JPH08122081A - Output regulating method for angular velocity sensor - Google Patents

Abstract

PURPOSE: To reduce the offset noise of an angular velocity sensor. CONSTITUTION: In a prismatic tuning fork type vibrator 10, vibrating reeds 11, 12 having sections of angle shape are disposed in parallel, driving elements 21, 24 for vibrating the reeds 11, 12 at a predetermined period in a predetermined direction are fixed to the sides 11a, 12a, and reference elements 22, 25 for referring to the vibrating states of the reeds 11, 12 are similarly fixed to the sides 11a, 12a. Detecting elements 23, 26 for detecting Coriolis' force generated when an angular velocity of a perpendicular direction to the vibrating direction is operated during the vibrating of the reeds 11, 12 are increased in its widths larger than those of the upper surfaces 11b, 12b of the reeds, extended in the inward direction I of the vibrator 10, and fixed to the upper surfaces 11b, 12b of the reeds 11, 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity sensor for detecting an angular velocity in a yaw direction and used for a vehicle suspension control, a navigation system, etc., and particularly to an output of an angular velocity sensor whose output voltage can be easily adjusted. Regarding adjustment method.

[0002]

2. Description of the Related Art Conventionally, in an angular velocity sensor using a tuning fork type vibrator, two sound pieces having a rectangular cross section and vibrating in a constant direction in a constant cycle are arranged in parallel, and drive for generating vibration of the sound piece is performed. The element for detection and the detection element for detecting the Coriolis force generated by the action of the angular velocity on the vibrating sound piece are bonded to the side surface and the upper surface of the sound piece which are orthogonal to each other to form an angular velocity sensor. There is something.

FIG. 11 shows a conventional prismatic tuning fork type vibrator 10. A prismatic tuning fork oscillator 10 formed of a constant elastic alloy or the like.
Has sound pieces 11 and 12 that vibrate in a fixed direction at a fixed cycle. The side surfaces 11a and 12a of the sound pieces 11 and 12 are referred to for referring to the driving elements 21 and 24 for vibrating the sound pieces 11 and 12 in a fixed direction at a constant cycle and the vibration states of the sound pieces 11 and 12. The working elements 22 and 25 are fixed by an adhesive. In addition, the upper surface portion 11 of the sound pieces 11 and 12
Detection elements 23 and 26 for detecting the Coriolis force generated when the angular velocity acts on the vibrating sound pieces 11 and 12 are fixed to the b and 12b with an adhesive.

This prismatic tuning-fork vibrator 10 has a frequency that matches the natural frequency of the prismatic tuning-fork vibrator 10 in a mode in which the tuning elements 11, 12 of the driving elements 21, 24 vibrate symmetrically in the x-axis direction. By applying an AC voltage, the sound piece 1
Symmetrically vibrating 1 and 12 in the x-axis direction, and in this vibrating state, z
When the angular velocity ω acts around the axis, the Coriolis force generated in the y-axis direction of the sound pieces 11 and 12 is detected by the detection elements 23 and 26.
Then, the angular velocity ω is detected through appropriate circuit processing.

Now, a circuit process for obtaining the angular velocity ω from the Coriolis force detected by the detecting elements 23 and 26 will be described. FIG. 12 is a schematic diagram showing a circuit for angular velocity detection. Upper surface portions 11b and 12b of the sound pieces 11 and 12
The detection elements 23 and 26 fixed to the are connected in parallel,
It is input to the positive terminal of the operational amplifier 30. The positive terminal of the operational amplifier 30 is grounded through the high resistance R. When angular velocity ω is applied while the prismatic tuning fork vibrator 10 is oscillating by the driving elements 21 and 24, Coriolis force is generated in the y-axis direction, and the vibration of the prismatic tuning fork vibrator 10 is caused in the x-axis direction. And the symmetrical vibration in the y-axis direction are combined in the direction of the arrow in the figure.

At this time, the positional relationship between the sound pieces 11 and 12 at a certain moment is shown in FIG. 12, in which the detection element 23 extends and the detection element 26 contracts. The detection element 23 and the detection element 26 have opposite polarities to the sound piece 11,
Since the signal is fixed to 12, the signals output from the detecting element 23 and the detecting element 26 are in phase, and the averaged signal is output from the operational amplifier 30, and the angular velocity ω is detected using this output value. It is a mechanism.

[0007]

However, when the prismatic tuning fork vibrator 10 vibrates in the x-axis direction by the drive elements 21 and 24, as shown in FIG.
When 12 is displaced, the detecting elements 23 and 26 fixed to the sound pieces 11 and 12 contract the neutral axis of the sound pieces 11 and 12, and the outer portion O of the detection elements 23 and 26 receives compressive stress. Since the inner portion I is stretched, a tensile stress acts on the inner portion I, and electric charges of opposite polarities are generated from the detecting elements 23 and 26, respectively.
The generated charges are canceled if they are adhered so as to match the neutral axes of 1 and 12, but the central axes of the detecting elements 23 and 26 are a little (0.1
If there is a deviation, the deviation causes excessive offset noise, and therefore the S / N of the angular velocity sensor is increased.
There is a problem that the ratio cannot be made large, and in the present technology, the bonding accuracy is limited to about ± 0.1 mm, and it is difficult to reduce the offset noise only by the bonding process considering the unevenness of the bonding surface. .

Therefore, an object of the present invention is to adjust the output value of the detecting element by removing a part of the detecting element for detecting the Coriolis force, which is adhered to the sound piece of the prismatic tuning fork vibrator. An object of the present invention is to provide an angular velocity sensor with high detection accuracy that can reduce offset noise and increase the S / N ratio.

[0009]

In order to solve the above-mentioned problems, the structure of the present invention is such that two prismatic sound pieces are arranged in parallel,
A vibrator that vibrates in a fixed direction in a fixed direction, a plate-shaped driving piezoelectric element that vibrates a prismatic sound piece of the vibrator in a fixed direction in a fixed direction, and a prism in a direction orthogonal to the vibration direction of the vibrator. In an angular velocity sensor for detecting an angular velocity, which has at least a plate-shaped detection piezoelectric element for detecting the Coriolis force generated when an angular velocity acts on the vibrator, the detection piezoelectric elements are opposite to each other. The width of the detection piezoelectric element is larger than the width of the prismatic sound piece of the transducer to which the detection piezoelectric element is fixed, and one side of the detection piezoelectric element is placed on the outer edge or inside of the prismatic sound piece. By sticking to the edge and fixing, and by removing the protruding side of the piezoelectric element for detection from the prismatic sound piece,
The output voltage generated from the detecting piezoelectric element is adjusted.

Further, according to the structure of the second invention, the prismatic sound piece is two.
Vibrators that are arranged in parallel and vibrate in a fixed direction in a fixed cycle, a plate-shaped driving piezoelectric element that vibrates a prismatic sound piece of the vibrator in a fixed direction in a fixed cycle, and a vibrating direction of the vibrator. In the angular velocity sensor for detecting the angular velocity, which is at least equipped with a plate-shaped detection piezoelectric element that is fixed on the prismatic sound piece in the direction orthogonal to and that detects the Coriolis force generated when the angular velocity acts on the vibrator, The piezoelectric elements are arranged in opposite polarities, and the width of the sensing piezoelectric element is
The width is larger than the width of the prismatic sound piece of the transducer to which the detection piezoelectric element is fixed, and both sides of the detection piezoelectric element stick out over the prismatic sound piece and are fixed. By removing the side, the output voltage generated from the detection piezoelectric element is adjusted.

According to the third aspect of the invention, two prismatic sound pieces are arranged in parallel and vibrate in a constant direction in a constant cycle, and a prismatic sound piece of the vibrator in a constant direction in a constant cycle. A plate-shaped driving piezoelectric element that vibrates and a plate-shaped detection piezoelectric element that is fixed to the prismatic sound piece in the direction orthogonal to the vibration direction of the vibrator and detects the Coriolis force generated when an angular velocity acts on the vibrator. In an angular velocity sensor for detecting an angular velocity including at least an element, the detecting piezoelectric elements are arranged in polarities opposite to each other, and the width of the detecting piezoelectric element is the prismatic sound piece of the vibrator to which the detecting piezoelectric element is fixed. It is narrower than the width, and the detection piezoelectric element is fixed close to the outer edge or the inner edge on the prismatic sound piece to which the detection piezoelectric element is fixed, and the angular velocity sensor is fixed on the two prismatic sound pieces. Each detected value A voltage conversion means for performing voltage conversion, and a resistor for dividing the output value of the voltage conversion means.The voltage division ratio is adjusted so that the output from the voltage dividing terminal becomes zero, and The output is taken out from the pressure terminal.

[0012]

According to the present invention, when an angular velocity acts on an oscillating means that oscillates in a certain direction by a certain means, about an axis orthogonal to the oscillating direction, the oscillating direction is different from the axial direction in which the angular velocity works. The angular velocity is detected by detecting the Coriolis force generated in the orthogonal direction by the detecting means. The first action is to arrange the detecting piezoelectric elements in opposite polarities to detect the detecting piezoelectric force. The width of the element is made larger than the width of the prismatic sound piece of the vibrator to which the detecting piezoelectric element is fixed, and one side of the detecting piezoelectric element is fixed by moving it to the outer edge or the inner edge on the prismatic sound piece. By removing the protruding side of the detection piezoelectric element with respect to the sound piece, the output voltage generated from the detection piezoelectric element is adjusted. (Claim 1) A second action is to make the width of the detection piezoelectric element larger than the width of the prismatic sound piece of the vibrator to which the detection piezoelectric element is fixed,
The output voltage generated from the detecting piezoelectric element is adjusted by protruding and fixing both sides of the detecting piezoelectric element onto the prismatic sound piece and removing either side of the protruding side of the detecting piezoelectric element. (Claim 2) A third effect is that the width of the detection piezoelectric element is made narrower than the width of the prismatic sound piece of the vibrator to which the detection piezoelectric element is fixed, and the detection piezoelectric element is fixed to the detection piezoelectric element. And a voltage conversion means for performing voltage conversion on respective detection values of the detection piezoelectric elements fixed on the two prismatic sound pieces, the angular velocity sensor being fixed close to the outer edge or the inner edge on the prismatic sound piece. A resistor for dividing the output value of the voltage converting means is provided, the voltage dividing ratio is adjusted so that the output from the voltage dividing terminal becomes zero, and the output is taken out from the voltage dividing terminal. (Claim 3)

[0013]

The first effect is that the detection piezoelectric element can be easily positioned by aligning the end surface of the detection piezoelectric element with the end surface of the prismatic sound piece. The bonding accuracy is improved, the offset noise of the detection piezoelectric element is reduced, and the S / N ratio is improved. (Claim 1 and Claim 3) A second effect is that since the detection piezoelectric element protrudes from the prismatic sound piece, the detection piezoelectric element is easily ground by a grinder or the like to eliminate the offset noise of the detection piezoelectric element. Can be adjusted. (Claim 1 and Claim 2) A third effect is that when the width of the detection piezoelectric element is smaller than the width of the prismatic sound piece, variations in offset noise of the detection piezoelectric element due to uneven adhesion or deterioration of adhesion accuracy. When the detection piezoelectric element cannot be easily ground by a grinder, etc., the movable resistor is connected to the output of the detection piezoelectric element and the offset noise of the detection piezoelectric element is adjusted by adjusting the voltage division ratio. can do. (Claim 3)

[0014]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 shows the configuration of the first embodiment of the present invention. In this embodiment, the widths of the detection elements 23 and 26 are made larger than the widths of the sound piece upper surface portions 11b and 12b of the prismatic tuning-fork vibrator 10, and the detection elements 23 and 26 are set to the sound piece 1.
The upper part 11 of the sound piece is projected so as to protrude in the inward direction I of 1 and 12.
It is fixed on b and 12b.

FIG. 2 is a circuit for detecting the displacement and angular velocity of the sound pieces 11 and 12 at a certain moment when the sound pieces 11 and 12 of the prismatic tuning fork vibrator 10 are vibrated in the x-axis direction by the driving elements 21 and 24. Is shown. Sensing element 23,
In Fig. 26, the outer O portions of the neutral axes of the sound pieces 11 and 12 are contracted by a compressive stress to contract, and the inner portions I of the neutral pieces 11 and 12 of the sound shaft are stretched by a tensile stress, but Since the detection elements 23 and 26 are projected to the inner side I of the sound pieces 11 and 12, the expansion rate of the detection elements 23 and 26 increases.

In the present embodiment, since the detecting elements 23 and 26 are fixed so that the polarities thereof are opposite to each other, offset noises having opposite polarities are generated from the detecting elements 23 and 26, If they are combined by the operational amplifier 30, they cancel each other, so that the offset noise can be reduced. Further, since the widths of the detection elements 23 and 26 are larger than the widths of the sound piece upper surface portions 11b and 12b, the outer end surfaces 11a and 12a of the sound pieces 11 and 12 and the detection element 2 are detected.
Positioning can be easily performed by aligning the outer end surfaces 23a and 26a of the Nos. 3 and 26, the bonding accuracy of the detection elements 23 and 26 is improved, and the left and right variations of the offset noise are reduced, and the operational amplifier 30 is provided. Offset noise is further reduced by passing through
The N ratio can be improved.

Further, even if there is a difference in the amplitude of the left and right offset noises due to variations in the width dimensions of the detecting elements 23 and 26 and uneven adhesion of the detecting elements 23 and 26, the offset is generated. Noisy detection element 2
The offset noise can be adjusted and the combined offset noise can be made zero by grinding either one of the inner end faces 23b and 26b of Nos. 3 and 26 with a grinder or the like. In this case, the detecting elements 23 and 26 are the sound piece 11,
Since it protrudes to the inner side I of 12, grinding with a grinder or the like can be easily performed, and offset noise can be easily adjusted.

In this embodiment, since the reference elements 22 and 25 are on the sound piece side surfaces 11a and 12a, the detection element 23 and
26 is made to project to the inside I of the sound pieces 11 and 12. Here, by disposing the reference elements 22 and 25 on the inner side surfaces 11c and 12c of the sound pieces 11 and 12, or
The reference elements 22 and 25 are abolished, and the drive elements 21 and 24 are removed.
By also using as a reference element, the detection element 2
The same effect can be obtained even if the components 3 and 26 are projected to the outside O of the sound pieces 11 and 12.

Next, a second embodiment will be described. FIG.
FIG. 6 is a structural diagram showing a configuration of a second embodiment. In the first embodiment, the widths of the detecting elements 23 and 26 are set to the sound piece upper surface portions 11b and 1
2b, and the detection elements 23 and 26 are protruded inside the sound pieces 11 and 12 so that the sound piece upper surface portion 11b,
Although the structure is fixed on 12b, in the second embodiment,
The widths of the detection elements 23 and 26 are set to the sound piece upper surface portions 11b and 12b.
And the outer end faces 23a, 26a of the detection elements 23, 26 are smaller than the width of the sound elements 11, 12,
The structure is characterized in that it is fixed to the top surfaces 11b and 12b of the voice piece in conformity with 12a.

FIG. 4 is a circuit for detecting the displacement and angular velocity of the sound pieces 11 and 12 at a certain moment when the sound pieces 11 and 12 of the prismatic tuning fork vibrator 10 are vibrated in the x-axis direction by the driving elements 21 and 24. Is shown. Sensing element 23,
26 is connected to the plus terminals of the operational amplifiers 31 and 32, respectively, and each plus terminal is grounded via a high resistance R. The output terminals of the operational amplifiers 31 and 32 are connected via a variable resistor, and the movable terminal V _S of the variable resistor is used to extract an angular velocity signal. Normally, V _S is a center value satisfying the relation that R1 and R2 are equal. In position.

Here, when the sound elements 11 and 12 exhibit the displacement shown in FIG. 4, the detecting elements 23 and 26 have the sound element upper surface 1
Narrower than the width of 1b and 12b, and the sensing elements 23 and 2
Since the outer end faces 23a and 26a of 6 are fixed close to the side face portions 11a and 12a of the sound pieces 11 and 12, the detection elements 23 and 26 have a greater contraction rate than expansion.
The polarities of the detecting elements 23 and 26 are similar to those in the first embodiment.
Since they are fixed so as to have polarities opposite to each other, offset noises having polarities opposite to each other are generated from the detection elements 23 and 26, but when they are combined by the operational amplifiers 31 and 32, they cancel each other out. The value of the combined offset noise is reduced, and the S / N ratio of the angular velocity sensor can be improved.

The variation in the magnitude (amplitude) of the offset noise from the detection elements 23, 26 is
The positional deviation of 26 is dominant, and in this embodiment, as in the first embodiment, the outer end surfaces 11a and 12a of the sound pieces 11 and 12 are the same.
By aligning the outer end surfaces 23a and 26a of the detecting elements 23 and 26 with each other, the detecting elements 23 and 2 can be easily aligned.
6 can be positioned, the adhesion accuracy is improved,
The combined offset noise is smaller and the S / N ratio can be further improved.

Further, the detecting elements 23 and 26 and the sound piece 11,
Even when the offset values on the left and right are largely changed due to unevenness in bonding with 12, a variation in width of the detection elements 23 and 26, deterioration of adhesion accuracy of the detection elements 23 and 26 in mass production, etc. The offset noise can be easily adjusted by moving the movable terminal V _S of No. 1 to adjust the ratio of R1 and R2, and an angular velocity sensor with a large S / N ratio can be provided.

A third embodiment will be described. FIG. 5 is a structural diagram showing the configuration. In this embodiment, as in the first embodiment, the widths of the detecting elements 23 and 26 are set to the sound piece upper surface portions 11b and 1b.
Although the width is set to be larger than the width of 2b, the difference from the first embodiment is that the detection elements 23 and 26 are protruded only on the inner side surfaces 11c and 12c of the sound pieces 11 and 12 in the first embodiment. However, in the third embodiment, the voice units 11 and 12 are
On the other hand, it is a point that the detecting elements 23 and 26 are fixed to the sound piece upper surface portions 11b and 12b so as to protrude to both sides thereof, that is, the sound piece side surface portions 11a and 12a and the sound piece inner side surfaces 11c and 12c.

FIG. 6 is an explanatory view showing an offset noise adjusting method and a circuit for adjusting the offset noise in the third embodiment. The detection element 26 provided on the sound piece 12 is connected to the operational amplifier 34, and current-voltage conversion is performed in the operational amplifier 34. By measuring the output voltage V ₁ of the operational amplifier 34, the detection element 26 is detected. The signal of can be obtained. Similarly, the detection element 23 provided in the sound piece 11 is connected to the operational amplifier 35, and the signal of the detection element 23 can be obtained by measuring the output voltage V ₂ of the operational amplifier 35.

Output voltages V ₁ and V of the operational amplifiers 34 and 35
_The combined output voltage V ₀ obtained by combining ₂ is the operational amplifiers 34, 3
The output end of each of the resistors 5 has the same resistance value R4,
It can be taken out by connecting through R5, and if the resistors R4 and R5 are set to 1, the combined output voltage V ₀ can be expressed by the relational expression shown in Expression 1.

[0027]

## EQU1 ## V ₀ = (V ₁ + V ₂ ) / 2 (1) where V ₁ is the output voltage of the operational amplifier 34, V ₂ is the output voltage of the operational amplifier 35, and V ₀ is the operational amplifier 34. Three
5 shows the combined output voltage of 5.

In the configuration shown in FIG. 6, the detecting elements 23, 2
Since the signals of 6 can be measured independently, the circuit shown in FIG. 6 is used when adjusting the offset of the angular velocity sensor. After the offset adjustment of the angular velocity sensor, since the independent signals of the detection elements 23 and 26 are not necessary, they are electrically equivalent (the output voltage V of the operational amplifier 33 in FIG. 5 = the composite output voltage V _{0 in} FIG. 6). The circuit shown in FIG. 5, which has a simple configuration with a small number of parts, is used.

Next, a method of adjusting the offset noise of the angular velocity sensor, that is, the offset voltage will be described. The configuration shown in FIG. 5 has the voice piece upper surface portions 11b and 12b.
It shows an ideal state in which there is no deviation in the bonding position of the detection elements 23 and 26 with respect to. However, in reality, an offset voltage is generated due to the bonding accuracy, the unevenness of the bonding surface, and the like. FIG. 6 shows a state in which the bonding positions of the detection elements 23 and 26 are displaced. Compared to FIG. 5, the detection element 23 is displaced by the displacement amount B to the outside O of the sound piece 11, and the detection element 26 is displaced. The amount A is deviated to the outside O of the sound piece 12. here,
Deviation amount B of detection element 23 and deviation amount A of detection element 26
As for the magnitude relationship with, the shift amount A is larger than the shift amount B.

FIG. 7 shows the result of measuring the offset voltage in the state of FIG. The size of the angular velocity sensor used in the experiment is that the sound pieces 11 and 12 have a length of 30 mm and a cross section of 3 mm.
× 3 mm, the driving elements 21 and 24 have a length of 13 mm, a width of 2.7 mm, and a plate thickness of 0.2 mm, and the detection elements 23 and 26 have a length of 13 mm, a width of 3.2 mm, and a plate thickness of 0.2 mm.
An alternating voltage of 1 V was applied to the driving elements 21 and 24, and a pencil grinder was used to grind the detecting elements 23 and 26.

The symbol ◯ in FIG. 7 indicates the offset voltage of the sensing element 26 before adjustment, and the symbol Δ indicates the offset voltage of the sensing element 23. Sensing element 23 and sensing element 26
Are provided so that the polarities thereof are opposite to each other, and the detection element 23 and the detection element 26 are respectively shifted to the outside, so that the polarities of the offset voltages are opposite to each other. Since the deviation amount A is larger than the deviation amount B of the detection element 23, the offset voltage of the detection element 26 is larger than the offset voltage of the detection element 23. In this case, the combined output voltage V ₀ which operational amplifier 34 and 35, V ₁ = 75mV, When V ₂ = -30 mV, from relational expression shown in Equation 1, the offset voltage of V ₀ = 22.5 mV occurs .

At this time, as shown in FIG. 8, the right side of the detecting element 26 is ground by the width W1 in the vertical direction, and the left side of the detecting element 26 is ground by the width W2 in the vertical direction. The experimental results showing the relationship between W2 and the offset voltage are shown in FIG. From FIG. 9, the inner end surface 26 of the detection element 26
If the grinding width W1 of b is increased, the offset voltage gradually increases, and if the grinding width W2 of the outer end surface 26a of the detection element 26 is increased without grinding the inner end surface 26b of the detection element 26. It can be seen that the offset voltage gradually decreases. The same can be said for the detection element 23. Therefore, it is understood that the offset voltage can be changed and the offset voltage can be adjusted by grinding the inner end surface and the left end surface of the detection elements 23 and 26.

A specific method of adjusting the offset voltage will be described with reference to FIG. 7, for example.
Since it is 2.5 mV, if the offset voltages (marked with ○ and Δ in the figure) generated from the detecting elements 23 and 26 are respectively changed by 22.5 mV in the negative direction, the combined offset voltage becomes 0 mV. be able to. In order to change the offset voltage generated from the detection element 26 by 22.5 mV in the negative direction, the outer end surface 26a of the detection element 26 may be ground by using the relationship shown in FIG. It is 0.06 mm from Fig. 9 (Fig. 6
Medium grinding width D).

Similarly, in order to vary the offset voltage generated from the detecting element 23 by 22.5 mV in the negative direction, the relationship between the grinding width of the detecting element 23 and the offset voltage has the same characteristic as that of the detecting element 26. For the sake of illustration, the inner end surface 23b of the detection element 23 may be ground by 0.06 mm (grinding width F in FIG. 6). By the method shown above, the combined offset voltage can be made zero, and an accurate angular velocity sensor can be provided.

Further, in the present embodiment, the left and right detecting elements 2
Since 3, 26 are ground by the same amount, the detection element 23,
The capacitances of the capacitors 26 are substantially equal to each other, and compared with the case where only one of the detection elements 23 and 26 is ground as shown in the first embodiment, the electrical noise of the offset noise due to the imbalance of the capacitances. Since the influence of such phase fluctuations is eliminated, the adjustment accuracy of the angular velocity sensor is further improved.
However, when there is no problem due to the imbalance of the capacitance, the adjusting method by grinding only one of the detecting elements 23 and 26 is used in the configuration shown in FIG. 5 as in the first embodiment. May be.

A fourth embodiment will be described. Figure 10
It is a structural diagram showing a configuration of a fourth embodiment. The feature of this embodiment is that the width of either one of the sensing elements 23 and 26 is
That is, the width is larger than that of the sound pieces 11 and 12.
In this embodiment, the width of the detecting element 26 is made equal to that of the sound piece 12, and the width of the detecting element 23 is made larger than that of the sound piece 11. The length L2 of the detection element 23 is shorter than the length L1 of the detection element 26, so that the electrostatic capacities of the detection element 23 and the detection element 26 are matched. The adjustment of the offset voltage can be performed by grinding either one side of the detection element 23.

[Brief description of drawings]

FIG. 1 is a structural diagram showing a configuration of a first embodiment according to the present invention.

FIG. 2 is a schematic diagram showing a circuit configuration for angular velocity detection according to the first embodiment of the present invention.

FIG. 3 is a structural diagram showing a configuration of a second embodiment according to the present invention.

FIG. 4 is a schematic diagram showing a circuit configuration for angular velocity detection according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram showing a circuit configuration for angular velocity detection according to a third embodiment of the present invention.

FIG. 6 is a schematic diagram showing a circuit configuration of angular velocity detection of another embodiment of the third embodiment according to the present invention.

FIG. 7 is a graph showing measurement results of offset voltage.

FIG. 8 is a schematic diagram showing a relationship between a detection element and a grinding width.

FIG. 9 is a graph showing the relationship between the grinding width and the offset voltage.

FIG. 10 is a structural diagram showing a configuration of a fourth embodiment according to the present invention.

FIG. 11 is a structural diagram showing a configuration of a conventional prismatic tuning fork vibrator.

FIG. 12 is a schematic diagram showing a circuit configuration for detecting angular velocity of a conventional prismatic tuning fork vibrator.

FIG. 13 is a schematic diagram showing how a tuning piece of a conventional prismatic tuning fork vibrator is displaced.

[Explanation of symbols]

10 prismatic tuning fork type vibrator 11, 12 sound piece 11a, 12a sound piece side surface part 11b, 12b sound piece upper surface part 11c, 12c sound piece inner side surface 21, 24 driving element 22, 25 reference element 23, 26 detection element 23a , 26a Detection element outer end surface 23b, 26b Detection element inner end surface 30 to 35 Operational amplifier ω Angular velocity V _S movable terminal V, V ₁ , V ₂ Operational amplifier output voltage A, B Detection element deviation amount W1, W2 Grinding width of sensing element L1 and L2 Length of sensing element I Inside of neutral piece neutral axis O Outside of neutral piece neutral axis R1 to R7 Resistance

Claims (3)

[Claims] 1. A vibrator in which two prismatic sound pieces are arranged in parallel and vibrates in a constant direction in a constant cycle, and a plate-shaped drive for vibrating the prismatic sound piece of the vibrator in a constant direction in a constant cycle. And a plate-shaped detection piezoelectric element that is fixed on a prismatic sound piece in a direction orthogonal to the vibration direction of the vibrator and that detects a Coriolis force generated when an angular velocity acts on the vibrator. In the angular velocity sensor for detecting an angular velocity, the detection piezoelectric elements are arranged in opposite polarities, and the width of the detection piezoelectric element is a prismatic sound of the vibrator to which the detection piezoelectric element is fixed. The width is larger than the width of the piece, and one side of the piezoelectric element for detection is fixed to be closer to the outer edge or the inner edge on the prismatic sound piece, and the protruding side of the piezoelectric element for detection is removed with respect to the prismatic sound piece. It, the output adjustment method of the angular velocity sensor wherein an output voltage generated from the detecting piezoelectric element is adjusted. 2. A vibrator in which two prismatic sound pieces are arranged in parallel and vibrates in a constant direction in a constant cycle, and a plate-shaped drive for vibrating the prismatic sound piece in the vibrator in a constant direction in a constant cycle. And a plate-shaped detection piezoelectric element that is fixed on a prismatic sound piece in a direction orthogonal to the vibration direction of the vibrator and that detects a Coriolis force generated when an angular velocity acts on the vibrator. In the angular velocity sensor for detecting an angular velocity, the detection piezoelectric elements are arranged in opposite polarities, and the width of the detection piezoelectric element is a prismatic sound of the vibrator to which the detection piezoelectric element is fixed. The width of the detection piezoelectric element is larger than the width of the detection piezoelectric element, and both sides of the detection piezoelectric element are fixed to the prismatic sound piece by sticking out and either side of the detection piezoelectric element is removed. Elementary Output adjusting method of the angular velocity sensor wherein the output voltage is adjusted to be generated from. 3. A vibrator in which two prismatic sound pieces are arranged in parallel and vibrates in a constant direction in a constant cycle, and a plate-like drive for vibrating the prismatic sound piece in the vibrator in a constant direction in a constant cycle. And a plate-shaped detection piezoelectric element that is fixed on a prismatic sound piece in a direction orthogonal to the vibration direction of the vibrator and that detects a Coriolis force generated when an angular velocity acts on the vibrator. In the angular velocity sensor for detecting an angular velocity, the detection piezoelectric elements are arranged in opposite polarities, and the width of the detection piezoelectric element is the width of the prismatic sound piece of the vibrator to which the detection piezoelectric element is fixed. More narrowly, the detection piezoelectric element is fixed close to an outer edge or an inner edge on the prismatic sound piece to which the detection piezoelectric element is fixed, and the angular velocity sensor is fixed on the two prismatic sound pieces. Detection It has a voltage converting means for converting the voltage of each detected value of the piezoelectric element, and a resistor for dividing the output value of the voltage converting means so that the output from the voltage dividing terminal becomes zero. An output adjusting method for an angular velocity sensor, characterized in that the voltage dividing ratio is adjusted to, and an output is taken out from the voltage dividing terminal.