JPH02163609A - Angular velocity meter - Google Patents

Abstract

PURPOSE:To prevent the deterioration of the detection accuracy of the angular velocity meter by installing an attenuating means for attenuating the vibration for propagating through a supporting body in this supporting body. CONSTITUTION:To the surface of one side of a body substrate 141 of a vibration driving part 14 being a plate-like member, and to the reverse side of the opposite side, a piezoelectric converting element 17 for driving the vibration, and a pizoelectric converting element 18 for detecting the driven vibration are fixed, respectively. When an exciting signal is inputted to the element 17 from a control circuit, the vibration driving part 14 and vibrating reeds 15a, 15b formed as one body with the driving part are vibrated in the reverse direction. The vibration driving part 14 of this vibration mechanism 11 is supported by a beam member of a supporting mechanism against a base 12 being a fixing body of a leans barrel, etc. This meter is constituted by winding and installing buffer materials 121a, 121b to the outside periphery of this beam member and fixing them with an adhesive agent. In such a way, the disturbance vibration which exerts an influence sometimes due to a fact that is propagates through the supporting mechanism is attenuated by the buffer material being an attenuating means, therefore, the detection accuracy of the angular velocity meter can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an angular velocity meter used as a vibration detection device for equipment that receives relatively low frequency vibrations, and specifically relates to an angular velocity meter that is mounted on, for example, a camera, IHz or 1211z
The present invention relates to an angular velocity meter that is suitably used in a system that detects vibration (angular velocity) with a certain frequency and uses the detected information to prevent image blur caused by the vibration.

[Prior Art] The conventional technology to which the present invention is applied will be described below, taking the case of a camera as an example.

In modern cameras, important tasks such as exposure determination and focus adjustment are automated in many cases, and the possibility of a photographic failure even by an inexperienced camera operator is extremely low. In addition, it has been said that it is difficult to automate the deterioration of captured images and failures in photography due to camera shake, but recently, cameras that solve the above problems such as failures in photography due to camera shake have been researched, and in particular, , Research and development is underway to prevent photographic failures due to camera shake by photographers.The single camera shake that poses a problem in cameras is usually a vibration with a frequency of about +11 Hz to 12 Hz.

In order to be able to take pictures without image blur even if such hand shake occurs at the time of camera shutter release, it is necessary to detect camera vibration caused by the above-mentioned camera shake, for example, and adjust the In principle, this can be achieved by displacing a correction lens placed in the photographic optical system to make the image on the film appear stationary.

Therefore, in order to be able to take photographs that do not cause image blur even when such camera shake occurs, it is first necessary to accurately detect the vibrations occurring in the camera.

Considering the detection of camera shake, this basically involves a vibration sensor that detects angular acceleration, angular velocity, etc. caused by camera shake, and a signal from this sensor that is electrically integrated to output a signal of angular displacement. This can be done by installing a camera shake detection system on the camera.

An example of an image blur prevention system constructed using an angular velocity meter based on the above idea will be outlined with reference to FIG.

The example shown in FIG. 6 detects vertical camera shake (pitching) 61a and camera horizontal shake (yawing) 61b caused by the photographing optical axis indicated by the arrow 61 in the figure, and corrects image blur at the image plane 69. FIG. 2 is a diagram of a system designed to prevent

In FIG. 6, 62 is a lens barrel, 63a and 63b are angular velocity meters for detecting the vertical and horizontal camera shake angular velocities, respectively, and the respective angular velocity detection directions are 64a and 63b.
4b. 65a and 65b are known analog integration circuits that integrate signals from the angular velocity meters 63a and 63b and convert them into shake angular displacement signals. Based on this angular displacement signal, the correction optical system 66 such as a lens arranged as a part of the photographing optical system is driven by driving parts 67a and 67b provided corresponding to the vibration directions detected as described above to move Y as shown in the figure. is moved in the x direction. Reference numerals 68a and 68b are position detection sensors of a correction optical system, and the correction optical system 66 accurately performs the above movement while detecting the position.

As a result of the above, the image on the image plane 69 is maintained in an apparently stationary state. Note that by providing the optical correction mechanism itself with a radical integral action, the analog integrating circuit 65a,
65b can also be omitted.

FIG. 5 shows the structure of an example of a vibrating gyroscope which is an angular velocity meter suitable for the above purpose.

As shown in FIG. 5(a), this vibrating gyroscope includes a vibrating mechanism U and a fixed base 52, which is a part of a lens barrel, etc., and beam members 52a and 52b in this example.
The support mechanism supported via the vibration mechanism 511.1
: Consisting of an electrically connected control circuit 53.

The vibration mechanism 51 in this illustrated example has an axis 51 of vibration to be detected.
a rectangular plate-shaped vibration drive unit 54 arranged perpendicular to 0 and directly supported by the support mechanism at the center;
It extends along the direction of the axis 510 from both flexible and deformable free ends of the vibration drive unit 54, and the rigidity in the direction perpendicular to the axis sho and the vibration plane of the vibration drive unit is weakened. It is formed by a pair of rectangular vibrating pieces 55a and 55b which are provided as shown in FIG. The vibration driving unit 54 has a first piezoelectric transducer 57 for vibration driving fixed to one surface of a main body base 541 (for example, a flat main body formed of a metal plate) in the shape of a rectangular plate, and A second piezoelectric transducer 58 for detecting drive vibration is fixed to the back surface opposite to the vibration drive unit 541, and the vibration drive unit 54 and Vibrating pieces 55a, 5 integrally formed therewith
5b are vibrated in opposite directions to each other in the direction of arrow 59. The second piezoelectric transducer 58 is for detecting drive vibration as described above, and detects the vibration generated in the vibration drive section and outputs it to the control circuit component.

The vibrating pieces 55a and 55b have an alternating speed in the direction indicated by reference numeral 59 in the figure given by the vibration of the vibration driving section 54. In this state, if a human force angular velocity Ω is applied around the axis 510 of the vibrating mechanism material, the vibrating pieces 55a, 55b,
Coriolis force Fc determined by the product of alternating speed 1 human force angular velocity Ω
is applied in the direction of arrows 511a and 511b. arrow 51
The directions of 1a and 511b are opposite to each other because the pair of vibrating pieces 55a and 55b vibrate in opposite directions.

Here, if the alternating speed is always maintained at a constant amplitude by the control circuit U, the masses of the vibrating pieces 55a and 55b do not change, so the Coriolis force Fc can be obtained as one that changes in proportion to the human angular velocity Ω. be able to.

Now, due to the above movement, the vibrating pieces 55a and 55b are distorted by the Coriolis force Fc, so this vibrating piece 5
The vibrating piece 55 is configured to detect the strain direction of the vibrating pieces 5a and 55b.
The magnitude of the human force angular velocity Ω can be determined by detecting distortion with the third piezoelectric transducer a and 55b, and processing this output with the control circuit 53.

The terminal outputs of the second piezoelectric transducer 58 and the third piezoelectric transducer are grounded through resistors 512 and 513, respectively, and then input to non-inverting amplifiers 514 and 515 to generate an amplified detection voltage and phase-shifted. Circuit 516 responds to the amplified sense voltage from non-inverting amplifier 514 by changing its phase by 90 degrees.
It is designed to generate phase-shifted voltages that are in phase with each other.

The role of this phase shift circuit 516 will be described below. The vibration mechanism 51 vibrates in response to the excitation signal input to the first piezoelectric transducer 57. It is better to vibrate at the resonant frequency of the vibration mechanism 51. However, in a resonant state,
The phase of the actual vibration is delayed by 90° with respect to the vibration No. 48 that is manually applied to the first piezoelectric transducer 57. Therefore, the second
The amplified detection voltage from the non-inverting amplifier 514 via the piezoelectric transducer 58 is delayed in phase by 90'' with respect to the excitation signal manually applied to the first piezoelectric transducer 57. 516, the phase is advanced by 90° to align the phase with the excitation signal, and this phase aligned signal is input to the first piezoelectric transducer 57 to form a so-called positive feedback circuit. The amplification detection voltage of the inverting amplifier 514 is increased to cause the vibration mechanism U to vibrate.

Note that the rectifier circuit 517 in the control circuit 53 rectifies the phase-shifted voltage in response to the phase-shifted voltage from the phase-shifted circuit 516 to generate a rectified voltage. The reference signal circuit 518 generates a reference voltage for controlling the excitation signal to the first piezoelectric transducer 57 in order to keep the amplified detection signal from the non-inverting amplifier 514 constant. The differential amplifier 519 generates a differential amplified voltage by amplifying the difference between the rectified voltage from the rectifier circuit 517 and the reference voltage from the reference signal circuit 518. Multiplication circuit 520
is a differential amplifier 519 to the phase-shifted voltage from the phase-shifted circuit 516.
The multiplication result is used as a feedback voltage corresponding to the excitation signal to the first piezoelectric conversion element 57.

By doing so, the vibration mechanism 51 stably vibrates with a constant amplitude. That is, as described above, when the amplification detection voltage of the non-inverting amplifier 514 is made larger than the excitation signal voltage, the vibration mechanism 51 starts to vibrate, but if this continues, the vibration will gradually increase and will eventually be limited by the power supply voltage. This results in unstable vibrations with distorted waveforms. However, when the amplified detection signal from the non-inverting amplifier 514 is rectified by the rectifier circuit 517 and the difference from the reference signal circuit 518 is multiplied by the feedback, the vibration increases and the rectified voltage increases, and when it approaches the reference voltage, the multiplication occurs. The multiplication result of the circuit 520 becomes smaller, and the ratio of the excitation signal voltage to the amplified voltage of the non-inverting amplifier 514 becomes smaller. In other words, the amplification factor of the positive feedback circuit is controlled by the vibration amplitude and the reference signal, and the vibration mechanism 51 performs stable vibration with a constant width.

On the other hand, regarding the output of the non-inverting amplifier 515, this is a bandpass circuit 521 that passes only the vibration frequency component.
First, a disturbance signal in an extremely low frequency band compared to the vibration frequency to be detected (for example, the vibrating pieces 55a and 55b are distorted due to gravitational acceleration, and that distortion is detected by the third piezoelectric transducer). The acceleration signal generated by the acceleration signal) is removed. In response to the phase shift voltage from the phase shift circuit 516, the synchronous detection circuit 522 synchronously detects the band amplified detection voltage from the band pass circuit 521 in relation to this phase shift voltage, and the synchronous detection result is is generated as a synchronous detection voltage.

FIG. 5(b) is a diagram illustrating the state of the synchronous detection as described above, and the vibration 5 of the vibrating mechanism material shown by the solid line in this figure
23, the alternating speed has a phase lead of 90° as shown by a dashed line 524. And the above 1lql15
As a result of the input angular velocity Ω around 10 acting on this system, the output of the third piezoelectric transducer, which is the imaging piece, is 2 in the same figure.
As shown by the dotted chain line 525, the phase is the same as the alternating speed. The broken line indicates the output 526 of the second piezoelectric transducer f5B that detects the vibration of the vibrating mechanism material, and this output 526 is phase-shifted [circuit 5ifi is used to convert the third piezoelectric transducer f with a phase shift voltage equal to 90° Figure 5(c) shows the synchronous detection voltage obtained by υF, and the area represented by this diagonal line is the area of the MOSFET circuit 52.
7 An angular velocity chamber that represents the input angular velocity Ω by integrating it,
You can get some pressure.

[Problem to be solved by the invention] By the way, in the conventional angular velocity meter that detects the human angular velocity by vibrating the vibrating element at high frequency using the configuration D, there are problems as shown below. 1. To explain this using FIG. 4, which shows only the vibration mechanism 51 of No. 511 (J), the vibrating piece 55a55b, in the direction of the arrow 5g, - is I [kl-1z] and the amplitude is 10 [
μm] and detecting the angular velocity Ω of the person 71, external vibrations of the same frequency from the object to be measured (that is, the fixed body to which the mechanism 51 corresponding to the base 52 is fixed) are transmitted to the beam member 52a.
, 52b as shown by the dotted line in FIG.
μI[l], and at this time, the vibrating pieces 55a, 55b
Since the alternating velocity of the motor will also increase by 20%, as a result, the angular velocity detection output will also increase by 20%. On the other hand, due to the influence of external vibration, the amplitude of the vibrating pieces 55a and 55b is 9.
[μm], similarly, the angular velocity detection output is 1
This will result in a 0% decrease.

Such a phenomenon is not limited to cases where the external vibration exactly matches the vibration frequency of the vibrating element, but can also occur when the frequency is in the vicinity, and moreover, there are extremely many frequencies in this band in the outside world. As a result, the angular velocity meter with the configuration explained in Figure 5 has the problem of frequent output changes due to the influence of external propagation vibrations, which significantly degrades the accuracy of angular velocity detection. It turns out that there is.

The present invention has been made for the purpose of solving such conventional problems and providing an angular velocity meter that improves the deterioration of detection accuracy due to external influences by using a buffering means that damps disturbance vibrations. It is.

[Means for Solving the Problems] A feature of the angular velocity meter according to the present invention, which has been made to achieve the above object, is that a flexibly deformable vibrating body is supported on a base via a support, and the vibrating body is At the end that bends and deforms,
In an angular velocity meter in which a vibrating body for detecting angular velocity is arranged perpendicularly to a vibration surface of the vibrating body, the support body is equipped with a damping means for damping vibrations propagating through the support body. It's everywhere.

In the above configuration, the means for attenuating propagated vibrations may include, for example, attaching a vibration-absorbing soft elastic member such as rubber or a magnetic fluid to the support member by wrapping it around the supporting member. For example, a method may be used in which a through hole or slit formed in the extending direction of the support member is filled with a liquid having a buffering effect such as oil.

[Function] According to the present invention, vibrations, etc. that affect the vibration mechanism from the outside via the support body that supports it are attenuated, and the vibration state of the vibration mechanism is affected by input angular velocities other than the input angular velocity to be detected. The influence of component contamination is reduced as much as possible.

[Embodiment 1] FIG. 1 is for explaining Embodiment 1 of the present invention, and since the control circuit may be the same as that described in FIG. 5 above, illustration is omitted, and the vibration mechanism 11 Only the part shown is shown.

In this drawing, members common to those in FIG. 5 described above are designated by subtracting 40 (or 400) from the member numbers in FIG. 5, and detailed explanation thereof is omitted.

In the example shown in FIG. 1, a main body base 141 is arranged perpendicularly to the axis 110 of vibration to be detected, and is made of a flexible metal piece formed into a predetermined rectangular plate shape. A beam member 12a extends from both width edges of the central portion of the main body base 141 in the longitudinal direction to the sides of the flat plate.
, 12b, the vibration drive unit 1 is supported on the base 12 by
4, and one side surface (
(upper side of the figure) along the axis 110 direction, and extends in the longitudinal direction of the main body substrate 141 and the axis 110 direction.
A pair of rectangular vibrating pieces 15a and 15b are arranged such that the rigidity in the direction perpendicular to the plate member is weakened, and the vibrating pieces 15a and 15b are arranged as a third piezoelectric transducer composed of a bimorph. The main body board of the vibration drive unit 14 +4
1 has a first piezoelectric transducer 1 for vibration driving on one side surface of the
7 is fixed, and on the opposite back surface of the main body board 141,
A second piezoelectric transducer 18 for detecting drive vibration is fixed. Then, by inputting an excitation signal to the first piezoelectric transducer 17 from a control circuit (not shown), the vibration drive unit 14
The vibrating pieces 15a and 15b integrated therewith constitute a vibrating mechanism 11 that vibrates in opposite directions in the direction of an arrow 19.

The vibration drive unit 14 of the vibration mechanism 11 is attached to the beam members 12a, 12 of the support mechanism with respect to the base 12, which is a fixed body such as a lens barrel.
The structure itself of being supported by b is the same as that of the example explained in FIG. 5 above.

The feature of the configuration of this example is that the beam member 12 of the support mechanism
A cushioning material 1 made of butadiene rubber is placed around the outer periphery of a and 12b.
21a and 121b are wound together and fixed with adhesive. Such a cushioning material may be of a type in which a cylindrical rubber is placed over the support mechanism, and the structure thereof is not particularly limited as long as it has a mode suitable for damping propagated vibrations. In addition to the above-mentioned butadiene rubber, cushioning materials can also be used such as neoprene sponge, magnetized beam members that make up the support mechanism, and magnetic powder, magnetic fluid, etc. It may be something.

FIG. 2 is for explaining Embodiment 2 of the present invention, and the reference numerals in the drawings of this embodiment include the addition of 10 to the reference numerals for the same members as in Embodiment 1.

The feature of this example is that a through hole in the plate width direction is provided in the central part of the flat plate-shaped main body board 241 that constitutes the vibration drive unit 24 of the vibration drive mechanism 21, and the vibration drive unit 24 is provided in the through hole in the plate width direction.
The hollow vibes 22a, 22b for support are fixed through the main body substrate 2 of the vibes 22a, 22b.
The image tip extending through the vibrator 41 is screwed and fixed to the base 12, which is the object to be measured, using clamp means 221a and 221b, and the inside of the vibrator 22a and 22b is filled with, for example, oil 23. This is to provide a damping effect to the propagating vibrations.

This configuration has the advantage that easily flowing liquids such as oil can be used, unlike the configuration of the first embodiment in which rubber, sponge, etc. are used.

FIG. 3 is for explaining Embodiment 3 of the present invention, and members common to Embodiment 1 are shown with 20 added to the reference numerals.

The feature of this example is that the beam members 31a and 31b of the support mechanism are formed by a member (for example, a metal plate) that is integrated with the main body substrate 341 of the vibration drive unit 34, and that the beam members 31a
, 31b are formed through the slits 321a and 321b in the plate thickness direction along the extension axis direction (longitudinal direction of the beam), and the slits 321a and 321b are filled with a cushioning material. .

This example has the same advantage as in Example 2 in that oil or the like can be used as the cushioning material if the state of filling and fixing it in the slit is maintained due to surface tension. Compared to the second embodiment, the shape of the beam member having the concave portion for attaching the Mi street agent is simpler, and the beam member is composed of a flat plate, so that the main substrate 341 of the vibration drive unit and this beam member 34a are , 34b can also be stamped from a single piece of metal.

Note that the present invention is not limited to the above examples, and in addition to the beam member in which the support body that supports the vibration mechanism is located in the same plane as the flat plate surface of the main body substrate of the vibration drive unit illustrated above, the vibration drive unit The same effect can be obtained even if the mounting is perpendicular to the mounting position.

[Effects of the Invention] As explained above, the angular velocity meter of the present invention having the above structure allows disturbance vibrations that may affect the vibration mechanism by propagating through the support to the support. Since it is attenuated by the attached attenuation means, the influence of such disturbances can be significantly reduced or virtually eliminated, which has the effect of improving the detection accuracy of the gyrometer. The practical benefits are extremely significant.

[Brief explanation of the drawing]

1 to 3 are examples 1 to 3 of the present invention, respectively.
Fig. 4 is a perspective view showing the vibration mechanism of each angular velocity meter of the comparative example, Fig. 5(a), (
b) and (c) show examples of conventional speedometers, Fig. 5(a) is a diagram for explaining the general configuration of the vibration mechanism and control circuit, and Fig. 5(b) is a diagram showing an overview of the overall configuration of the vibration mechanism and control circuit. Figure 5(C) is a diagram for explaining the gist of synchronous vibration detection.
) is a diagram for explaining a synchronous detection voltage in relation to. FIG. 6 is a diagram for explaining the basic configuration of a camera equipped with an image blur prevention device, which is an example of a device to which the angular velocity meter of the present invention is applied. 11.21.31 + Vibration mechanism 12.22.32 + Base 12a 12b 32a, 32b beam member +21a,
121b: Rubber 14.24, 34: Vibration drive unit 141.241J41: Vibration drive unit main board 22
a 22b: Vibrator 221a 221b: Clamping means 321a 32
1b Nislit 15a, 15b, 25a, 25b, 35a, 35b
: Vibration piece 51/vibration mechanism 52: Base 52a
52b: Beam member 53. Control circuit 54 Two vibration drive parts 55a, 55b: Vibration piece 58a,
56b: Third piezoelectric conversion element 57: First piezoelectric conversion element 58: Second piezoelectric conversion element and 4 others

Claims (1)

[Scope of Claims] 1. A vibrating body that can be deflected and deformed is supported by a base via a support, and an angular velocity sensing device is installed at the end of the vibrating body that is deflected and parallel to the vibration surface of the vibrating body. An angular velocity meter having a vibrating element arranged therein, wherein the support body is equipped with a damping means for damping vibrations propagating through the support body. 2. The angular velocity meter according to claim 1, wherein the damping means is an elastic body wrapped around a support. 3. The angular velocity meter according to claim 1, wherein the damping means is a liquid buffer filled in a hole or slit provided in the support.