JPH06294654A - Oscillation gyro - Google Patents

Abstract

PURPOSE:To provide an oscillation gyro which can be machined easily because of simple shape and suitable for mass production, and in which the mounting area is decreased, downsizing and low price can be realized easily, and a plurality of angular speeds can be detected simultaneously. CONSTITUTION:A plurality of oscillators 11, 12 are formed integrally with one oscillation member 10 in the direction matched with the angle of target detection angular speed. The oscillators 11, 12 are provided, in the axial direction thereof, with groove electrodes 20, 21 as common electrodes for driving and detection and external electrodes 22, 23. Furthermore, driving electrodes 29-32 and detection electrodes 35-42 are provided for the drive side arms 27, 28 and the detection side arms 33, 34 of the oscillators 11, 12 on the opposing outsides thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a sensor for posture control, detection of spatial coordinates, etc., by detecting the moving direction of an object that moves in space, for example, as a camera shake detection of a VTR camera or a three-dimensional input device. The present invention relates to a vibrating gyro.

[0002]

2. Description of the Related Art Conventionally, as this type of vibration gyro,
Although not particularly shown, a vibration piece gyro having a driving piezoelectric element and a detecting piezoelectric element provided on the side surface of a vibrating body having a quadrangular, triangular, or circular cross section, a ring-shaped vibrating gyro, or an H-shaped vibrating element There is known a vibration gyro of a type in which a support rod of a book is combined in an orthogonal direction (for example, JP-A-2-51066 and JP-A-2-1983).
15 and Japanese Patent Laid-Open No. 64-16911).

[0003]

However, the voice piece type gyro among the ones described in the prior art has a simple structure and is easy to process, but the support structure is difficult and only one angular velocity can be measured. In addition, the ring-shaped vibrating gyroscope has a problem that the angular velocity in two directions can be measured, but the structure is complicated, the support structure is difficult, and the processing is not easy. The gyro can measure angular velocities in two directions, but has a problem that the structure is complicated and it is difficult to balance the vibration balance of each part.

As described above, in the conventional vibration gyro, if it is intended to detect a plurality of angular velocities at the same time, a plurality of gyros must be arranged in the case of the vibration gyro in a single direction, so that the mounting area is small. It becomes wider and economically worse, and the vibration gyro that can measure angular velocities in two directions is difficult to downsize because of its complicated structure and shape.
Therefore, the price reduction could not be expected.

The present invention has been made in view of the above-mentioned problems of the prior art. The object of the present invention is that it has a simple shape, is easy to process, is suitable for mass production, and is made of a material. It is an object of the present invention to provide a vibrating gyro that can detect a plurality of angular velocities at the same time with high quality that can be miniaturized and reduced in price easily with a small variation and a small mounting area.

[0006]

To this end, according to the present invention, a single vibrating member is integrally formed with a plurality of vibrators having different resonance frequencies in a direction corresponding to the target angular velocity of detection. A groove electrode and an external electrode as a common electrode for driving and detecting are formed in the axial direction of each vibrator, and the driving-side arm and the detection-side arm of each vibrator have two outer surfaces facing each other. , And each of which is provided with a drive electrode and a detection electrode.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings and its operation. FIG. 1 is a perspective view of an example of a vibrating gyroscope according to the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of the same. In these figures, the vibrating gyroscope is polarized in the plate thickness direction before cutting. The two vibrators 11 and 12 are integrally formed on a single vibrating member 10 such as voltage ceramics, which is formed in accordance with the target detection speed angle (X and Y axis directions). With a two-way vibrating gyro,
The vibrators 11 and 12 are processed as vibrators having different resonance frequencies so as not to cause unnecessary interference with each other. The vibrators 11 and 12 are of a single-support type that are orthogonal to each other, and have a simple shape in which the support portion 13 can be shared. In this way, one vibrator 10 is provided with two vibrators 1.
Since 1 and 12 are integrally formed, the material variation is extremely small.

Grooves 14 and 15 are formed by cutting up to substantially the middle portion of the vibrators 11 and 12 in the axial direction.
Electrode treatment is performed on the entire outer surface parallel to the groove surfaces except for the electrodes 4, 15 and the end surfaces 16, 17, 18, 19, and the groove electrodes 20, 21 and the external electrodes 22, 2 as common electrodes for driving and detection.
3 (shown in phantom in FIG. 1) are formed,
The groove electrodes 20 and 21 are connected to the ground electrode 26 (shown by hatching in FIG. 1) via the pattern portions 24 and 25, and the driving side arm 2 in each of the vibrators 11 and 12.
The driving electrodes 29, 30, 31, 3 are provided on the two outer surfaces 7 and 28 (only one surface is shown in FIG. 1) facing each other.
2 is formed, and two outer surfaces of the detection-side arms 33 and 34 that face each other (only one surface is shown in FIG. 1).
Two detection electrodes 35 to 42 (indicated by hatching in FIG. 1) are formed on each of them.

The vibrating gyro having the above structure is mass-produced by the steps shown in FIGS. More specifically, as illustrated in FIG. 3, a plate-shaped vibrating material 10 such as piezoelectric ceramics that has been polarized in the plate thickness direction in advance is provided with a groove 14 and one of the grooves 14 in one vibrator 11 by a dicing saw. Cutting groove 43 forming the vibrator 11
Are sequentially cut, and then the length width D of the other vibrator 12 is cut.
Then, the vibrating material 10 is cut along the cutting groove 44 to obtain the cutting element 45, and thereafter, a large number of cutting elements 45 are obtained by the same cutting process. Next, a large number of cutting elements 45 are stacked and the groove portion 15 in the other vibrator 12 is cut at the same time, and then the cutting groove 46 forming the other vibrator 12 is cut at the same time to cut off the unnecessary portion 47. A substantially L-shaped tuning fork-shaped element having a groove can be processed. In addition,
The element can be obtained by a molding process such as a mold in addition to the cutting process.

The tuning fork shaped element which has been cut and processed is plated on the entire surface including the groove portions 14 and 15 (see FIG. 4), and the element is entirely resisted by electrodeposition resist (see FIG. 5). , Align the elements on the positioning jig (Fig. 6
(See FIG. 7), aligning glass masks on both sides of all elements, exposing to form electrodes (see FIG. 7), then performing a phenomenon (see FIG. 8), and performing an edge treatment to remove the resist,
After the washing process, a finished product as shown in FIG. 1 is obtained.

Next, the operation will be described with reference to FIGS. 9, 10 and 11. Drive side arm 27 (28)
(See FIGS. 9 and 11), the driving electrode 29
When an alternating voltage from the oscillator 50 is applied to (31) and 30 (32), expansion and contraction occur near the electrode surface, and contradictory expansion and contraction occur on the two surfaces. This causes bending vibration in the X-axis direction (longitudinal direction). On the other hand, the detection side arm 33 (3
In 4) (see FIGS. 10 and 11), vibration is generated at the same vibration frequency as that of the drive arm 27 (28). At this time, both arms vibrate in opposite X-axis directions.
When this is rotated in the Z-axis direction, Coriolis force is generated and vibration is transmitted in the orthogonal direction (Y-axis direction). Figure 12
FIG. 3 is a waveform diagram showing a state of an electric signal generated in each electrode of the embodiment shown in FIG.
It is a number corresponding to 5 to 42. When the vibration gyro is not rotating, only vibration in the X-axis direction (longitudinal vibration) appears, and when rotating, a vibration in the Y-axis direction (lateral vibration) and a vibration in the X-axis direction (longitudinal vibration) that are proportional to the Coriolis force are combined. The output of the combined vibration appears, and the rotation direction appears as the phase of the vibration (transverse vibration) in the Y-axis direction, which appears as a change in the output of the four electrodes.

The vibrating gyro having the above structure is shown in FIG.
As shown in FIG.
And used in a circuit configuration as shown in FIG. To explain further, the drive side arm 27 (2
8) electrodes 20 (21), 22 (23), 29 (3)
1), 30 (32) and the electrode 22 (23) of the detection side arm 33 (34) are connected to an oscillator 50,
The driving side arm 27 (28) is vibrated by the AC voltage from 0, and the electrode 38 (4) of the detection side arm 33 (34) is
2) and 36 (40) are connected to the differential amplifier 51 and electrodes 37 (4
1) and 35 (39) are respectively connected to the differential amplifier 52, and the electrodes 3 are rotated by the differential amplifiers 51 and 52 during rotation.
8 (42), 36 (40), 37 (41), 35 (3
In 9), the difference between each two output voltages generated by the Coriolis force is measured. The differential amplifiers 51 and 52 are connected to an adder 53, and the detection level is raised by the adder 53,
Further, it is converted into a left-right rotation speed level by the mixer 54, amplified by the DC amplifier 55, and output as a DC voltage corresponding to the angular speed.

Although the illustrated embodiment is a two-way vibrating gyro in which two tuning forks are connected by a supporting portion, the present invention is not limited to this, and a three-way vibrating gyro in which three tuning forks are connected by a supporting portion is used. It can also be a gyro.

[0014]

According to the present invention, however, since a plurality of vibrators are formed on one vibrating material, the material variation is very small and a plurality of angular velocities can be detected simultaneously with high accuracy. . Also, since the overall shape is simple,
It is easy to process, suitable for mass production, and cost reduction is possible. In addition, it is possible to share the control circuit etc. on the same printed circuit board, reduce input / output, and reduce the mounting area. It has the effect that it becomes possible.

[Brief description of drawings]

FIG. 1 is a perspective view of an example of a vibrating gyroscope according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a process explanatory view of cutting a substantially L-shaped tuning fork-shaped element from one diaphragm material.

FIG. 4 to FIG. 8 are process diagrams of forming electrodes on a tuning fork shaped element.

FIG. 9 is an explanatory diagram of waveforms of a drive side arm in a vibration mode.

FIG. 10 is a waveform explanatory diagram of a detection-side arm in a vibration mode.

FIG. 11 is an explanatory diagram of a vibration mode of a vibrator.

FIG. 12 is a waveform diagram showing a state of an electric signal in each electrode portion of the embodiment shown in FIG.

FIG. 13 is a schematic explanatory view showing a usage state of the present vibration gyro.

FIG. 14 is a circuit diagram for using the present vibration gyro.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibrating material 11, 12 Vibrator 13 Support part 14, 15 Groove part 20, 21 Groove part electrode 22, 23 External electrode 24, 25 Pattern part 26 Grounding electrode 27, 28 Driving side arm 29-32 Driving electrode 33, 34 Detection side Arm 35-42 Detection electrode

Claims (1)

[Claims] 1. A single vibrating member is integrally formed with a plurality of vibrators whose resonance frequencies are separated from each other in a direction corresponding to an angle of a target detection angular velocity, and driving and detecting are performed in an axial direction of each vibrator. A groove electrode and an external electrode are formed as a common electrode, and a driving electrode and a detection electrode are provided on the two outer surfaces of the driving side arm and the detection side arm of each vibrator, which face each other. A vibrating gyro.