodiment.

That is, the effective length of the lower bellows is shortened by making the width of the welding margin of the lower bellows larger than other positions. Then, when the pitch side glass plate 2a is rotated upward (C-shape), since the bellows in that direction have a shorter effective length than the reverse, a larger torque is required. Similarly, when the pitch side glass plate 2a is rotated downward (an inverted C-shape), the rotational moment due to the own weight of the internal liquid 1 is applied in reverse. However, since the bellows in the rotation direction is longer than the reverse, the bellows can be rotated with a small torque, so that this is also offset.

Therefore, also in this embodiment, since the torque required during rotation is constant irrespective of the direction, the adverse effect resulting from the asymmetry of the load torque due to the weight of the variable apex angle prism, which is the vibration correcting means, is avoided. It is possible to correct a camera shake in any direction and obtain a good screen without image shake.

(Fifth Embodiment) FIG. 8 is a diagram showing a variable apex angle prism which is a shake correcting means disposed in a vibration isolator according to a fifth embodiment of the present invention, and shows a first and a second embodiment. The same portions as 2 are denoted by the same reference numerals.

In FIG. 8, reference numeral 401 denotes an annealing jig. The annealing jig 401 is composed of three members.
Each of them engages with the bellows and is fixed at a position where the variable apex angle prism has a predetermined apex angle.

When a bellows is forcibly left in a predetermined shape at a high temperature close to the welding temperature and then returned to a normal temperature, the bellows has a property that the shape is permanently maintained until the temperature becomes high again. Then, after the variable apex angle prism is completed, it is placed in an annealing jig 401 and left at room temperature for about 12 hours in an environment of, for example, 70 degrees while maintaining the apex angle at a predetermined angle. The shape of the tool 401 is transferred, and a variable apex angle prism having a shape inclined to one side at a predetermined angle in a natural state is obtained.

The above-mentioned inclination is adjusted by the pitch-side glass plates 2a, 2a.
When b is taken into the frames 4a and 4b in the direction in which
When this is rotated upward (C-shape) to a predetermined angle, the amount of rotation is large due to the inclination of the natural state, so a larger torque is required. On the other hand, when rotating to an angle, the amount of rotation is small, and the required torque is also small. However, since the difference between the required torques is offset by the rotational moment due to the weight of the internal liquid 1, the third and fourth torques are eventually obtained.
In the same manner as in the first embodiment, the torque required during rotation is constant irrespective of the direction, so that it is possible to avoid the adverse effect from the asymmetry of the load torque due to the weight of the variable apex angle prism, which is the shake correction means, Even if the camera shake is corrected, a good screen without image blur can be obtained.

(Sixth Embodiment) The structure of a vibration isolator according to a sixth embodiment of the present invention is the same as that shown in FIG. 1 shown in the first embodiment, so that the illustration is omitted here.

The operation of the anti-vibration device in this embodiment will be described step by step.

When a shake occurs in the entire apparatus due to a shake or the like holding the photographing apparatus, the shake detectors 14a and 14b output a signal proportional to the magnitude of the shake. This signal is input to the control circuit 15, where the signal is multiplied by an appropriate multiplier to calculate the magnitude of the apex angle necessary for removing the shake by the variable apex prism.

Here, the appropriate multiplier is the refractive index n of the liquid.
The value “1 / (nd−1)” determined by d, for example, “n
In the case of silicone oil with d = 1.40, “1 / (1.40−
1) = 2.5 ".

On the other hand, the shaft 5 of the facing glass plates 2a, 2b
The rotation angles around a and 5b, that is, the variation of the pitch of the variable apex angle prism and the apex angle in the yaw direction are changed by the light emitting elements 12a and 12b.
b, the luminous flux emitted from the glass plates 2a, 2
arm 11a, 11b of frame 4a, 4b rotating integrally with b
This appears in the movement of the spot position on the light receiving surface when the light passes through the slits 10a and 10b attached to the light receiving element 13a and 13b and irradiates the light receiving elements 13a and 13b. The light receiving elements 13a and 13b transmit to the control circuit 15 an output according to the movement amount of the spot, that is, the magnitude of the apex angle of the variable apex angle prism.

The control circuit 15 calculates the difference between the magnitude of the calculated apex angle described above and the magnitude of the apex angle at the present time, and multiplies this by a predetermined amplification factor to obtain the coils 6a, 6a.
It is transmitted to the coil drive circuit 16 as the drive command signal b. The coil drive circuit 16 supplies a drive current according to the coil drive command signal to the coils 6a and 6b to generate a coil drive force.

The variable apex angle prism performs a rotary motion about the axes 5a and 5b by the coil driving force, and is deformed to match the calculated apex angle. In other words, the variable apex angle prism uses a deflection angle of 1 / (nd-1) times the apex angle calculated to correct the shake as a reference signal, and the current apex angle value as a feedback signal. It is configured to perform shake correction control according to a feedback control law.

FIG. 9 is a flow chart showing the operation procedure of the control circuit 15 in the sixth embodiment, and the description will be made in accordance with this.

The apparatus is activated every time a main switch (not shown) is turned on, and ends when the main switch is turned off. When the power is turned on, the operation from step 151 is started. [Step 151] The counter i, which is a variable, is reset to “0”. "Step 152"
Check the status of the main switch. If it is OFF, this program ends. If it is ON, step 153.
Go ahead. "Step 153" Each of the time counter Nc and the state counters Ny and Np, which are variables, is set to "0".
Reset to. [Step 154] The detection value of the yaw-side shake detector 14b is taken in through the A / D converter to obtain the shake angle θy of the device, and the output of the light-receiving element 13b at the yaw-side apex angle is obtained through the A / D converter. It is taken as the apex angle αy of the variable apex prism. "Step 1
55] Using the refractive index nd, the following formula θy / (nd) is used, with the value of the apex angle required to correct the current deflection angle θy of the device by refraction of the optical axis of the variable apex angle prism as a target value. -1), and multiplies the difference between the target value and the current apex angle αy by a predetermined gain constant Ki to obtain a coil drive signal εy εy = Ki * {θy / (nd−1) −αy}. calculate. [Step 156] The coil drive signal εy is output to the output port and transmitted to the coil drive circuit 16 via the D / A converter. "Step 157"
The detected value of the pitch side shake detector 14a is taken in through an A / D converter to obtain the shake angle θp of the device, and the output of the light receiving element 13a of the pitch side apex angle is taken in through an A / D converter to obtain a variable peak. The vertex angle αp of the angular prism is defined as αp. [Step 158] Using the refractive index nd and the target angle value required to correct the current deflection angle θp of the apparatus by refraction of the optical axis of the variable angle prism, the following equation θp / (Nd-1), and the difference between the target value and the current apex angle αp is multiplied by a predetermined gain constant Ki to obtain a coil drive signal εp εp = Ki * ｛θp / (nd-1) −αp ｝ Is calculated. [Step 159] The coil drive signal εp is output to the output port and transmitted to the coil drive circuit 16 via the D / A converter.

By the above-described series of operations, the vertical angle of the variable apex angle prism is tilted by a predetermined value with respect to the shake of the apparatus, and the shake is automatically corrected, so that a good image without image shake can be obtained. [Step 160] It is determined whether or not the absolute value of the coil drive signal εy calculated in the above step 155 is larger than a predetermined large value εm. As a result, when the absolute value of the coil drive signal εy is equal to or smaller than εm, it is determined that a normal operation is performed at least in the yaw direction, and the process proceeds to step 161 . Also, the coil drive signal εy
Is greater than or equal to εm, the flow proceeds to step 162 . "Step 161" Yaw-side state counter Ny
"1" is added to the value of, and the process proceeds to step 162. "Step 162" It is compared whether or not the absolute value of the coil drive signal εp calculated in the above step 158 is larger than a predetermined large value εm. As a result, when the absolute value of the coil drive signal εp is equal to or smaller than εm, it is determined that the normal operation is performed at least in the yaw direction, and step 163 is performed.
Proceed to. If the absolute value of the coil drive signal εp is equal to or larger than εm, the process proceeds to step 164 . "Step 1
63 ”Adds“ 1 ”to the value of the state counter Np on the pitch side, and proceeds to step 164. “Step 164” “1” is added to the value of the time counter Nc, and the process proceeds to step 165. "Step 165" It is compared whether or not the value of the time counter Nc is larger than a predetermined value No. As a result, when the value of the time counter Nc is equal to or smaller than the predetermined value No, it is determined that an abnormality cannot be confirmed yet, and the routine from step 154 to fetch data is repeated. When the value of the time counter Nc is larger than the predetermined value No, the process proceeds to step 166. [Step 166] It is compared whether the state counter Ny on the yaw side is smaller than a predetermined value Nyo. As a result, if the value of the state counter Ny is smaller than the predetermined value Nyo, it is determined that an abnormality such as oscillation has occurred in the yaw-side drive of the variable apex angle prism, and the routine proceeds to step 168. If the value of the state counter Ny is equal to or more than the predetermined value Nyo, the process proceeds to step 167. [Step 167] It is determined whether the state counter Np on the pitch side is smaller than a predetermined value Nyo. As a result, when the value of the state counter Np is smaller than the predetermined value Nyo, it is determined that an abnormality such as oscillation has occurred in the drive of the variable apex angle prism on the pitch side, and the process proceeds to step 168.
If the value of the state counter Np is equal to or more than the predetermined value Nyo, it is determined that there is no more on the yaw side and the pitch side, and the routine returns to the routine from step 152 where the main switch state is confirmed. "Step 168""1" is added to the counter i for selecting the gain constant K, and the routine proceeds to step 169. "Step 169" It is determined whether or not the value of the counter i is smaller than a predetermined value imax. As a result, if the value of the counter i is smaller than the predetermined value imax, the routine returns to the routine from step 152 where the state of the main switch is checked. When the value of the counter i is a predetermined value ima
When equal to x, the yaw side of the variable apex prism, or
It is determined that the problem such as the oscillation on the pitch side could not be suppressed by adjusting the gain constant Ki, and the process proceeds to step 170. [Step 170] After notifying the occurrence of an abnormality to a system microcomputer such as a video camera in which the device is incorporated, the operation of the image stabilizing device is stopped, and the process ends.

When a problem such as oscillation occurs in the driving of the variable apex angle prism on the yaw side or pitch side by the above operation, first, the gain constant is switched so as to avoid the problem. Here, a plurality of prepared gain constants Ki have gradually smaller values, and the loop gain of the feedback control is gradually reduced.
However, if the problem cannot be avoided even if it is repeated a predetermined number of times imax, the control is notified to the video camera or the like in which the device is incorporated, and the process is terminated. After the processing is completed, only the image stabilizing operation stops functioning, and there is no problem in other photographing operations. Therefore, the photographer can continue photographing as it is.

According to the sixth embodiment described above, the deflection angle θ of the apparatus and the apex angle α of the variable apex angle prism are read, and the difference ε between them is monitored. Value ε
If the cumulative time N that can be regarded as normal is equal to or less than the predetermined value No, it is determined that the variable apex angle prism is oscillating (swinging alone), and the gain constant is switched. To avoid problems,
In other words, since a problem such as an oscillation phenomenon due to a change in the ambient temperature of the variable apex angle prism or a change with time is detected and controlled so as to be suppressed, a problem that the screen is not stopped due to vibrations can be solved.

Further, according to this embodiment, since both the detection and handling of a defect can be realized by software, there is no need to add a special circuit, and an increase in cost due to an increase in the number of parts can be avoided. .

In the sixth embodiment, an example is described in which a variable apex angle prism is used as the shake correcting means. However, the present invention is not limited to this. For example, a correcting lens may be provided in the pitch and yaw directions. A method of shifting in the direction orthogonal to the optical axis may be used.

FIG. 10 and FIG. 11 are views showing the main configuration of a vibration isolator according to a seventh embodiment of the present invention.

In FIG. 10, reference numerals 202a and 202b denote two glass plates facing each other, and a silicon oil having a refractive index of 1.40, for example, is provided in a space sealed by the two glass plates and a bellows-like elastic film 203 sealing the outer periphery thereof. , Etc., which form a variable apex angle prism.

The variable apex angle prism includes a frame 204a,
The glass plates 202a and 202b are held so as to be rotatable around a pitch axis 205a and a yaw axis 205b. A flat coil 206a is fixed to one end of the front frame 204a, and the permanent magnet 207a and the yoke 208a,
09a are arranged to form a closed magnetic circuit. An arm 211a having a slit 210a is provided at a symmetric position of the coil 206a of the frame 204a, and a light emitting element 212a and a light receiving element 213a are arranged on both sides of the arm 211a to face each other, and the light beam emitted from the light emitting element 212a is provided. Is transmitted to the light receiving element 213a after passing through the slit 210a.

Here, the light emitting element 212a is, for example, an IRE
The light receiving element 213a is, for example, a photoelectric conversion element such as a PSD whose output changes depending on the position of a spot of a received light beam.

Although not shown in the drawing, the flat coil 206b, the permanent magnet 207b, the yoke 208b and 209b, the slit 210b, and the arm 211 are also provided on the yaw side.
b, a light emitting element 212b, and a light receiving element 213b are arranged,
Functions in the same way as the operation on the pitch side.

Reference numeral 214 denotes a SiI for detecting the temperature inside the apparatus.
It is a temperature-sensitive element such as a C sensor. Reference numerals 215a and 215b denote shake detectors attached to the apparatus so as to detect the shake amounts in the pitch direction and the yaw direction of the entire apparatus. 216
Is a control circuit configured by an A / D converter, a D / A converter, a CPU, a memory, and the like, for controlling the system. 217 is a coil 20 according to a command from the control circuit 216.
This is a coil drive circuit that supplies current to 6a and 206b.

FIG. 11 shows the shake detectors 215a, 215
It is a figure which shows the internal structure of 5b.

In FIG. 11, reference numeral 251 denotes an outer cylinder, which is filled with a liquid 252 having a high specific gravity. In this liquid 252, a sensing blade 253 rotates around the axis 255 of the holding arm 254. It is freely held.

A reflecting surface 256 on the slit is provided near the center of the sensing blade 253. In addition, the outer cylinder 25
A light-emitting element 257 and a light-receiving element 258 are disposed outside the light-emitting element 257 toward the reflection surface 256 so that a light beam emitted from the light-emitting element 257 is reflected by the reflection surface 256 and is applied to the light-receiving surface of the light reception element 258. Has become.

Here, the light emitting element 257 is, for example, an IRED.
The light receiving element 258 is, for example, a PS whose output changes according to the position of the spot of the received light beam.
D or the like.

Next, the operation of the above configuration will be described step by step.

When a shake occurs in the entire apparatus due to a shake of the hand holding the photographing apparatus or the like, the shake detectors 215a, 215
Outer cylinder 251, holding arm 254, light emitting element 257 inside 5b
And the light receiving element 258 swings integrally with the main body. However, the high-specific-gravity liquid 252, the sensing blade 253, and the reflection surface 256 provided at the center of the liquid 252 tend to stand still relative to the absolute seat due to their own inertia. Therefore, the outer cylinder 25
1 and the sensing blade 253, a relative angle corresponding to the amount of shake is generated, and the light beam emitted from the light emitting element 257 and reflected by the reflecting surface 256 is formed on the light receiving surface of the light receiving element 258 by the relative angle. Occurs, and a signal corresponding to the amount of change is output from the light receiving element 258.

Therefore, the output of the light receiving element 258, that is, the output of the shake detectors 215a and 215b is a signal having a value indicating the magnitude of the shake around the respective axes 205a and 205b.

This shake signal is supplied to the control circuit 21 shown in FIG.
6 and is then multiplied by an appropriate multiplier to calculate the magnitude of the apex angle required to remove this wobble with the variable apex prism. Here, the appropriate multiplier is a value “1 / (nd−1)” determined by the refractive index nd of the liquid. For example, in the case of silicon oil of “nd = 1.40”, “1 / 1.40”
-1) = 2.5 ".

On the other hand, opposing glass plates 202a, 202
The rotation angle of b around the axes 205a and 205b, that is, the fluctuation of the pitch of the variable apex angle prism and the apex angle in the yaw direction is such that the luminous flux emitted from the light emitting elements 212a and 212b is integrated with the opposing glass plates 202a and 202b. Rotating frame 2
The light-receiving element 21 passes through the slits 210a and 210b attached to the arms 211a and 211b of the first and second arms 04a and 204b.
This causes a shift of the spot position on the light receiving surface when irradiating 3a and 213b. These light receiving elements 213a, 213
13b transmits to the control circuit 216 an output corresponding to the movement amount of the spot, that is, the magnitude of the apex angle of the variable apex angle prism.

The control circuit 216 calculates the difference between the calculated apex angle described above and the current apex angle, and multiplies this by a predetermined amplification factor to obtain the coil 206.
a, a coil drive circuit 21
Transmit to 7. The coil drive circuit 217 receiving this coil drive command signal supplies a drive current corresponding to the signal to the coil 20.
6a and 206b are energized to generate a coil driving force.

The variable apex angle prism rotates around the axes 205a and 205b by the coil driving force, and is deformed to match the calculated apex angle.
That is, the variable apex angle prism uses the apex angle “1 / (nd−1)” times the apex angle calculated to correct the shake as a reference signal, and uses the current apex angle value as a feedback signal. It is configured to perform shake correction control according to a control law.

However, when the ambient temperature is higher than room temperature, the refractive index of the liquid inside the variable apex angle prism has a small value, and when the ambient temperature is low, it has a large value.

For example, in the case of the aforementioned silicone oil,
As the temperature rises or falls by 25 degrees C, the index of refraction decreases by about "0.01". Therefore, the above control circuit 216
If the reference signal calculated in step (1) is always set at a constant ratio with respect to the camera shake angle, the correction amount is insufficient at high temperatures, and the image blur remains uncorrected on the screen. For example, at 50 ° C., the refractive index of silicon oil is about “1.39”. Even if the apex angle of the variable apex angle prism is set to 2.5 degrees by the above-described calculation value in order to correct one degree of shake, the actual correction angle is ( nd-
1) * Only 2.5 = 0.975 degrees can be corrected, it cannot be corrected by 0.025 degrees, and it remains as shake on the screen.

On the other hand, when the temperature is low, the drive is performed with a necessary correction amount or more by the same principle, so that the image blur remains on the screen.

Therefore, at the start of photographing, the temperature sensing element 214 detects the ambient temperature and converts it into a voltage signal corresponding to the detected temperature.
This is notified to the control circuit 216 via the D converter. Based on the voltage signal, the control circuit 216 determines whether the flat glass 2 of the variable apex prism is higher when the temperature is higher than when the temperature is normal.
Is controlled to tilt more, and conversely, when the temperature is low, the tilt is controlled to be smaller than at normal temperature.

Thus, even when the refractive index of the fluid inside the variable apex angle prism changes due to a change in temperature, control is performed so as to cancel the change, so that image blur does not remain on the screen at any temperature. .

FIG. 12 is a flow chart showing the operation when the control circuit 216 is constituted by a microcomputer.

This program is started each time the main switch of the video camera is turned on, and is ended by turning off the main switch. When the main switch is turned on, the operation from step 261 is started. [Step 261] A signal Tp corresponding to the temperature inside the device is fetched from the temperature-sensitive element 214 via the A / D converter, and the process proceeds to step 261. [Step 262] The refractive index nd at that time is determined with reference to a table of the temperature Tp and the refractive index nd, which is predetermined as shown in FIG. [Step 26
3) The state of the main switch is determined, and if it is OFF, this program ends. If it remains ON, the process proceeds to step 264. [Step 264] The state of the anti-vibration switch (AS-sw) is checked. If it is ON, the process proceeds to the anti-vibration operation of step 265 and below, and if it is OFF, the process proceeds to the non-vibration operation of step 271 and below. [Step 2
65] A detection value (a shake signal) from the yaw-side shake detector 215b is taken in through an A / D converter to obtain a shake angle θy of the camera body, and an output of the light receiving element 213b , which is a yaw-side apex angle, is obtained. The variable apex prism apex angle αy is taken in through an A / D converter. [Step 266]
From the value of the refractive index nd referred to in the above table, the target angle value required to correct the current shake angle θy of the camera body by the refraction of the optical axis of the variable angle prism is set as a target value, and the following equation θy / (Nd-1), and multiplies the difference between this target value and the current apex angle αy of the variable apex prism by a predetermined gain constant K ₁ to obtain a coil drive signal εy = K ₁ * ｛θy / (Nd-1) -αy｝ is calculated. [Step 267] This coil drive signal εy is output to the output port and transmitted to the coil drive circuit 217 via the D / A converter. [Step 268]
This time, the detection value from the pitch-side shake detector 215a is taken in through an A / D converter to obtain the camera body shake angle θp, and furthermore, the light-receiving element 213 which is the pitch-side apex angle.
The output of “ a” is taken in via an A / D converter and is set as a variable apex angle prism apex angle αp. [Step 269] From the value of the refractive index nd referred to in the above table, the target value is the apex angle required to correct the current shake angle θp of the camera body by the refraction of the optical axis of the variable apex prism. The following equation θp / (nd-1) is calculated, and the difference between the target value and the current apex angle αp of the variable apex angle prism is multiplied by a predetermined gain constant K ₁ to obtain a coil drive signal εp = K ₁ * {θp / (nd-1) -αp} is calculated. [Step 270] The coil drive signal εp is output to the output port and transmitted to the coil drive circuit 217 via the D / A converter.

By the above series of operations, the vertical angle of the variable apex angle prism is tilted by a predetermined value with respect to the shake of the camera body, the shake is automatically corrected, and a good image without image shake is obtained.

At this time, even if the temperature inside the apparatus is higher or lower than the normal temperature and the refractive index of the internal liquid is high or low, step 262 determines at step 262 the amplification factor K corresponding to the temperature at that time. _{Since 1} is selected by the table and used in the calculation, the effect of temperature is negated.

If the image stabilization switch is OFF in step 264 described above, the process proceeds to the non-vibration operation in step 271 and subsequent steps as described above. [Step 271]
The output of the light receiving element 213b , which is the apex angle on the yaw side, is A / D
It is taken in as a vertex angle αy of a variable vertex angle prism via a converter. [Step 272] The coil drive signal εy is calculated by the following equation εy = −K ₂ * αy by multiplying the apex angle αy of the variable apex angle prism by a predetermined gain constant K ₂ . [Step 273] The coil drive signal εy is output to the output port and transmitted to the coil drive circuit 217 via the D / A converter. [Step 27
4] This time, the output of the light receiving element 213a , which is the apex angle on the pitch side, is taken in as the apex angle αp of the variable apex angle prism via the A / D converter. [Step 275] A predetermined gain constant K for the apex angle αp of the variable apex angle prism
By multiplying by ₂ , the coil drive signal εp is calculated by the following equation: εp = −K ₂ * αp. [Step 276] This coil drive signal εp is output to the output port and transmitted to the coil drive circuit 217 via the D / A converter.

By the above-described series of operations, even when the image stabilizing switch is OFF, the variable apex angle prism is always held at the neutral position to prevent refraction of the optical axis.

In the above-described embodiment, an example has been described in which the temperature signal Tp is fetched from the temperature-sensitive element 214 only once immediately after the power of the apparatus is turned on, but once after the power is turned on. Assuming that there is a rapid change in temperature within a short time until the photographing operation is completed, the refractive index nd may be corrected by taking in the temperature Tp at regular intervals. Nor. In this embodiment, the temperature T
In order to determine the refractive index from p, the relationship between the two is held as a table and a method of referring to the table is used. However, it is also possible to calculate each time by using a linear expression or another appropriate approximate expression. Good.

(Eighth Embodiment) FIG. 14 is a diagram showing a main part of a vibration isolator according to an eighth embodiment of the present invention. The same parts as in the seventh embodiment are designated by the same reference numerals. is there.

In the eighth embodiment, the temperature compensation function is
Instead of using the combination of the temperature sensing element 214 and the control circuit 216 including a microcomputer in the first embodiment, the control is performed using an automatic gain adjuster.

In FIG. 14, reference numeral 218a denotes a shake detector 2
15 is a first amplifying circuit for amplifying the detection signal from 15 at a predetermined magnification. 219a is, for example, a kind of a temperature-sensitive element inside, and has an N value whose resistance value decreases with increasing temperature.
The temperature compensating circuit includes a TC thermistor and the like, and has a gain of “1” or less when the temperature is high, and has a gain of “1” or more when the temperature is low. 220a
A second amplifier circuit amplifies the detection signal from the light receiving element 213a, that is, the value of the apex angle of the variable apex prism at a predetermined magnification.

Here, the ratio of the gain of the first amplifier circuit 218a to the gain of the second amplifier circuit 220a is determined so as to remove the image blur caused by the camera shake.

A subtraction circuit 221a outputs a signal corresponding to the difference between the output of the first amplifier circuit 218a and the output of the second amplifier circuit 220a. 222a is a subtraction circuit 221a
Is a third amplifier circuit that supplies a current proportional to the output of the coil 206 to the coil 206.

Although not shown in FIG. 14, as a control system on the yaw side, a first amplifier circuit 218b, a temperature compensation circuit 219b, a second amplifier circuit 220b, and a subtraction circuit 22
1b and the third amplifier circuit 22b are arranged.

With the above configuration, even when the temperature inside the device changes, the temperature compensation circuit 2
19a automatically adjusts the loop gain so that if the temperature is high, the glass plate of the variable apex prism is driven to tilt more than at room temperature, and conversely, if the temperature is low, , And is driven to tilt smaller than at normal temperature.

Therefore, even when the refractive index of the liquid inside the variable apex angle prism changes due to a change in the ambient temperature, compensation is made so as to cancel the change, so that image blur remains on the screen at any temperature. And good images without image blur are always obtained.

According to the seventh and eighth embodiments, even when the correction rate of the variable apex angle prism changes due to a change in the ambient temperature, the temperature is detected and the correction drive amount is adjusted. Therefore, perfect image blur correction can be performed. For example, when applied to a video camera, a good image without image blur can be obtained.

[0110]

As described above, according to the present invention, optimal image blur compensation is always performed irrespective of the ambient temperature during image stabilization.
Positive can be done.

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a main part of a vibration isolator according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining an example of arrangement of actuators on the pitch side in the conventional and the first embodiment.

FIG. 3 is a diagram for explaining a generated torque in the example of arrangement of the actuator on the pitch side in the conventional example and the first example of FIG. 2;

FIG. 4 is a diagram for explaining an example of arrangement of actuators on the pitch side of a vibration isolator according to a second embodiment of the present invention.

FIG. 5 is a diagram for explaining generated torque of an actuator on a pitch side in FIG. 4;

FIG. 6 is a view for explaining a structure of a variable apex angle prism provided in a vibration isolator according to a third embodiment of the present invention.

FIG. 7 is a diagram for explaining a structure of a variable apex angle prism provided in a vibration isolator according to a fourth embodiment of the present invention.

FIG. 8 is a view for explaining a structure of a variable apex angle prism provided in a vibration isolator according to a fifth embodiment of the present invention.

FIG. 9 is a flowchart showing an operation of the vibration isolator according to the sixth embodiment of the present invention.

FIG. 10 is a configuration diagram showing a main part of a vibration isolator according to a seventh embodiment of the present invention.

11 is a perspective view showing a configuration in a shake detection period in FIG.

FIG. 12 is a flowchart showing an operation of the vibration isolator according to the seventh embodiment of the present invention.

FIG. 13 is a diagram showing a relationship between an ambient temperature and a refractive index used in a seventh embodiment of the present invention.

FIG. 14 is a configuration diagram showing a main part of a vibration isolator according to an eighth embodiment of the present invention.

[Explanation of symbols]

2a, 2b, 202a, 202b Glass plate 3, 203 Bellows-like film 6a, 206a Coil 7a, 207a Permanent magnet 8a, 9a, 208a, 209a Yoke 12a, 212a Light emitting element 13a, 213a Light receiving element 14a, 14b, 215a, 215b Runout detector 15 Control circuit 203, 301 Bellows welding margin 219a Temperature compensation circuit 221a Subtraction circuit 401 Annealing jig

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03B 5/00

Claims (1)

(57) [Claims] 1. A variable apex angle comprising at least two optical members, a deformable connecting member connecting the two optical members, and a liquid sealed in a space formed by the two optical members and the connecting member. A prism, a shake detecting means for detecting shake of the apparatus, a driving means for driving the variable apex angle prism, and a control means for controlling the driving means in accordance with a signal from the shake detecting means to perform image shake correction Temperature detecting means for detecting an ambient temperature; and the variable apex angle prism.
Storage means for storing refractive index information for each temperature of the liquid of the system
And the step according to the temperature information from the temperature detecting means.
Reading the refractive index information of the storage means and based on the refractive index information
And a drive amount changing means for changing a drive amount of the variable apex angle prism by changing a signal from the shake detecting means .