JPH0875475A - Resonator, and optical scanning device, visual confirming device, vibration sensor, and vibration gyro, using this resonator - Google Patents

Abstract

PURPOSE: To facilitate the adjustment of resonance characteristic of a resonator. CONSTITUTION: A vibration input part 2 for applying a vibration is provided on one end of an elastic deforming part 1 having two resonance vibration mode in bending direction and torsional direction, and a movable part 3 having a mirror surface 4 for scanning an optical beam is provided on the other end of the elastic deforming part 1. A rectangular mass adjusting part 6 which is removable, is provided in the top end side part of the movable part 3, and the mass adjusting part 6 can be removed by cutting a laterally narrowed connecting part 7. The inertial moment of the movable part 3 is changed by the removal of the mass adjusting part, and the bending directional resonance frequency and the torsional directional resonance frequency can be regulated, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator, an optical scanning device using the resonator, a visual recognition device, a vibration sensor and a vibration gyro. Specifically, the present invention relates to a resonator using resonance vibration and various devices using the resonator.

[0002]

2. Description of the Related Art FIG. 20 is a perspective view showing a conventional resonator T. The resonator T has a bending direction (θ _B direction) about an axis P and an axis Q. Elastic deformation portion 10 having a resonance vibration mode in the twisting direction (θ _T direction)
A vibration input unit 102 is provided at one end of the movable member 1, and a movable unit 103 capable of reflecting a light beam is provided at the other end thereof. The resonator T is formed by etching a silicon substrate or a thin metal plate. Therefore, when a vibration having a frequency equal to the resonance frequency f _B in the bending direction (θ _B direction) is applied to the vibration input unit 102, the elastic deformation unit 101 moves the shaft center P.
Rotate around θ _{B in the} direction of θ _B. Therefore, the light beam (not shown) incident on the movable portion 103 can be scanned in the θ _B direction.

[Problems to be Solved by the Invention]

When an optical scanning device is constructed by utilizing the resonance vibration of the resonator T as described above, the performance (eg, optical scanning angle, scanning speed, etc.) of the optical scanning device depends on the resonance characteristics (resonance frequency) of the resonator used. , Resonance vibration mode, vibration direction, etc.). Therefore, in the process of manufacturing a resonator, for example, silicon etching, metal etching, or the like, processing variations occur in the shape of the resonator, which greatly affects the resonance characteristics of the resonator and the characteristics of the optical scanning device. It was

Further, in order to draw a specific scanning locus, for example, a circular scanning locus in the optical scanning device, resonance vibration is simultaneously performed in two resonance vibration modes in the bending direction and the twist direction, and two resonance vibration modes are also generated. It was necessary to match the resonance frequencies of the, but the adjustment was not easy.

The present invention has been made in view of the above-mentioned drawbacks of the conventional examples, and an object thereof is to reduce variations in the resonance characteristics of the resonator due to a machining process and the like, and to improve the resonance frequency and the resonance mode. It is to easily adjust the resonance characteristics such as.

[0006]

A resonator according to the present invention comprises a vibration input section, a movable section, and an elastic deformation section having at least one resonance vibration mode and connecting the vibration input section and the movable section. The resonator has a resonance characteristic adjusting means for adjusting the resonance characteristic.

Further, the resonator of the present invention can be provided with a plurality of resonance characteristic adjusting means having different effects of resonance characteristic adjustment.

For example, mass may be added to at least one of the movable portion and the elastically deformable portion. Also,
Resonance characteristics can be adjusted by providing a removable mass adjusting part on at least one of the movable part and the elastically deforming part, and a plurality of mass adjusting parts may be provided. At this time, it is preferable that the mass adjusting portion is melted by a thermal means, and it is desirable to generate heat by passing an electric current. Further, the mass adjusting portion may be broken by vibration.

Further, the resonance characteristics can be adjusted by implanting ions into the elastically deformable portion to form a modified layer or by forming a film on the surface of the elastically deformable portion. further,
It is also possible to adjust the resonance characteristic by removing at least one of the movable portion and the elastically deformable portion by fine processing.

An optical scanning device according to the present invention is an optical scanning device including the resonator according to the present invention and a vibration source that applies vibration to a vibration input portion of the resonator to cause an elastic deformation portion to resonate. It is characterized in that the movable portion of the resonator has a mirror, and the light beam is scanned by being reflected by the mirror portion.

At this time, the resonator makes the light beam orthogonal to each other.
It is preferable to have two resonance vibration modes for scanning in the direction, and to adjust the phase difference between the two resonance vibration modes to be π / 2.

The visual recognition device of the present invention is characterized by including a light projecting portion for emitting a light beam, the optical scanning device of the present invention, and a light receiving element for detecting the light intensity.

Further, the vibration sensor of the present invention comprises the resonator of the present invention and means for detecting the displacement of the movable portion of the resonator. The vibration gyro of the present invention monitors the vibration of the resonator. And means for doing so.

[0014]

In the resonator of the present invention, the resonance characteristic of the resonator can be easily adjusted by the resonance characteristic adjusting means for adjusting the resonance characteristic such as the resonance frequency, the resonance vibration mode, the vibration direction, etc. A resonator having the same can be easily manufactured.

If a plurality of resonance characteristic adjusting means having different effects of resonance characteristic adjustment are provided, the resonance characteristic adjusting means can be adjusted according to the purpose and various adjustments can be performed.

For example, the moment of inertia of the resonator can be adjusted by adding a mass to at least one of the movable portion and the elastically deformable portion. In addition, the mass moment of inertia can be adjusted by deleting the removable mass adjusting part provided on at least one of the movable part and the elastically deforming part. By providing a plurality of mass adjusting parts, the mass to be deleted can be adjusted. The amount of adjustment can be controlled by the number of adjusting units.

At this time, if the mass adjusting section is fused by a thermal means, heat is applied to the mass adjusting section,
The mass adjusting unit can be easily separated by generating heat. If heat can be generated by passing an electric current, heat can be generated and the mass adjusting unit can be separated only by passing an electric current. In particular, this is an effective means when the mass adjusting section is minute, and the minute mass adjusting section can be easily separated.

If the mass adjusting unit is broken by vibration, the mass adjusting unit can be easily separated by applying vibration to the mass adjusting unit from the outside.

By changing the Young's modulus of the elastically deformed portion by ion-implanting the elastically deformed portion to form a modified layer,
The resonance characteristics can also be adjusted.

Further, by forming a film on the surface of the elastically deformable portion, the Young's modulus of the elastically deformable portion can be changed to adjust the resonance characteristic.

Alternatively, the resonance characteristics can be adjusted easily and precisely by partially removing the movable portion or the elastically deformable portion by fine processing, for example, laser processing.

In the optical scanning device of the present invention, by using the resonator of the present invention, the resonance characteristics of the light beam can be precisely adjusted and the scanning locus of the light beam can be accurately controlled. it can. At this time, if a resonator having two resonance vibration modes for scanning in two orthogonal directions is used and the phase difference between the two resonance vibration modes is adjusted to be π / 2, a circular optical scanning locus is obtained. Obtainable. Therefore, by using this optical scanning device, the optical recognition device can detect the state of the inner wall surface of the cylindrical hole.

Besides this, the resonator of the present invention can be used for a vibration sensor, a vibration gyro and the like.

[0024]

1 is a perspective view of a resonator A according to an embodiment of the present invention, in which the resonator A has a bending direction (θ _B direction) about an axis P and an axis Q. The vibration input section 2 is provided at one end of the elastically deformable section 1 having two resonance vibration modes in the twisting direction (θ _T direction) centering on the center, and the movable section 3 is provided at the other end. The elastically deformable portion 1, the vibration input portion 2 and the movable portion 3 are integrally formed by etching a silicon substrate, a metal thin plate or the like, and the movable portion 3 is provided with a mirror surface 4 so as to reflect a light beam. Has been done. A weight portion 5 for adjusting the resonance characteristic of the resonator A is added to the opposite surface of the movable portion 3 on which the mirror surface 4 is formed. The weight portion 5 can be made of, for example, metal or resin, but the material is not limited to these. Thus, to apply the vibration of each frequency equal the resonance frequency f _T of the resonance frequency f _B and torsional bending direction from the vibration source such as a piezoelectric element to the vibration input unit 2 (theta _B direction) (theta _T direction) As a result, the movable portion 3 can be resonantly vibrated in the resonant vibration modes in the bending direction (θ _B direction) and the twisting direction (θ _T direction).

In the resonator A, since the weight portion 5 is provided at the upper end corner of the movable portion 3, the movable portion 3 is twisted in the twisting direction (θ _T
Direction), an inertial moment can be generated, and the movable portion 3 can be resonantly vibrated in two resonant vibration modes of a bending direction (θ _B direction) and a twisting direction (θ _T direction).

Here, the resonance frequency f of the resonator A can be expressed by the following equation. _{f B = √ (K B /} I B) / 2π ...... f T = √ (K T / I T) / 2π ...... where, K _B, the spring constant of K _T are resonator A, I _B, I _T is the moment of inertia. If a rectangular cross-section of the elastically deformable portion 1 are respectively spring constant K _T of the spring constant K _B and torsional direction (theta _T direction) of the bending direction (theta _B direction) represented by the following formula and formula. K _B = (E × w × t ³ ) / (4 × l) ...... K _T = (G × a × b ³ ) / l) where E is the Young's modulus of the material used for the elastically deformable portion 1. , W is the width of the elastically deformable portion 1, t is the thickness of the elastically deformable portion 1,
l is the length of the elastically deformable portion 1, G is the lateral elastic modulus of the elastically deformable portion 1, a is the length of the long side of the elastically deformable portion 1, and b is the short side of the elastically deformable portion 1. The length of the side. Therefore, if w ≧ t, then a = w, b = t, and w <
If t, then a = t and b = w.

The moments of inertia I _B and I _T are dm for the minute mass of the movable part 3 and the weight part 5, and r is the distance from the center of rotation of the small mass dm (center axis of inertia P or Q of the moment of inertia).
Then, it is expressed by the following equation and equation.

[Equation 1]

[Equation 2] However,

(Equation 3) Is the sum of the mass m of the movable part 3 and the mass M of the weight part 5.

Therefore, in the resonator A, the weight portion 5
By adding the, the moments of inertia I _B and I _{T in} the twist direction (θ _T direction) and the bending direction (θ _B direction) respectively change, and the resonance frequency f _T in the twist direction (θ _T direction) and the bending direction The resonance frequency f _B in the (θ _B direction) can be changed.

Further, as can be seen from the equation, the equation and the equation, the bending direction of the resonator A is changed by changing the weight of the weight portion 5, the number of the weight portions 5, or the position where the weight portion 5 is added. (Θ _B direction) and twist direction (θ _T direction)
The moments of inertia I _B and I _T of the
It is possible to adjust the bending resonance frequency f _T direction resonant frequency f _B and the direction of torsion (theta _B direction) (theta _T direction), respectively. For example, if the weight portion 5 is added to the point A in FIG. 1, the weight portion 5 has a center in the bending direction (θ _B direction) as compared with the case where the weight portion 3 is added to another portion of the movable portion 3. Since it is located closest to the axis P, the bending direction (θ _B
Direction) has the least influence on the inertia moment I _B, and the change of the resonance frequency f _{B in} the bending direction (θ _B direction) can be suppressed to a minimum. On the other hand, the twist direction (θ _T
The resonance frequency f _T in the (direction) can be greatly reduced. Further, if adding a weight portion 5 in Lee point, the weight portion 5 gives the moment of inertia I _T twist direction (theta _T direction) central axis becomes twisting direction to be located on the Q of the (theta _T direction) The influence is the smallest, and the change in the resonance frequency f _{T in} the twist direction (θ _T direction) can be suppressed to a minimum, while the resonance frequency f _B in the bending direction (θ _B direction) can be greatly reduced. .

In this way, the weight portion 5 added to the movable portion 3
By changing the weight, number, position, etc.
The resonance frequency and amplitude of each mode can be adjusted. It is also possible to finely adjust the resonance frequency of the vibrator A by adjusting the mass of the weight portion 5 by scraping off the added weight portion 5 little by little.

FIG. 2 is a perspective view showing a resonator B according to another embodiment of the present invention, in which the movable portion 3 of the resonator B is provided with a connecting portion 7 at the tip side portion thereof. A removable mass adjusting part 6 having a rectangular shape is provided, and the mass adjusting part 6 can be removed by cutting the connecting part 7. The mass adjusting part 6 and the connecting part 7 can be formed integrally with the movable part 3, and the material is not limited to the same material as the movable part 3 and is not particularly limited to metal or resin.

The connecting portion 7 is formed in a narrow width as shown in FIG. 2, and has a resonance vibration mode having a resonance frequency f _M different from the resonance frequencies f _B and f _{T of} the elastically deformable portion 1. When a vibration having a frequency equal to the resonance frequency f _M is applied to the connecting portion 7 from the vibration input portion 2, the connecting portion 7 causes the resonance frequency f
Resonates at a frequency equal to _M. At this time, if the magnitude of the vibration to be applied is adjusted so that the resonance vibration of the connecting portion 7 greatly exceeds the spring limit of the connecting portion 7, elastic breaking occurs in the connecting portion 7. Therefore, the mass adjusting unit 6 is not
The resonance characteristics such as the resonance frequencies f _B and f _T of the resonator _B can be adjusted.

Further, the connecting portion 7 is made of a material which is easily melted by heat, for example,
If it is made of resin or a low melting point metal, the mass adjusting portion 6 can be easily cut off by applying heat. In particular, when the connecting portion 7 is made of a conductive resin or metal that generates a large amount of heat generated by an electric current as in the resonator C shown in FIG. 3, the electrodes 8 provided on the movable portion 3 and the mass adjusting portion 6 respectively. ，
A large amount of heat is generated in the connection portion 7 by passing the current i between the connection portions 8, and the connection portion 7 can be easily melted to remove the mass adjusting portion 6. In this way, when the electric current is passed to generate heat to melt the connection portion 7,
Even when the mass adjusting unit 6 is formed small, the mass adjusting unit 6 can be easily removed, and the small mass adjusting unit 6 can be provided to slightly adjust the resonance frequency.

The shape of the mass adjusting portion 6 that can be deleted is not particularly limited, and for example, the resonator D shown in FIG.
As described above, the mass adjusting portion 6 may be formed in a substantially T-shape, and the magnitude of the resonance frequency to be adjusted can be freely changed. Also, although not shown, the elastic deformation portion 1
The mass adjusting section 6 may be formed in the.

FIG. 5 is a perspective view showing a resonator E which is another embodiment of the present invention (thickness is omitted).
The same applies to FIGS. 6 and 8. In addition, the mass adjusting portion 6 is formed by combining a plurality of adjusting members 6a having different lengths, and has a structure in which each adjusting member 6a can be deleted. In such a mass adjusting unit 6, the adjustment amount of the resonance frequency can be controlled by changing the position and the number of the adjusting members 6a to be deleted to gradually change the adjusting mass and the like. Therefore, even if variations occur during processing of the resonator, the adjustment member 6a can absorb variations in the resonance frequency, and a resonator having a stable resonance frequency can be manufactured.

FIG. 6 is a perspective view showing a resonator F which is still another embodiment of the present invention. In the mass adjusting section 6, a plurality of adjusting members 6a having the same length are combed in parallel with the axis Q. It is formed like a tooth. By sequentially removing the adjusting member 6a, as shown in FIG. 7, the resonance frequency f _T in the twist direction (θ _T direction) is changed with almost no change in the resonance frequency f _B in the bending direction (θ _B direction). It can be increased gradually. Further, by adding the weight portion 5 to the movable portion 3, the weight portion 5 roughly adjusts the resonance characteristic, and then the adjusting member 6a adjusts the fine resonance characteristic to adjust the resonance characteristic over a wide range. It also becomes possible.

FIG. 8 shows a perspective view of a resonator G which is still another embodiment of the present invention. The resonator G is provided with a mass adjusting portion 6 including a plurality of symmetrically adjusting members 6a on the axis Q in the twist direction (θ _T direction), and the side portion of the movable portion 3 is also vertically symmetrical. A mass adjusting unit 6 including a plurality of adjusting members 6a is provided. In this resonator G, by removing the pair of left and right symmetrical adjustment members 6a on the axis Q, the resonance frequency f _T in the twist direction (θ _T direction) is not significantly affected, and bending is performed. The resonance frequency f _B in the direction (θ _B direction) can be changed. Also, by removing the adjusting member 6a on the side of the movable portion 3, the resonance frequency f _T in the twist direction (θ _T direction) is changed without significantly changing the resonance frequency f _B in the bending direction (θ _B direction). Can be made. In this way, by providing a plurality of mass adjusting parts 6, the bending direction (θ _B direction)
Alternatively, the resonance frequencies f _B and f in the twist direction (θ _T direction)
Each _T can be changed, various resonance characteristics can be adjusted, and a resonator having desired resonance characteristics can be easily manufactured.

FIG. 9 is a partially cutaway perspective view of a resonator H which is another embodiment of the present invention. The resonator H is made of a semiconductor substrate such as a silicon substrate, and on the upper and lower surfaces of the elastically deformable portion 1, a modified layer 9 into which ions such as boron and phosphorus are implanted is provided. In this way, when ions such as boron and phosphorus are implanted into the semiconductor substrate, the Young's modulus E (or lateral elastic modulus G) of the semiconductor substrate changes,
The resonance characteristic of the resonator H can be changed. Also,
Since the Young's modulus E (or the transverse elastic modulus G) of the semiconductor substrate changes depending on the ion species to be injected and the injection amount, it is possible to easily obtain the resonator H having a desired resonance characteristic.

In the resonator I shown in FIG. 10, the thin film 1 made of a material having a Young's modulus E different from the material of the resonator I, such as gold, platinum, or polysilicon, is formed on the upper and lower surfaces thereof.
0 is formed by sputtering or the like. Thus, if the thin film 10 having different Young's moduli is formed on at least the surface of the resonator I and the elastically deformable portion 1, the Young's modulus E (or the lateral elastic coefficient G) of the elastically deformable portion 1 as a whole changes, and the resonator I. The resonance characteristic of can be changed.

FIG. 11 is a partially cutaway perspective view of a resonator J which is another embodiment of the present invention. The movable portion 3 of the resonator J is cut by a fine processing such as laser processing. The notch 11 and the hole 12 are provided, and a part of the movable portion 3 is deleted. By deleting a part of the movable portion 3 in this manner, the inertia moment I in the bending direction (θ _B direction) or the twisting direction (θ _T direction) changes, and the resonance frequencies f _B and f _T of the resonator J are changed. Each can be changed. Moreover, the width w (or b) or the thickness t (or a) of the elastically deformable portion 1 is changed by cutting the surface of the elastically deformable portion 1, or the notch 14 is provided in the connecting portion 13 with the movable portion 3. By changing the length 1 of the elastically deformable portion 1, the spring constants K _B and K _T of the elastically deformable portion 1 are changed, and the resonance frequency f in the bending direction (θ _B direction) and the twisting direction (θ _T direction) is changed.
_B and f _T can also be varied.

FIG. 12 is a block diagram showing the optical scanning device K according to the present invention, in which the vibration input section 22 of the resonator 21 of the present invention is provided with a minute vibration such as a piezoelectric resonator or a magnetostrictive resonator. A small vibration source 23 for generating is provided. Also,
The movable part of the resonator 21 is provided with a mirror part 25 so as to reflect light emitted from a light source (not shown).
Further, the resonator 21 is provided with a mass adjusting portion 27 on the movable portion 24, and the resonance frequency f _{B in the} bending direction (θ _B direction) is provided.
And the resonance frequency f _{T in the} twist direction (θ _T direction) is adjusted so as to obtain the following predetermined relationship.

The bending direction by equal to adjust the resonance frequency f _T of the resonance frequency f _B and the twisting direction (theta _T direction) of the (theta _B direction), the frequency f _B = f _T of the sinusoidal vibration of the vibration input unit 22 In addition, it is possible to obtain vibrations in two resonance vibration modes at the same time. However, according to this method, the resonator 21 vibrates in two directions (θ _B direction and θ _T direction) at the same phase, so that only the vibration in the direction corresponding to the vector sum in the two directions can be obtained.

Therefore, in this optical scanning device K, FIG.
(A), the bending direction (.theta.B direction) and the twisting direction (theta _T direction) of the two resonance frequency characteristics are adjusted so as to intersect, intersection that is the optical scanning angle equal certain frequency f _{At C} , the phase difference between the vibration in the bending direction (θ _B direction) and the vibration in the torsion direction (θ _T direction) is 1/2.
13 so that the phase delay in the twisting direction (θ _T direction) is 1 / 4π and the phase delay in the bending direction (θ _B direction) is 3 / 4π, as shown in FIG. 13B. The two resonance frequencies f _B and f _T are respectively adjusted. Therefore, the bending direction (θ _B direction) and the twisting direction (θ _T direction)
When the vibration source 23 applies a vibration having a frequency equal to the frequency f _c so that the vibration amplitudes of the vibrations are equal, the phase of the vibration in the bending direction (θ _B direction) and the phase of the vibration in the twisting direction (θ _T direction) And oscillate with a phase difference of 1 / 2π, and the light beam γ emitted from the light source is reflected by the mirror section 25,
As shown in FIG. 12, scanning is performed in a circular shape. Therefore, by using the optical scanning device K, the light beam γ can be circularly scanned along the inner wall of the cylindrical object 26.

FIG. 14 is a block diagram showing an embodiment of the visual recognition device L of the present invention. Visual recognition device L
Is an optical scanning device 31 such as the optical scanning device K capable of scanning a light beam γ in a circular shape, a light emitting section 32 including a light emitting element 32 such as a semiconductor laser element and an optical element 33 such as a lens. A light receiving element 34 such as a photodiode, a drive circuit 35 for driving the light emitting element 32 to emit a light beam γ, an oscillator 36 for driving a resonator of the optical scanning device 31,
A signal processing circuit 37 for electrically processing a light reception signal from the light receiving element 34, a drive circuit 35, an oscillator 36, and a control section 38 for controlling the signal processing circuit 37.
In the visual recognition device L, the light beam γ emitted from the light emitting element 32 is directed by the optical scanning device 31 to a detection area on the inner wall of a cylindrical object 39 (for example, an object like 26 in FIG. 12). And is circularly scanned within the detection area. The scanned light beam γ is scattered by the inner wall of the object 39, and the scattered light beam γ is detected by the light receiving element 34. Then, the light receiving element 3 that receives the light beam γ
The light receiving signal output from the object 4 is subjected to signal processing and signal analysis by the signal processing circuit 37, so that the object 3 in the detection area
9. The state of the inner wall can be grasped, and the shape of the inner wall and the adhesion or damage of foreign matter can be inspected.

FIG. 15 shows another example of the visual recognition device M of the present invention, which is provided with an amplifier 40 capable of increasing / decreasing the drive signal output from the oscillator 36 which drives the resonator of the optical scanning device 31. . Therefore, when the drive signal is increased or decreased by the amplifier 40 to change the vibration amplitude of the optical scanning device 31, the scanning angle of the light beam γ is θ ₁ , as shown in FIG.
The scanning position can be sequentially changed along the central axis R of the cylindrical object 39 to the scanning positions d ₁ , d ₂ , and d ₃ by changing θ ₂ and θ _3, and the inner wall of the object 39 can be three-dimensionally Can be scanned. By using the optical scanning device 31 capable of scanning the light beam γ in a circular shape like the visual recognition devices L and M, it is possible to easily inspect the inner wall of a cylindrical object which has been difficult in the past. it can.

FIG. 17 shows a schematic configuration diagram of the vibration sensor N of the present invention. The vibration sensor N is the resonator 4 of the present invention.
1 and an optical displacement sensor 43 that detects the displacement of the movable portion 42 of the resonator 41. The vibration input part of the resonator 41 is fixed to the object 44, and when vibration having a frequency equal to the resonance frequency of the resonator 41 is applied from the object 44, the movable part 42 rotates at a constant angle. Therefore, the displacement sensor 43 detects the rotation state of the movable portion 42,
By analyzing the detected detection signal with the signal processing circuit 45, the vibration applied to the object 44 can be detected. In particular, the mass adjusting unit 6 including a plurality of adjusting members 6a
In the resonator 41 provided with, since the resonance frequency can be changed little by little by removing the adjusting member 6a, it is desirable in that the vibration sensor N corresponding to various frequencies can be easily manufactured. Although not shown, the resonator 41
The vibration of the resonator 41 is detected by detecting the change in the value of the electrostatic capacitance between the movable electrode formed on the movable portion 42 and the fixed electrode that is arranged so as to face the movable electrode 42.
It may be possible to capture the vibration of.

FIG. 18 is a block diagram of the vibrating gyro S of the present invention. The vibrating gyro S is a resonator 51 of the present invention, a vibration source 52 for vibrating the resonator 51, and a vibration source 51. An oscillator 53 that drives the detector 53, a detection monitor 54 that detects a movable state of a movable portion of the resonator 51 such as an optical displacement sensor, a signal processing circuit 55 that electrically processes a detection signal from the detection monitor 54, and an oscillator 53. The control unit 56 controls the signal processing circuit 55.
In the vibration gyro S, the oscillator 53 drives the vibration source 52, and vibration having a frequency equal to the resonance frequency of the resonator 51 is applied to the resonator 51 from the vibration source 52. Further, the vibration of the movable portion of the resonator 51 is detected by the detection monitor 5
4 has been detected. As shown in FIG. 19, the resonator 51 is moved by the vibration source 52, for example, in the bending direction (Y-axis direction).
When driven at the resonance frequency f of, the electric signal from the detection monitor 54 is detected by the signal processing circuit 55 as a sine wave of the frequency f. Then, the resonator 51
When a rotational motion about the Z axis is applied to the resonator 51, a Coriolis force is generated in the resonator 51 in the X axis direction, the resonance vibration in the Y axis direction is disturbed, and the detection signal as a sine wave of frequency f is disturbed. . Therefore, the disturbance of the detection signal is treated as the signal processing circuit 5
By detecting with 5, it is possible to know the direction and size of the motion applied to the vibration gyro S, for example, the size of the angular acceleration due to the rotary motion. Of course, the detection monitor 54 is not limited to the optical displacement sensor,
The movable state of the movable part is grasped by a change in the electrostatic capacitance between the movable electrode provided on the movable part of the resonator 51 and the fixed electrode arranged so as to face the movable electrode, or the resonator 5 is formed by a piezoelectric method.
The movable state of the first movable portion may be grasped, and the grasped movable state may be detected and analyzed by the signal processing circuit 55.

In the visual recognition device and the vibration gyro using the resonator of the present invention, since the resonance characteristic of the resonator can be easily adjusted, the drive circuit and the drive mechanism necessary for driving the resonator are provided. It is simple, and these devices can be downsized and the cost can be kept low.

[0049]

Since the resonator of the present invention has one or more resonance characteristic adjusting means, various adjustments can be made by adjusting the resonance characteristic adjusting means according to the purpose. .

For example, by adding a mass or by providing a demountable mass adjusting section to adjust the moment of inertia, ions are injected into the elastically deforming section, or a film is provided on the surface of the elastically deforming section so that the elastically deforming section has a Young's modulus. The resonance characteristics can be adjusted by adjusting the ratio or by finely processing the movable portion and the elastically deforming portion and deleting a part thereof.

In the optical scanning device using the resonator of the present invention, the resonance characteristic of the light beam can be precisely adjusted and the scanning locus of the light beam can be obtained. Moreover,
By scanning a light beam in two directions orthogonal to each other with a phase difference of π / 2, a circular optical scanning locus can be easily obtained. In a visual recognition device using such an optical scanning device, The state of the inner wall surface of the cylindrical hole can be detected.

Further, in the vibration sensor or the vibration gyro using the resonator of the present invention, it is possible to accurately detect vibration or rotation of a specific frequency.

[Brief description of drawings]

FIG. 1 is a perspective view showing a resonator that is an embodiment of the present invention.

FIG. 2 is a perspective view showing a resonator which is another embodiment of the present invention.

FIG. 3 is an enlarged perspective view in which a resonator according to another embodiment of the present invention is partially broken.

FIG. 4 is a partially cutaway perspective view showing a resonator which is still another embodiment of the present invention.

FIG. 5 is a perspective view showing a resonator which is still another embodiment of the present invention.

FIG. 6 is a perspective view showing a resonator which is still another embodiment of the present invention.

FIG. 7 is a diagram showing a relationship between the number of adjusting members to be deleted and a resonance frequency in the resonator of the above.

FIG. 8 is a perspective view showing a resonator which is still another embodiment of the present invention.

FIG. 9 is a partially cutaway perspective view showing a resonator which is still another embodiment of the present invention.

FIG. 10 is a partially cutaway perspective view showing a resonator which is still another embodiment of the present invention.

FIG. 11 is a partially cutaway perspective view showing a resonator which is still another embodiment of the present invention.

FIG. 12 is a configuration diagram showing an optical scanning device of the present invention.

FIG. 13A is a diagram showing resonance frequency characteristics of a bending mode and a torsion mode of a resonator of the optical scanning device of the above.
(B) shows the phases of the bending mode vibration and the torsion mode vibration.

FIG. 14 is a block diagram showing a visual recognition device of the present invention.

FIG. 15 is a block diagram showing another example of the visual recognition device of the present invention.

FIG. 16 is an explanatory diagram of an optical scanning situation in the visual recognition device of the above.

FIG. 17 is a schematic configuration diagram showing a vibration sensor of the present invention.

FIG. 18 is a block diagram showing a vibration gyro of the present invention.

FIG. 19 is an explanatory diagram showing a movable state of a resonator in the vibration gyro of the same.

FIG. 20 is a perspective view showing a resonator as a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Elastic deformation part 3 Movable part 5 Weight part 6 Deletable mass adjusting part 6a Adjusting member 7 Bonding part 10 Thin film 21, 41, 51 Resonator according to the present invention

Claims (16)

[Claims] 1. A resonator having a vibration input section, a movable section, and an elastic deformation section having at least one resonance vibration mode and connecting the vibration input section and the movable section, for adjusting resonance characteristics. 2. A resonator comprising the resonance characteristic adjusting means of. 2. The resonator according to claim 1, further comprising a plurality of resonance characteristic adjusting means having different effects of resonance characteristic adjustment. 3. The resonator according to claim 1, wherein the resonance characteristic adjusting means is a mass added to at least one of the movable portion and the elastically deformable portion. 4. The resonator according to claim 1 or 2, wherein the resonance characteristic adjusting means is a removable mass adjusting section provided on at least one of the movable section and the elastically deforming section. 5. The resonator according to claim 4, wherein a plurality of the mass adjusting portions that can be deleted are provided. 6. The resonator according to claim 4, wherein the mass adjusting unit is blown by a thermal means. 7. The resonator according to claim 6, wherein the thermal means generates heat by passing an electric current. 8. The resonator according to claim 4, wherein the mass adjusting portion is broken by vibration. 9. The resonator according to claim 1, wherein the resonance characteristic adjusting portion is a modified layer formed by ion-implanting the elastic deformation portion. 10. The resonance characteristic adjusting section is a film formed on the surface of the elastically deforming section.
Or the resonator according to 2. 11. The resonator according to claim 1, wherein the resonance characteristics can be adjusted by removing at least one part of the movable portion and the elastically deformable portion by microfabrication. 12. The method according to claim 1, 2, 3, 4, 5, 6, 7,
An optical scanning device comprising: the resonator according to any one of 8, 9, 10 or 11, and a vibration source that applies vibration to a vibration input section of the resonator to resonate an elastically deformable section, An optical scanning device comprising a movable part having a mirror, wherein the light beam is scanned by reflecting the light beam by the mirror part. 13. The resonator has two resonance vibration modes for scanning a light beam in two orthogonal directions, and is adjusted so that a phase difference between the two resonance vibration modes becomes π / 2. The optical scanning device according to claim 12. 14. A visual recognition device comprising a light projecting unit for emitting a light beam, the optical scanning device according to claim 13, and a light receiving element for detecting light intensity. 15. The method according to claim 1, 2, 3, 4, 5, 6, 7,
A vibration sensor comprising the resonator according to any one of 8, 9, 10 or 11 and means for detecting a displacement of a movable portion of the resonator. 16. The method according to claim 1, 2, 3, 4, 5, 6, 7,
A vibrating gyroscope comprising the resonator according to 8, 9, 10 or 11 and means for monitoring the vibration of the resonator.