JPH04349431A - Camera provided with vibration proof function - Google Patents

Abstract

PURPOSE:To attain power saving and to improve vibration proofing accuracy. CONSTITUTION:This camera is provided with a phase adjusting means 733 which changes the phases of vibration proof output from a vibration detecting means and the vibration added to a lens barrel between a 1st period when photographing composition is decided and a 2nd period when exposure is performed to a film. Therefore, a vibration proof function is hardly adversely affected (it easily receives the effect of disturbance, or it takes time until the vibration proof function normally works) in the case that it is a short time, so that the phases of the vibration proof output from the vibration detecting means and the vibration added to the lens barrel are made to coincide only in the 2nd period when the exposure is performed to the film in order to improve the vibration proofing accuracy.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention provides a correction optical means that is provided in a lens barrel portion that holds a lens group and decenters the optical axis of the lens group, and a vibration detector that detects vibrations applied to the lens barrel. The present invention relates to an improvement in a camera image stabilization device, which includes a device and a drive device for displacing the correction optical device relative to the lens barrel based on the image stabilization output from the vibration detection device.

0002

BACKGROUND OF THE INVENTION The prior art to which the present invention is applied will be explained below.

[0003] In modern cameras, all important tasks for photography, such as exposure determination and focus adjustment, are automated, so even those who are inexperienced in operating the camera are less likely to make a mistake in taking a picture. However, it has been difficult to automatically prevent failures in photography due to camera shake.

[0004] Therefore, in recent years, there has been active research into cameras that can prevent shooting failures caused by camera shake, and in particular, cameras that can prevent shooting failures due to camera shake. Development and research is underway.

[0005] The above-mentioned hand shake of the camera during photography usually has a frequency of 1Hz to 12Hz, but even if such hand shake occurs at the time of shutter release, it is possible to take a picture without image blur. As a basic idea, it is necessary to detect the vibration of the camera due to the above-mentioned camera shake, and to displace the correction lens according to the detected value. Therefore, in order to achieve the above purpose (i.e., to be able to take photographs that do not cause image blur even when the camera shakes), the first step is to accurately detect camera vibration, and the second is to accurately detect camera vibration.
It is necessary to correct optical axis changes caused by camera shake.

[0006] In principle, detection of this vibration (camera shake) can be carried out using a vibration sensor that detects angular acceleration, angular velocity, angular displacement, etc., and an output signal of the means in the case of a vibration sensor that detects angular acceleration or angular velocity. This can be done by mounting a vibration detection means on the camera that electrically integrates and outputs the angular displacement. Based on this detection information, a correction optical means for decentering the photographing optical axis is driven to suppress image blur.

[0007] Here, an outline of an image blur suppression system (vibration isolation system) using an angular displacement detection device will be explained using FIG. 31.

The example shown in FIG. 31 is a diagram of a system for suppressing image blur caused by vertical camera shake 81p and horizontal camera shake 81y in the direction of arrow 81 in the figure.

In the figure, 82 is a lens barrel, 83p, 83
y is an angular displacement detection device that detects the vertical and horizontal angular displacement of the camera, and the respective angular displacement detection directions are indicated by 84p and 84y. This angular displacement detection device 83
The correction optical means 85 (86p
, 86y drive their respective drive units, and 87p, 87y drive their corrective optical position detection sensors) to ensure stability on the image plane 88.

FIG. 32 shows a vibration isolation system using an angular accelerometer, and the difference from FIG. 31 is that integrators 89p and 8
9y is provided, and the camera shake angular acceleration from the angular accelerometers 810p and 810y is second-order integrated by integrators 89p and 89y, converted into a camera shake angular displacement, and then input to the correction optical means 85. Further, the correction optical means 85 can also be provided with a known mechanical integration function, and the integrators 89p and 89y can perform first-order integration. In this case, if an angular velocity meter such as a vibrating gyroscope is used as the vibration detecting means, , the integrator 89p
, 89y can be omitted.

FIGS. 14 to 16 show examples of the configuration of the angular displacement detection device, and will be explained below using these figures.

In FIGS. 14 to 16, reference numeral 71 indicates a base plate on which each component constituting the apparatus is attached, and reference numeral 72 indicates an outer cylinder having a chamber in which a floating body 73 and a liquid 712, which will be described later, are enclosed. 73 is a floating body holder 74 which will be described later and is rotatable around an axis 74a.
The protrusion 73a is formed with a slit-shaped reflective surface, and is made of a material made of a permanent magnet and is magnetized in the direction of the axis 74a. Further, this floating body 73 is configured to have a rotational balance around an axis 74a and a buoyancy balance.

A floating body holder 74 is fixed to the outer cylinder 72 while holding the floating body 73 via a pivot bearing 75 which will be described later. Reference numeral 76 is a U-shaped yoke attached to the main plate 71, which forms a closed magnetic path together with the floating body 73. Reference numeral 77 denotes a winding coil, which is disposed between the floating body 73 and the yoke 76 and is provided in a fixed relationship with the outer cylinder 72. 78 is a light emitting element (iRED) that generates light when energized, and is attached to the base plate 71. 79 is a light receiving element (PSD) whose output changes depending on the position of the received light;
It is attached to 1. These light emitting elements 78 and light receiving elements 79 are connected to the projections (reflecting surfaces) 73a of the floating body 73.
This constitutes an optical angular displacement detection means that transmits light through the angular displacement sensor.

A mask 710 is placed in front of the light emitting element 78, and has a slit hole 710a through which light passes. 711 is a stopper member attached to the outer cylinder 72;
Rotation is restricted so that the floating body 73 does not rotate beyond a predetermined range. Incidentally, the above-mentioned floating body 73 is rotatably held in the following manner. That is, in the center of the floating body 73, as shown in FIG. 15 (A-A cross section in FIG. 14), pivots 713 having sharp tips are press-fitted at the top and bottom. on the other hand,
Pivot bearings 75 are provided at the tips of the U-shaped upper and lower arms of the floating body holder 74 so as to face each other inwardly, and when the sharp tips of the pivots 713 fit into the pivot bearings 75, the floating body 73 is maintained.

Reference numeral 714 denotes an upper lid of the outer cylinder 72, which is sealed and bonded to seal the liquid 712 inside the outer cylinder 72 by a known technique using silicone adhesive or the like.

In the above configuration, the floating body 73 rotates around the rotating shaft 74a so that no rotational moment is generated due to the influence of gravity in any posture, and no load is substantially applied to the pivot bearing 75. It has a symmetrical shape. Furthermore, it is made of a material having the same specific gravity as the liquid 712. In reality, it is impossible to have zero unbalance component, but the shape error component is sufficiently small since only the specific gravity difference acts as unbalance.
It is easy to understand that the S/N ratio of friction to inertia is extremely good.

In this configuration, even if the outer cylinder 72 rotates around the rotation axis 74a, the internal liquid 712 remains stationary with respect to absolute space due to inertia, so that the floating body 71 in a floating state
2 does not rotate, so the outer cylinder 72 and the floating body 73 rotate around the rotation axis 74.
It will rotate relatively around a. These relative angular displacements can be detected by optical detection means using the light emitting element 78 and light receiving element 79.

Now, in the apparatus having the above configuration,
Angular displacement detection is performed as follows.

First, light emitted from the light emitting element 78 passes through the slit hole 710a of the mask 710 and is irradiated onto the floating body 73, where it is reflected by the slit-shaped reflective surface of the protrusion 73a and reaches the light receiving element 79. When the light is transmitted, the light becomes substantially parallel light due to the slit hole 710a and the slit-like reflecting surface, and an unblurred image is formed on the light receiving element 79.

Since the outer cylinder 72, the light emitting element 78, and the light receiving element 79 are all fixed to the base plate 71 and move together, relative angular displacement movement occurs between the outer cylinder 72 and the floating body 73. When this occurs, the slit image on the light receiving element 79 moves by an amount corresponding to the displacement. Therefore,
The output of the light receiving element 79, which is a photoelectric conversion element whose output changes depending on the position of the received light, is an output proportional to the positional displacement of the slit image, and the output is used as information for the outer cylinder 72.
The angular displacement of can be detected.

By the way, as mentioned above, the floating body 73 is made of a permanent magnetic material having the same specific gravity as the liquid 712, and this can be done, for example, as follows.

When a fluorine-based inert liquid is used as the liquid 712, if fine powder of a permanent magnet material (for example, ferrite, etc.) is contained as a filler in a plastic material base and the content is adjusted, the volume can be increased. It is easy to make the specific gravity similar to the liquid's specific gravity "1.8" at a content of around 8%. If the floating body 73 is molded from such a material or simultaneously magnetized in the direction of the rotating shaft 74a, the floating body 73 will have properties as a permanent magnet.

FIG. 17 is a cross section taken along line BB in FIG. 14, showing the relationship among the floating body 73, yoke 76, and winding coil 77.

As shown in the figure, the floating body 73 is magnetized in the direction of the rotating shaft 74a, and in this figure, the upper side is magnetized to the north pole and the lower side is magnetized to the south pole. The magnetic field lines coming out from the N pole form a U-shaped yaw.
It forms a closed magnetic path that passes through the magnetic circuit 76 and enters the S pole.If a current is passed through the winding coil 77 placed in this magnetic path from the back side of the page to the front side as shown in the figure, Fleming's left-hand rule Accordingly, the winding coil 77 receives a force in the direction of arrow f. However, the winding coil 77 is not connected to the outer cylinder 7 as described above.
Since it is fixed to 2, it cannot move, so a reaction force acts in the direction of arrow F, and the floating body 73 is driven by this force. It goes without saying that this force is proportional to the current flowing through the winding coil 77, and that the force acts in the opposite direction if the current is caused to flow in the opposite direction to that described above. That is, in the above configuration, it is possible to freely drive the floating body 73.

The spring force exerted on the floating body 73 by this driving force is, in principle, a force that maintains the floating body 73 in a constant posture with respect to the outer cylinder 72 (that is, moves it together with the outer cylinder 72). If the force is strong, the outer cylinder 72 and the floating body 73 will move together, causing the problem that the relative angular displacement for the desired angular displacement will not occur, but the driving force (spring force)
If it is sufficiently small relative to the inertia of the floating body 73, it can be configured to respond to angular displacement at a relatively low frequency.

FIG. 18 is a diagram showing an electric circuit of the angular displacement detecting device as described above.

Current-voltage conversion amplifiers 715a, 715b
(and resistors R33 to R36) are the reflected light 7 of the light emitting element 78.
16 converts the photocurrent generated in the light-receiving element 79 into a voltage, and then converts the photocurrent generated in the light-receiving element 79 into a voltage, which is then applied to the next stage differential amplifier 717 (and resistors R37 to R40).
calculates the output difference between the current-voltage conversion amplifiers 715a and 715b, that is, the angular displacement (relative angular displacement movement between the outer cylinder 72 and the floating body 73). This output is connected to resistors 718 and 719
divides the output into an extremely small output, and inputs it to the drive amplifier 720 (and resistor R41, transistors TR11, TR12) that sends current to the wire-wound coil 77, and provides negative feedback (when the differential amplifier 717 outputs, the floating body 73 is the center If the wiring of the winding coil 77 and the magnetization direction of the floating body 73 are set so as to return to , a spring force (driving force) that is sufficiently small with respect to the inertia of the liquid 712 is generated as described above.

Adding amplifier 721 (and resistors R42 to R4
5) is the sum of the amplifiers 715a and 715b (light receiving element 7
9) is calculated, and its output is input to the drive amplifier 722 (and resistors R47 to R48, transistor TR13, and capacitor C11) that causes the light emitting element 78 to emit light. .

Although the light emitting element 78 changes its light emission amount extremely unstable due to temperature difference, if the light emitting element 78 is driven by the total amount of received light as described above, the total photocurrent output from the light receiving element 79 will change. is always constant, and the differential amplifier 717
The angular displacement detection sensitivity of can be made extremely stable.

In addition to the position control loop that provides a weak spring force as described above, the angular displacement detection device also includes a speed control loop that adjusts the damping characteristic of the transmission characteristic of the system. This is because the damping characteristics of the liquid 712 and the floating body 73 contained in the outer cylinder 72 are always kept constant regardless of changes in external temperature (the viscosity of the liquid 712 changes depending on the external temperature). . This speed control loop is comprised of amplifiers 723, 724, 725, etc. in FIG.

The amplifier 723, together with resistors 726, 727 and capacitors 728, 729, differentiates the angular displacement (position) detection output of the amplifier 717 to produce a speed output, and also removes high-frequency noise. The amplifier 724 connects the resistors 718, 7
19 divided voltage output buffer amplifier, amplifiers 723, 7
24 output (velocity and position) to amplifier 725 (and resistor R
49 to R51) and sent to the drive amplifier 720.

Returning to FIG. 14 again, the block diagram shown in FIG. 14 is a simplified version of the circuit shown in FIG. 18.

730 is the amplifier 715a, 715b,
717 (and resistors R33 to R49), which amplifies the output of the light receiving element 79. 731 is the amplifier 723, resistors 726, 727, and capacitor 7.
28 shows a differential circuit composed of 28. 732 is the resistor 718
, 719, and 733 is a circuit that shows the amplification degree G2 determined by the amplifier 723 and resistors 726 and 727, and adjusts the position control loop gain and speed control loop gain, respectively. can be done.

FIG. 19 is a Bode diagram showing the frequency characteristics of the above-mentioned angular displacement detection device, where the horizontal axis is the frequency, and the vertical axis is the output gain (734G) of the angular displacement detection device, input camera shake, and angular displacement detection. The phase (734P) of the output of the device is shown.

As shown in FIG. 19, the output of the angular displacement detector is small at frequencies lower than 0.2 Hz.
This indicates that the angular displacement detection device does not output an output for extremely low frequency camera shake. Then, this analysis point (in Figure 19, “0
．． 2Hz") is determined by the circuit 732 (amplification degree G1) in FIG. 14. If the amplification degree G1 here is increased, the springiness between the floating body 73 and the outer cylinder 72 becomes stronger, and the analysis point moves to the higher frequency side. However, if the amplification degree G1 is made smaller, the springiness becomes weaker and the analysis point moves to the lower frequency side.

[0036]

[Problems to be Solved by the Invention] As described above, the angular displacement detection device accurately detects the amount of camera shake of "0.2Hz" or higher, but there are several problems. There is.

[0037] Hand shake usually has a frequency distribution of about 1 Hz to 10 Hz, and shake of about 2 Hz frequently occurs. As shown by the output gain (gain) 734G in FIG. 19, the angular displacement detection device accurately detects the deflection amount in this range, but the phase 734P is still "0°" around 2Hz.
”, and the phase is ahead by ψ71 with respect to the input camera shake.

FIG. 20 is an exaggerated diagram to help explain the deterioration in image stabilization accuracy due to this. In FIG. 20, the horizontal axis represents time and the vertical axis represents the amount of camera shake.

Here, 735 indicates the amount of camera shake that is actually applied to the lens barrel, and as a result, the output 736 of the angular displacement detector has a phase that is ahead of the actual camera shake when the actual camera shake is about 1 to 2 Hz. I'm here. And this output 7
35, the correction optical means performs image stabilization by decentering the optical axis, but the difference 737 between the actual camera shake amount 735 and the output 736 of the angular displacement detection device remains as an error, and naturally the error (due to phase shift) If the error is large), the vibration isolation accuracy will deteriorate.

Of course, in FIG. 19, the analysis point is set to "0.2
Hz", that is, if the amount of current to the winding coil 77 is reduced and the springiness is weakened, the phase shift amount ψ71 will become smaller. However, if the springiness is weakened in this way, the floating body 73 will be extremely susceptible to disturbances. If the floating body 73 becomes unstable, for example, the floating body 73 is slightly unbalanced around the rotation axis 74a, and a sudden weight change occurs to the angular displacement detection device such as "holding the camera again", the floating body 73 will be greatly displaced. When the stopper 711 hits, the angular displacement detection function is lost. Therefore, the analysis point could not be moved to a very low frequency, and the above-mentioned phase shift was an unavoidable problem.

Furthermore, the next problem is that the light emitting element 78 in FIG. 14 is always turned on after the anti-vibration system activation switch (not shown) is input, but if it is constantly emitting light, the battery will be consumed. This occurs extremely quickly, resulting in a situation where functions other than vibration isolation cannot be used. However, when the light emitting element 78 is turned on with a low current to prevent battery consumption, the S/N ratio of the signal itself of the light receiving element 79 deteriorates, resulting in a problem of deterioration of image stabilization accuracy.

Next, the structure and operating principle of the angular accelerometers 810p and 810y used in the vibration isolation system shown in FIG. 32 will be explained.

FIG. 21 shows the angular accelerometers 810p, 810
2 shows a structural diagram of a servo angular acceleration sensor used as y.

In FIG. 21, reference numeral 738 indicates the bottom of the outer frame, and the support portion 73 is integrally fixed to the bottom of the outer frame 738.
9 and a bearing 740a with low friction such as a ball bearing,
Both ends of a shaft 741 are supported by 740b, and coils 742a, 742b are supported by the shaft 741.
A seesaw 743 to which the lever is attached is swingably supported.

Above and below the coils 742a, 742b and seesaw 743, magnetic circuit boards 744a, 744b and permanent magnets 745a1, 745a and 745a are spaced apart from each other and serve as lids.
45a2, 745b1, and 745b2 are arranged to face each other, and the magnetic circuit boards 744a and 744b also serve as the lid of the outer frame as described above. Permanent magnet 745a1, 745a
2,745b1 and 745b2 are mounted on magnetic circuit back plates 746a and 746b, respectively, which are fixed to the outer frame bottom 738.

[0046] Also, the coil 742a of the seesaw 743
, 742b has a slit 74 penetrating in the thickness direction.
Slit plates 748a, 748 forming 7a, 747b
b, and the magnetic circuit board 744a, which also serves as the lid of the outer frame above the slit 747a, is made of SPC (Seed).
A photoelectric displacement detector 749, such as a photodiode, is disposed, and a light emitting element 750, such as an infrared light emitting diode, is disposed on the magnetic circuit back plate 746a below the slit 747a.

In the above configuration, if the angular acceleration a acts on the outer frame in FIG. 21 as shown by the arrow 751, the seesaw 743 tilts in the direction opposite to the angular acceleration a, and this The deflection angle can be detected by the position of the beam from the light emitting element 750 through the slit 747a on the displacement detector 749. By the way, the permanent magnets 745a1, 7
The magnetic flux from 45b1 is transmitted to permanent magnets 745a1 and 74, respectively.
5b1 → Coils 742a, 742b → Magnetic circuit board 744
a, 744b → coil 742a, 742b → permanent magnet 7
45a2, 745b2, the other permanent magnet 745a2, 7
The magnetic flux from 45b2 is transmitted to permanent magnets 745a2 and 74, respectively.
5a2 → Magnetic circuit back plate 437a, 437b → Permanent magnet 7
45a1 and 745b1, forming a closed magnetic circuit as a whole, and forming magnetic flux in a direction perpendicular to the coils 742a and 742b. Then, by applying a control current to the coils 742a and 742b, the seesaw 743 is moved to the above angular acceleration a according to Fleming's law.
It is provided so that it can be moved to both sides along the deflection direction.

FIG. 22 shows an example of the configuration of an angular acceleration detection circuit used in the servo angular acceleration sensor having the above configuration. This circuit includes a displacement detection amplifier 752 for amplifying the output from the displacement detector 749, a compensation circuit 753 for making this feedback circuit a stable circuit system, and an amplified output from the displacement detection amplifier 752. A drive circuit 754 that further amplifies the current of the output and energizes the coils 742a and 742b is connected in series with the coils 742a and 742b.

In this example, the coil 742
a, 742b is energized, the external angular acceleration a
The winding direction of the coils 742a, 742b and the permanent magnets 745a1, 745a2, 745b1, 745b are adjusted so that force is generated in the opposite direction to the swinging direction of the seesaw 743 due to the
2 polarities are set.

To explain the operating principle of the servo angular acceleration sensor with the above configuration, if angular acceleration a is applied from the outside to the angular acceleration sensor with the above configuration as shown in FIG. The force swings in the opposite rotational direction relative to the outer frame, and therefore the slit 747a provided in the seesaw 743 moves in the L direction. For this reason, the center of the light beam incident on the displacement detector 749 from the light emitting element 750 is displaced, and the displacement detector 749 generates an output proportional to the amount of displacement.

The output is sent to the displacement detection amplifier 75 as described above.
2 and is further amplified by the drive circuit 7 via the compensation circuit 753.
The current is amplified by 54 and energized to coils 742a and 742b.

As described above, when the control current is applied to the coils 742a and 742b, a force is generated on the seesaw 743 in the R direction, which is the opposite direction to the L direction of the external angular acceleration a, and the displacement A control current is adjusted and generated so that the light beam incident on the detector 749 returns to its initial position when the external angular acceleration a is not applied.

[0053] At this time, the value of the control current flowing through the coils 742a and 742b is proportional to the rotational force applied to the seesaw 743, and furthermore, the rotational force applied to the seesaw 743 is Since the returning force is proportional to the magnitude of the external angular acceleration a, the current flows through the resistor 755 to the voltage V.
By reading this, the magnitude of the angular acceleration a can be obtained as control information necessary for, for example, a camera image blur suppression system.

FIG. 23 is a diagram showing the angular acceleration detection circuit of FIG. 22 in more detail.

In FIG. 23, the current-voltage conversion amplifier 7
56 corresponds to the displacement detection amplifier 752 in FIG. 22, and performs position detection by converting and amplifying the photocurrent from the displacement detector 749 into voltage. The capacitor 759 and resistors 757 and 758 correspond to the compensation circuit 753, and the drive amplifier 760 and the like correspond to the coil 7.
This corresponds to a drive circuit 754 that drives 42a and 742b. Further, 749 and 750 are the aforementioned displacement detectors and light emitting elements.

The above is the configuration of the servo angular acceleration sensor that detects camera shake angular acceleration.However, as mentioned in the angular displacement detection device, there is a low frequency phase shift and the power consumption of the light emitting element is large or the power consumption is reduced. If the value is made smaller, the problem of deterioration of S/N also occurs.

[0057] This will be explained.

When detecting camera shake angular displacement using an angular accelerometer, it is necessary to perform second-order integration of its output, as shown in Figure 32.
mentioned in.

FIG. 24 is a Bode diagram showing the frequency characteristics of the second-order integrator required at this time, and as can be seen from this gain diagram 756, the angular acceleration output is It has a characteristic of attenuating (second-order integration) in proportion to the square of . Therefore, the camera shake angular acceleration is from camera shake band 1 to
The amount of runout displacement is accurately converted at 10Hz. However, even if the amount of runout displacement is accurately converted, the phase with the actual runout does not match sufficiently. 757 indicates the phase of the second-order integrator used, and the point where the phase is delayed by "180°" is the range where the second-order integration is performed accurately and the phase matches the actual camera shake. However, from this figure, “0.
At 2Hz, the phase is still delayed by only 90°,
Even at 2Hz, ψ72 (
Approximately 6°) is insufficient. Therefore, the vibration isolation accuracy deteriorates as shown in FIG. 20.

Of course, if the characteristics in FIG. 24 are changed from the characteristic that integrates over 0.2 Hz to the characteristic that integrates over 0.05 Hz, the phase shift at 2 Hz can be considerably improved, but as the characteristics of the integrator The lower the frequency that can be integrated, the longer it will take to stabilize after the power is turned on.
For example, if you try to integrate over "0.05Hz", 2
The integral output will not become sufficiently stable unless you wait about 0 seconds, which is not an acceptable time for consumer equipment such as cameras. Therefore, like this (integrate over "0.05Hz")
An integrator could not be used, and therefore deterioration of vibration isolation accuracy due to phase shift was an unavoidable problem.

The servo angular acceleration sensor also uses optical position detection means composed of a light emitting element 750 and a light receiving element 749, as shown in FIG. need to be stored, which increases power consumption. If this amount of current is reduced, the S/N ratio of the light receiving element 749 will deteriorate, causing a problem of degrading the vibration isolation accuracy.

Even if an eddy current or magnetic method is used as the position detecting means, it is necessary to keep the detection current flowing, and needless to say, if an attempt is made to reduce power consumption, the problem of S/N deterioration will occur. Nor.

FIG. 25 is a diagram showing the configuration of a correction optical mechanism (consisting of a correction optical means and a circuit for driving the same) suitably used in the above-mentioned image stabilization system. 2 mutually perpendicular lines perpendicular to the axis
It can be freely driven in the directions (pitch direction 81p and yaw direction 81y). Its configuration is shown below.

In FIG. 25, a fixed frame 759 holding a correction lens 758 is made of polyacetal resin (hereinafter referred to as POM).
It is possible to slide on a pitch slide shaft 761p via a slide bearing 760p such as . Further, the fixed frame 759 is held between pitch coil springs 763p coaxial with the pitch slide shaft 761p, and is held near the neutral position. The pitch slide shaft 761p is connected to the first holding frame 76
It is attached to 2.

The pitch coil 764p attached to the fixed frame 759 is connected to the pitch magnet 765p and the pitch yoke 7.
The fixed frame 759 is placed in a magnetic circuit composed of 66p, and the fixed frame 759 is driven in the pitch direction 81p by passing a current. Further, a pitch slit 767p is provided in the pitch coil 764p, and a light emitting element 768
The position of the fixed frame 759 in the pitch direction 81p is detected by the relationship between the light receiving element 769p (infrared light emitting diode) and the light receiving element 769p (semiconductor position detecting element).

A slide bearing 760y such as a POM is fitted into the first holding frame 762, and a yaw slide shaft 761
can slide on the housing 770 to which the y is attached. The housing 770 is the lens barrel 8 shown in FIG.
2, the first holding frame 762 is movable in the yaw direction 81y with respect to the lens barrel 82. Also, yo-
A yaw coil spring 763y is provided coaxially with the slide shaft 761y, and is held near the neutral position like the fixed frame 759.

Further, the fixed frame 759 is provided with a yaw coil 76.
4y is provided, and the yaw coil 764y is sandwiched between the yaw coils 764y and 764y.
The fixed frame 759 is also driven in the yaw direction 81y due to the relationship between the magnet 765y and the yoke 766y. The yaw coil 764y is provided with a yaw slit 767y to detect the position of the fixed frame 759 in the yaw direction 81y as well as in the pitch direction.

In FIG. 25, light receiving elements 769p, 76
The output of 9y is amplified by amplifiers 771p and 771y and sent to the coil (pitch coil 7) through each circuit as shown in the figure (described later).
64p, yaw coil 764y), fixed frame 7
59 is driven, and the outputs of the light receiving elements 769p and 769y change. If the driving direction (polarity) of the coils 764p, 764y is set in the direction in which the output of the light receiving elements 769p, 769y becomes smaller, a closed system (closed loop) is formed, and the output of the light receiving elements 769p, 769y becomes almost zero. Stable at some point.

Note that the compensation circuits 772p and 772y are shown in FIG.
This is a circuit that further stabilizes the system of No. 5, and the adder circuit 801
p, 801y are circuits that add the input command signals 774p, 774y to amplifiers 771p, 771y, and drive circuits 773p, 773y are circuits that add the input command signals 774p, 774y to the amplifiers 771p, 771y.
This is a circuit that compensates for the applied current.

A command signal 774p is sent to the system as described above from the outside.
, 774y, the correction lens 758 receives the command signals 774p, 774y in the pitch direction 81p and the yaw direction 81y.
It is driven extremely faithfully to y. And this command signal 7
By inputting the outputs of the vibration detection means as described above as 74p and 774y, a vibration-proofing effect can be realized.

FIG. 26 is a diagram showing the driving means for driving the correction optical means in more detail, and here, the driving means for driving the correction optical means is shown in detail.
Only p will be explained.

Current-voltage conversion amplifiers 775a, 775b
The light emitting element 768p causes the light receiving element 769p (resistance R1
, R2) generated in the current-to-voltage conversion amplifiers 775a and 77.
5b, and this difference signal represents the position of the correction lens 758 in the pitch direction 81p. Above, the current −
Voltage conversion amplifier 775a, 775b, differential amplifier 776
and resistors R3 to R10 constitute an amplifier 771p in FIG.

The amplifier 777 adds the command signal 774p to the difference signal of the differential amplifier 776, and is connected to the resistor R1.
1 to R14 constitute an adder circuit 801p in FIG.

Resistors R15, R16 and capacitor C1 are a known phase advance circuit, which is the compensation circuit 7 of FIG.
72p and stabilizes the system.

The output of the adder circuit 801p is sent to the compensation circuit 7.
72p to a drive amplifier 778, where a drive signal for a coil 764p is generated, and the correction lens 758 is displaced. The drive circuit 773p in FIG. 25 is composed of the drive amplifier 778, the resistor R17, and the transistors TR1 and TR2.

The summing amplifier 782 calculates the sum of the outputs of the current-voltage conversion amplifiers 775a and 775b (total amount of light received by the light receiving element 769p), and the drive amplifier 783 receives this signal.
drives the light emitting element 768p in accordance with this. As above, addition amplifier 782, drive amplifier 783, resistor R18~
R22 and the capacitor C2 constitute a drive circuit for the light emitting element 768p (not shown in FIG. 25).

The amount of light emitted by the light emitting element 768p changes extremely unstable due to temperature, etc., and accordingly, the differential amplifier 7
Although the positional sensitivity of the light emitting element 768p changes, the light emitting element 768p is controlled by the drive circuit described above so that the total amount of light received remains constant as described above.
If this is controlled, the position sensitivity will not change.

FIG. 27 shows the frequency characteristics of the correction optical means, and the gain 784 is flat from DC to about 20 Hz, accurately reproduces the amplitude of the output from the vibration detection means, and the phase is also suitable for cases where the amount of camera shake is large. At 1 to 3 Hz, there is almost no deviation and the vibration isolation accuracy is high.

However, there are also problems with such a correction optical means, which will be explained below.

Gravity is applied to the correction lens 758 as shown by arrow g in FIG. Then, as described above, when the power is turned on, the correction optical means performs position control, so the output of the light receiving element 769p is approximately zero (near neutral), and the correction lens 758 is stabilized. When the power is off, the correction lens 758 is stable due to the balance between gravity and the spring force of the pitch coil spring 763p, but when the power is on, it becomes neutrally stable, so the force that continues to hold the correction lens 758 against gravity (Gravity correcting lens 7
58 and the reaction force of the pitch coil spring 763p) is borne by the pitch coil 764p, and the current required for this is large, so it is desired to reduce power consumption. Furthermore, since the camera may be held in a vertical position, gravity may continue to flow a large current through the yaw coil 764y, not only in the direction of the arrow g in FIG.

As a method of preventing such an increase in power consumption due to gravity, a control method shown in FIG. 28 has been considered.

The difference between FIG. 28 and FIG. 25 is that the drive circuit 7
Low frequency removal filters 786p, 786 are connected in series between 73p, 773y, pitch coil 764p, and yaw coil 764y.
This means that y is included. Therefore, since the low-pass removal filters 786p and 786y remove DC inputs such as gravity, no current flows through the pitch and yaw coils 764p and 764y, making it possible to save power.

[0083] And low frequency removal films 786p, 78
By appropriately setting the time constant of 6y and the position control loop gain, the frequency characteristics shown in FIG. 29 are obtained, and the gain 787 becomes flat in the camera shake band of 1 to 10 Hz. However, since the low frequency removal filters 786p and 786y are included, the output is attenuated at low frequencies, especially the phase 788 is 2Hz.
Since there is a deviation of ψ73 even in the vicinity, the vibration isolation accuracy deteriorates accordingly. In other words, when attempting to save power, the vibration isolation accuracy deteriorates.

Furthermore, as described in the angular displacement detection device and the angular accelerometer, the light emitting elements 768p and 7 are also used in the correction optical means.
Since 68y is used, it is necessary to constantly supply current to the light emitting elements 768p and 768y, and if the light emitting current is reduced to save power, the S/N of the light receiving elements 769p and 769y will deteriorate. Anti-vibration accuracy decreases.

As a method of reducing the power consumption due to gravity, there is a method of lowering the position control loop gain apart from the method shown in FIG.

The higher the position control loop gain is, the more accurately the correction lens 758 stabilizes at the neutral point in the example of FIG. 25, and the lower the position control loop gain is, the more stable the correction lens 758 becomes. It descends in the direction of gravity. This is due to the force exerted by gravity on the correction lens 758 and the coil spring 763.
This shows that the difference between the reaction forces of p and 763y becomes smaller,
The current flowing through the coils 764p and 764y due to gravity is reduced, resulting in power savings. However, as is well known, the position control loop gain directly becomes a value indicating the driving accuracy; for example, if the position control loop gain is 40 [dB] (100 times), the drive error will be [1/100]. However, when the position control loop gain is lowered to save power, the driving accuracy deteriorates accordingly, resulting in a deterioration of the vibration isolation accuracy.

Next, another type of correction optical means will be explained.

FIG. 30 is a structural diagram of the correction optical means using a variable apex angle prism.

In FIG. 30, 789 has a high refractive index.
For example, it is a silicon-based liquid, and two flat glasses 79
It is sealed without air bubbles by 0p, 790y and polyethylene film 791. The flat glass 790p is held by a pitch holding frame 792p, and this pitch holding frame 792p
p is rotatably fixed around a pitch axis 81p'. The flat glass 790y is held by a yaw holding frame 792y, and the yaw holding frame 792y is fixed around a yaw axis 81y'.

[0090] The pitch and yaw holding frames 792p and 792y are provided with a pitch coil 793p and a yaw coil 793y, respectively, and these coils hold fixed pitch and yaw positions.
Magnet 794p, 794y, pitch, yo-yo-7
Because it is placed in a closed magnetic path formed by 95p and 795y,
By passing current through the pitch and yaw coils 793p and 793y, the pitch and yaw holding frames 792p and 792y are driven to rotate around the pitch and yaw axes, respectively.

[0091] Also, pitch and yaw holding frames 792p, 792
The arms 796p and 796y of y each have a displacement detection light receiving element 7.
97p, 797y are attached, and these are connected from the fixed infrared light emitting elements 798p, 798y to the holes 799p, 797y.
Rotation around the pitch axis 81p' and the yaw axis 81y' is detected by the narrowed light beams irradiated through 799y. Known position control is also performed between the displacement detection light receiving elements 797p, 797y and the pitch and yaw coils 793p, 793y, and since this has been described with respect to the sliding type correction optical means, a description thereof will be omitted.

In the above configuration, the pitch holding frame 7
92p rotates around the pitch axis and the flat glass 790p tilts around the pitch axis 81p', the liquid 78 with a high refractive index
When the yaw holding frame 792y rotates around the yaw axis and the flat glass 790y tilts around the yaw axis 81y', the ray of light passing through the interior of 9 is decentered in the direction of the arrow 81p. eccentric in the direction. As mentioned above, the greatest feature of the correction optical means consisting of such a variable apex angle prism is that the optical axis can be decentered no matter what optical system is placed before or after the correction optical means in the optical axis direction. For example, the optical axis can be corrected no matter what type of lens it is attached to.

However, even in such a variable apex angle prism, when gravity is applied, the liquid 789 gathers in that direction, so the flat glasses 790p and 790y are not parallel, but "
In order to keep them parallel (to control the position, they automatically become parallel when the power is turned on), current is passed through the coils 793p and 793y, which consumes a large amount of current. Also, in order to save power, it is possible to use a method similar to the above-mentioned sliding type correction optical means, but of course the same deterioration in vibration isolation accuracy will occur.

[0094] In view of the above points, an object of the present invention is to provide a camera with an image stabilization function that can achieve power saving and improve image stabilization accuracy.

[0095]

[Means for Solving the Problems] The present invention provides a method for adjusting the vibration-proofing output of the vibration detection means and the lens barrel during the first period in which the photographic composition is determined and the second period in which the film is exposed. A phase adjustment means is provided to change the phase of the applied vibration, which will have a negative effect on the vibration isolation function if it is for a short period of time (susceptible to external disturbances, it takes time for the vibration isolation function to function properly).
Therefore, in order to improve the anti-vibration accuracy only during the second period when the film is exposed, the anti-vibration output of the vibration detection means and the phase of the vibration applied to the lens barrel are made to match. I have to.

Further, a loop gain changing means is provided for changing the position control loop gain of the correcting optical means in the first period during which the photographic composition is determined and the second period during which the film is exposed. Therefore, since image stabilization accuracy is not so required during the first period, which is a long time period during which the photographic composition is determined, the position control loop gain is made small in order to reduce the drive current of the correction optical means during this period. However, since the second period during which the film is exposed is short, the position control loop gain is increased with more emphasis on image stabilization accuracy than on reduction of drive current.

[0097] Also, during the first period in which the photographic composition is determined and the second period in which the film is exposed, the position detection provided in at least one of the correction optical means and the vibration detection means is performed. A supply current changing means for changing the current supplied to the means is provided, and since image stabilization accuracy is not so required during the first period, which is a long period during which photographing composition is determined, the position detecting means is changed during this period. In order to reduce the current consumption in the position detection means, the current supplied to the position detection means is reduced,
Since the second period during which the film is exposed is only for a short time, the current supplied to the position detecting means is increased with more emphasis on vibration isolation accuracy than on reducing current consumption.

[0098]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on the illustrated embodiments.

FIG. 1 shows a first embodiment of the present invention in which an angular displacement detection device is used as the vibration detection means, and the difference from the angular displacement detection device shown in FIG. The loop gain (output of the circuit 733) can be changed during release (when the switch 11 (hereinafter referred to as SW2), which is turned on by pressing the release button, is turned on).

Here, changing the speed control loop gain means changing the attenuation characteristics of the system. When aiming at the subject, the attenuation is strong, and during exposure (switch S
When W2 is turned on), the attenuation is weakened, and the attenuation is further strengthened by an exposure completion signal (shutter completion signal, etc.).

FIG. 2 shows the change in frequency characteristics due to the above operations, and the gain 734G is the same as before when aiming at the subject, and the phase 734p is also ψ71 at 2Hz.
However, during exposure (when switch SW2 is turned on), the gain has a weak attenuation characteristic (the gain of 12G shows a peak at the analysis point) as shown by 12G (dashed line). Since the phase 12p (broken line) changes rapidly near the analysis point, the amount of phase shift ψ11 near 2 Hz becomes extremely small, and therefore the vibration isolation accuracy becomes extremely high.

[0102] Also, when aiming at the subject, 12G, 1
If the characteristic of weak attenuation shown by 2p is used, the problem shown in FIG. 3 will occur.

In FIG. 3, when the angular displacement detection device detects the repeated low-frequency camera shake indicated by 13, the output is 1.
As shown in 4, the amount of camera shake increases over time, resulting in an output that exceeds the actual amount of camera shake. This is due to the peak of the gain 12G in FIG. 2 near the analysis point, and the closer the actual camera shake frequency is to this analysis point frequency, the greater the output will be, which will deteriorate the vibration isolation accuracy.

However, in FIG. 3, the influence of the analysis point peak has not yet appeared at the beginning of camera shake detection (arrow 15). Therefore, although it is a short period after the attenuation is weakened, there is a period in which the phase shift is small and there is no influence of the analysis point peak. In this embodiment, by utilizing this fact, it was possible to weaken the attenuation only during short seconds during exposure and increase the vibration isolation accuracy.

FIG. 4 is a diagram for explaining the effect of this embodiment, and shows the output of the angular displacement detection device 17 when the damping characteristic is not changed as before for actual camera shake 16.
It is shown in The residual shake after image stabilization (the difference between the actual camera shake 16 and the output 17 of the angular displacement detector) is as shown by 18, and the amount of residual shake on the film surface during exposure (period 19) is 45 μm ( 1/8 second (when using a 200mm telephoto lens) and 252μm when the anti-vibration system is not activated.
It is about 1/5 of that.

Furthermore, when the attenuation characteristic is always weakened (both when aiming at the subject and during exposure), the residual shake 111 with respect to the output 110 of the angular displacement detection device is approximately equal to the peak of the deposition point as shown in FIG. The effect has not yet appeared and is still being exposed (period of 19)
The amount of runout has been reduced to 20 μm. However, in the case of a photographer who produces a lot of low-frequency shake, the influence of the spot peak will be noticeable on the residual shake, resulting in significant image deterioration.

[0107] Then, as in this embodiment, when the attenuation is strong when aiming at the subject and the attenuation is weak during exposure, the amount of shake during exposure is determined relative to the output 112 of the angular displacement detection device and the residual shake 113. is 15 μm, which is 1 for the residual runout of 17.
/3, approximately 1/17 of the case when the vibration isolation system is not activated
I can do it. When this device was actually implemented, it was possible to further reduce the amount of shake by 40% in about 70% of the photos taken with the conventional anti-shake system.

[0108] Here, as shown in Fig. 3, the influence of the precipitation peak appears as time passes, so if this example is applied to long exposures (1 second, 2 seconds, etc.), the reverse effect will occur. Since this will degrade the image stabilization accuracy, it is necessary to control the attenuation characteristics so as not to change them during long exposures.

[0109] In the system described above, the attenuation characteristic is adjusted by the speed control loop gain, but the invention is not limited to this. For example, a protrusion that changes the flow in the liquid 712 of the angular displacement detection device may be aimed at the subject. The attenuation may be changed by moving the light in and out during exposure and during exposure.

Furthermore, when an angular accelerometer and an integrator are used as the vibration detection means, this can be applied by changing the damping characteristics of the integrator. Since the circuit of the second-order integrator and the adjustment of its attenuation characteristic are well known, a description thereof will be omitted, and only the important part of this example, which is to change the characteristic when aiming at the subject and during exposure, will be described.

The solid lines in FIG. 5 are the gain 756 and phase 757 of the integrator described in FIG. 24, and these characteristics are used when aiming at an object. During exposure, the gain is changed to 21 and the phase is changed to 22 as shown by the broken line, and the phase shift ψ72 is reduced to ψ71, thereby increasing the vibration isolation accuracy.

FIG. 6 shows a second embodiment of the present invention in which an angular displacement detecting device is used as the vibration detecting means. What is different from FIG. The low-pass filter 32 is connected to the circuit block 730, and the correction optical means is driven based on the output of the high-pass filter 32.

That is, while aiming at the object, the correction optical system is driven by the output of the amplifier circuit 730, and during exposure, the correction optical system is driven by the output via the high-frequency removal filter 32.

FIG. 7 shows the frequency characteristics, and during exposure, the characteristics of the angular displacement detection device (gain 32G, phase 32p)
, a first-order high-frequency removal filter 32 with an analysis point at 20Hz.
With the addition of the characteristics of It becomes zero, and the phase shift ψ71 before adding the high-frequency removal filter 32 disappears.

[0115] Therefore, the vibration isolation accuracy near this frequency is extremely high. Of course, the image stabilization accuracy has decreased in the high range, so some image blur remains, but the amount of camera shake itself is very small in the high range, so compared to the deterioration in accuracy in the high range, it is
The degree of accuracy improvement is large in the vicinity of Hz, leading to an overall improvement in vibration isolation accuracy.

[0116] The reason why the high frequency removal filter 32 is not connected when aiming at a subject is because fine vibration in the high frequency range is quite noticeable even if the amount is small, and it is important for the photographer to prevent this high frequency vibration. This is because you can strongly feel the anti-shake effect when looking at the subject through the finder.

[0117] In this second embodiment, the high frequency removal filter 32 is used to correct the phase shift ψ71, but the invention is not limited to this. For example, a known phase circuit may be used to correct the phase shift. Needless to say, it's okay to do so.

FIG. 8 shows a third embodiment of the present invention in which a sliding correction optical means is used.
Compared to the correction optical means in FIG. 28, the switches 41p and 41y are turned on by the low-pass removal filter 786 when the switch SW2 is turned on.
The difference is that the connections of p and 786y are turned on and off.

In FIG. 8, while aiming at the subject, the switches 41p and 41y operate the low frequency removal filters 786p and 786p.
86y is connected, and during exposure, low-pass removal filter 786p,
It is set not to go through 786y.

[0120] Therefore, when aiming at a subject for a long time, the correction lens 75 is
It is possible to cut the coil current that supports 8 against gravity,
This saves power, and during exposure, the frequency characteristics shown by the solid line in Figure 9 (
Gain is 784, phase is 785), and the low frequency phase shift ψ73 that occurs in the characteristics shown by the broken line (gain 787, phase 788) when aiming at the subject becomes extremely small as ψ41, improving image stabilization accuracy. . Of course, during exposure, since the low-pass removal filters 786p and 786y are not passed through, it is necessary to send a large current to the coil to support the correction lens 758 against gravity, but since it is a short exposure time, it consumes power. is not large.

In the example of FIG. 8, simply the switch 41
When the characteristics are switched with p, the drive center of the correction lens 758 changes stepwise before and after the change, which is not only uncomfortable but also prevents accurate composition determination. When aiming at a subject, use low frequency removal filters 786p and 786
Since y is included, the correction lens 758 is affected by the force that gravity applies to the correction lens 758 and the coil springs 763p and 763y.
The drive is performed centering on the point that balances the spring force of This is because the framing will be misaligned.

Therefore, the amplifiers 771p and 771y are replaced by the sample and hold circuits 42p and 42y and the differential amplifier 43p.
, 43y, and by switching with switches 44p and 44y (
(by the ON signal of switch SW2) is added to the adder circuit 801p.
, 801y to the compensation circuits 772p and 772y.

Here, the sample and hold circuits 42p, 4
2y is normally in a sample state (when aiming at a subject) and sends its output to differential amplifiers 43p and 43y.
Amplifiers 771p, 771y of differential amplifiers 41p, 41y
The difference output from (because of the subtraction of the same outputs) always shows zero. Also, at this time, the switch 44p connects the amplifier 771p,
The output of 771y is directly connected to compensation circuits 772p, 772y via adder circuits 801p, 801y, and switches 41p, 41y are further connected to low frequency removal filters 786p, 772y.
786y is connected and driven, and the driving center of the correction lens 758 is the weight of the correction lens 758 and the coil spring 763.
This is the point where the spring force of p, 763y is balanced. When exposure is started, the sample and hold circuits 42p and 42y are put into a hold state by turning on the switch SW2, and the outputs of the differential amplifiers 43p and 43y start outputting with the output immediately before the switch SW2 turned on as zero. In other words, the receiver 769p
, 769y is the point of balance between the weight of the correction lens 758 and the spring force of the coil springs 763p and 763y. The switch SW2 also connects the switch 44p to the differential amplifier outputs 43p, 43y and the compensation circuits 772p, 772y, and the switches 41p, 41y connect the low-pass removal filter 786.
Connect without going through p, 786y.

[0124] With the above configuration, while aiming at the subject, power saving can be achieved due to the action of the low-pass removal filters 786p and 786y, and when exposure starts, the sample and hold circuits 42p and 42y and the differential The amplifiers 43p and 43y allow the low-pass removal filters 786p and 786p to be removed without changing the framing.
The state is changed to a state without 786y, and a state is changed to a state in which there is no image stabilization precision removal filter with less phase shift, making it possible to perform imaging with less phase shift and high image stabilization precision.

The above configuration is similar to the correction optical means using the variable apex angle prism, and as shown in FIG. 10 (the control circuit is shown only in the pitch direction 81p), the same effect can be achieved with the same configuration as in FIG. 8. It can be achieved.

[0126] What has been explained above is an example in which the phase characteristics of the image stabilization system are changed while aiming at the subject and during exposure to prevent deterioration of image stabilization accuracy. This problem is caused not only by insufficient S/N of the position detection sensor in the vibration detection means and correction optical means, but also by insufficient control loop gain thereof. As described in "Problems to be Solved by the Invention", if the position sensor drive current is reduced or the position control loop gain is reduced in order to save power, the vibration isolation accuracy deteriorates.

FIGS. 11 to 13 are examples of attempts to solve these problems. In FIG. 11, the driving current of the light projecting element 78 of the angular displacement detecting device is determined by the driving circuit 51, and the driving current is determined by the driving circuit 51. When it is in use, it is driven by extremely low current. Therefore, although the power consumption is very small, the S/N of the relative position signal between the floating body 73 and the outer cylinder 72 that the light receiving element 79 receives becomes poor. However, this S/N deterioration is hardly noticeable when the photographer observes the image stabilization effect through the finder. When the switch SW2 is turned on for photographing, the on signal is input to the drive circuit 51,
Increase the driving current of the light projecting element 78. Therefore, the S/N ratio of the relative position signal is improved, the image stabilization accuracy is not degraded, and a good photograph without image blur can be obtained. Note that if the drive current of the light projecting element 78 is simply increased, the sensitivity of the relative position signal received by the light receiving element 79 will change. Therefore, the variable amplifier 52 receives the ON signal of the switch SW2 and adjusts the sensitivity of the relative position signal, so that the sensitivity does not change when aiming at the subject and during exposure.

The above method can be applied not only to the angular displacement detection device but also to the correction optical means shown in FIG.

Also in FIG. 12, the light projecting elements 768p, 7
The drive current of 68y is determined by the light projection drive circuits 54p and 54y, and the amount of this current is increased by the ON signal of switch SW2, and at this time, the amplification sensitivity of amplifiers 771p and 771y is also adjusted to aim at the subject. This ensures that the sensitivity does not change during exposure and exposure.

These methods of using the angular displacement detecting device and the correcting optical means are extremely effective methods for preventing battery consumption during long periods of time when aiming at an object, and for not deteriorating the image stabilization accuracy during exposure.

[0131] Although both the angular displacement detection device and the correction optical means are shown as optical position detection means having a light emitting and light receiving configuration, magnetic position detection means using, for example, a Hall element etc. may also have a drive current. It goes without saying that the same effect can be obtained by changing before and after exposure.

FIG. 13 shows an example in which the position control loop gain of the correction optical means is changed while aiming at a subject and during exposure.
The amplification sensitivity of 1y is changed, and the position control loop gain is set to be large during exposure.

With this configuration, since the position control loop gain is small while aiming at the subject, the correction lens 758 transfers most of its own weight to the coil springs 763p and 763p, as described above.
It is supported by the spring force of the coil 763y, and the current flowing through the coils 764p and 764y for holding it in the neutral position is small, which can save power. However, of course, since the position control loop gain is small, many errors are superimposed on the drive of the correction optical means, degrading the image stabilization accuracy, but this is not a problem for the photographer to observe the image stabilization effect through the viewfinder. It is. and,
During exposure, the position control loop gain is increased to reduce the drive error of the correction optical means, so that the image stabilization accuracy is not degraded. At this time, in order to keep the correction lens 758 neutral, the coil 7
Although it is necessary to flow a large amount of current to 64p and 764y, since the exposure is for a short period of time, battery consumption is hardly a problem.

[0134] With the above configuration, it is possible to realize a correction optical means that saves power and does not deteriorate the image stabilization accuracy.

[0135] According to each of the above embodiments, the long time period during which the subject is aimed and the exposure time during which highly accurate image stabilization is actually required (
Since the phase characteristics of the vibration detection means consisting of an angular displacement detection device or an angular accelerometer and the characteristics of the position detection sensor in the correction optical means are changed in a short period of time, it is possible to save power and take pictures without camera shake. A camera that can take pictures can be realized.

[0136]

[Effects of the Invention] As explained above, according to the present invention,
Since there is almost no negative effect on the anti-vibration function for a short period of time, the anti-vibration output of the vibration detection means and the lens mirror are used to improve the anti-vibration accuracy only during the second period when the film is exposed. The phase of the vibration applied to the cylinder is made to match.

[0137] Also, during the first period, which is a long period of time during which photographic composition is determined, the image stabilization accuracy is not required so much, so during this period, the position control loop gain is adjusted to reduce the drive current of the correction optical means. Since only the second period during which the film is exposed to light is short, the position control loop gain is increased with more emphasis on vibration isolation accuracy than on reduction of drive current.

[0138] In addition, during the first period, which is a long period of time during which the photographic composition is determined, high image stabilization accuracy is not required, so during this period, in order to reduce the current consumption in the position detecting means, Since the second period during which the film is exposed to light is short, the current supplied to the position detection means is set with more emphasis on anti-vibration accuracy than on reducing current consumption. I'm trying to make it bigger.

[0139] Therefore, power saving can be achieved,
Furthermore, it is possible to improve vibration isolation accuracy.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an angular displacement detecting device as a vibration detecting means and circuit blocks of its main parts in a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the characteristics of the angular displacement detection device in FIG. 1;

FIG. 3 is a diagram for explaining the characteristics of FIG. 2 in detail.

FIG. 4 is a diagram for explaining the effects of the first embodiment of the present invention.

FIG. 5 is a diagram for explaining the characteristics when an angular accelerometer is used as the vibration detection means of the first embodiment of the present invention.

FIG. 6 is a configuration diagram showing an angular displacement detecting device as a vibration detecting means and circuit blocks of its main parts in a second embodiment of the present invention.

FIG. 7 is a diagram for explaining the characteristics of the angular displacement detection device shown in FIG. 6;

FIG. 8 is a configuration diagram showing a circuit block of a sliding correction optical means and its driving means in a third embodiment of the present invention.

9 is a diagram for explaining the characteristics of the correction optical mechanism shown in FIG. 8. FIG.

FIG. 10 is a configuration diagram showing a circuit block of a correction optical means comprising a variable apex angle prism and its driving means in a third embodiment of the present invention.

FIG. 11 is a configuration diagram showing an angular displacement detecting device as a vibration detecting means and circuit blocks of its main parts in a fourth embodiment of the present invention.

FIG. 12 is a configuration diagram showing a circuit block of a sliding correction optical means and its driving means in a fourth embodiment of the present invention.

FIG. 13 is a configuration diagram showing a circuit block of a sliding correction optical means and its driving means in a fifth embodiment of the present invention.

FIG. 14 is a configuration diagram showing an angular displacement detection device as a vibration detection means in a conventional device and circuit blocks of its main parts.

FIG. 15 is a sectional view taken along line AA in FIG. 14;

FIG. 16 is a perspective view of the angular displacement detection device of FIG. 14;

FIG. 17 is a sectional view taken along line BB in FIG. 14;

18 is a circuit diagram showing a specific configuration of each circuit in FIG. 14. FIG.

19 is a diagram showing characteristics of the angular displacement detection device of FIG. 14. FIG.

FIG. 20 is a diagram for explaining deterioration of vibration isolation of the angular displacement detection device of FIG. 14;

FIG. 21 is an exploded perspective view showing the structure of an angular accelerometer as vibration detection means in a conventional device.

FIG. 22 is a block diagram showing an angular acceleration detection circuit of the angular accelerometer of FIG. 21;

FIG. 23 is a circuit diagram showing a specific configuration of each circuit in FIG. 22;

24 is a diagram for explaining the characteristics of the angular accelerometer shown in FIG. 21. FIG.

FIG. 25 is a configuration diagram showing a sliding type first correction optical means and its driving means in a conventional device.

26 is a circuit diagram showing a specific configuration of each circuit in FIG. 25. FIG.

27 is a diagram for explaining the characteristics of the correction optical mechanism shown in FIG. 25. FIG.

FIG. 28 is a configuration diagram showing a sliding type second correction optical means and its driving means in a conventional device.

29 is a diagram for explaining the characteristics of the correction optical mechanism shown in FIG. 28. FIG.

FIG. 30 is a perspective view showing the configuration of a correction optical means using a variable apex prism in a conventional device.

FIG. 31 is a perspective view showing a conventional camera vibration isolation device using an angular displacement detection device as vibration isolation detection means.

FIG. 32 is a perspective view showing a conventional camera vibration isolation device using an angular accelerometer as vibration isolation detection means.

[Explanation of sign]

11p, 11y Switch 32p, 32y High frequency removal filter 41p, 41
y switch 42p, 42y sample hold circuit 43p,
43y Differential amplifier 44p, 44y Switch 51p, 51y Light projection drive circuit 52p, 52y Variable amplifier 54p, 54y Light projection drive circuit 61p, 61y Variable amplifier 78 Light emitting element 79
Light receiving element 730
Amplification circuits 732, 733 Circuits indicating amplification degree 768p, 768y Light-emitting elements 769p, 769y Light-receiving elements 797p, 797y Light-receiving elements 798p, 798y Light-emitting elements

Claims (3)

[Claims] 1. A correction optical means provided in a lens barrel holding a lens group and decentering the optical axis of the lens group, a vibration detection means detecting vibrations applied to the lens barrel, and the vibration detection means. and a drive means for displacing the correction optical means relative to the lens barrel based on the image stabilization output from the means. A camera with an anti-vibration function, characterized in that a phase adjustment means is provided for changing the phase of the anti-vibration output of the vibration detection means and the vibration applied to the lens barrel during a second period during which film is exposed. . 2. A correction optical means, which is provided in a lens barrel portion holding a lens group and decenters the optical axis of the lens group, a vibration detection means for detecting vibrations applied to the lens barrel, and the vibration detection means. and a drive means for displacing the correction optical means relative to the lens barrel based on the image stabilization output from the means, a first period in which photographing composition is determined; During the second period during which the film is exposed, the position control rule of the correction optical means is
A camera with an anti-vibration function, characterized in that the camera is provided with a loop gain changing means for changing the loop gain. 3. A correction optical means, which is provided in a lens barrel portion holding a lens group and decenters the optical axis of the lens group, a vibration detection means for detecting vibrations applied to the lens barrel, and the vibration detection means. and a drive means for displacing the correction optical means relative to the lens barrel based on the image stabilization output from the means. Supply current changing means is provided for changing the current supplied to the position detecting means provided in at least one of the correcting optical means and the vibration detecting means during a second period during which the film is exposed. A camera with an anti-shake function.